JP5087801B2 - Base station apparatus, communication system and communication method - Google Patents

Description

The present invention relates to a base station apparatus, a communication system and a communication method.

  Receive signal power, SNR (Signal to Noise power Ratio), etc., as a way to improve communication efficiency (total throughput of the system, or substantial transmission speed taking into account the occurrence of reception errors) Based on the indexes indicating the propagation path state and reception state of the channel, a method of changing the communication parameters such as the modulation method, channel coding rate, error correction coding method, spreading factor, code multiplexing number, transmission power, etc. has been proposed. (Non-Patent Document 1). In particular, a method for adaptively selecting modulation parameters such as a modulation method and a channel coding rate is called an adaptive modulation method.

  Further, in a communication system that includes a base station device and a plurality of terminal devices and uses multicarrier communication in communication (downlink) from the base station device to the terminal device, each channel device receives a downlink signal. A technique for performing scheduling for assigning a channel to each terminal apparatus according to a state and a technique for performing adaptive modulation for each channel including one subcarrier or several subcarriers for the downlink are known. (Non-patent document 2, Non-patent document 3).

Note that in a communication system that employs scheduling based on the reception state of a terminal device or an adaptive modulation scheme, in order to determine allocation and modulation parameters, the propagation path state and reception such as the received signal power and SNR of the channel used for communication It is necessary to notify the communication partner of an index indicating the state.
In the system as described above, each terminal device needs to notify the base station device of reception status information regarding each channel using an uplink control channel or the like. For this reason, there has been a problem that the amount of reception state information transmitted from the terminal apparatus to the base station apparatus in the uplink becomes enormous in proportion to the number of terminal apparatuses and the number of channels.

In order to solve the above problem, for the purpose of reducing the amount of information of reception status information transmitted in the uplink, for each terminal device, the reception status of all channels assigned to each terminal device for communication by the base station device, A method (first method) is known in which each terminal apparatus measures and notifies only the average value of the reception states of all channels to the base station apparatus.
Also, out of all channels assigned by the base station device to each terminal device for communication, a predetermined number of channels with good reception status are selected from those with good reception status, and only the reception status of those channels is selected. A method (second method) of notifying a station apparatus is known.
Also, a method of compressing the value of the reception state of each channel of all channels allocated for communication by the base station apparatus to each terminal apparatus by performing discrete cosine transform (DCT) in the frequency axis direction (third) Is known).
In addition, the base station device selects some reference channels from all the channels assigned to each terminal device for communication, and represents the value of the reception state of each channel as a difference value of the reception state of the reference channel, A method (fourth method) for notifying this to the base station apparatus is known.
The above first to fourth methods are described in Patent Document 1, Patent Document 2, Non-Patent Document 3, Non-Patent Document 4, and Non-Patent Document 5.

  As an example of the above-described conventional system, a system will be described in which a terminal device selects a predetermined number from channels with good reception status and notifies only the reception status information of the channel to the base station device.

  FIG. 27 is a schematic block diagram showing a configuration of a base station device 9000 in the prior art. The base station device 9000 includes an RF (Radio Frequency) receiving circuit 9001, a demodulation / decoding unit 9002, a scheduling unit 9003, a header information acquisition unit 9004, a packet identification unit 9005, a buffer management unit 9006, a PDU (Protocol Data). Unit) generation unit 9007, transmission buffer 9008, selector 9009, encoding / modulation unit 9010, and RF transmission circuit 9011.

A control signal including control information from each terminal apparatus is received by the RF receiving circuit 9001 via an antenna (not shown), and the received control signal is down-converted into a baseband signal and converted into a digital signal. Is input to the demodulation / decoding unit 9002. Demodulation / decoding section 9002 performs control signal demodulation / decoding processing, and reports uplink control information (downlink reception channel state for each frequency block) of each terminal apparatus to scheduling section 9003.
On the other hand, when an IP packet transmitted from the network is received, the header information acquisition unit 9004 acquires packet header information such as a destination address from the received IP packet, and sends the acquired packet header information to the buffer management unit 9006. The IP packet is input to the packet selector 9005.

Based on the notified packet header information and the transmission buffer 9008 described later from the notified buffer header 9006 via the buffer managing unit 9006, the buffer managing unit 9006 transmits the packet data to the packet identifying unit 9005. Specify the storage location. Further, the buffer management unit 9006 inputs the destination address and the memory address of the queue corresponding to the address to the transmission buffer 9008.
Also, the buffer management unit 9006 notifies the scheduling unit 9003 of the packet header information and the status of each queue notified from the transmission buffer 9008.
The packet identification unit 9005 sorts the input IP packet based on the storage location of the packet data designated by the buffer management unit 9006, and inputs it to the PDU generation unit 9007 for each sorted packet. The PDU generation unit 9007 converts the input packet into a PDU and inputs it to the transmission buffer 9008.

  The transmission buffer 9008 forms an independent queue for each destination (terminal device) from the input PDU based on the destination address input by the buffer management unit 9006 and the memory address of the corresponding queue. The buffer manager 9006 is notified of the queue status.

The selector 9009 extracts data from the transmission buffer 9008 based on the queue designated by the scheduling unit 9003 and inputs the data to the encoding / modulation unit 9010 for the designated frequency block. This frequency block is allocated by the scheduling unit 9003. Based on the notified uplink control information (downlink reception channel state of the frequency block with good quality), packet header information, and the state of each queue, the scheduling unit 9003 determines the frequency block of each user. An index (priority) for allocation is obtained, and frequency block allocation is determined based on this index.
The data output from the selector 9009 is subjected to encoding / modulation processing in the encoding / modulation section 9010, and the encoded / modulated data is transmitted to each terminal apparatus by the RF transmission circuit 9011.
JP 2004-208234 A JP 2006-50545 A Kishiyama et al. “Experimental results of throughput characteristics of adaptive modulation / demodulation and channel coding in downlink VSF-OFCDM broadband wireless access”, IEICE Technical Report, May 2003, RCS 2003-25 Maehara et al. “Study of OFDM / TDD transmission system using subcarrier adaptive modulation”, 2001 IEICE General Conference, March 2001, B-5-100, p. 498 “CQI report and scheduling procedure”, 3GPP, TSG-RAN WG1 Meeting # 42bis, R1-051045, October 2005 “Sensitivity of DL / UL Performance to CQI-Compression with Text Proposal”, 3GPP, TSG-RAN WG1 ad hoc meeting on LTE, R1-060228, January 2006 “Assembment of adaptive transmission technologies”, WINNER, IST-2003-507581, D2.4 ver1.0, February 2005

  In the first method described above, adaptive modulation according to the reception state of each channel cannot be performed. For this reason, the channel having a better reception state than the average value has a transmission rate that is too low, resulting in inefficiency, and the channel having a lower reception state than the average value deteriorates the error rate characteristics. Further, since it is not possible to perform scheduling for assigning terminal devices to channels having good reception states using the frequency selectivity of the propagation path, the transmission efficiency of the entire system is lowered.

  Further, in the second method described above, a predetermined number of channels having good reception status are notified, and therefore, a predetermined number of channels having good reception status notified from a plurality of terminal devices overlap. As a result of scheduling, there is a possibility that a terminal device to which the channel that has notified the reception state is not allocated is generated. At this time, since the reception state of the other channel of the terminal device is not known at all, scheduling and adaptive modulation based on the reception state of the terminal device cannot be performed on the empty channel, and transmission efficiency is reduced.

  Further, in the third method and the fourth method described above, communication is inefficient because detailed reception state information is notified even for a terminal device that does not require detailed reception state information for each channel.

  However, in the conventional technique, a terminal device with a large communication amount with the base station device and a terminal device with a small communication amount with the base station device notify the base station device of reception quality information with the same information amount. There is a problem that the total notification amount of the reception state information is large.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a base station apparatus capable of obtaining excellent transmission efficiency by enabling adaptive modulation and adaptive scheduling while suppressing the total amount of notification of reception state information. to provide a communication system and a communication method.

(1) The present invention has been made to solve the above problems, and a base station apparatus according to an aspect of the present invention is a base station apparatus that communicates with a terminal apparatus, and transmits the terminal apparatus. A transmission information amount acquisition unit that acquires an information amount of information, and a channel reception state information that the terminal device notifies the base station device based on the information amount of the transmission information acquired by the transmission information amount acquisition unit An information amount determination unit that determines the amount of information, and a notification unit that notifies the terminal device of the information amount of the reception state information of the channel determined by the information amount determination unit.
In the present invention, the information amount of the reception state information of the channel notified from the terminal device to the base station device is determined based on the information amount of the transmission information transmitted from the base station device to the terminal device. Therefore, when the information amount of transmission information that the base station device transmits to the terminal device is large, by setting the information amount of the reception state information of the channel that the terminal device notifies the base station device to increase, A terminal device with a small amount of communication with the base station device can reduce the amount of reception state information compared to a terminal device with a large amount of communication with the base station device.

(2) In addition, the information amount determination unit of the base station device according to one aspect of the present invention may be configured such that the terminal device is assigned to the base station device when the information amount of the transmission information acquired by the transmission information amount acquisition unit is different. The amount of information on the reception status information of the channel to be notified is made different.
In the present invention, when the information amount of transmission information transmitted from the base station device to the terminal device is large, the information amount is set so that the information amount of the reception state information of the channel notified to the base station device by the terminal device increases. By setting the determining unit so that the amount of information of the reception state information is different, the terminal device having a small communication amount with the base station device is compared with the terminal device having a large communication amount with the base station device. The amount of information can be reduced.

(3) Further, the reception state information of the base station apparatus according to an aspect of the present invention includes identification information of a predetermined channel among all channels and information indicating the reception state of the predetermined channel.
In the present invention, the reception state information includes identification information of a predetermined channel among all channels and information indicating the reception state of the predetermined channel. Therefore, the information amount of the reception state information transmitted from the terminal device to the base station device can be reduced as compared with the case where the reception state information includes information indicating the reception state for all channels.

(4) Moreover, the reception state information of the base station apparatus according to an aspect of the present invention includes a reception state of a predetermined channel and a difference value between reception states of adjacent channels.
In the present invention, the reception state information includes a difference value between a reception state of a predetermined channel and a reception state of an adjacent channel. Therefore, the information amount of the reception state information transmitted from the terminal device to the base station device can be reduced as compared with the case where the reception state information includes information indicating the reception state for all channels.

(5) In addition, the information amount determination unit of the base station apparatus according to one aspect of the present invention causes the terminal device to change to the base station apparatus as the amount of transmission information acquired by the transmission information amount acquisition unit increases. On the other hand, the information amount of the reception status information of the channel to be notified is increased.
In the present invention, a terminal device with a small amount of communication with the base station device can reduce the information amount of the reception state information as compared with a terminal device with a large amount of communication with the base station device. Further, for a terminal device with a large amount of communication with the base station device, detailed channel reception status information can be obtained, so that appropriate scheduling can be performed on transmission information to be transmitted to the terminal device.

(6) Moreover, the base station apparatus by 1 aspect of this invention is provided with the transmission information storage part which accumulate | stores the transmission information transmitted to the said terminal device, The said transmission information amount acquisition part is transmission information transmitted to the said terminal device. As the information amount, the information amount of the transmission information accumulated by the transmission information accumulation unit is acquired.
In the present invention, the information amount determination unit determines the information amount of the reception state information of the channel notified from the terminal device to the base station device based on the information amount of the transmission information addressed to the terminal device accumulated by the transmission information accumulation unit. can do.

(7) Moreover, the base station apparatus by 1 aspect of this invention is provided with the transmission information storage part which accumulate | stores the transmission information transmitted to the said terminal device, The said transmission information amount acquisition part is transmission information transmitted to the said terminal device. As the information amount, the bit rate of the transmission information output by the transmission information storage unit is acquired.
In the present invention, based on the bit rate of the transmission information addressed to the terminal device output from the transmission information storage unit, the information amount determination unit determines the information amount of the channel reception state information notified from the terminal device to the base station device. can do.

(8) In addition, the information amount determination unit of the base station device according to an aspect of the present invention may be configured so that the terminal device can The information amount of the reception status information of the channel to be notified is determined from among three or more types of information amounts.
In the present invention, the information amount determination unit determines the information amount of the channel reception state information notified from the terminal device to the base station device from among three or more types of information amounts. Compared to the case where the information amount is determined from two types of information amounts, it is possible to determine an information amount that is more suitable for the information amount of the transmission information acquired by the transmission information amount acquisition unit.

(9) Moreover, the base station apparatus according to an aspect of the present invention includes a maximum Doppler frequency measurement unit that measures a maximum Doppler frequency of a signal received by the base station apparatus from the terminal device, and the information amount determination unit includes: Based on the information amount of the transmission information acquired by the transmission information amount acquisition unit and the maximum Doppler frequency measured by the maximum Doppler frequency measurement unit, the reception state of the channel notified by the terminal device to the base station device Determine the amount of information.
In the present invention, based on the information amount of the transmission information acquired by the transmission information amount acquisition unit and the maximum Doppler frequency measured by the maximum Doppler frequency measurement unit, the reception state of the channel that the terminal device notifies to the base station device The information amount determination unit can determine the information amount of the information.

