JP5605471B2 - Wireless communication system, base station device, terminal device, and wireless communication method in wireless communication system - Google Patents

Description

  The present invention relates to a radio communication system, a base station apparatus, a terminal apparatus, and a radio communication method in the radio communication system.

  In the LTE-A (LTE-Advanced) system, wireless communication using CoMP (Coordinate Multi Point access) has been studied (for example, Non-Patent Documents 1 and 2 below).

  CoMP is executed, for example, when each terminal station transmits different data to the terminal using MIMO (Multiple Input Multiple Output) when the terminal is located in an area where the terminal can communicate with a plurality of base stations (or sectors). The

  On the other hand, in a radio communication system such as LTE, a base station performs scrambling processing on transmission data (for example, Non-Patent Documents 3 and 4 below). For example, the base station transmits the transmission data b (0),. . . , B (Mbit-1) and the scrambling code c (i) are added, and the remainder (Modulo) of “2” is calculated to scramble. That is,

It becomes. Here, the scramble code c (i) is a gold code having a length of “31” and is obtained by the following generator polynomial.

  here,

Furthermore, the initial value of the scramble code c (i) is given by

  That is, the initial value of the scramble code c (i) is the terminal number

, (Physical) cell (or sector) number

And slot number

The value determined by.

  As this type of prior art, for example, based on the reception quality notified from the mobile station, at least two transmission sectors to be transmitted to the mobile station are selected, and transmission allocation for performing transmission allocation to the mobile station is performed. And a control device or the like including a transmission means for transmitting to a mobile station using the same scrambling code for sector identification from the transmission sector is disclosed (for example, Patent Document 1 below).

  In addition, for example, based on the necessity of software synthesis for each physical channel, a base station specific scramble generation unit that generates a base station specific scrambling code, a sector specific orthogonal sequence generation unit that generates a sector specific orthogonal sequence, A base station apparatus or the like that includes a multiplication control unit that controls whether or not to multiply the base station specific scrambling code and the sector specific orthogonal sequence is disclosed (for example, Patent Document 2 below).

JP 2006-31475 A JP 2008-92379 A

R1-084203 3GPP TS 36.210 V8.6.0 3GPP TS 36.211 V8.2.0 R1-081229

  As described above, the initial value of the scramble code is determined from the terminal number, the cell number, and the slot number. The terminal number is set by the base station for each cell, and the cell number is also different for each cell. Also, the slot number may be a different number between cells. Therefore, when CoMP transmission is performed from a different cell to the terminal, the initial value of the scramble code is different for each cell. Therefore, each base station and terminal create different scrambling codes and use them to perform scrambling and descrambling processes. Accordingly, the processing of each base station and terminal becomes complicated, and the power consumption increases.

  Moreover, what was described in patent documents 1 and 2 is not disclosed about the case where different data are transmitted from two sectors. As described in Patent Document 1, when different data is transmitted from two sectors using the same scramble code, the mobile station receives two signals, but these two signals interfere with each other. This is because data transmitted from two sectors cannot be identified.

  Accordingly, an object of the present invention is to provide a radio communication system, a base station apparatus, a terminal apparatus, and a radio communication method in the radio communication system, in which processing is reduced in the terminal apparatus or base station apparatus.

  Another object of the present invention is to provide a wireless communication system or the like that can reduce power consumption in a terminal device or a base station device.

  According to an aspect, in the wireless communication system that performs wireless communication between the first and second base station apparatuses each having one or a plurality of cells or sectors and the terminal apparatus, the first and second bases The station apparatus scrambles each of the first and second transmission data using a common scramble code when transmitting the first and second transmission data respectively different for each cell or each sector to the terminal apparatus. A processing unit for processing, and a transmission unit for transmitting the scrambled first and second transmission data to the terminal device, respectively, and the terminal device stores the first and second transmission data. A receiving unit that receives and descrambles the first and second transmission data using the common scramble code.

  According to another aspect, in the wireless communication system that performs wireless communication between the first and second base station apparatuses each having one or a plurality of cells or sectors and the terminal apparatus, the terminal apparatus includes: A processing unit that scrambles the first and second transmission data different for each cell or sector using a common scramble code, and the scrambled first and second transmission data. Each of the first and second base station apparatuses receives the first and second transmission data, and transmits the common scramble code to each of the first and second base station apparatuses. And a receiving unit for performing descrambling processing on the first transmission data and the first transmission data.

  It is possible to provide a radio communication system, a base station apparatus, a terminal apparatus, and a radio communication method in the radio communication system in which processing is reduced in the terminal apparatus or base station apparatus. Further, it is possible to provide a wireless communication system or the like that can reduce power consumption in a terminal device or a base station device.

FIG. 1 is a diagram illustrating a configuration example of a wireless communication system. FIG. 2 is a diagram illustrating a configuration example of a wireless communication system in the downlink direction. FIG. 3 is a diagram illustrating a configuration example of the master base station apparatus. FIG. 4 is a diagram illustrating a configuration example of the slave base station apparatus. FIG. 5 is a diagram illustrating a configuration example of a terminal device. FIG. 6 is a diagram illustrating a configuration example of the scramble code creating unit. FIG. 7 is a flowchart showing an operation example. FIG. 8 is a flowchart showing an operation example. FIG. 9 is a diagram illustrating a configuration example of a radio communication system in the uplink direction. FIG. 10 is a diagram illustrating a configuration example of a master base station apparatus. FIG. 11 is a diagram illustrating a configuration example of the slave base station apparatus. FIG. 12 is a diagram illustrating a configuration example of a terminal device. FIG. 13 is a flowchart showing an operation example. FIG. 14 is a flowchart showing an operation example. FIG. 15 is a diagram illustrating a configuration example of a terminal device. FIG. 16 is a diagram illustrating a configuration example of a terminal device. FIG. 17 is a diagram illustrating a configuration example of the base station apparatus.

