JP2014160940A - Radio communication device in radio communication system, and radio resource allocation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio communication system, a radio communication device, and a radio resource allocation method which can enhance a system capacity and radio transmission efficiency regardless of data size.SOLUTION: In a radio communication system, a base station 100 calculates relative ratio of data size of actual data to be transmitted to data size which can be transmitted via a radio link to a terminal (200), as a transmission efficiency index (S22 and S23), and determines allocation of a radio resource for transmitting the actual data on the basis of at least the transmission efficiency index (S24).

Description

  The present invention relates to a radio communication system, and more particularly to a radio communication apparatus and a radio resource allocation method thereof.

  In wireless communication systems such as LTE (Long Term Evolution) standardized by 3GPP (3rd Generation Partnership Project), it is assumed that there are multiple wireless base stations, and each wireless base station is within its own communication area. It communicates with a wireless terminal (hereinafter referred to as a terminal). This communication area is called a cell, but the cell can be divided into a plurality of parts by giving the antenna directivity. This divided area is called a sector cell. Hereinafter, the cell refers to a sector cell.

  In LTE, dynamic scheduling is usually applied as a user data scheduling method. In dynamic scheduling, radio resources are allocated in accordance with the quality of service (QoS: Quality of Service) of radio bearers, channel quality of terminals, buffer status, and the like (see Non-Patent Document 1). Generally, QoS defines the allowable delay time and the packet loss rate. Note that the radio resources indicate PRB (Physical Resource Block), MCS (Modulation and Coding Schemes), which are band allocation units for each TTI (Transmission Time Interval).

  In general, in LTE downlink, a terminal measures channel quality information such as SINR (Signal to Interference plus Noise Ratio) and is quantized by referring to a lookup table, etc. And is reported to the base station as CSI (Channel Sate Information). The lookup table is generally created by link level simulation simulating a physical layer. When the base station transmits data to the terminal by dynamic scheduling, it estimates the SINR of the downlink data channel (PDSCH: Physical Downlink Shared Channel) using the reported CQI, and refers to the MCS by referring to the base station lookup table. Select the index (MCS Index). Similar to the terminal, this lookup table is generally created by link level simulation simulating the physical layer. Then, the base station determines a TBS (Transport Block Size) index (TBS Index) from the selected MCS Index with reference to a lookup table (Non-Patent Document 2), and transmits data to the terminal with the determined TBS size. Send.

  Similarly, in the LTE uplink, the base station measures the reception strength of the SRS (Sounding Reference Signal) transmitted from the terminal, estimates the SINR of the uplink data channel (PUSCH: Physical Uplink Shared Channel), and dynamically Perform scheduling. Further, in order to perform dynamic scheduling, the terminal reports the buffer status to the base station as BSR (Buffer Status Report) (Non-patent Document 3).

  By the way, in recent years, with the spread of smartphones and the like, downlink traffic has increased, and accordingly, in the uplink, control packets for downlink traffic, such as TCP (Transmission Control Protocol) ACK packets, etc. The number is increasing. Also in the downlink, various applications that frequently transmit small packets, such as Twitter (registered trademark) and social network service (SNS), have become widespread.

3GPP TS 36.300 V9.7.0 (2010-11), 3GPP TSG RAN E-UTRA and E-UTRAN Overall description Stage2, pp.101 3GPP TS 36.213 V9.3.0 (2010-09), 3GPP TSG RAN E-UTRA Physical layer procedures, pp.27 3GPP TS 36.321 V9.3.0 (2010-06), 3GPP TSG RAN E-UTRA MAC protocol specification, pp.25-26 3GPP TR 36.814 V9.0.0 (2010-03), 3GPP TSG RAN E-UTRA Further advancements for E-UTRA physical layer aspects, pp.76

  However, since such a small packet has a small packet size, there is a problem that when the above-described dynamic scheduling is applied, the wireless transmission efficiency is lowered and the system capacity is lowered.

  Specifically, as illustrated in FIG. 1, when the payload size that is the actual data size is smaller than the transmittable data size determined by the above-described TBS Index, useless data A certain padding bit increases and the wireless transmission efficiency decreases. Therefore, the cell capacity per unit time (cell throughput) (Non-Patent Document 4) calculated with the transmitted actual data is reduced, so that the system capacity is also reduced.

  Therefore, the problem to be solved by the present invention is to solve the above problems, and an object of the present invention is to provide a radio communication system, a radio communication apparatus, and a radio resource allocation capable of improving radio transmission efficiency and system capacity. It is to provide a method.

The wireless communication apparatus according to the present invention is based on index calculation means for calculating the relative size of the actual data size with respect to the transmittable data size on the radio link with the terminal as a transmission efficiency index, and at least based on the transmission efficiency index Wireless resource allocation determination means for determining allocation of radio resources for transmission of the actual data.
A radio resource allocation method according to the present invention is a radio resource allocation method in a radio communication apparatus connected to a terminal, and transmits a relative size of an actual data size to a transmittable data size on a radio link with the terminal. It is calculated as an efficiency index, and the radio resource allocation determining means performs allocation determination of radio resources for transmission of the actual data based on at least the transmission efficiency index.
A radio communication system according to the present invention is a radio communication system in which a base station and a terminal perform radio communication, and the base station is configured to have a relative data size relative to a transmittable data size on a radio link with the terminal. An index calculation means for calculating a size of the transmission data as a transmission efficiency index, and a radio resource allocation determination means for determining allocation of a radio resource for transmission of the actual data based on at least the transmission efficiency index. To do.

  According to the present invention, the relative size of the actual data size with respect to the transmittable data size is calculated as a transmission efficiency index, and at least based on the transmission efficiency index, radio resource allocation determination for actual data transmission is performed, Wireless transmission efficiency and system capacity can be improved.