(10) In addition, the information amount determination unit of the base station apparatus according to one aspect of the present invention may be configured such that the terminal apparatus controls the base station apparatus as the maximum Doppler frequency measured by the maximum Doppler frequency measurement unit increases. Increase the amount of reception status information of the channel to be notified.
In the present invention, when the maximum Doppler frequency is large, for example, when the terminal device is moving at a high speed, by increasing the amount of reception state information transmitted from the terminal device to the base station device, the terminal device Can be accurately grasped.

(11) In addition, in the base station device according to an aspect of the present invention, the information amount determination unit is configured such that the terminal device is based on the information amount of transmission information for each terminal device acquired by the transmission information amount acquisition unit. The amount of channel reception status information notified to the base station apparatus is determined for each terminal apparatus.
In the present invention, since the information amount determination unit of the base station apparatus determines the information amount of the channel reception state information for each terminal device, the information amount of the channel reception state information is determined for each terminal device. can do.

(12) In addition, the base station apparatus according to an aspect of the present invention includes a reception state information receiving unit that receives channel reception state information notified from the terminal device, and reception of a channel received by the reception state information receiving unit. A channel allocation unit that allocates transmission information for the terminal device to each channel based on state information.
In the present invention, when the reception state information receiving unit acquires reception state information with a large amount of information from the terminal device, scheduling can be performed on the terminal device based on the detailed reception state information.

(13) In addition, the channel allocation unit of the base station apparatus according to one aspect of the present invention may be configured such that the reception status information reception unit receives the channel reception status information received from the terminal device as the amount of information increases. The transmission data for is preferentially assigned to the channel.
In the present invention, it is possible to perform scheduling by assigning a channel to a terminal device with a large communication amount with the base station device in preference to a terminal device with a small communication amount with the base station device.

(14) A terminal apparatus according to an aspect of the present invention is a terminal apparatus that communicates with a base station apparatus, and that receives a channel reception state information amount and a channel reception state. The reception state measurement unit, the reception state information generation unit that generates the reception state information of the channel measured by the reception state measurement unit using the amount of information received by the reception unit, and the reception state information generation unit A transmission unit that transmits reception state information to the base station apparatus.

(15) In addition, the reception state information generation unit of the terminal device according to an aspect of the present invention uses the amount of information received by the reception unit, and uses the amount of information received by the reception state measurement unit from among the channels for which the reception state is measured. The reception state information of a predetermined channel is generated, and the transmission unit transmits the identification information of the predetermined channel and the reception state information generated by the reception state information generation unit to the base station apparatus.

(16) In addition, the reception state information generation unit of the terminal device according to one aspect of the present invention uses the amount of information received by the reception unit, and uses the amount of information received by the reception state measurement unit from among the channels whose reception state is measured Generating reception state information including a difference between a reception state of a predetermined channel and a reception state of an adjacent channel, and the transmission unit includes the identification information of the predetermined channel, the identification information of the adjacent channel, and the reception state The reception state information generated by the information generation unit is transmitted to the base station apparatus.

(17) A communication system according to an aspect of the present invention is a communication system including a base station device and a terminal device, and the base station device acquires an information amount of transmission information to be transmitted to the terminal device. Information for determining the information amount of the reception state information of the channel notified by the terminal device to the base station device based on the information amount of the transmission information acquired by the transmission information amount acquisition unit and the transmission information amount acquisition unit An amount determining unit; and a notifying unit for notifying the terminal device of the information amount of the channel reception state information determined by the information amount determining unit, wherein the terminal device receives the channel reception state information notified by the notification unit. A reception state receiving unit that receives the information amount of the channel, a reception state measurement unit that measures the reception state of the channel, and a reception state information of the channel measured by the reception state measurement unit using the information amount received by the reception unit. Comprising a reception state information generation unit that, a transmission unit which transmits the reception state information which the reception state information generation unit is generated to the base station apparatus.

(18) A communication method according to an aspect of the present invention is a communication method using a base station device and a terminal device, and the base station device acquires an information amount of transmission information to be transmitted to the terminal device. And determining the information amount of the reception status information of the channel notified by the terminal device to the base station device based on the transmission information amount acquisition process to be performed and the information amount of the transmission information acquired in the transmission information amount acquisition process An information amount determination process, and a notification process for notifying the terminal device of the information amount of the reception state information of the channel determined in the information amount determination process, wherein the terminal device The reception process for receiving the information amount of the reception state information, the reception state measurement process for measuring the reception state of the channel, and the channel state measured in the reception state measurement process using the information amount received in the reception process. Performing a reception state information generation process of generating a signal status information, and a transmission process of transmitting the reception state information generated by the reception state information generation process in the base station apparatus.

  In the base station apparatus, terminal apparatus, communication system, and communication method of the present invention, adaptive modulation and adaptive scheduling can be performed while suppressing the total notification amount of reception state information.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each embodiment to be described later, a cellular system that employs an Orthogonal Frequency Division Multiplex (hereinafter referred to as OFDM) system and performs adaptive modulation and adaptive scheduling (channel allocation) for each channel composed of at least one subcarrier. Although the case of using the system will be described, the present invention is not limited to this.
In each embodiment, a case where an index calculated based on a pilot symbol, for example, a CNR (Carrier to Noise power Ratio) is used as reception state information will be described. However, the present invention is not limited to this. is not.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating an example of a downlink subframe configuration according to the first embodiment of the present invention. As shown in FIG. 1, the channel in this embodiment means one or a plurality of subcarriers. A subframe means a transmission unit, and a channel is assigned to this subframe in one scheduling process. Further, the subframe is divided into T pieces (T is a natural number) with a predetermined time length TTI (Transmission Time Interval) in the time axis direction, and one TTI in one channel is set as a scheduling unit (hereinafter referred to as a resource block). The case will be described.

The upper right diagram of FIG. 1 shows the details of one of the resource blocks transmitted first in one subframe. This resource block includes 10 subcarriers and 10 TTIs. In the first TTI, pilot symbols are arranged on the first and last subcarriers, another two pilot symbols are arranged at equal intervals, and downlink control information symbols are arranged on the other subcarriers. . All downlink control information symbols are arranged in the second TTI. Data symbols are arranged in the third to tenth TTIs, but in the fifth TTI, downlink control information symbols are arranged on the second, fifth, and eighth subcarriers from the lowest frequency. In the TTI, downlink control information symbols are arranged on the third, sixth, and ninth subcarriers from the lowest frequency. The lower right diagram of FIG. 1 representatively shows details of one of the resource blocks transmitted from the second to the tenth. The arrangement of this resource block is the same as that in the upper right, but data symbols are arranged instead of the downlink control information.
Note that the scope of application of each embodiment of the present invention is not limited to the subframe configuration of FIG. 1, and in a system that performs communication using a plurality of channels, the reception status of each channel in each terminal device differs. It can be applied to possible systems.

  FIG. 2 is a schematic block diagram showing the configuration of the base station apparatus 200 according to the first embodiment of the present invention. The base station apparatus 200 includes a transmission buffer unit 201 (also referred to as a transmission information amount acquisition unit), an encoding unit 202, a mapping unit 203, an IFFT (Inverse Fast Fourier Transformation) unit 204, and a GI (Guard Interval: Guard period) insertion unit 205, D / A (Digital-to-Analog) conversion unit 206, wireless transmission unit 207 (also referred to as a notification unit), antenna unit 208, wireless reception unit 209 (also referred to as a reception state information reception unit), A / D (Analog-to-Digital) conversion unit 210, demapping unit 211, decoding unit 212, notification request determination unit 213 (also referred to as information amount determination unit), scheduling unit 214 (also referred to as channel allocation unit), downlink A link control information generation unit 215, a pilot generation unit 216, and a reception state information storage unit 217 are included.

The transmission buffer unit 201 accumulates input transmission data (transmission information) in a buffer for each terminal device 300 that is a transmission destination, and an information amount of transmission data addressed to each terminal device accumulated in the buffer, that is, a transmission buffer. The transmission data amount that is the information amount of the transmission information accumulated by the unit 201 is acquired and output to the encoding unit 202 and the notification request determination unit 213.
The notification request determination unit 213 increases the information amount of the reception state information of the channel that the terminal device 300 notifies the base station device 200 as the information amount of the transmission information acquired by the transmission buffer unit 201 increases. This is determined for each terminal device communicating with the base station device 200. Specifically, based on the transmission data amount information addressed to each terminal device 300 (FIG. 3) from the transmission buffer unit 201, each terminal device 300 is made to receive each reception state for all channels by b1 per channel. L1 (L1 is a natural number satisfying 2 ^b1-1 <L1 ≦ 2 ^b1 ) level expressed by bits (b1 is a natural number) (hereinafter referred to as L1 reception state information) and all channels Receiving state information (hereinafter referred to as L2) (L2 is a natural number satisfying 2 ^b2-1 <L2 ≦ 2 ^b2 ) expressed by b2 bits per channel (a natural number satisfying b2> b1) , L2 reception state information) is determined to be notified. Then, the notification request determination unit 213 outputs the determination result to the downlink control information generation unit 215 as notification request information. For example, when b1 = 2 and b2 = 4, 2 <L1 ≦ 4 and 8 <L2 ≦ 16. Details of the notification request information determination procedure by the notification request determination unit 213 will be described later.

  In addition, all channels represent all channels to which transmission data addressed to each terminal device may be assigned with respect to each terminal device. For example, all channels included in the frequency band used for the downlink, each terminal This represents all channels included in a part of the frequency band of the downlink determined with the base station apparatus as a band to be received by each apparatus, or all channels for which each terminal apparatus requests allocation. The same applies to the following embodiments.

The scheduling unit 214 assigns transmission information for the terminal device 300 to each channel based on the channel reception state information received by the wireless reception unit 209. For example, as the information amount of the reception state information of the channel received by the wireless reception unit 209 from the terminal device 300 (the number of bits of reception state information per channel) increases, the transmission data for the terminal device 300 is given priority over the channel. Assign. That is, in the example of the present embodiment, transmission data for the terminal apparatus that has notified the L2 reception state information is assigned to a channel with priority over transmission data for the terminal apparatus that has notified the L1 reception state information.
Specifically, the scheduling unit 214 reads the reception status information notified from each terminal device 300 stored in the reception status information storage unit 217, and allocates the terminal device to each resource block of each channel based on the information. And scheduling by selecting the modulation parameter to be used in each resource block. Then, scheduling section 214 outputs the scheduling result (scheduling information) and the modulation parameter selection result (modulation parameter information) to encoding section 202, mapping section 203, and downlink control information generation section 215.
The scheduling by the scheduling unit 214 may be further performed based on transmission data amount information from the transmission buffer unit 201. Details of the operation of the scheduling unit 214 will be described later.

The downlink control information generation unit 215 generates downlink control information including notification request information from the notification request determination unit 213, scheduling information from the scheduling unit 214, and modulation parameter information, and outputs the downlink control information to the mapping unit 203. In addition, regarding the terminal device with the same notification request information as the previous notification request information, the notification request information may not be included in the downlink control information.
Also, for example, regarding one of the notification request information of the L1 reception state information and the notification request information of the L2 reception state information, no bit is assigned to the downlink control information for the request notification information related to the corresponding destination terminal device. You may do it.

  The encoding unit 202 reads the necessary amount of transmission data addressed to each terminal device 300 from the transmission buffer unit 201 according to the allocation information (scheduling information) of each terminal device to the downlink notified from the scheduling unit 214, and further, the scheduling unit In accordance with the modulation parameter information and scheduling information notified from 214, error correction coding processing is performed on transmission data addressed to each terminal apparatus 300, a data sequence is generated, and output to mapping section 203.

Pilot generating section 216 generates a parrot sequence to be inserted into a transmission signal for reception state measurement in terminal apparatus 300, and outputs it to mapping section 203.
Mapping section 203 maps each bit of the data sequence to a modulation symbol on a subcarrier based on modulation parameter information and scheduling information notified from scheduling section 214, and is generated by downlink control information and pilot generation section 216. The pilot sequence is mapped to a predetermined modulation symbol on a predetermined subcarrier and output to IFFT section 204.
For example, the data sequence is mapped to the data symbols in the upper right and lower right diagrams of FIG. 1 based on the scheduling information, the pilot sequence is mapped to the predetermined pilot symbol of FIG. 1, and the downlink control information is mapped to the predetermined downlink of FIG. Each is mapped to a link control information symbol.

IFFT section 204 performs IFFT processing on the modulation symbol sequence output from mapping section 203, converts it into a time-axis OFDM signal, and outputs the converted signal to GI insertion section 205.
The GI insertion unit 205 adds a guard period (GI) to the OFDM signal generated by the IFFT unit 204 and outputs the result to the D / A conversion unit 206.
The D / A conversion unit 206 converts the signal with the guard period added from a digital signal to an analog signal and outputs the analog signal to the wireless transmission unit 207.
The wireless transmission unit 207 up-converts the analog signal output from the D / A conversion unit 206 and transmits the analog signal to the terminal device 300 from the antenna unit 208. For example, the wireless transmission unit 207 transmits the information amount of the reception state information of the channel determined by the notification request determination unit 213 to the terminal device 300.

The radio reception unit 209 receives a signal such as the reception state information of the channel notified from the terminal device 300 via the antenna unit 208, down-converts the received analog signal, and then transmits the received analog signal to the A / D conversion unit 210. Output.
The A / D conversion unit 210 converts the analog signal output from the wireless reception unit 209 into a digital signal and outputs the digital signal to the demapping unit 211.
The demapping unit 211 demaps the digital signal (modulation symbol) output from the A / D conversion unit 210, separates the reception state information and the data series, and outputs the reception state information to the reception state information storage unit 217. The data series is output to the decoding unit 212.