  The form for implementing this invention is demonstrated below. FIG. 1 is a diagram illustrating a configuration example of a wireless communication system 10. The radio communication system 10 includes two base station devices (eNB: evolved Node_B, hereinafter referred to as “base station”) 100-1 and 100-2, and a terminal device (UE: User Equipment, hereinafter referred to as “terminal”) 200. The base stations 100-1 and 100-2 transmit different data, and the terminal 200 receives this (downward direction). Terminal 200 can also transmit different data to base stations 100-1 and 100-2 (uplink direction). Both the base stations 100-1 and 100-2 and the terminal 200 can perform so-called CoMP communication. In the following, description will be made separately for the down direction (first embodiment) and the up direction (second embodiment). In 3GPP, a “cell” is defined with the same content as a so-called “sector”, and will be described as “cell” = “sector” in the following embodiments unless otherwise specified.

<First embodiment>
First, the downward direction will be described. FIG. 2 is a diagram illustrating a configuration example of the wireless communication system 10 in the downlink direction. Of the two base stations 100-1 and 100-2, the base station 100-1 is a master base station, and the base station 100-2 is a slave base station. The master base station 100-1 is, for example, a base station that is connected to the terminal 200 before performing CoMP transmission, and the slave base station 100-2 is, for example, a base station that performs CoMP transmission. Master base station 100-1 transmits a control signal to terminal 200. The terminal 200 receives different transmission data (DSCH) transmitted from the master base station 100-1 and the slave base station 100-2 based on the control signal.

<Configuration example of master base station>
A configuration example of the master base station 100-1 in the first embodiment will be described. FIG. 3 is a diagram showing the master base station 100-1.

  The master base station 100-1 includes an antenna 101, a reception radio unit 102, a demodulation / decoding unit 103, a connection request signal extraction unit 104, a radio channel control unit 105, a cell information signal creation unit 106, and CoMP communication. Request signal extraction unit 107, CoMP communication execution determination and control unit (hereinafter, “control unit”) 108, radio channel quality information extraction unit 109, scheduler 110, control signal generation unit 111, and scrambling code generation unit 112, a transmission data buffer 113, an encoding / modulation unit 114, and a transmission radio unit 115.

  The antenna 101 transmits and receives radio signals to and from the terminal 200.

  Reception radio section 102 outputs a radio signal received by antenna 101 as a reception signal.

  The demodulation / decoding unit 103 demodulates and decodes the reception signal output from the reception radio unit 102.

  The connection request signal extraction unit 104 extracts a connection request signal from the demodulated received signal. The connection request signal is a signal used when, for example, the terminal 200 requests a line connection with the master base station 100-1.

  When the connection request signal is input from the connection request signal extraction unit 104, the wireless line control unit 105 selects, for example, one of a plurality of cell numbers and terminal numbers held therein, The information is output to the information signal generator 106 and the scrambling code generator 112.

  Cell information signal creation section 106 creates cell information from the cell number and terminal number output from radio channel control section 105 and the slot number output from scheduler 110. The created cell information is transmitted as a cell information signal to a base station (for example, slave base station 100-2) that performs CoMP transmission. The cell information signal is also output to encoding / modulation section 114 for transmission to terminal 200.

  The CoMP communication request signal extraction unit 107 extracts a CoMP communication request signal from the reception signal output from the demodulation / decoding unit 103. The CoMP communication request signal is a signal transmitted from the terminal 200 when the terminal 200 wants to perform CoMP communication, for example.

  The control unit 108 determines whether or not to perform CoMP transmission, and when determining that CoMP transmission is to be performed, notifies the slave base station 100-2 of a CoMP transmission execution notification. For example, the control unit 108 determines whether to perform CoMP transmission based on the radio channel quality output from the radio channel quality information extraction unit 109 and the radio channel quality transmitted from the slave base station 100-2. To do. The CoMP transmission execution notification is also output to the scheduler 110 and the cell information signal creation unit 106. Details of CoMP transmission execution determination will be described later.

  Radio channel quality information extraction section 109 extracts radio channel quality information from the received signal output from demodulation / decoding section 103. The wireless channel quality information is information transmitted from the terminal 200, for example.

  Based on the radio channel quality information output from radio channel quality information extraction section 109, scheduler 110 determines the coding rate, modulation method, etc. used in downlink communication with terminal 200 (performs scheduling). . The scheduler 110 outputs scheduling information related to the determined coding rate and the like to the control signal creation unit 111. Also, scheduler 110 transmits the use frequency and precoding information in the scheduling information as a CoMP control signal to slave base station 100-2, and outputs the slot number to cell information signal creation section 106 and scramble code creation section 112. . Note that the scheduler 110 controls the encoding / modulation unit 114 and the transmission radio unit 115 so that the encoding process or the like is performed on the transmission data according to the determined scheduling information.

  The control signal creation unit 111 creates a control signal including scheduling information output from the scheduler 110 and outputs the control signal to the encoding / modulation unit 114.

  The scrambling code creation unit 112 creates an initial value of the scramble code based on the slot number output from the scheduler 110, the cell number and the terminal number output from the radio channel control unit 105, and sequentially generates the scramble code. create. Details of the scrambling code creation unit 112 will be described later.

  The transmission data buffer 113 temporarily stores transmission data transmitted from the master base station 100-1 to the terminal 200.

  The encoding / modulation unit 114 scrambles the transmission data output from the transmission data buffer 113 using the scramble code generated by the scrambling code generation unit 112, and codes the scrambled transmission data based on the scheduling information. And modulate. The encoding / modulation unit 114 performs processing such as encoding on the cell information output from the cell information signal generation unit 106 and the control signal output from the control signal generation unit 111. A scramble process may be performed on the image.

  The transmission radio unit 115 performs weighting processing (or weight processing) of transmission data and the like on the transmission data output from the encoding / modulation unit 114 according to the precoding information created by the scheduler 110. The transmission radio unit 115 generates a pilot signal (or a known signal), for example. The output from transmission radio section 115 is transmitted to terminal 200 via antenna 101 as a radio signal.