Decoding section 212 performs error correction decoding on the data series extracted by demapping section 211 and extracts received data.
The reception state information storage unit 217 stores the reception state information notified from each terminal device 300 separated by the demapping unit 211 for each terminal device 300 and outputs the reception state information to the scheduling unit 214.

  FIG. 3 is a schematic block diagram showing the configuration of the terminal device 300 according to the first embodiment of the present invention. The terminal device 300 includes an antenna unit 301, a radio reception unit 302 (also referred to as a reception unit), an A / D conversion unit 303, a GI removal unit 304, an FFT (Fast Fourier Transformation) unit 305, and a demapping unit 306. A decoding unit 307, a reception state measurement unit 308, a reception state information generation unit 309, an encoding unit 310, a mapping unit 311, a D / A conversion unit 312, a wireless transmission unit 313 (also referred to as a transmission unit), and a demodulation control unit 314. Have

The radio reception unit 302 receives the radio signal transmitted from the base station apparatus 200 via the antenna unit 301 and outputs it to the A / D conversion unit 303. For example, the radio reception unit 302 receives the amount of channel reception state information from the base station apparatus 200.
The A / D conversion unit 303 converts the analog signal received and down-converted by the wireless reception unit 302 into a digital signal and outputs the digital signal to the GI removal unit 304.
The GI removal unit 304 removes the guard period from the digital signal output from the A / D conversion unit 303 and outputs a signal from which the guard period is removed to the FFT unit 305.
The FFT unit 305 converts the OFDM signal output from the GI removal unit 304 into a modulation symbol sequence by performing a fast Fourier transform, and outputs the modulation symbol sequence to the demapping unit 306.
Demapping section 306 separates pilot symbols from the modulation symbol sequence output from FFT section 305 and outputs the result to reception state measurement section 308. Also, the demapping unit 306 demaps the downlink control information and outputs it to the demodulation control unit 314. Further, demapping section 306 demaps the data sequence according to the scheduling information and modulation parameter information output from demodulation control section 314 and outputs the result to decoding section 307. Note that channel compensation may be performed on the modulation symbol sequence based on the pilot symbols.

Decoding section 307 performs error correction decoding processing on the data sequence output from demapping section 306 according to the scheduling information and modulation parameter information output from demodulation control section 314, and outputs received data.
The demodulation control unit 314 determines scheduling information (information related to channels allocated to transmission data addressed to the terminal device 300), modulation parameter information (information related to modulation parameters of allocated channels) from downlink control information output from the demapping unit 306. ), And notification request information is extracted, scheduling information and modulation parameter information are output to the demapping unit 306 and the decoding unit 307, and notification request information is output to the reception state information generation unit 309.

In addition, when the downlink control information is error correction encoded in advance in the base station apparatus 200, error correction decoding is performed. Further, in a system in which the base station apparatus 200 does not notify the notification request information to the terminal apparatus 300 whose notification request information is the same as the previous one, there is no notification request information addressed to the terminal apparatus 300 in the downlink control information. In this case, the reception state information generation unit 309 is instructed to generate the same reception state information as that notified to the base station apparatus 200 last time.
Further, in a system in which the base station apparatus 200 does not assign a bit to the downlink control information for one of the notification request information of the L1 reception state information and the notification request information of the L2 reception state information, the base station device 200 uses the downlink control information. This corresponds to the case where there is no notification request information addressed to the terminal apparatus 300. In this case, the reception state information generation unit 309 is instructed to generate corresponding reception state information.

Reception state measurement section 308 measures the reception state in each channel using the pilot symbols output from demapping section 306, and outputs the reception state measurement result to reception state information generation section 309. In this embodiment, the case where the reception state is measured using the pilot symbol will be described. However, the reception state measurement using the data symbol and the reception state measurement using the error correction decoding determination result of the received data are performed. Anyway.
The reception state information generation unit 309 generates reception state information of the channel measured by the reception state measurement unit 308 using the information amount received by the wireless reception unit 302. Specifically, based on the notification request information output from the demodulation control unit 314, the reception state information generation unit 309 determines that the reception state measurement unit 308 determines that the notification state information is information requesting L1 reception state information. Reception state information represented by L1 levels is generated from reception state measurement results for each output channel. Then, the reception state information generation unit 309 outputs the generated reception state information to the mapping unit 311. In addition, when the notification request information is information requesting L2 reception state information, the reception state information generation unit 309 uses L2 levels from the reception state measurement results in each channel output from the reception state measurement unit 308, respectively. The represented reception state information is generated and output to the mapping unit 311.

Encoding section 310 performs error correction encoding on transmission data to base station apparatus 200 and outputs the data sequence to mapping section 311.
Mapping section 311 maps the reception state information generated by reception state information generation section 309 and the data sequence output from encoding section 310 to modulation symbols, and outputs the result to D / A conversion section 312. Note that the reception state information may be notified to the base station apparatus 200 separately from the transmission data to the base station apparatus 200.
The D / A conversion unit 312 converts the signal output from the mapping unit 311 into an analog signal and outputs the analog signal to the wireless transmission unit 313.
The radio transmission unit 313 up-converts an analog signal output from the analog signal and transmits the analog signal from the antenna unit 301 to the base station apparatus 200 by radio. For example, the wireless transmission unit 313 transmits the reception state information generated by the reception state information generation unit 309 to the base station apparatus 200 via the mapping unit 311 and the D / A conversion unit 312.

FIG. 4A to FIG. 4C are diagrams for explaining the L1 reception state information and the L2 reception state information used in the first embodiment of the present invention. 4 (a) to 4 (c) show that the L1 reception status information is 4 levels per channel (L1 = 4, b1 = 2 bits), and the L2 reception status information is 16 levels per channel (L2 = 16, b2). (4 bits) is an example of the correspondence between the reception state (here, CNR is used as the reception state) and each level.
For example, as shown in FIG. 4A, the L2 reception status information may be set so that one level of the L1 reception status information is subdivided into L2 / L1 levels (four levels).
Further, as shown in FIG. 4B, the reception state represented by the lowest level is the same, and the L2 reception state information subdivides each level of the L1 reception state information at other levels (subdivides into five levels). ) May be set as follows.
Further, as shown in FIG. 4C, the L2 reception state information may be set so as not to be subdivided with respect to the L1 reception state information. 4A to 4C are examples, and other settings may be used.

  Further, the relationship between each level of the L1 reception state information and the L2 reception state information and the reception state (CNR) is a correspondence relationship between the modulation parameter and the reception state (CNR) in adaptive modulation in the base station apparatus 200 (each modulation parameter). It can be determined based on the CNR threshold at the time of selection, etc., can be determined in consideration of scheduling, or can be determined by dividing a certain range of reception state (CNR) by L1 or L2. However, it is not limited to these methods.

FIG. 5 is a diagram for explaining another example of the L1 reception state information and the L2 reception state information used in the first embodiment of the present invention. FIG. 5 shows a combination of a modulation scheme (three types of QPSK, 16QAM, and 64QAM in FIG. 5) and a channel coding rate R (1/3, 1/2, 3/4 in the example of FIG. 5) as reception state information. 2 shows an example of a correspondence relationship between each level of a reception state (CNR), L1 reception state information, and L2 reception state information when notifying MCS (Modulation and Coding Scheme) as shown in FIG. ing.
In FIG. 5, 4 levels (L1 = 4, b1 = 2 bits) of MCS per channel as L1 reception state information, and 8 levels (L1 = 8, b2 = 3 bits) of MCS per channel as L2 reception state information. An example of representing is shown. For the L1 reception status information, “no transmission”, “QPSK, R = 1/3”, “16QAM, R = 1/3”, “16QAM, R =” according to four levels determined by b1 = 2 bits. 1/2 "is specified. Here, QPSK means 4-level phase modulation, 16QAM means 16-value quadrature amplitude modulation, and R means redundancy. As for the L2 reception status information, “no transmission”, “QPSK, R = 1/3”, “QPSK, R = 1/2”, “16QAM, R =” depending on eight states determined by b2 = 3 bits. “1/3”, “QPSK, R = 3/4”, “16QAM, R = 1/2”, “16QAM, R = 3/4”, “64QAM, R = 3/4” are designated. Here, 64QAM means 64-value quadrature amplitude modulation.

  As described with reference to FIG. 4A to FIG. 4C and FIG. 5, the L2 reception state information can notify a more detailed reception state of each channel. The amount of information (number of bits) to be notified to is large, and the L1 reception state information can be reduced although the reception state of each channel to be notified becomes rough.

FIG. 6 is a flowchart showing a process of the notification request determination unit 213 of the base station apparatus 200 according to the first embodiment of the present invention. That is, FIG. 6 shows the notification request information determination operation in the notification request determination unit 213.
First, the notification request determination unit 213 acquires the amount of transmission data addressed to each terminal device 300 from the transmission buffer unit 201 (step S601). Then, the notification request determination unit 213 repeats the following processing for each terminal device (terminal device 300-1 to terminal device 300-N (N is a natural number greater than or equal to 2)) (loop 1 from step S602 to S606). .
Next, the notification request determination unit 213 compares, for each terminal device, the amount of transmission data addressed to the terminal device and a predetermined threshold, for example, the average value of the amount of transmission data addressed to all terminal devices (step S603). If the transmission data amount is equal to or greater than the threshold, the terminal device is requested to request L2 reception state information (step S604). If the transmission data amount is less than the threshold value, the terminal device is selected. Is selected to request L1 reception status information (step S605).

  In the present embodiment, the amount of traffic of data transmitted from the base station device 200 to each terminal device is determined, and a predetermined threshold used for determining notification request information is set as “the amount of transmission data addressed to all terminal devices”. The case where the “average value” is used has been described. However, the predetermined threshold value used for determining the notification request information is not limited to this. For example, the number of terminal devices that notify the L1 reception state information and the number of terminal devices that notify the L2 reception state information are determined in advance. A value that realizes the ratio of the number of terminal devices such that the total information amount of the reception status information notified from all the terminal devices according to the notification request information is not more than a predetermined value. As described above, an index that can determine the amount of traffic of data transmitted from the base station apparatus to each terminal apparatus may be used as the threshold value.

  The predetermined threshold value used for determining the notification request information is preferably larger than 0 and less than or equal to the maximum transmission data amount per terminal device that can be stored in the transmission buffer unit 201.

FIG. 7 is a flowchart showing a process of the scheduling unit 214 of the base station apparatus 200 according to the first embodiment of the present invention. That is, FIG. 7 shows the scheduling operation and modulation parameter selection operation in the scheduling unit 214.
The scheduling unit 214 reads the reception state information notified from each terminal device from the reception state information storage unit 217 (step S701). Then, the scheduling unit 214 allocates the transmission data to be transmitted to each terminal apparatus that has notified the L2 reception state information to the resource block based on the reception state information of each channel of each terminal apparatus (step S702).
Next, the scheduling unit 214 selects a modulation parameter for each resource block assigned in step S702, based on reception state information in the channel of the terminal device assigned to each resource block (step S703).

Next, the scheduling unit 214 allocates the transmission data to be transmitted to each terminal apparatus that has notified the L1 reception state information to the remaining resource blocks allocated in step S702 based on the reception state information of each terminal apparatus (step S702). S704).
Then, the scheduling unit 214 selects a modulation parameter for each resource block assigned in step S704, based on the reception state information of each terminal device assigned to each resource block (step S705).
Next, the scheduling unit 214 outputs the scheduling result (scheduling information) and the modulation parameter selection result (modulation parameter information) to the encoding unit 202, the mapping unit 203, and the downlink control information generation unit 215 (step S706).

  FIG. 8 is a diagram for explaining a reception state information notification request determination method according to the first embodiment of this invention. FIG. 8 shows an example of the reception state of each channel (CNR is used as the reception state in FIG. 8) in a certain terminal apparatus, and modulation parameters (modulation in FIG. 8) that realize the maximum transmission rate selectable in each channel at that time. Eight types of MCS that are combinations of a modulation scheme and a channel coding rate as parameters, ie, MCS0 to MCS7 are used, and the larger the number, the higher the transmission rate is MCS). It is the figure which showed an example whether transmission data can be allocated to the resource block of each channel about each when the amount is small (case 1) and large (case 2).

The maximum modulation parameter indicates a case where the maximum modulation parameter is determined based on an average of reception states in each channel. In addition, the L1 reception status information uses 2 bits per channel to report by selecting from four levels of MCS0, MCS2, MCS4, and MCS6 underlined, and the L2 reception status information uses 3 bits per level. Select from all 8 levels. This point is as already described in FIG.
As shown in FIG. 8, in the case 1 in which the amount of transmission data stored in the transmission buffer unit 201 is small and the modulation method can be transmitted by one resource block of MCS having a low transmission rate, the resource of any channel Transmission data can be assigned to a block. In such a case 1, it is not necessary to notify the L2 reception state information that expresses each reception state related to all channels in detail using a large number of bits, and each reception state related to all channels is used using a small number of bits. It is sufficient to notify the L1 reception state information that is roughly expressed.

In case 2 where the amount of transmission data stored in the transmission buffer unit 201 is large and transmission is possible with only one resource block of channel 3 whose modulation scheme is MCS7 or more in one resource block, resources that can be allocated Blocks must be extracted and assigned transmission data. In such a case 2, scheduling based on the L1 reception state information that cannot be notified of MCS7 because it is coarse at four levels is inefficient because a plurality of resource blocks are allocated, and the L2 reception state in which all levels can be notified in detail Detailed scheduling is preferably performed by notifying information.
The same applies to the following embodiments.

As described above, according to the present embodiment, when notifying the reception state information from the plurality of terminal apparatuses 300 to the base station apparatus 200, each of the channels related to all channels according to the amount of downlink transmission data addressed to each terminal apparatus. L1 reception status information that represents the reception status by L1 levels expressed by b1 bits per channel or L2 reception status expressed by L2 levels expressed by b2 bits (b2> b1) per channel Select whether to notify information.
Therefore, for a terminal device that needs to allocate many resource blocks in the downlink and transmit a large amount of transmission data, it is based on the L2 reception state information that represents the reception state of each channel in detail using a large number of levels. Efficient scheduling and adaptive modulation can be preferentially performed, and higher speed transmission can be realized.

  On the other hand, for terminal devices with relatively little data to be transmitted in the downlink, scheduling and adaptive modulation are performed by performing scheduling and adaptive modulation based on L1 reception state information that roughly represents the reception state of each channel with a smaller number of levels. It is possible to reduce the amount of reception state information notified from the terminal device using the uplink.

  Based on the above, efficient scheduling and adaptation to terminal devices that require high-speed and large-capacity communication while suppressing the total amount of uplink reception status information notification from each terminal device in the entire system Modulation can be applied.

(Second Embodiment)
Next, a second embodiment of the present invention will be described.
In the first embodiment, as reception status information for requesting notification from the base station device 200 to each terminal device 300, each reception status for all channels is represented by L1 levels expressed by b1 bits per channel. A case has been described in which either reception status information or L2 reception status information represented by L2 levels expressed by b2 bits (b2> b1) per channel is selected.
The base station apparatus 900 according to the second embodiment uses the L1 reception state information and the L2 reception state relating to a predetermined number M of good reception states (M is a natural number and less than the total number of channels) as reception state information for requesting notification. One of information including identification information of M channels (hereinafter referred to as L1-M reception state information and L2-M reception state information) is selected.

  FIG. 9 is a schematic block diagram showing the configuration of the base station device 900 according to the second embodiment of the present invention. The base station apparatus 900 includes a transmission buffer unit 201, an encoding unit 202, a mapping unit 203, an IFFT unit 204, a GI insertion unit 205, a D / A conversion unit 206, a wireless transmission unit 207, an antenna unit 208, and a wireless reception unit 209. , An A / D conversion unit 210, a demapping unit 211, a decoding unit 212, a notification request determination unit 913, a scheduling unit 914, a downlink control information generation unit 215, a pilot generation unit 216, and a reception status information storage unit 917.

  In base station apparatus 900, notification request determining section 913 corresponding to notification request determining section 213 of base station apparatus 200, scheduling section 914 corresponding to scheduling section 214 of base station apparatus 200, and reception state information storage of base station apparatus 200 A reception state information storage unit 917 corresponding to the unit 217 is different from that of the first embodiment (FIG. 2). Since other configurations of the base station apparatus 900 are the same as those in the first embodiment, description thereof is omitted.

  Based on the transmission data amount information addressed to each terminal device from the transmission buffer unit 201, the notification request determination unit 913 sends L1-M reception state information and L2-M reception state information to each terminal device 300. Which is to be notified is determined, and the determination result is output to the downlink control information generation unit 215 as notification request information. The details of the notification request information determination procedure will be described later. In the present embodiment, the L1-M reception status information and the L2-M reception status information include identification information of predetermined channels (M channels) among all channels, and the reception status of the predetermined channels. Information to be included.

The scheduling unit 914 reads out the reception state information notified from each terminal device 300 stored in the reception state information storage unit 917 and performs scheduling by assigning the terminal device 1000 to each resource block of each channel based on the information. Then, the modulation parameter used in each resource block is selected, and the scheduling result (scheduling information) and the modulation parameter selection result (modulation parameter information) are output.
The scheduling by the scheduling unit 914 may be further performed based on the transmission data amount information from the transmission buffer unit 201. Details of the operation of the scheduling unit 914 will be described later.
The reception state information storage unit 917 stores the reception state information notified from each terminal device 1000 separated by the demapping unit 211 together with the identification information of the corresponding channel for each terminal device, and outputs it to the scheduling unit 914.

  FIG. 10 is a schematic block diagram showing the configuration of the terminal apparatus 1000 according to the second embodiment of the present invention. The terminal device 1000 includes an antenna unit 301, a radio reception unit 302, an A / D conversion unit 303, a GI removal unit 304, an FFT unit 305, a demapping unit 306, a decoding unit 307, a reception state measurement unit 308, and reception state information. A generation unit 1009, an encoding unit 310, a mapping unit 311, a D / A conversion unit 312, a wireless transmission unit 313, and a demodulation control unit 314 are included.

  In the terminal device 1000, a reception state information generation unit 1009 corresponding to the reception state information generation unit 309 of the terminal device 300 is different from that of the first embodiment (FIG. 3). Since the other configuration of the terminal device 1000 is the same as that of the first embodiment, the description thereof is omitted.

The reception state information generation unit 1009 uses the amount of information received by the wireless reception unit 302 to receive reception state information (L1-M reception state) of a predetermined channel from the channels whose reception state measurement unit 308 has measured the reception state. Information or L2-M reception status information). Specifically, M channels having good reception state measurement results output from the reception state measurement unit 308 are selected, and the notification request information is L1-M based on the notification request information output from the demodulation control unit 314. In the case of information requesting reception state information, reception state information indicating identification information of the M channels and reception state measurement results of the M channels represented by L1 levels is generated. Then, the reception status information generation unit 1009 outputs the generated reception status information to the mapping unit 311. In addition, when the notification request information is information requesting L2-M reception state information, the reception state information generation unit 1009 recognizes the M channel identification information and M pieces of L information represented by L2 levels, respectively. Reception state information representing the reception state measurement result of the channel is generated and output to the mapping unit 311.
Radio transmission section 313 transmits identification information of a predetermined channel and reception status information generated by reception status information generation section 1009 from antenna section 301 to base station apparatus 200.

FIG. 11 is a flowchart showing processing of the notification request determination unit 913 of the base station apparatus 900 according to the second embodiment of the present invention. That is, FIG. 11 shows the notification request information determination operation in the notification request determination unit 913.
First, the notification request determination unit 913 acquires the transmission data amount addressed to each terminal device from the transmission buffer unit 201 (step S1101). The notification request determination unit 913 repeats the following processing for each terminal device (terminal device 1000-1 to terminal device 1000-N) (loop 2 from step S1102 to S1106).
That is, the notification request determination unit 913 compares, for each terminal device, the amount of transmission data addressed to the terminal device and a predetermined threshold, for example, the average value of the amount of transmission data addressed to all terminal devices (step S1103). When the transmission data amount is equal to or larger than the threshold, the terminal apparatus is requested to request L2-M reception state information (step S1104), and when the transmission data amount is less than the threshold, the terminal A request is made to request L1-M reception status information from the device 1000-n (step S1105).

In the present embodiment, the amount of traffic of data transmitted from the base station apparatus 900 to each terminal apparatus 1000 is determined, and a predetermined threshold value used for determining notification request information is “amount of transmission data addressed to all terminal apparatuses” The case of using the “average value” has been described.
However, the predetermined threshold value used for determining the notification request information is not limited to this. For example, the number of terminal devices that notify L1-M reception state information and the terminal device that notifies L2-M reception state information The ratio of the number of terminal devices such that the total number of reception status information notified from all terminal devices in accordance with notification request information is equal to or less than a predetermined value. As long as it is an index that can determine the amount of traffic of data transmitted from the base station apparatus 900 to each terminal apparatus 1000, such as a value that realizes the above, other indices may be used.

  The predetermined threshold value used for determining the notification request information is preferably larger than 0 and less than or equal to the maximum transmission data amount per terminal device that can be stored in the transmission buffer unit 201.

FIG. 12 is a flowchart showing a process of the scheduling unit 914 of the base station apparatus 900 according to the second embodiment of the present invention. That is, FIG. 12 shows the scheduling operation and modulation parameter selection operation in the scheduling unit 914.
The scheduling unit 914 reads the reception state information notified from each terminal device from the reception state information storage unit 917 (step S1201).
Then, the scheduling unit 914 allocates transmission data to be transmitted to each terminal apparatus that has notified the L2-M reception state information to resource blocks based on the reception state information of each channel notified by each terminal apparatus (step S1202).

Next, the scheduling unit 914 selects a modulation parameter for each resource block assigned in step S1202 based on reception state information in the channel of the terminal device assigned to each resource block (step S1203).
Next, the scheduling unit 914 allocates the transmission data to be transmitted to each terminal apparatus that has notified the L1-M reception state information to the remaining resource blocks allocated in step S1202 based on the reception state information of each terminal apparatus. (Step S1204).
Then, the scheduling unit 914 selects a modulation parameter for each resource block assigned in step S1204 based on the reception state information of each terminal device assigned to each resource block (step S1205).
Next, the scheduling unit 914 outputs the scheduling result (scheduling information) and the modulation parameter selection result (modulation parameter information) to the encoding unit 202, the mapping unit 203, and the downlink control information generation unit 215 (step S1206).

  Thus, according to the present embodiment, when the reception state information is notified from the plurality of terminal apparatuses 1000 to the base station apparatus 900, the reception state is good according to the amount of downlink transmission data addressed to each terminal apparatus. The L1-M reception state information including identification information of M channels is notified to the reception states related to the predetermined number M channels, or M reception states are related to the predetermined number M channels in good reception state. Whether to notify the L2-M reception status information including the identification information of the selected channel.

  Therefore, for a terminal device that needs to allocate many resource blocks in the downlink and transmit a large amount of transmission data, L2− is a detailed representation of the reception state regarding a channel having a good reception state using a large number of levels. Efficient scheduling and adaptive modulation based on the M reception state information can be preferentially performed, and higher speed transmission can be realized.

  On the other hand, for a terminal device with relatively little data to be transmitted in the downlink, scheduling and adaptive modulation are performed based on L1-M reception state information that roughly represents the reception state of a channel having a good reception state with a smaller number of levels. By doing so, it is possible to reduce the amount of information of the reception status information notified from those terminal apparatuses using the uplink.

  Based on the above, efficient scheduling and adaptation to terminal devices that require high-speed and large-capacity communication while suppressing the total amount of uplink reception status information notification from each terminal device in the entire system Modulation can be applied.

  In this embodiment, as the L1-M reception status information and the L2-M reception status information, channel identification information and reception status information indicating the reception status for each of a predetermined number M of channels with good reception status are used. However, instead of this, channel identification information on a predetermined number M of channels with good reception status and reception status information representing the average value of reception status in M channels with L1 or L2 levels May be used.

(Third embodiment)
Next, a third embodiment of the present invention will be described.
In the first embodiment, as reception status information for requesting notification from the base station device 200 to each terminal device 300, each reception status for all channels is represented by L1 levels expressed by b1 bits per channel. A case has been described in which either reception status information or L2 reception status information represented by L2 levels expressed by b2 bits (b2> b1) per channel is selected.
The base station apparatus 1300 according to the third embodiment includes, as reception status information for requesting notification, information indicating a reception status regarding the first channel and a difference value from an adjacent channel of information indicating the reception status regarding other channels. Reception state information (hereinafter referred to as L1) expressed by a difference level of L1 ′ (L1 ′ is a natural number satisfying 2 ^b1′−1 <L1 ′ ≦ 2 ^{b1 ′} ) expressed by b1 ′ bits (b1 ′ is a natural number). L2 ′ (L2 ′ is a natural number satisfying 2 ^b2′−1 <L2 ′ ≦ 2 ^{b2 ′} ) expressed by b2 ′ bits (natural number satisfying b2 ′> b1 ′) and “differential reception state information” ) Of the reception status information (hereinafter referred to as L2 ′ differential reception status information) represented by the difference level.

  For example, reception state information using −2, −1, ± 0, +1 as 4 differential levels expressed by 2 bits, and −4, −3, − as 8 differential levels expressed by 3 bits. One of reception status information using 2, -1, ± 0, +1, +2, +3 is selected. Also, for example, reception status information using −4, −2, ± 0, +2 as 4 differential levels expressed by 2 bits, and −4, −3 as 8 differential levels expressed by 3 bits. , −2, −1, ± 0, +1, +2, +3 may be selected. Thus, as the difference level expressed by the b1 ′ bit and the b2 ′ bit, a value expressed by the two's complement of each bit number is used, or the range of the expressed difference value is almost the same. Although it is preferable to set and use a value, it is not limited to this.

  FIG. 13 is a schematic block diagram illustrating the configuration of a base station device 1300 according to the third embodiment of the present invention. The base station apparatus 1300 includes a transmission buffer unit 201, an encoding unit 202, a mapping unit 203, an IFFT unit 204, a GI insertion unit 205, a D / A conversion unit 206, a wireless transmission unit 207, an antenna unit 208, and a wireless reception unit 209. , An A / D conversion unit 210, a demapping unit 211, a decoding unit 212, a notification request determination unit 1313, a scheduling unit 1314, a downlink control information generation unit 215, a pilot generation unit 216, and a reception state information storage unit 1317.