<Configuration example of slave base station>
Next, a configuration example of the slave base station 100-2 in the first embodiment will be described. The slave base station 100-2 has the same configuration as the master base station 100-1.

  When the control unit 108 receives the CoMP communication request signal from the CoMP communication request signal extraction unit 107 and further receives the CoMP execution notification from the master base station 100-1, the control unit 108 outputs the CoMP execution notification to the scheduler 110.

  The scheduler 110 performs downlink scheduling based on the radio channel quality information output from the radio channel quality information extraction unit 109. Further, when the scheduler 110 receives the CoMP execution notification from the control unit 108 and receives the CoMP control signal from the master base station 100-1, the scheduler 110 performs scheduling for CoMP transmission. The scheduler controls the encoding / modulation unit 114 and the transmission radio unit 115 so that encoding processing and the like are performed according to the scheduling.

  The scrambling code creation unit 112 receives cell information from the master base station 100-1, creates an initial value of the scramble code based on the cell information, and sequentially creates a scramble code. Details thereof will be described later. Since the scrambling code creation unit 112 creates a scramble code based on the cell information notified from the master base station 100-1, the master base station 100-1 and the slave base station 100-2 create the same scramble code. . The generated scramble code is output to the encoding / modulation unit 114, and the transmission data transmitted from the slave base station 100-2 is scrambled.

<Example of terminal configuration>
Next, a configuration example of the terminal 200 will be described. FIG. 5 is a diagram illustrating a configuration example of the terminal 200.

  The terminal 200 includes an antenna 201, a reception radio unit 202, a demodulation / decoding unit 203, a radio channel quality measurement and calculation unit (hereinafter, calculation unit) 204, a radio channel quality information creation unit 205, and a cell information extraction unit. 206, a scrambling code creation unit 207, a reception control signal extraction unit 208, a terminal setting control unit 209, a reception power measurement unit 210, a line connection control unit 211, a connection request signal creation unit 212, and an encoding A modulation unit 213, a transmission radio unit 214, a CoMP communication control unit 220, and a CoMP communication request signal creation unit 221 are provided.

  The antenna 201 transmits and receives radio signals to and from the base stations 100-1 and 100-2.

  Reception radio section 202 outputs a radio signal received by antenna 201 as a received signal.

  The demodulator / decoder 203 descrambles the received signal using the scramble code generated by the scrambling code generator 207 and demodulates the received signal according to the demodulation method set by the terminal setting controller 209. And decryption.

  The calculation unit 204 measures the radio quality of each radio channel with respect to a pilot signal or the like transmitted from the master base station 100-1 or the slave base station 100-2. The calculation unit 204 measures the radio channel quality by measuring, for example, the SINR (Signal to Interference Noise Ratio) of the pilot signal.

The radio channel quality information creation unit 205 creates radio channel quality information based on the radio channel quality output from the calculation unit 204. The radio channel quality information is, for example, CQI (Channel Quality Indicator). The created wireless channel quality information is output to the encoding / modulation unit 213.

  The cell information extraction unit 206 extracts cell information from the received signal output from the demodulation / decoding unit 203. The extracted cell information is output to the scramble code creation unit 207.

  The scrambling code creation unit 207 creates an initial value of the scramble code based on the cell information (including the cell number, terminal number, and slot number), and sequentially creates the scramble code. The scramble code creating unit 107 outputs the created scramble code to the demodulation / decoding unit 203.

  Reception control signal extraction section 208 extracts a control signal from the reception signal and outputs it to terminal setting control section 209.

  Terminal setting control section 209 causes reception radio section 202 and demodulation / decoding section 203 to demodulate and decode received data from base stations 1000-1 and 100-2 according to scheduling information included in the control signal. Control.

  The received power measuring unit 210 measures, for example, the received power of a pilot signal among the received signals, and outputs the measurement result to the line connection control unit 211 and the CoMP communication control unit 220.

  The line connection control unit 211 determines whether to connect the lines with the base stations 100-1 and 100-2 based on the received power. For example, the line connection control unit 211 determines to connect the line when the received power is equal to or higher than the threshold, and determines not to connect the line otherwise. When the line connection control unit 211 determines to connect to the line, it outputs an instruction signal to the connection request signal creation unit 212.

  The connection request signal creation unit 212 creates a connection request signal based on the instruction signal and outputs the connection request signal to the encoding / modulation unit 213.

  The CoMP communication control unit 220 outputs a CoMP communication request signal generation instruction to the CoMP communication request signal generation unit 221 when the received power is, for example, a threshold value or more.

  The CoMP communication request signal creation unit 221 creates a CoMP communication request signal based on an instruction from the CoMP communication control unit 220 and outputs the CoMP communication request signal to the encoding / modulation unit 213.

  The encoding / modulation unit 213 performs encoding and modulation processing on radio channel quality information, a connection request signal, a CoMP communication request signal, and the like.

  The transmission radio unit 214 performs control of transmission power on the encoded radio channel quality information and the like, and outputs it to the antenna 201 as a radio signal. Radio channel quality information and the like are transmitted as radio signals to the base stations 100-1 and 100-2.

<Configuration example of scramble code generator>
Next, configuration examples of the scrambling code creation unit 112 of the master base station 100-1 and the slave base station 100-2 and the scrambling code creation unit 207 of the terminal 200 will be described. FIG. 6 is a diagram illustrating a configuration example of the scrambling code creation units 112 and 207, which is a known gold code generator.

  The scrambling code generators 112 and 207 include first and second registers (or flip-flops) 112-1 and 112-3 and first to third exclusive OR circuits 112-2 and 112-4. 112-5.

  The scrambling code generators 112 and 207 generate a gold code (or scramble code) having a length of “31”, and the output is a scramble code c (n). The generator polynomial of the scramble code c (n) is expressed by the above-described equations 2 to 4.

<Example of operation in the down direction>
Next, an operation example in the first embodiment will be described. 7 and 8 are flowcharts showing an operation example. It is assumed that terminal 200 is located in an area where communication connection is possible for both master base station 100-1 and slave base station 100-2.

  First, the master base station 100-1 broadcasts cell information and the like to the terminal 200 (S10). The cell information broadcast by the master base station 100-1 may include, for example, cell information (cell number, terminal, and slot number) created by the cell information signal creation unit 106.

  Next, the master base station 100-1 transmits a pilot signal (S11). For example, the pilot signal is generated by the transmission radio unit 115 of the master base station 100-1.

  Next, the terminal 200 selects a cell to be communicated based on the received pilot signal or the like (S12), and sets a line with the selected cell (S13). For example, the reception power measurement unit 210 of the terminal 200 measures the reception power of the pilot signal, and the line connection control unit 211 selects a cell (for example, the master base station 100-1) by determining line connection. Then, the connection request signal creation unit 212 creates a connection request signal and transmits it to the master base station 100-1 to set a line. Terminal 200 first connects to master base station 100-1.

  Next, the terminal 200 measures the quality (for example, CQI) of the radio channel with the master base station 100-1 (S14), and transmits the radio channel quality information to the master base station 100-1 (S15). For example, the calculation unit 204 of the terminal 200 measures the radio channel quality based on the pilot signal, the radio channel quality information creation unit 205 creates the radio channel quality information, and the information is transmitted to the master base station 100-1. .

  Next, the master base station 100-1 performs scheduling based on the radio channel quality information (S16). For example, the scheduler 110 of the master base station 100-1 performs scheduling based on the radio channel quality information extracted by the radio channel quality information extraction unit 109.

  Next, the master base station 100-1 performs transmission signal processing (S17). For example, the encoding / modulation unit 114 reads the transmission data stored in the transmission data buffer 113 and performs processing such as encoding according to the encoding rate scheduled by the scheduler 110. Also, the encoding / modulating unit 114 performs processing such as encoding on the control signal including scheduling information generated by the control signal generating unit 111.

  Next, the master base station 100-1 transmits a control signal and transmission data to the terminal 200 (S18, S19).

  When the terminal 200 receives the control signal and the transmission data, the terminal 200 performs reception signal processing (S20). For example, the terminal setting control unit 209 controls the reception radio unit 202 and the demodulation / decoding unit 203 so that demodulation, decoding, and the like are performed according to the scheduling information included in the received control signal.

  Next, the terminal 200 receives cell information and the like broadcast from the slave base station 100-2 and a pilot signal (S21, S22). Then, the terminal 200 selects the slave base station 100-2 as a connection base station (S23), and sets a line with the slave base station 100-2 (S24).

  Next, processing for CoMP transmission is performed between terminal 200 and base stations 100-1 and 100-2. First, terminal 200 receives pilot signals from master base station 100-1 and slave base station 100-2 (S25, S26), and measures the channel quality of each radio channel (S27). For example, each wireless channel quality is measured by the calculation unit 204 of the terminal 200. At this time, in order to facilitate identification of pilot signals from the master base station 100-1 and the slave base station 100-2, the cell number of the master base station 100-1 and the original cell of the slave base station 100-2 are used. It is good also as a different pilot signal produced based on the number.

  Next, the terminal 200 transmits each measured radio channel quality to the slave base station 100-2 and the master base station 100-1 (S28, S30). For example, each wireless channel quality information is created by the wireless channel quality information creation unit 205, and the information is transmitted.

  The slave base station 100-2 transmits the wireless channel quality information transmitted from the terminal 200 to the master base station 100-1 (S29). For example, the radio channel quality information extraction unit 109 of the slave base station 100-2 transmits the extracted radio channel quality with the terminal 200 to the master base station 100-1.

  Next, the master base station 100-1 determines whether or not CoMP transmission is possible (S31). For example, the control unit 108 of the master base station 100-1 determines whether the radio channel quality from the slave base station 100-2 and the radio channel quality extracted by the CoMP communication request signal extraction unit 107 are both equal to or greater than a threshold value. It is determined that communication is possible. The threshold value compared with the radio channel quality from the master base station 100-1 and the threshold value compared with the radio channel quality from the slave base station 100-2 may be the same or different. Note that when the control unit 108 determines that CoMP transmission is not possible, the series of processing ends.

  Next, the terminal 200 transmits a CoMP transmission execution request to the slave base station 100-2 and the master base station 100-1 (S32, S33). For example, the execution request instruction is output from the CoMP communication control unit 220 of the terminal 200, and the request signal is transmitted from the CoMP communication request signal creation unit 221.

  The master base station 100-1 determines that CoMP transmission is possible (S31), receives a CoMP execution request from the terminal 200 (S33), and transmits a CoMP execution notification to the slave base station 100-2 and the terminal 200 (S34, S35). For example, the control unit 108 of the master base station 100-1 transmits a CoMP execution notification to the slave base station 100-2. For example, the control unit 108 outputs a CoMP execution notification to the scheduler 110, and the CoMP execution notification is transmitted from the scheduler 110 to the terminal 200 as a control signal.

  Next, the master base station 100-1 and the slave base station 100-2 perform processing for synchronizing the base stations (S36). This is because transmission data is transmitted to the terminal 200 in synchronization in CoMP transmission. For example, the synchronization processing is performed by the control units 108 of the master base station 100-1 and the slave base station 100-2 transmitting and receiving signals and synchronizing the phases.

  Next, the master base station 100-1 performs scheduling for CoMP transmission (S37). For example, when receiving a CoMP execution notification from the control unit 108, the scheduler 110 performs scheduling based on the radio channel quality (S29, S30) and the like. The created scheduling information includes the frequency used for CoMP transmission and precoding information.