  In base station apparatus 1300, notification request determining section 1313 corresponding to notification request determining section 213 of base station apparatus 200, scheduling section 1314 corresponding to scheduling section 214 of base station apparatus 200, and reception state information storage section of base station apparatus 200 A reception state information storage unit 1317 corresponding to 217 is different from that of the first embodiment (FIG. 2). The other configuration of the base station apparatus 1300 is the same as that of the first embodiment, and thus the description thereof is omitted.

  Based on the transmission data amount information addressed to each terminal device 1400 from the transmission buffer unit 201, the notification request determination unit 1313 sends L1 ′ difference reception state information, L2 ′ difference reception state information, and information to each terminal device 1400. Which of these is to be notified is determined, and the determination result is output to the downlink control information generation unit 215 as notification request information. In the present embodiment, the L1 ′ difference reception state information and the L2 ′ difference reception state information include a reception state of a predetermined channel and a difference value between reception states of adjacent channels. The details of the notification request information determination procedure will be described later.

  The scheduling unit 1314 reads out the reception state information notified from each terminal device 1400 stored in the reception state information storage unit 1317, performs scheduling by assigning the terminal device to each resource block of each channel based on the information, A modulation parameter to be used in each resource block is selected, and the scheduling result (scheduling information) and the modulation parameter selection result (modulation parameter information) are encoded into a coding unit 202, a mapping unit 203, and a downlink control information generation unit 215. Output to. Note that the scheduling by the scheduling unit 1314 may be further performed based on transmission data amount information from the transmission buffer unit 201. Details of the operation of the scheduling unit will be described later.

  The reception state information storage unit 1317 sequentially adds the difference values of the respective channels starting from the reception state information of the first channel based on the reception state information notified from each terminal device separated by the demapping unit 211. Thus, information indicating the reception state regarding each channel is restored, stored for each terminal device, and output to the scheduling unit 1314.

  FIG. 14 is a schematic block diagram illustrating a configuration of a terminal device 1400 according to the third embodiment of the present invention. The terminal device 1400 includes an antenna unit 301, a radio reception unit 302, an A / D conversion unit 303, a GI removal unit 304, an FFT unit 305, a demapping unit 306, a decoding unit 307, a reception state measurement unit 308, and reception state information. A generation unit 1409, an encoding unit 310, a mapping unit 311, a D / A conversion unit 312, a wireless transmission unit 313, and a demodulation control unit 314 are included.

  In the terminal device 1400, a reception state information generation unit 1409 corresponding to the reception state information generation unit 309 of the terminal device 300 is different from that of the first embodiment (FIG. 3). Since the other configuration of the terminal device 1400 is the same as that of the first embodiment, the description thereof is omitted.

The reception state information generation unit 1409 uses the amount of information received by the wireless reception unit 302 to receive a channel adjacent to the reception state of a predetermined channel from the channels whose reception state measurement unit 308 has measured the reception state. Reception state information (L1 ′ difference reception state information or L2 ′ difference reception state information) including a state difference value is generated. Specifically, the reception state information generation unit 1409 uses the reception state measurement result of the first channel output from the reception state measurement unit 308 as a starting point, and calculates the difference value from the adjacent channel of the reception state measurement results for other channels. Based on the notification request information respectively calculated and output from the demodulation control unit, L1 ′ difference levels expressed by b1 ′ bits or L2 ′ differences expressed by b2 ′ bits from the difference value calculation result One of the information represented by the level is calculated, and reception state information indicating the information of each channel other than the calculated first channel and the reception state measurement result of the first channel is generated and output.
Radio transmitting section 313 transmits identification information of a predetermined channel and reception state information generated by reception state information generating section 1009 from antenna section 301 to base station apparatus 900. When the predetermined channel is fixed to a predetermined channel such as the first channel, identification information of the predetermined channel is not necessary.

FIG. 15 is a flowchart showing processing of the notification request determination unit 1313 of the base station device 1300 according to the third embodiment of the present invention. That is, FIG. 15 shows the notification request information determination operation in the notification request determination unit 1313.
First, the notification request determination unit 1313 acquires the amount of transmission data addressed to each terminal device from the transmission buffer unit 201 (step S1501). The notification request determination unit 1313 repeats the following processing for each terminal device (terminal device 1400-1 to terminal device 1400-N) (loop 3 from step S1502 to S1506).
Then, the notification request determination unit 1313 compares, for each terminal device, the amount of transmission data addressed to the terminal device and a predetermined threshold, for example, the average value of the amount of transmission data addressed to all terminal devices (step S1503). If the transmission data amount is equal to or greater than the threshold, the terminal apparatus is selected to request L2 ′ differential reception status information (step S1504), and if the transmission data amount is less than the threshold, the terminal It is selected that L1 ′ difference reception status information is requested from the apparatus (step S1505).

In the present embodiment, the amount of traffic of data transmitted from the base station device to each terminal device is determined, and a predetermined threshold used for determining notification request information is “average transmission data amount addressed to all terminal devices”. The case where “value” is used has been described.
However, the predetermined threshold value used for determining the notification request information is not limited to this. For example, the number of terminal devices that notify L1 ′ differential reception state information and the terminal device that notifies L2 ′ differential reception state information The ratio of the number of terminal devices such that the total number of reception status information notified from all terminal devices in accordance with notification request information is equal to or less than a predetermined value. Other indices may be used as long as they are indices that can determine the amount of traffic of data transmitted from the base station apparatus to each terminal apparatus, such as values that realize the above.

  The predetermined threshold value used for determining the notification request information is preferably larger than 0 and less than or equal to the maximum transmission data amount per terminal device that can be stored in the transmission buffer unit 201.

FIG. 16 is a flowchart showing a process of the scheduling unit 1314 of the base station apparatus 1300 according to the third embodiment of the present invention. That is, FIG. 16 shows a scheduling operation and a modulation parameter selection operation in the scheduling unit 1314.
The scheduling unit 1314 reads the reception state information notified from each terminal device from the reception state information storage unit 1317 or the reception state information restored by the difference value addition process (step S1601).
The scheduling unit 1314 then transmits the transmission data to be transmitted to each terminal apparatus that has notified the L2 ′ difference reception state information based on the reception state information of each channel as a result of the addition process of the difference value of each terminal apparatus. (Step S1602).

Next, the scheduling unit 1314 selects a modulation parameter for each resource block assigned in step S1602 based on the reception state information restored in the channel of the terminal device assigned to each resource block (step S1603). ).
Then, the scheduling unit 1314 allocates the transmission data to be transmitted to each terminal apparatus that has notified the L1 ′ reception state information to the remaining resource blocks allocated in step S1602 based on the reception state information of each terminal apparatus (step S1602). S1604).
Next, the scheduling unit 1314 selects a modulation parameter for each resource block assigned in step S1604 based on the restored reception state information of each terminal device assigned to each resource block (step S1605).
Then, the scheduling unit 1314 outputs the scheduling result (scheduling information) and the modulation parameter selection result (modulation parameter information) to the encoding unit 202, the mapping unit 203, and the downlink control information generation unit 215 (step S1606).

  As described above, according to the present embodiment, when the reception state information is notified from the plurality of terminal apparatuses 1400 to the base station apparatus 1300, reception for the first channel is performed according to the amount of downlink transmission data addressed to each terminal apparatus. Regarding the information indicating the state and other channels, the difference value from the adjacent channel of the information indicating the reception state is notified of the L1 ′ difference reception state information represented by L1 ′ difference levels expressed by b1 ′ bits, or The difference value from the adjacent channel of the information indicating the reception state regarding the first channel and the information indicating the reception state regarding the other channels is represented by L2 ′ difference levels expressed by b2 ′ bits (b2 ′> b1 ′). Whether to notify the received L2 ′ difference reception status information.

  Therefore, for a terminal device that needs to allocate many resource blocks in the downlink and transmit a large amount of transmission data, detailed L2 ′ differential reception status information that represents the reception status of each channel with a differential value having a large number of levels. Efficient scheduling and adaptive modulation based on the above can be preferentially performed, and higher-speed transmission can be realized.

  On the other hand, for a terminal device that has relatively little data to be transmitted in the downlink, scheduling and adaptive modulation are performed based on coarse L1 ′ differential reception state information in which the reception state of each channel is represented by a difference value having a smaller number of levels. As a result, it is possible to reduce the information amount of the reception state information notified from the terminal devices using the uplink.

  Based on the above, efficient scheduling and adaptation to terminal devices that require high-speed and large-capacity communication while suppressing the total amount of uplink reception status information notification from each terminal device in the entire system Modulation can be applied.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described.
In the first to third embodiments, the amount of transmission data addressed to each terminal device stored in the transmission buffer unit is used as a reference for determining reception state information to be notified from the base station device to each terminal device. Explained the case.
The base station apparatus 1700 according to the fourth embodiment uses a time fluctuation amount (hereinafter referred to as transmission data) of the transmission data amount addressed to each terminal apparatus stored in the transmission buffer unit 1701 as a reference for determining reception state information to be notified. Or an average amount thereof (hereinafter referred to as an average bit rate of transmission data).
That is, the instantaneous bit rate and the average bit rate in the present embodiment are stored in the transmission buffer unit 1701 when the base station apparatus actually transmits based on the reception state information notified by each terminal apparatus according to the notification request information. This is an index representing the expected amount of transmitted data.

  FIG. 17 is a schematic block diagram showing the configuration of a base station apparatus 1700 according to the fourth embodiment of the present invention. This base station apparatus 1700 is a schematic block diagram which shows the structure of the base station apparatus 1700 by the 4th Embodiment of this invention. The base station apparatus 1700 includes a transmission buffer unit 1701, an encoding unit 202, a mapping unit 203, an IFFT unit 204, a GI insertion unit 205, a D / A conversion unit 206, a wireless transmission unit 207, an antenna unit 208, and a wireless reception unit 209. , An A / D conversion unit 210, a demapping unit 211, a decoding unit 212, a notification request determination unit 1713, a scheduling unit 214, a downlink control information generation unit 215, a pilot generation unit 216, and a reception state information storage unit 217.

In the base station device 1700, the transmission buffer unit 1701 corresponding to the transmission buffer unit 201 of the base station device 200 and the notification request determination unit 1713 corresponding to the notification request determination unit 213 of the base station device 200 are the first embodiment ( Different from FIG. The other configuration of the base station apparatus 1700 is the same as that of the first embodiment, and thus the description thereof is omitted.
Here, a case will be described in which the reference for determining the reception status information for which notification is requested for the first embodiment is changed to the instantaneous bit rate or the average bit rate of the transmission data. The fourth embodiment can also be applied.

The transmission buffer unit 1701 acquires the bit rate of the transmission information that the transmission buffer unit 1701 outputs to the encoding unit 202 as the information amount of transmission information transmitted from the base station device 1700 to the terminal device, and the notification request determination unit 1713. Output to. For example, the transmission buffer unit 1701 accumulates the input transmission data in a buffer for each terminal device as a transmission destination, and is newly added to the transmission buffer within a predetermined time, for example, one subframe in FIG. Calculate the amount of transmission data addressed to each terminal device, that is, the instantaneous bit rate of transmission data, or the average bit rate of transmission data that is an average value over a predetermined time of the transmission data instantaneous bit rate, for example, a predetermined number of subframes, and request notification The data is output to the determination unit 1713.
As the bit rate of transmission data addressed to each terminal device, the quality of service (Quality) associated with the transmission data in the upper layer such as the network control layer or the medium access control layer (Media Access Control layer: MAC layer) is used. of service (QoS) information may be used.
In this case, QoS information regarding each transmission data is input to the transmission buffer unit 1701 from an upper layer, and based on this QoS information, a bit rate of transmission data addressed to each terminal apparatus is calculated and output to the notification request determination unit 1713.

Based on the instantaneous bit rate of the transmission data addressed to each terminal device from the transmission buffer unit 1701 or the average bit rate of the transmission data, the notification request determination unit 1713 informs each terminal device of the reception status for all channels. L1 reception state information represented by L1 levels (L1 is a natural number satisfying 2 ^b1-1 <L1 ≦ 2 ^b1 ) expressed by b1 bits (b1 is a natural number) per channel, and respective reception states for all channels Of L2 reception state information expressed by L2 levels (L2 is a natural number satisfying 2 ^b2-1 <L2 ≦ 2 ^b2 ) expressed by b2 bits per channel (a natural number satisfying b2> b1) And the determination result is output to the downlink control information generation unit 215 as notification request information.

  In the present embodiment, the configuration of the terminal device is the same as the configuration of the terminal device 300 (FIG. 3) according to the first embodiment, and thus the description thereof is omitted.

FIG. 18 is a flowchart showing processing of the notification request determination unit 1713 of the base station device 1700 according to the fourth embodiment of the present invention. That is, FIG. 18 shows the notification request information determination operation in the notification request determination unit 1713.
First, the notification request determination unit 1713 acquires the instantaneous bit rate or average bit rate of transmission data addressed to each terminal device from the transmission buffer unit 1701 (step S1801). Then, the notification request determination unit 1713 repeats the following processing for each terminal device (N terminal devices) (loop 4 from steps S1802 to S1806).