  Next, the master base station 100-1 transmits cell information to the slave base station 100-2 (S38). For example, the cell information signal creation unit 106 inputs the cell number and terminal number from the radio channel control unit 105, receives the slot number output from the scheduler 110, and includes cell information including the cell number, terminal number, and slot number. Create and send. For example, the cell number and the terminal number are created by the radio channel control unit 105 when setting up a line (S13) with the terminal 200, and the cell information creation unit 106 is triggered by a CoMP execution notification from the control unit 108. Thus, the cell number and the like can be read out from the wireless line control unit 105. Also for the slot number, the scheduler 110 may output the number to the cell information creation unit 106 by scheduling (S37). Note that the terminal 200 may directly notify the master base station 100-1 of the radio channel quality with the slave base station 100-2 that has been measured and calculated.

  Next, the master base station 100-1 transfers transmission data (for example, transmission data 2) to the slave base station 100-2 (S39). For example, the scheduler 110 of the master base station 100-1 reads a part (eg, transmission data 2) of transmission data stored in the transmission data buffer 113 and transmits it to the slave base station 100-2. The transmission data buffer 113 of the slave base station 100-2 stores the transmission data transmitted from the master base station 100-1. Transmission data 1 and transmission data 2 are, for example, different transmission data for each cell.

  Next, the master base station 100-1 notifies the transmission control information to the slave base station 100-2 (S40). For example, the scheduler 110 transmits scheduling information (S37) including precoding information and the like as transmission control information to the slave base station 100-2.

  Next, the master base station 100-1 and the slave base station 100-2 perform transmission signal processing (S41, S42). For example, the scramble code creation unit 112 of the master base station 100-1 creates a scramble code based on the cell number and terminal number from the radio channel control unit 105 and the slot number from the scheduler 110. The encoding / modulation unit 114 performs scramble processing on the transmission data 1 using the scramble code. The transmission data 1 is encoded according to scheduling (S37). On the other hand, the scramble code creating unit 112 of the slave base station 100-2 creates a scramble code using the cell information (S38) transmitted from the master base station 100-1, and the encoding / modulating unit 114 transmits the transmission data 2 Is scrambled. The transmission data 2 is encoded based on the transmission control information transmitted from the master base station 100-1. As described above, since the master base station 100-1 and the slave base station 100-2 generate the scramble code from the common cell number, terminal number, and slot number, the same scramble code is generated.

  Next, the master base station 100-1 transmits a control signal and transmission data to the terminal 200 (S43, S44). In addition to the coding rate used for CoMP transmission, the control signal includes a use frequency and precoding information, and may include cell information created by the cell information signal creation unit 106.

  Next, the slave base station 100-2 transmits transmission data (for example, transmission data 2) different from the transmission data transmitted by the master base station 100-1 to the terminal 200 (S45). For example, transmission data 1 and transmission data 2 are weighted and transmitted according to precoding information.

  Next, the terminal 200 performs reception signal processing on transmission data transmitted from the master base station 100-1 and the slave base station 100-2 (S46). For example, the terminal setting control unit 209 of the terminal 200 receives the transmission data from the master base station 100-1 and the slave base station 100-2 according to the scheduling information included in the control signal (S43). The radio unit 202 and the demodulation / decoding unit 203 are controlled. At this time, the scrambling code creation unit 207 of the terminal 200 creates a scramble code based on the cell information (S10 or S43). Since the cell information is the same as that used by the master base station 100-1 and the slave base station 100-2, the terminal 200 has the same scramble code created by the base stations 100-1 and 100-2. A scramble code can be created. The demodulation / decoding unit 203 performs descrambling processing on the transmission data 1 and the transmission data 2 based on the scramble code.

  As described above, according to the first embodiment, when performing CoMP transmission, the master base station 100-1 transmits cell information to the slave base station 100-2 (S38), and thus information for creating a scramble code. Can be shared and a common scramble code can be created. Therefore, the radio communication system 10 can reduce the processing compared to the case where the scramble process is performed by creating different scramble codes in the base stations 100-1 and 100-2. Further, since the processing is reduced, the power consumption of the terminal 200 and the base stations 100-1 and 100-2 can be reduced.

  The master base station 100-1 transmits precoding information to the slave base station 100-2 (S40), and the two base stations 100-1 and 100-2 send different data to the terminal 200 based on the precoding information. Sending. Therefore, even if different data is transmitted from the two base stations 100-1 and 100-2 using a common scramble code, the terminal 200 performs reception processing based on precoding information included in the control signal (S43, S46). Therefore, it is possible to prevent interference between two different data.

<Second embodiment>
Next, an example in the upward direction will be described. The second embodiment is an example in the uplink direction in which data is transmitted from the terminal 200 to the base stations 100-1 and 100-2.

  FIG. 9 is a diagram showing a configuration example of the wireless communication system 10 in the second embodiment. Master base station 100-1 transmits a control signal to terminal 200. The terminal 200 transmits different transmission data (USCH) to the master base station 100-1 and the slave base station 100-2 based on the received control signal.

<Configuration example of master base station>
Next, a configuration example of the master base station 100-1 in the second embodiment will be described. FIG. 10 is a diagram illustrating a configuration example of the master base station 100-1.

  Master base station 100-1 further includes a radio channel quality measurement and calculation unit (hereinafter, calculation unit) 121. The calculation unit 121 measures the radio channel quality with the terminal 200 based on the pilot signal transmitted from the terminal 200, and measures the radio channel quality (for example, CQI).

  In addition, the scheduler 110 of the master base station 100-1 controls the demodulation / decoding unit 103 and the reception radio unit 102 according to the created scheduling information in order to perform uplink scheduling.

  Further, the scrambling code creation unit 112 outputs the created scrambling code to the demodulation / decoding unit 103 in order to perform descrambling processing on the transmission data transmitted from the terminal 200 and the like.

<Configuration example of slave base station>
Next, a configuration example of the slave base station 100-2 in the second embodiment will be described. FIG. 11 is a diagram illustrating a configuration example of the slave base station 100-2.

  The slave base station 100-2 further includes a calculation unit 121.