  That is, the notification request determination unit 1713, for each terminal device, all terminals having an instantaneous bit rate or average bit rate of transmission data addressed to the terminal device and a predetermined threshold, for example, an instantaneous bit rate or average bit rate of transmission data. The average value of the device is compared (step S1803), and if the instantaneous bit rate or the average bit rate of the transmission data is equal to or greater than the threshold value, it is selected to request L2 reception status information from the terminal device ( In step S1804), if the instantaneous bit rate or average bit rate of the transmission data is less than the threshold, it is selected to request L1 reception state information from the terminal device (step S1805).

In the above embodiment, the amount of traffic of data transmitted from the base station device to each terminal device is determined, and the predetermined threshold used for determining the notification request information is “average transmission data amount addressed to all terminal devices”. The case where “value” is used has been described.
However, the predetermined threshold value used for determining the notification request information is not limited to this. For example, the number of terminal devices that notify the L1 reception state information and the number of terminal devices that notify the L2 reception state information are determined in advance. A value that realizes the ratio of the number of terminal devices such that the total information amount of the reception status information notified from all the terminal devices according to the notification request information is not more than a predetermined value. As described above, any other index may be used as long as it is an index that can determine the amount of traffic of data transmitted from the base station apparatus to each terminal apparatus.

  The predetermined threshold used for determining the notification request information is preferably greater than 0 and less than or equal to the maximum communication speed (bit rate) per terminal device that can be stored in the transmission buffer unit.

  As described above, according to the present embodiment, when the reception state information is notified from the plurality of terminal apparatuses 300 to the base station apparatus 1700, it depends on the instantaneous bit rate or average bit rate of the downlink transmission data addressed to each terminal apparatus. L1 reception state information that represents each reception state for all channels by L1 levels expressed by b1 bits per channel or L2 items expressed by b2 bits (b2> b1) per channel Whether to notify the L2 reception state information represented by the level of is selected.

  Therefore, for a terminal device that needs to allocate many resource blocks in the downlink and transmit a large amount of transmission data per unit time, L2 reception that represents the reception status of each channel in detail using a large number of levels. Efficient scheduling and adaptive modulation based on state information can be preferentially performed, and higher-speed transmission can be realized.

  On the other hand, scheduling and adaptive modulation are performed based on L1 reception state information that roughly represents the reception state of each channel with a smaller number of levels for a terminal device that has relatively few data to be transmitted per unit time in the downlink. Accordingly, it is possible to reduce the information amount of the reception state information notified from those terminal apparatuses using the uplink.

  From the above, the entire system is efficient for terminal devices that require high-speed and large-capacity communication per unit time while suppressing the total amount of uplink reception status information from each terminal device. Scheduling and adaptive modulation can be applied.

(Fifth embodiment)
In the first embodiment, as reception status information for requesting notification from the base station device 200 to each terminal device 300, each reception status for all channels is represented by L1 levels expressed by b1 bits per channel. When selecting one of two types of reception status information and L2 reception status information represented by L2 levels represented by b2 bits (b2> b1) per channel for each reception status for all channels explained.
The base station apparatus 1900 according to the fifth embodiment has L1 (L1 is 2 ^b1 ) expressed as b1 bits (b1 is a natural number) per channel as the reception status information for requesting notification. ⁻¹ <L1 ≦ 2 is a natural number satisfying ^b1 ) L1 reception state information, and L2 (L2 is a natural number satisfying b2> b1) each reception state regarding all channels expressed by b2 bits per channel 2 ^b2-1 L3 amino represented by <L2 level L2 reception state information represented by the ≦ ^{2 b2} natural number satisfying), and b3 bits (b3 1 channel per each reception status for all channels> b2 natural number satisfying) (L3 is ^{2 b3-1} <L3 ≦ ^{2 b3} natural number satisfying) of L3 reception state information indicating the level of To select one of the kind.

  FIG. 19 is a schematic block diagram showing the configuration of a base station device 1900 according to the fifth embodiment of the present invention. The base station apparatus 1900 includes a transmission buffer unit 201, an encoding unit 202, a mapping unit 203, an IFFT unit 204, a GI insertion unit 205, a D / A conversion unit 206, a wireless transmission unit 207, an antenna unit 208, and a wireless reception unit 209. , An A / D conversion unit 210, a demapping unit 211, a decoding unit 212, a notification request determination unit 1913, a scheduling unit 1914, a downlink control information generation unit 215, a pilot generation unit 216, and a reception state information storage unit 1917.

  In base station apparatus 1900, notification request determination section 1913 corresponding to notification request determination section 213 of base station apparatus 200, scheduling section 1914 corresponding to scheduling section 214 of base station apparatus 200, and reception state information storage section of base station apparatus 200 A reception state information storage unit 1917 corresponding to 217 is different from that of the first embodiment (FIG. 2). The other configuration of the base station apparatus 1900 is the same as that of the first embodiment, and thus the description thereof is omitted.

Based on the information amount of the transmission information acquired by the transmission buffer unit 1701, the notification request determination unit 1913 determines the information amount of the reception state information of the channel that the terminal device 2000 notifies the base station device 1900 of three types. Decide from the amount of information. Note that the notification request determination unit 1913 may determine the information amount of the channel reception state information from among three or more types of information amounts.
Specifically, the notification request determination unit 1913 sends L1 reception state information, L2 reception state information, and L3 to each terminal device based on the transmission data amount information addressed to each terminal device from the transmission buffer unit 201. The reception status information to be notified is determined from the reception status information. Then, the notification request determination unit 1913 outputs the determination result to the downlink control information generation unit 215 as notification request information. The details of the notification request information determination procedure will be described later.
The scheduling unit 1914 reads out the reception state information notified from each terminal device stored in the reception state information storage unit 1917, performs scheduling by assigning the terminal device to each resource block of each channel based on the information, The modulation parameter used in the resource block is selected, and the scheduling result (scheduling information) and the modulation parameter selection result (modulation parameter information) are output. The scheduling may be further performed based on transmission data amount information from the transmission buffer unit 201. Details of the operation of the scheduling unit 1914 will be described later.
The reception state information storage unit 1917 stores the reception state information notified from each terminal device 2000 separated by the demapping unit 211 together with the identification information of the corresponding channel for each terminal device, and outputs it to the scheduling unit 1914.

  FIG. 20 is a schematic block diagram showing the configuration of the terminal device 2000 according to the fifth embodiment of the present invention. The terminal device 2000 includes an antenna unit 301, a radio reception unit 302, an A / D conversion unit 303, a GI removal unit 304, an FFT unit 305, a demapping unit 306, a decoding unit 307, a reception state measurement unit 308, and reception state information. A generation unit 2009, an encoding unit 310, a mapping unit 311, a D / A conversion unit 312, a wireless transmission unit 313, and a demodulation control unit 314 are included.

  In the terminal device 2000, a reception state information generation unit 2009 corresponding to the reception state information generation unit 309 of the terminal device 300 is different from that of the first embodiment (FIG. 3). Since the other configuration of the terminal device 2000 is the same as that of the first embodiment, the description thereof is omitted.

Based on the notification request information output from the demodulation control unit 314, the reception state information generation unit 2009, when the notification request information is information for requesting L1 reception state information, each reception state measurement unit 308 outputs Reception state information represented by L1 levels is generated from the reception state measurement results in the channel, and is output to the mapping unit 311.
In addition, when the notification request information is information requesting L2 reception state information, the reception state information generation unit 2009 uses L2 levels from the reception state measurement result in each channel output from the reception state measurement unit 308. The represented reception state information is generated and output to the mapping unit 311.
In addition, when the notification request information is information requesting L3 reception state information, the reception state information generation unit 2009 uses L3 levels from the reception state measurement results in each channel output from the reception state measurement unit 308. The represented reception state information is generated and output to the mapping unit 311.

FIG. 21 is a flowchart showing processing of the notification request determination unit 1913 of the base station apparatus 1900 according to the fifth embodiment of the present invention. That is, FIG. 21 shows notification request information determination operation in the notification request determination unit 1913.
First, the notification request determination unit 1913 acquires the transmission data amount addressed to each terminal device from the transmission buffer unit 201 (step S2101). The notification request determination unit 1913 repeats the following processing for each terminal device (terminal device 2000-1 to terminal device 2000-N) (loop 5 from step S2102 to S2107).

  That is, the notification request determination unit 1913, for each terminal device, a transmission data amount addressed to the terminal device and a predetermined first threshold, for example, a value of 1/3 of the sum of the transmission data amounts addressed to all terminal devices, When a predetermined second threshold value that is larger than the first threshold value, for example, a value that is 2/3 of the total transmission data amount addressed to all terminal apparatuses is compared (step S2103), and the transmission data amount is equal to or greater than the second threshold value Selects to request the L3 reception state information from the terminal device (step S2104), and when the transmission data amount is not less than the first threshold value and less than the second threshold value, the terminal device receives L2 reception. Select to request status information (step S2105), and if the amount of transmission data is less than the first threshold, select to request L1 reception status information from the terminal device (step S2105). 106).

In the above embodiment, the amount of traffic of data transmitted from the base station device to each terminal device is determined, and the predetermined first threshold value and the predetermined second threshold value used for determining the notification request information are “all terminals”. The case where “1/3 value and 2/3 value of the total amount of transmission data addressed to the apparatus” is used has been described.
However, these predetermined threshold values used for determining the notification request information are not limited to this. For example, the number of terminal devices that notify L1 reception state information, the number of terminal devices that notify L2 reception state information, and L3 The value determined so that the number of terminal devices that notify the reception status information becomes a predetermined ratio, or the total amount of reception status information notified from all the terminal devices according to the notification request information is less than or equal to the predetermined value Any other index may be used as long as it is an index that can determine the amount of traffic of data transmitted from the base station apparatus to each terminal apparatus, such as a value that realizes the ratio of the number of terminal apparatuses.

  The predetermined first threshold value and the predetermined second threshold value used for determining the notification request information are values larger than 0 and less than or equal to the maximum transmission data amount per terminal device that can be stored in the transmission buffer unit. It is desirable.

FIG. 22 is a flowchart showing a process of the scheduling unit 1914 of the base station apparatus 1900 according to the fifth embodiment of the present invention. That is, FIG. 22 illustrates a scheduling operation and a modulation parameter selection operation in the scheduling unit 1914.
The scheduling unit 1914 reads the reception state information notified from each terminal device from the reception state information storage unit (step S2201).
Then, the scheduling unit 1914 allocates transmission data to be transmitted to each terminal apparatus that has notified the L3 reception state information to resource blocks based on the reception state information of each channel notified by each terminal apparatus (step S2202). .
Next, the scheduling unit 1914 selects a modulation parameter for each resource block assigned in step S2202 based on reception state information in the channel of the terminal device assigned to each resource block (step S2203).

Then, the scheduling section 1914 allocates transmission data to be transmitted to each terminal apparatus that has notified the L2 reception status information from the remaining resource blocks allocated in step S2202 based on the reception status information of each terminal apparatus (step S2204). ).
Next, the scheduling unit 1914 selects a modulation parameter for each resource block assigned in step S2205, based on the reception state information of each terminal device assigned to each resource block (step S2206).
Next, the scheduling unit 1914 sends the transmission data to be transmitted to each terminal apparatus that has notified the L1 reception state information to the remaining resource blocks allocated in step S2202 and step S2204 based on the reception state information of each terminal apparatus. Assign (step S2206).

Then, the scheduling unit 1914 selects a modulation parameter for each resource block assigned in step S2206, based on the reception state information of each terminal apparatus assigned to each resource block (step S2207).
Next, the scheduling unit 1914 outputs the scheduling result (scheduling information) and the modulation parameter selection result (modulation parameter information) to the encoding unit 202, the mapping unit 203, and the downlink control information generation unit 215 (step S2208).

  In the above description, the case where one of the three types of reception status information is selected has been described. However, one of two or more types of reception status information may be selected.

  As described above, according to the present embodiment, when the reception status information is notified from the plurality of terminal apparatuses 2000 to the base station apparatus 1900, each of the channels related to all channels according to the amount of downlink transmission data addressed to each terminal apparatus. L1 reception status information that represents the reception status by L1 levels expressed by b1 bits per channel or L2 reception status expressed by L2 levels expressed by b2 bits (b2> b1) per channel Select whether to notify information or to notify L3 reception state information represented by L3 levels expressed by b3 bits (b3> b2> b1) per channel. Therefore, for a terminal device that needs to allocate many resource blocks in the downlink and transmit a large amount of transmission data, it is based on the L3 reception state information that represents the reception state of each channel in detail using a large number of levels. Efficient scheduling and adaptive modulation can be preferentially performed, and higher speed transmission can be realized.

  Furthermore, for terminal devices that need to allocate medium resource blocks among all terminal devices in the downlink and transmit medium amounts of transmission data, the reception status of each channel is determined from the L3 reception status information. However, based on the L2 reception state information expressed using the number of levels that is less than the L1 reception state information, it is possible to perform scheduling and adaptive modulation preferentially after the terminal device that has notified the L3 reception state information. Therefore, it is possible to reduce the information amount of the reception state information notified using the uplink without excessively reducing the data transmission efficiency in the downlink.

On the other hand, for terminal devices with relatively little data to be transmitted in the downlink, scheduling and adaptive modulation are performed by performing scheduling and adaptive modulation based on L1 reception state information that roughly represents the reception state of each channel with a smaller number of levels. It is possible to reduce the amount of reception state information notified from the terminal device using the uplink.
Based on the above, efficient scheduling and adaptation to terminal devices that require high-speed and large-capacity communication while suppressing the total amount of uplink reception status information notification from each terminal device in the entire system Modulation can be applied.

(Sixth embodiment)
In the first to fifth embodiments described above, the OFDM system is used, and the channel is described as meaning one or a plurality of subcarriers.
In the present embodiment, an example of an application method in a MIMO (Multiple Input Multiple Output) -OFDM system will be described in the case where one or a plurality of subcarriers of each transmission antenna is used as a channel.
As the base station apparatus and terminal apparatus used in the present embodiment, the same base station apparatus 200 (FIG. 2) and terminal apparatus (FIG. 3) of the first embodiment can be used. Description is omitted.

FIG. 23 is a diagram illustrating an example of a downlink subframe configuration according to the sixth embodiment of the present invention. The base station device includes A (A is an integer of 2 or more) transmission antennas a _{1 to} a _A, and transmits different signals from the transmission antennas a _{1 to} a _A to the terminal device. The subframe includes A areas transmitted from antennas a ₁ to a _A , and each area is further divided into K areas (K is a natural number) in the frequency direction. Each of the A × K areas is a channel, and this subframe is a transmission unit, which is a range in which a channel is allocated in one scheduling process.
Further, the subframe is divided into T pieces (T is a natural number) with a predetermined time length TTI (Transmission Time Interval) in the time axis direction, and one TTI in one channel is set as a unit of scheduling (resource block).
Even in a MIMO-OFDM system having such a subframe configuration, the same processing as in the first to fifth embodiments described above can be applied only in the area indicated by the term channel or resource block.

  As described above, in a system that performs communication using a plurality of channels in a subframe, the present embodiment can be applied to a system in which the reception state of each channel in each terminal device may be different. Efficient scheduling and adaptive modulation are applied to terminal devices that require high-speed and large-capacity communication while suppressing the total amount of uplink reception status information from each terminal device in the entire system It becomes possible to do.

(Seventh embodiment)
In the seventh embodiment, in the first to sixth embodiments described above, when the notification request determination unit first requests reception status information from the terminal device, Reception state information with the smallest number of bits (number of levels) (L1 reception state information, L1-M reception state information, L1 ′ reception state information in the above embodiments. These are hereinafter referred to as first reception state information. ) Request request information is generated.
As the base station apparatus and terminal apparatus used in the present embodiment, the same base station apparatus 200 (FIG. 2) and terminal apparatus (FIG. 3) of the first embodiment can be used. Description is omitted. In addition, although this embodiment demonstrates the case where the base station apparatus and terminal device by 1st Embodiment are used, it is not limited to this, The base station apparatus by 2nd to 6th Embodiment and A terminal device may be used.

FIG. 24 is a sequence diagram showing processing of the base station device and the terminal device according to the seventh embodiment of the present invention. FIG. 24 illustrates processing related to notification of initial notification request information and reception state information between the base station apparatus and the terminal apparatus.
First, when the first downlink transmission data addressed to the terminal device is input to the transmission buffer unit (step S2401), the base station device transmits L1 reception state information that is first reception state information to the terminal device. Notification request information to be requested is generated (step S2402).
The base station apparatus notifies the notification request information generated in step S2402 to the terminal apparatus A as a part of the downlink control information (step S2403).

The terminal apparatus receives the notification request information requesting the L1 reception state information, and measures the reception state regarding each channel from the downlink pilot symbol (step S2404).
Then, the terminal device generates L1 reception state information represented by L1 levels from the reception state measurement result of each channel (step S2405).
Next, the terminal apparatus notifies the base station apparatus of the L1 reception state information generated in step S2405 (step S2406).

Next, the base station apparatus receives the L1 reception state information transmitted by the terminal apparatus in step S2406, and performs downlink scheduling and adaptive modulation together with the reception state information from other terminal apparatuses (step S2407). .
Then, based on the amount of transmission data addressed to the terminal device, the base station device selects reception status information to be requested from the terminal device from L1 reception status information and L2 reception status information, and generates notification request information (step S2408).
Next, the base station apparatus notifies the terminal apparatus of the notification request information generated in step S2408 as part of the downlink control information (step S2409).
FIG. 24 illustrates a case where L2 reception state information is selected in step S2408.

The terminal apparatus receives notification request information for requesting L2 reception state information from the base station apparatus, and measures the reception state regarding each channel from downlink pilot symbols (step S2410).
Then, the terminal device generates L2 reception state information represented by L2 levels from the reception state measurement result of each channel (step S2411).
Next, the terminal apparatus notifies the base station apparatus of the L2 reception state information generated in step S2411 (step S2412).

  Thereafter, while there is transmission data addressed to the terminal device, the processing from step S2407 to S2412 is repeated. Steps S2402 to S2406 are the first notification request information and reception state information notification processing in this embodiment.

  In FIG. 24, the timing at which the first transmission data addressed to the target terminal apparatus is input to the transmission buffer unit is described as the timing at which the reception state information is first requested. However, the present invention is not limited to this. From the timing when the target terminal device makes a connection request to the base station device, the timing when authentication is completed between the base station device and the target terminal device, and the state where the terminal device temporarily interrupts communication It can also be applied to the return timing.

  As described above, in this embodiment, when the reception state information is first requested from the terminal device, the first reception state information having the smallest bit number (level number) is requested from the terminal device. To do. As a result, when starting data communication between the base station apparatus and the terminal apparatus, the first reception state information that roughly represents the reception state of each channel from the terminal apparatus with a smaller number of levels is used. It is possible to reduce the amount of reception state information notified using a link.

(Eighth embodiment)
In the first embodiment, a case has been described in which the amount of transmission data in the transmission buffer 201 is referred to when determining reception state information to be notified from the base station apparatus 200 to each terminal apparatus 300.
When the base station apparatus 2500 in the eighth embodiment determines reception state information to be notified from the base station apparatus 2500 to each terminal apparatus 300, the transmission data amount in the transmission buffer 201 and the maximum Doppler frequency in each terminal apparatus Refer to fd.

  FIG. 25 is a schematic block diagram showing the configuration of the base station device 2500 according to the eighth embodiment of the present invention. The base station device 2500 includes a transmission buffer unit 201, an encoding unit 202, a mapping unit 203, an IFFT unit 204, a GI insertion unit 205, a D / A conversion unit 206, a wireless transmission unit 207, an antenna unit 208, and a wireless reception unit 209. , A / D conversion section 210, demapping section 211, decoding section 212, notification request determination section 2513, scheduling section 914, downlink control information generation section 215, pilot generation section 216, reception state information storage section 217, maximum Doppler A frequency measurement unit 218 is included.

  In the base station device 2500, a notification request determination unit 2513 corresponding to the notification request determination unit 213 of the base station device 200 is different from that of the first embodiment (FIG. 2). Moreover, the point from which the maximum Doppler frequency measurement part 218 is provided differs from 1st Embodiment. The other configuration of the base station apparatus 2500 is the same as that of the first embodiment, and thus the description thereof is omitted.

The notification request determination unit 2513 notifies the base station device 2500 of the terminal device based on the information amount of the transmission information acquired by the transmission buffer unit 201 and the maximum Doppler frequency measured by the maximum Doppler frequency measurement unit 218. The amount of channel reception status information is determined.
For example, the notification request determination unit 2513 determines each terminal based on the measurement result of the maximum Doppler frequency fd measured by the maximum Doppler frequency measurement unit 218 and the transmission data amount information addressed to each terminal device from the transmission buffer unit 201. Receiving status of all channels for the device is expressed by L1 levels (L1 is a natural number satisfying 2 ^b1-1 <L1 ≦ 2 ^b1 ) expressed by b1 bits per channel (b1 is a natural number). L2 reception state information and each reception state for all channels are expressed by b2 bits (a natural number satisfying b2> b1) per channel (L2 is a natural number satisfying 2 ^b2-1 <L2 ≦ 2 ^b2 ). Which of the L2 reception status information represented by the level is to be notified is determined. Then, the notification request determination unit 2513 outputs the determination result to the downlink control information generation unit 215 as notification request information. Details of the notification request information determination procedure will be described later.
Specifically, the notification request determination unit 2513 includes the information amount of the reception state information of the channel that the terminal apparatus notifies the base station apparatus 2500 as the maximum Doppler frequency fd measured by the maximum Doppler frequency measurement unit 218 increases. The amount of channel reception status information is determined so as to reduce the number of received channels. Detailed processing of the notification request determination unit 2513 will be described later with reference to FIG.

  Maximum Doppler frequency measurement section 218 measures the maximum Doppler frequency of the signal received by base station apparatus 2500 from the terminal apparatus, based on the signal output from demapping section 211. The maximum Doppler frequency measurement unit 218 may be included in the base station device 2500 or the terminal device 300. When the terminal device 300 is provided, the measurement result of the maximum Doppler frequency fd may be reported to the base station device 2500.

  Note that the terminal device used in the present embodiment can be the same as the terminal device (FIG. 3) of the first embodiment, and thus the description thereof is omitted.

FIG. 26 is a flowchart showing processing of the notification request determination unit 2513 of the base station device 2500 according to the eighth embodiment of the present invention. That is, FIG. 26 shows the notification request information determining operation in the notification request determining unit 2513.
First, the notification request determination unit 2513 acquires the amount of transmission data addressed to each terminal device from the transmission buffer unit 201 (step S2601). Then, the notification request determination unit 2513 acquires the measurement result of the maximum Doppler frequency fd in each terminal device (step S2602).
The notification request determination unit 2513 repeats the following processing for each terminal device (N terminal devices) (loop 8 from step S2603 to S2608).
That is, the notification request determination unit 2513 compares, for each terminal device, the amount of transmission data addressed to the terminal device and a predetermined first threshold value, for example, the average value of the amount of transmission data addressed to all terminal devices (step S2604). ), When the transmission data amount is equal to or greater than the first threshold, the measurement result of the maximum Doppler frequency fd in the terminal device, a predetermined second threshold, for example, the time when the terminal device measures the reception state, and the base station device Is a coherent time obtained by multiplying the reciprocal of the maximum Doppler frequency fd by a time between the time when the terminal device receives transmission data that is scheduled / adaptively modulated based on the reception state measurement result, and so-called processing delay. A value determined so as to coincide with the time is compared (step S2605), and the measurement result of the maximum Doppler frequency fd is the second. If it is less than the value, it is selected to request L2 reception state information (step S2606), and if the transmission data amount is less than the first threshold or the measurement result of the maximum Doppler frequency fd is greater than or equal to the second threshold. Selects to request the terminal device for L1 reception status information (step S2607).

In the present embodiment, the amount of data traffic transmitted from the base station apparatus to each terminal apparatus is determined, and a predetermined first threshold value used for determining notification request information is “amount of transmission data addressed to all terminal apparatuses”. The case of using the “average value” has been described.
However, the predetermined first threshold value used for determining the notification request information is not limited to this. For example, the number of terminal devices that notify L1 reception state information and the number of terminal devices that notify L2 reception state information are determined. Realizes a value that is set to a predetermined ratio or a ratio of the number of terminal devices that the total amount of reception status information notified from all terminal devices according to notification request information is less than or equal to a predetermined value As long as it is an index that can determine the amount of traffic of data transmitted from the base station apparatus to each terminal apparatus, such as a value to be used, another index may be used.

The predetermined first threshold value used for determining the notification request information is preferably greater than 0 and less than or equal to the maximum transmission data amount per terminal device that can be stored in the transmission buffer unit.
The predetermined second threshold is “between the time when the terminal device measures the reception state and the time when the terminal device receives the transmission data that the base station device performs scheduling / adaptive modulation based on the reception state measurement result”. The case where a value determined so that the so-called processing delay, the so-called processing delay, coincides with the coherent time obtained by multiplying the reciprocal of fd by a constant has been described.
However, the predetermined second threshold value used for determining the notification request information is not limited to this. For example, the reception state at the time when the terminal device measures the reception state indicates that the base station device indicates the reception state measurement result. The effect is obtained if the value is the maximum Doppler frequency fd that is substantially the same value as the reception state at the time when the terminal apparatus receives the transmission data subjected to scheduling / adaptive modulation based thereon.

  In the above description, the case where the maximum Doppler frequency fd in the terminal apparatus is used as an index indicating the speed of fluctuation of the reception state measurement result of the channel of each terminal apparatus has been described. However, the present invention is not limited to this. For example, the coherent time at the terminal device, the reception state at the time when the terminal device measures the reception state, and the reception at the time when the terminal device receives transmission data that is scheduled / adaptively modulated based on the reception state measurement result by the base station device Other indicators related to the speed of fluctuation of the reception state measurement result of the channel of each terminal device, such as a difference from the state and a value obtained by measuring the moving speed of the terminal device, may be used.

  As described above, according to the present embodiment, when the reception state information is notified from the plurality of terminal apparatuses 300 to the base station apparatus 2500, the amount of downlink transmission data addressed to each terminal apparatus and the fd in each terminal apparatus are determined. L1 reception state information that represents each reception state for all channels by L1 levels expressed by b1 bits per channel or L2 items expressed by b2 bits (b2> b1) per channel Whether to notify the L2 reception state information represented by the level of is selected.

  Therefore, for a terminal apparatus that needs to allocate many resource blocks in the downlink and transmit a large amount of transmission data, obtain L2 reception state information that represents the reception state of each channel in detail using a large number of levels. Therefore, efficient scheduling and adaptive modulation based on detailed reception status information of each channel can be preferentially performed, and higher-speed transmission can be realized.