  Further, the scheduler 110 of the slave base station 100-2 controls the demodulation / decoding unit 103 and the reception radio unit 102 according to the scheduling information in order to perform uplink scheduling.

  Furthermore, the scrambling code creation unit 112 also outputs the created scrambling code to the demodulation / decoding unit 103 in order to perform descrambling processing on the transmission data and the like transmitted from the terminal 200.

<Example of terminal configuration>
Next, a configuration example of the terminal 200 in the second embodiment will be described. FIG. 12 is a diagram illustrating a configuration example of the terminal 200. This terminal 200 has the same configuration as the terminal 200 (FIG. 5) in the downlink direction.

  The terminal setting control unit 209 controls the encoding / modulating unit 213 so that processing such as encoding is performed on the transmission data transmitted to the base stations 100-1 and 100-2 according to the control signal. Further, terminal setting control section 209 controls transmission radio section 214 according to precoding information included in the control signal so that different transmission data is weighted and transmitted to base stations 100-1 and 100-2.

  In addition, scrambling code creation section 207 outputs the created scrambling code to encoding / modulation section 213 in order to perform scrambling processing on transmission data to base stations 100-1 and 100-2.

<Configuration example of scramble code generator>
The scrambling code generators 112 and 207 of the base stations 100-1 and 100-2 and the terminal 200 are the same as in the first embodiment.

<Example of operation in the upward direction>
Next, an operation example in the second embodiment will be described. 13 and 14 are flowcharts showing an operation example.

  After channel setting between the master base station 100-1 and the terminal 200 (S10 to S13), the terminal 200 transmits a pilot signal to the master base station 100-1 (S50). For example, the transmission radio unit 214 of the terminal 200 generates and transmits a pilot signal. The cell information (S10) transmitted by the master base station 100-1 may include cell information created by the cell information signal creation unit 106.

  Next, the master base station 100-1 measures the uplink radio channel quality (for example, CQI) based on the pilot signal (S51). For example, measurement or the like is performed by the calculation unit 121 of the master base station 100-1.

  Next, the master base station 100-1 performs uplink scheduling based on the measured radio channel quality (S16). For example, the scheduler 110 performs scheduling based on the radio channel quality output from the calculation unit 121.

  Next, the master base station 100-1 transmits a control signal including uplink scheduling information (S18), and the terminal 200 performs transmission signal processing based on the control signal (S52). For example, the control signal creation unit 111 of the master base station 100-1 creates a control signal including scheduling information, and transmits the control signal via the encoding / modulation unit 114 and the like. Also, the encoding / modulation section 213 of the terminal 200 performs transmission data encoding and modulation processing according to scheduling information included in the received control signal.

  Next, the terminal 200 transmits the transmission data to the master base station 100-1 (S53).

  Next, the terminal 200 performs processing such as line setting with the slave base station 100-2 (S21 to S24). Then, processing for CoMP transmission is performed between terminal 200 and base stations 100-1 and 100-2.

  First, the terminal 200 transmits a CoMP transmission execution request to the base stations 100-1 and 100-2 (S32 to S33). For example, the CoMP communication control unit 220 of the terminal 200 instructs a CoMP transmission execution request when the received power of each radio channel quality is equal to or greater than a threshold value. In response to this instruction, the CoMP communication request signal creation unit 221 creates a CoMP communication request signal and transmits it to the base stations 100-1 and 100-2.

  Next, the terminal 200 transmits a pilot signal to each of the base stations 100-1 and 100-2 (S54, S55).

  Next, each of the base stations 100-1 and 100-2 measures the radio channel quality (S56, S57). For example, the wireless channel quality is measured by the calculation unit 121 of each of the base stations 100-1 and 100-2.

  Next, the slave base station 100-2 transmits the measured radio channel quality to the master base station 100-1 (S58). For example, the wireless channel quality measured by the calculation unit 121 of the slave base station 100-2 is transmitted to the master base station 100-1.

  Next, the master base station 100-1 determines CoMP transmission based on two radio channel qualities (S31). For example, the control unit 108 determines to perform CoMP transmission when both of the two wireless channel qualities are equal to or higher than a threshold value. Note that the threshold value to be compared with the radio channel quality measured and calculated by the master base station 100-1 and the threshold value to be compared with the radio channel quality measured and calculated by the slave base station 100-2 may be the same or different. Also good.

  When performing CoMP transmission, the master base station 100-1 transmits a CoMP transmission execution notification to the slave base station 100-2 and the terminal 200 (S34 to S35).

  Then, the master base station 100-1 performs synchronization processing with the slave base station 100-2 (S36), performs scheduling for CoMP transmission (S37), and then performs the same process as in the first embodiment. The cell information is notified to the slave base station 100-2 (S38). The cell information includes a cell number, a terminal number, and a slot number.

  Next, the master base station 100-1 transmits transmission control information including scheduling information (S37) for uplink transmission data and the like to the slave base station 100-2 (S40), and transmits a control signal to the terminal 200 ( S43). The control signal may include cell information created by the cell information signal creation unit 106. Further, the transmission control information and the control signal include a use frequency and precoding information.

  Next, the terminal 200 performs transmission signal processing based on the received control signal (S59). For example, the scrambling code creation unit 207 creates a scramble code based on the cell information (S10 or S43) extracted by the cell information extraction unit 206, and outputs the created scramble code to the encoding / modulation unit 213. For example, the encoding / modulation unit 213 performs scramble processing on the transmission data 1 and the transmission data 2 which are different for each cell, using the same (or common) scramble code. Further, the terminal setting control unit 209 of the terminal 200 controls the encoding / modulating unit 213 so that processing such as encoding is performed based on the received scheduling information. Further, terminal setting control section 209 controls transmission radio section 214 so that transmission data weighted according to precoding information included in the control signal is output.

  Next, the terminal 200 transmits different transmission data (for example, transmission data 1 and transmission data 2) to the master base station 100-1 and the slave base station 100-2, respectively (S60, S61). For example, the transmission radio unit 214 outputs transmission data weighted according to precoding information included in the control signal.

  Next, the master base station 100-1 performs reception signal processing on the transmission data 2 (S62). For example, the scrambling code creation unit 112 of the master base station 100-1 creates a scramble code based on the slot number (S37) determined by the scheduler 110, and the cell number and terminal number from the radio channel control unit 105. . The generated scramble code is output to the demodulator / decoder 103 and descramble processing is performed on the transmission data 2. Thereafter, the demodulation / decoding unit 103 performs processing such as demodulation and decoding on the transmission data.

  Further, the slave base station 100-2 performs reception signal processing on the transmission data 1 (S63). For example, the scrambling code creation unit 112 of the slave base station 100-2 creates a scramble code based on the cell information (S38) transmitted from the master base station 100-1. The generated scramble code is output to the demodulator / decoder 103 and descramble processing is performed on the transmission data 1. For example, base stations 100-1 and 100-2 perform descrambling processing on transmission data 1 and transmission data 2, respectively, using the same scrambling code as that used by terminal 200 in scrambling processing.

  Next, the slave base station 100-2 transfers the demodulated transmission data 1 to the master base station 100-1 (S64). For example, the demodulation / decoding unit 103 of the slave base station 100-2 transmits the transmission data 1 to the master base station 100-1 under the control of the scheduler 110 or the like.

  As described above, also in the second embodiment, the master base station 100-1 transmits the cell information to the slave base station 100-2 (S38), so that the slave base station 100-2 is connected to the master base station 100- A scramble code identical to 1 is created. Also, since cell information is transmitted from master base station 100-1 to terminal 200, terminal 200 can also create the same scrambling code as base stations 100-1 and 100-2. Therefore, the radio communication system 10 can reduce the processing compared to the case of creating different scramble codes. In addition, the transmitting terminal 200 and the receiving base stations 100-1 and 100-2 do not create different scramble codes, thereby reducing power consumption.

<Other examples>
Next, other embodiments will be described. Each of the above-described embodiments has been described assuming that the master base station 100-1 determines CoMP transmission (S31 in FIG. 8 and the like). For example, the terminal 200 may make such a determination. For example, the CoMP communication control unit 220 of the terminal 200 can determine whether both are equal to or higher than the threshold based on the measured wireless communication quality (S27 in FIG. 7). In this case, since the measured wireless communication quality is not transmitted to the base stations 100-1 and 100-2, the processing of the master base station 100-1 can be further reduced.

  Further, each of the above-described embodiments has been described on the assumption that the terminal 200 makes an execution request for CoMP transmission. For example, the master base station 100-1 may make an execution request. In the downlink direction, for example, when the master base station 100-1 determines to perform CoMP transmission (S31), a CoMP execution request can be transmitted to the terminal 200 and the slave base station 100-2. Thereafter, the master base station 100-1 can be implemented by notifying the implementation notification (S34, S35). Further, the uplink direction can also be implemented by transmitting a CoMP transmission request to the terminal 200 or the like after CoMP transmission determination (S31) and notifying the CoMP execution notification (S34 to S35). A configuration example of the terminal 200 in such a case is shown in FIG. 15 (downward direction) and FIG. 16 (upward direction). Since the terminal 200 does not have the CoMP communication control unit 220 and the CoMP communication request signal generation unit 221 as compared with the above-described embodiment, the power consumption can be further reduced.

  Further, each of the above-described embodiments has described an example in which transmission data is transmitted from the two base stations 100, the master base station 100-1 and the slave base station 100-2. For example, one base station 100 having a plurality of cells (or sectors) may transmit transmission data. FIG. 17 is a diagram illustrating a configuration example of the base station apparatus 100. The base station apparatus 100 includes a master communication unit 150-1, a slave communication unit 150-2, and antennas 101-1 and 101-2 connected to the communication units 150-1 and 150-2. The master communication unit 150-1 includes each unit 102 in the master base station 100-1, and the slave communication unit 150-2 includes each unit 102 in the slave base station 100-2. For example, the slave communication unit 150-2 outputs radio channel quality information to the master communication unit 150-1, and the master communication unit 150-1 outputs cell information and the like to the slave communication unit 150-2. Thereby, the base station 100 can be implemented in the same way as the first and second embodiments in the downlink direction and the uplink direction.

  Further, in each of the above-described embodiments, the cell number, terminal number, and slot number used in CoMP transmission may be a CoMP dedicated cell number, terminal number, and slot number. For example, when the control unit 108 of the master base station 100-1 determines to perform CoMP transmission (S31), the notification is output to the cell information signal creation unit 106. The cell information signal creation unit 106 can also rewrite the cell number, terminal number, and slot number to respective numbers dedicated to CoMP by the notification. Further, since the cell information signal generator 106 transmits the cell information to the slave base station 100-2, the slave base station 100-2 can also generate the same scramble code as the master base station 100-1.

  Further, each of the above-described embodiments has described an example in which CoMP transmission is performed between the two base stations 100-1 and 100-2 and the terminal 200. For example, CoMP transmission may be performed between three or more base stations 100 and the terminal 200. In this case, one of the three or more base stations is a master base station, and the other base stations are slave base stations, and cell information is transferred from the master base station to a plurality of slave base stations in the same manner as in the above-described embodiments. This can be done by sending to

10: Wireless communication system 100: Base station apparatus (base station)
100-1: Master base station 100-2: Slave base station 103: Demodulation / decoding unit 105: Radio channel control unit 106: Cell information signal creation unit 107: CoMP communication request signal extraction unit 108: CoMP communication execution determination and control unit (Control part)
109: Radio channel quality information extraction unit 110: Scheduler 111: Control signal creation unit 112: Scrambling code creation unit 114: Encoding / modulation unit 150-1: Master communication unit 150-2: Slave communication unit 200: Terminal device ( Terminal)
203: Demodulation / decoding unit 204: Radio channel quality measurement and calculation unit (calculation unit)
205: Radio channel quality information creation unit 206: Cell information extraction unit 207: Scrambling code creation unit 208: Reception control signal extraction unit 209: Terminal setting control unit 210: Received power measurement unit 213: Encoding / modulation unit 220: CoMP Communication control unit 221: CoMP communication request signal creation unit