  Furthermore, even if it is necessary to transmit a large amount of transmission data, the channel reception state varies rapidly, and the reception state changes before and after the processing delay. Since the L1 reception state information is roughly represented by a smaller number of levels, the amount of reception state information notified from the terminal devices using the uplink can be reduced.

On the other hand, since L1 reception status information is reported for terminal devices with relatively little data to be transmitted on the downlink, it is possible to reduce the amount of reception status information notified from the terminal devices using the uplink. it can.
Based on the above, efficient scheduling and adaptation to terminal devices that require high-speed and large-capacity communication while suppressing the total amount of uplink reception status information notification from each terminal device in the entire system Modulation can be applied.

In the first to eighth embodiments described above, a multicarrier transmission system (in particular, an OFDM transmission system) is used as a transmission system, a channel configuration including at least one subcarrier is used as a channel configuration, and the target unit of adaptive modulation is a channel. A case has been described where a CNR calculated based on pilot symbols is used as a reception state in a cellular system in which adaptive scheduling (channel allocation) is performed for each channel.
However, the modulation scheme, channel configuration, target unit for adaptive modulation, adaptive scheduling (channel allocation), and reception status are not limited to such conditions.
For example, an MC-CDMA (Multi Carrier-Code Division Multiple Access) system using spreading technology as a transmission system is used, and the unit of adaptive modulation and adaptive scheduling is SDMA (Multiple Input Multiple Output) such as MIMO (Multiple Input Multiple Output): In other systems that communicate using a plurality of channels, such as a plurality of channels indicated by a transmission antenna or eigenmode in space division multiple access), a plurality of code channels in CDMA, or a combination of these channels, Each embodiment of the present invention can be used in a system in which the reception state may be different for each channel.

  The reception state information includes RSSI (Received Signal Strength Indicator), SNR, SIR (Signal to Interference power Ratio), SINR (Signal to Interference plus Noise power Ratio). Power and noise power ratio), CIR (Carrier to Interference power Ratio), CINR (Carrier to Interference plus Noise power Ratio), etc. It relates to the transmission rate of the modulation parameter selected according to the propagation path state such as the index indicating the reception state in relation to the power, the modulation parameter such as MCS which is a combination of the modulation method and the channel coding rate, and the transmission rate. Other indices may be used as long as they are indices.

In the first to eighth embodiments described above, the communication system adopts FDD (Frequency Division Duplex) composed of a base station device and a plurality of terminal devices, and is a downlink communication. 1 uses an OFDM adaptive modulation system, and uplink communication uses a system that does not perform OFDM and adaptive modulation, but is not limited thereto.
Further, in the first to eighth embodiments described above, any one of a plurality of wireless communication apparatuses can perform a scheduling function and adaptive modulation, and another wireless communication apparatus can perform a reception state information transmission function. It can be applied to the wireless communication devices in

Note that, between the two wireless communication devices, the side that notifies the reception status information of the channel (the side having the reception status information transmission function) is the terminal device, and the transmission data to each terminal device is sent based on the notified reception status information. Although the side that performs adaptive modulation assigned to each channel (the side that performs the scheduling function) has been described as a base station apparatus, a single wireless communication apparatus may have both functions.
This wireless communication device is a device that performs wireless communication, and includes a base station device, a terminal device, a wireless device, a mobile terminal device, a mobile phone, and the like.

  In the embodiment described above, each part of the base station device (FIGS. 2, 9, 13, 17, 17, and 25) in the first to eighth embodiments and the terminal device (FIG. 3, 10, 14, and 20) or a program for realizing a part of these functions is recorded on a computer-readable recording medium, and the program recorded on the recording medium is stored in a computer system. The base station apparatus and the terminal apparatus may be controlled by reading and executing. Here, the “computer system” includes an OS and hardware such as peripheral devices.

  The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Further, the “computer-readable recording medium” dynamically holds a program for a short time, like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, it is also assumed that a server that holds a program for a certain time, such as a volatile memory inside a computer system that serves as a server or client. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and the design and the like within the scope of the present invention are also within the scope of the claims. include.

It is the figure which showed an example of the sub-frame structure of the downlink in the 1st Embodiment of this invention. It is a schematic block diagram which shows the structure of the base station apparatus 200 by the 1st Embodiment of this invention. It is a schematic block diagram which shows the structure of the terminal device 300 by the 1st Embodiment of this invention. It is a figure for demonstrating the L1 reception status information and L2 reception status information which are used in the 1st Embodiment of this invention. It is a figure for demonstrating another example of the L1 reception status information and L2 reception status information used in the 1st Embodiment of this invention. It is a flowchart which shows the process of the notification request determination part 213 of the base station apparatus 200 by the 1st Embodiment of this invention. It is a flowchart which shows the process of the scheduling part 214 of the base station apparatus 200 by the 1st Embodiment of this invention. It is a figure for demonstrating the determination method of the notification request | requirement of the reception status information in the 1st Embodiment of this invention. It is a schematic block diagram which shows the structure of the base station apparatus 900 by the 2nd Embodiment of this invention. It is a schematic block diagram which shows the structure of the terminal device 1000 by the 2nd Embodiment of this invention. It is a flowchart which shows the process of the notification request determination part 913 of the base station apparatus 900 by the 2nd Embodiment of this invention. It is a flowchart which shows the process of the scheduling part 914 of the base station apparatus 900 by the 2nd Embodiment of this invention. It is a schematic block diagram which shows the structure of the base station apparatus 1300 by the 3rd Embodiment of this invention. It is a schematic block diagram which shows the structure of the terminal device 1400 by the 3rd Embodiment of this invention. It is a flowchart which shows the process of the notification request determination part 1313 of the base station apparatus 1300 by the 3rd Embodiment of this invention. It is a flowchart which shows the process of the scheduling part 1314 of the base station apparatus 1300 by the 3rd Embodiment of this invention. It is a schematic block diagram which shows the structure of the base station apparatus 1700 by the 4th Embodiment of this invention. It is a flowchart which shows the process of the notification request determination part 1713 of the base station apparatus 1700 by the 4th Embodiment of this invention. It is a schematic block diagram which shows the structure of the base station apparatus 1900 by the 5th Embodiment of this invention. It is a schematic block diagram which shows the structure of the terminal device 2000 by the 5th Embodiment of this invention. It is a flowchart which shows the process of the notification request determination part 1913 of the base station apparatus 1900 by the 5th Embodiment of this invention. It is a flowchart which shows the process of the scheduling part 1914 of the base station apparatus 1900 by the 5th Embodiment of this invention. It is a figure which shows an example of the sub-frame structure of the downlink in the 6th Embodiment of this invention. It is a sequence diagram which shows the process with the base station apparatus and terminal device in the 7th Embodiment of this invention. It is a schematic block diagram which shows the structure of the base station apparatus 2500 by the 8th Embodiment of this invention. It is a flowchart which shows the process of the notification request determination part 2513 of the base station apparatus 2500 by the 8th Embodiment of this invention. It is a schematic block diagram which shows the structure of the base station apparatus 9000 in a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 200 ... Base station apparatus, 201 ... Transmission buffer part, 202 ... Coding part, 203 ... Mapping part, 204 ... IFFT part, 205 ... GI insertion part, 206 ... D / A conversion unit, 207... Wireless transmission unit, 208... Antenna unit, 209... Wireless reception unit, 210... A / D conversion unit, 211. Decoding unit, 213 ... notification request determination unit, 214 ... scheduling unit, 215 ... downlink control information generation unit, 216 ... pilot generation unit, 217 ... reception state information storage unit, 218: Maximum Doppler frequency measurement unit, 300 ... Terminal device, 301 ... Antenna unit, 302 ... Wireless reception unit, 303 ... A / D conversion unit, 304 ... GI removal unit, 305 ... FFT unit, 3 6 ... Demapping unit, 307 ... Decoding unit, 308 ... Reception state measurement unit, 309 ... Reception state information generation unit, 310 ... Encoding unit, 311 ... Mapping unit, 312 ... D / A conversion unit, 313 ... wireless transmission unit, 314 ... demodulation control unit, 913 ... notification request determination unit, 914 ... scheduling unit, 917 ... reception state information storage , 1009... Reception state information generation unit, 1313... Notification request determination unit, 1314... Scheduling unit, 1317. ..Transmission buffer unit, 1713... Notification request determining unit, 1913... Notification request determining unit, 1914... Scheduling unit, 1917. Information generating unit, 2513 ... notification request determining unit

Claims (11)

A base station device that communicates with a terminal device,
A transmission information storage unit for storing transmission information to be transmitted to the terminal device;
A transmission information amount acquisition unit that acquires an information amount of transmission information to be transmitted to the terminal device, the transmission information storage unit acquiring an information amount of transmission information;
An information amount determination unit that determines an information amount of channel reception state information that the terminal device notifies to the base station device based on an information amount of transmission information acquired by the transmission information amount acquisition unit;
A notification unit for notifying the terminal device of the information amount of the reception state information of the channel determined by the information amount determination unit;
Bei to give a,
The information amount determination unit increases the information amount of the reception state information of the channel notified to the base station device by the terminal device as the information amount of the transmission information acquired by the transmission information amount acquisition unit increases. A base station apparatus .   The base station apparatus according to claim 1, wherein the reception state information includes identification information of a predetermined number of channels among all channels and information indicating reception states of the predetermined channels.   The base station apparatus according to claim 1, wherein the reception state information includes a difference value between a reception state of a predetermined channel and a reception state of an adjacent channel.   The information amount determination unit has three or more types of information amounts of the reception state information of the channel that the terminal device notifies the base station device based on the information amount of the transmission information acquired by the transmission information amount acquisition unit. The base station apparatus according to claim 1, wherein the base station apparatus is determined from the information amount of the base station. A maximum Doppler frequency measurement unit for measuring a maximum Doppler frequency of a signal received by the base station device from the terminal device;
The information amount determination unit is configured so that the terminal device transmits the information to the base station device based on the information amount of the transmission information acquired by the transmission information amount acquisition unit and the maximum Doppler frequency measured by the maximum Doppler frequency measurement unit. The base station apparatus according to claim 1, wherein an information amount of reception state information of a channel to be notified is determined. The information amount determination unit decreases the information amount of the reception state information of the channel notified by the terminal device to the base station device as the maximum Doppler frequency measured by the maximum Doppler frequency measurement unit increases. The base station apparatus according to claim 5 , wherein:   The information amount determination unit, based on the information amount of the transmission information for each terminal device acquired by the transmission information amount acquisition unit, the information amount of the reception state information of the channel that the terminal device notifies to the base station device The base station apparatus according to claim 1, wherein the base station apparatus is determined for each terminal apparatus. A reception state information receiving unit for receiving the reception state information of the channel notified from the terminal device;
A channel allocation unit that allocates transmission information for the terminal device to each channel based on the reception status information of the channel received by the reception status information reception unit;
The base station apparatus according to any one of claims 1 to 7 , further comprising: The channel allocating unit allocates transmission data for the terminal device preferentially to the channel as the information amount of the reception state information of the channel received from the terminal device by the reception state information receiving unit increases. The base station apparatus according to claim 8 . A communication system comprising a base station device and a terminal device,
The base station device
A transmission information storage unit for storing transmission information to be transmitted to the terminal device;
A transmission information amount acquisition unit that acquires an information amount of transmission information to be transmitted to the terminal device, the transmission information storage unit acquiring an information amount of transmission information;
An information amount determination unit that determines the information amount of the reception state information of the channel that the terminal device notifies the base station device based on the information amount of the transmission information acquired by the transmission information amount acquisition unit;
A notification unit for notifying the terminal device of the information amount of the reception state information of the channel determined by the information amount determination unit,
The information amount determination unit increases the information amount of the reception state information of the channel notified to the base station device by the terminal device as the information amount of the transmission information acquired by the transmission information amount acquisition unit increases. And
The terminal device
A receiving unit that receives an amount of information of reception state information of a channel notified by the notification unit;
A reception state measurement unit for measuring the reception state of the channel;
A reception state information generation unit that generates reception state information of the channel measured by the reception state measurement unit using the amount of information received by the reception unit;
A communication system comprising: a transmission unit that transmits the reception state information generated by the reception state information generation unit to the base station apparatus. A communication method using a base station device and a terminal device,
The base station device
A transmission information amount acquisition process for acquiring an information amount of transmission information to be transmitted to the terminal device and acquiring an information amount of transmission information accumulated by the transmission information accumulation unit;
An information amount determination step of determining an information amount of channel reception state information notified by the terminal device to the base station device based on an information amount of transmission information acquired in the transmission information amount acquisition step;
Performing a notification step of notifying the terminal device of the information amount of the reception state information of the channel determined in the information amount determination step;
The terminal device
A reception process for receiving the amount of information of the reception status information of the channel notified in the notification process;
A reception state measurement process for measuring the reception state of the channel;
A reception state information generation step of generating reception state information of the channel measured in the reception state measurement step using the amount of information received in the reception step;
Performing the transmission process of transmitting the reception status information generated in the reception status information generation process to the base station device ,
In the information amount determination process, the larger the information amount of the transmission information acquired in the transmission information amount acquisition step, the larger the information amount of the reception state information of the channel that the terminal device notifies the base station device A communication method characterized by:

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