Claims (11)

In a wireless communication system that performs wireless communication between a terminal device and first and second base station devices that transfer data between base station devices each having one or a plurality of cells or sectors,
The first base station apparatus
A transfer unit for transmitting transmission data to be transmitted to the terminal device to the second base station device;
The first and second base station devices are
When each transmitting the transmission data for each of the cell or the sector to the terminal device, a processing unit for respectively scrambling the transmission data using a common scrambling code,
A transmission unit for transmitting the scrambled transmission data to each of the terminal devices ,
The terminal device
A wireless communication system comprising: a receiving unit that receives the transmission data and descrambles the transmission data using the common scramble code. The first base station apparatus
It has a scheduler that creates precoding information,
The scheduler transmits the precoding information to the second base station apparatus;
2. The wireless communication system according to claim 1, wherein each of the transmission units of the first and second base station apparatuses weights the transmission data based on the precoding information and transmits the weighted transmission data to the terminal apparatus. . A wireless communication method in a wireless communication system for performing wireless communication between a terminal device and first and second base station devices that transfer data between base station devices each having one or a plurality of cells or sectors. And
The first base station apparatus
Transmitting transmission data to be transmitted to the terminal device to the second base station device;
The first and second base station devices are
When each transmitting the transmission data for each of the cell or the sector to the terminal device, the transmission data processed respectively scrambled using a common scrambling code,
Transmitting the scrambled transmission data to the terminal device,
The terminal device receives the transmission data and descrambles the transmission data using the common scramble code;
A wireless communication method. In a base station apparatus that performs data transfer with another base station apparatus having one or a plurality of cells or sectors and performs wireless communication with the terminal apparatus together with the other base station apparatus,
A transfer unit that transmits transmission data to the other base station device;
When transmitting the transmission data respectively with the other base station apparatus for each of the cell or the sector to the terminal device, a processing unit for respectively scrambling the transmission data using a common scrambling code,
A base station apparatus comprising: a transmission unit that transmits the scrambled transmission data to the terminal apparatus. In a terminal apparatus that performs wireless communication with the first and second base station apparatuses that transfer data between base station apparatuses each having one or a plurality of cells or sectors,
The transmission data transferred from the first base station apparatus to the second base station apparatus and transmitted from the first and second base station apparatuses are received from the first and second base station apparatuses, respectively. The transmission data includes a receiving unit that receives the transmission data scrambled using a common scramble code and descrambles the transmission data using the common scramble code. Terminal device. In a wireless communication system that performs wireless communication between a terminal device and first and second base station devices that transfer data between base station devices each having one or a plurality of cells or sectors,
The terminal device
A processing unit that scrambles transmission data to be transmitted to the first and second base station devices for each cell or each sector using a common scrambling code;
A transmission unit that transmits the scrambled transmission data to the first and second base station devices, respectively.
The first and second base station devices are
Receiving the transmission data, each comprising a receiving unit that performs descrambling processing on the transmission data using the common scramble code ,
The second base station apparatus transfers the descrambled data to the first base station apparatus
Wireless communication system comprising: a. A wireless communication method in a wireless communication system for performing wireless communication between a terminal device and first and second base station devices that transfer data between base station devices each having one or a plurality of cells or sectors. And
The terminal device
Scramble processing using a common scramble code for transmission data to be transmitted to the first and second base station devices for each cell or sector;
Transmitting the scrambled transmission data to the first and second base station devices, respectively;
The first and second base station devices are
Receiving the transmitted data, have rows descrambling processing on the transmission data using the common scrambling code,
The second base station apparatus transfers the descrambled data to the first base station apparatus . In a base station apparatus that performs data transfer with another base station apparatus having one or a plurality of cells or sectors and performs wireless communication with the terminal apparatus together with the other base station apparatus,
The transmission data transmitted to the base station apparatus and the other base station apparatus for each cell or the sector is scrambled using a common scramble code, and the scrambled transmission data is received. A receiving unit that performs descrambling processing on the transmission data using the common scramble code ;
A base station apparatus comprising: a transfer unit configured to transfer the descrambled data to the other base station apparatus. In a terminal apparatus that performs wireless communication with the first and second base station apparatuses that transfer data between base station apparatuses each having one or a plurality of cells or sectors,
A processing unit that scrambles transmission data transmitted to the first and second base station apparatuses for each cell or each sector using a common scrambling code;
And a transmission unit configured to transmit the scrambled transmission data to the first and second base station devices, respectively. In a wireless communication system that performs wireless communication between a base station apparatus having a plurality of sectors and first and second communication units for each sector, and a terminal apparatus,
The first communication unit of the base station device is
Transfer unit for transferring transmission data to the second communication unit
With
The first and second communication units of the base station device are
When each transmitting the transmission data to the terminal device for each of the sector, a processing unit for respectively scrambling the transmission data using a common scrambling code,
A transmission unit for transmitting the scrambled transmission data to the terminal device, respectively.
The terminal device
A wireless communication system, comprising: a receiving unit that receives the transmission data and descrambles the transmission data using the common scramble code. In a wireless communication system that performs wireless communication between a base station apparatus having a plurality of sectors and first and second communication units for each sector, and a terminal apparatus,
The terminal device
A processing unit that scrambles the transmission data for each sector using a common scramble code;
A transmission unit that transmits the scrambled transmission data to a base station device, respectively.
The first and second communication units of the base station device are
A receiving unit that receives the transmission data and performs descrambling processing on the transmission data using the common scramble code.
With each
The second communication unit of the base station apparatus is
A transfer unit that transfers the descrambled data to the first communication unit
Wireless communication system comprising: a.

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