It is a format figure of the transmission packet which illustrates the relationship between TBS and payload size in the existing radio | wireless communications system. It is a sequence diagram which shows the radio | wireless resource allocation method by this embodiment. 1 is a block diagram schematically showing a functional configuration of a wireless communication system according to a first embodiment of the present invention. It is a flowchart which shows the allocation procedure of the radio | wireless resource by 1st Example. It is a block diagram which shows roughly the function structure of the radio | wireless communications system by 2nd Example of this invention. It is a flowchart which shows the allocation procedure of the radio | wireless resource by 2nd Example. It is a block diagram which shows roughly the function structure of the radio | wireless communications system by 3rd Example of this invention. It is a flowchart which shows the allocation procedure of the radio | wireless resource by 3rd Example.

  According to the embodiment of the present invention, the relative size of the actual data size with respect to the transmittable data size is calculated as a transmission efficiency index, and when the transmission efficiency index is equal to or greater than a predetermined value, wireless transmission is performed for transmission of actual data. Resources are allocated, and radio resources are not allocated to actual data whose transmission efficiency index is less than a predetermined value. This allows efficient use of radio resources and further improves system capacity. At that time, it is desirable to consider the transmission wait time of actual data. For example, even for actual data whose transmission efficiency index does not reach a predetermined value, it is desirable to allocate and transmit radio resources if the transmission delay is longer than a predetermined value. Thereby, the transmission efficiency of wireless communication can be improved while satisfying the allowable delay. Hereinafter, an embodiment and an example of the present invention will be described in detail with reference to the drawings.

1. In FIG. 2, the base station 100 and the terminal 200 measure uplink and downlink radio quality based on a reference (RS) signal transmitted by the other party, and the terminal 200 determines the downlink radio quality measurement result. The transmission buffer status is reported to base station 100 as CSI and BSR, respectively (operation S21).

  The base station 100 determines the downlink TBS size from the downlink radio resources (PRB and MCS) selected based on the downlink radio quality reported from the terminal 200, and is selected based on the uplink radio quality. The uplink TBS size is determined from the uplink radio resources (PRB and MCS) (operation S22).

  Subsequently, the TBS size is compared with the transmission buffer size S_Buff (S_Buff_BS or S_Buff_UE). If the TBS size is larger, the allocated PRB is reduced to determine the transmittable size, and the MCS and TBS are recalculated. (Operation S23).

  Subsequently, the ratio of the transmission buffer size to the transmittable size is calculated as the transmission efficiency index Eff, and the transmission efficiency index Eff is sufficiently high, or the delay index D that is the transmission waiting time of the actual data is unacceptably long. Then, the selected or recalculated radio resources (PRB and MCS) are allocated, and if the transmission efficiency index Eff is low and the delay D is acceptable, the radio resources (PRB and MCS) are not allocated (operation S24). If radio resources are allocated, a downlink transmission block is generated, and scheduling information for allocating the radio resources is notified to terminal 200 (operation S25). Thus, data transmission is performed between the base station 100 and the terminal 200 using the allocated radio resources (operation S26).

  By assigning or not assigning radio resources for data transmission in consideration of the transmission efficiency Eff and the delay D in this way, it is possible to improve the transmission efficiency of radio communication while satisfying the allowable delay.

1. First Embodiment The first embodiment of the present invention is an LTE radio resource allocation control using the transmission buffer size / maximum payload size as the transmission efficiency index Eff, and the BSR report time as the delay D, respectively. And

1.1) Configuration Referring to FIG. 3, the radio communication system according to the present embodiment includes a base station 100 and a terminal 200 that performs radio communication in the radio area in order not to complicate the description. Base station 100 is a wireless communication apparatus that performs wireless communication with terminal 200 through a wireless channel. Note that the base station 100 can communicate with a plurality of terminals, and the terminal 200 can also communicate with a plurality of base stations by radio. The base station 100 is connected to a network (not shown) and can perform data communication with other base stations. A radio band usable between the base station 100 and the terminal 200 is divided into PRB (Physical Resource Block) which is an allocation unit.

  The base station 100 includes a base station operation unit 101, a reference signal measurement unit 102, and a scheduler 103 as main functional units.

The base station operation unit 101 includes a function of receiving and demodulating an uplink channel signal and a function of notifying the scheduler 103 of the QoS level (QCI: QoS Class Identifier) of each LCH (Logical Channel). Since it has the same function as that of a commonly used base station and its configuration and operation are well known, the description thereof will be omitted. A plurality of LCHs can be established between the base station 100 and the terminal 200.

  Reference signal measurement section 102 has a function of measuring channel quality such as SINR from the reference signal received from terminal 200 and a function of estimating SINR of the uplink data channel (PUSCH) using the measured SINR. If there is a difference between the transmission power of the reference signal and the PUSCH, the difference is corrected to estimate the SINR of the PUSCH. In this embodiment, it is assumed that there is no difference in the transmission power.

  The scheduler 103 uses an index calculation function 103a and resource allocation in addition to a function function to calculate radio resource candidates such as PRB and MCS Index to be allocated to the terminal using the estimated SINR of PUSCH and the BSR (Buffer Status Report) received from the terminal 200. It has a determination function 103b. The index calculation function 103a calculates a transmission efficiency index for determining the radio transmission efficiency using the BSR and a delay index for determining the packet transmission delay, and the resource allocation determination function 103b is a transmission efficiency index or a transmission efficiency index. And a function for determining whether or not to allocate a radio resource candidate using a delay index. The information of the radio resource for which allocation has been determined is transmitted as scheduling information to the terminal 200 via the base station operation unit 101. The radio resource allocation process is performed in units of subframes. . One subframe is 1 ms.

  Next, the terminal 200 will be described. The terminal 200 includes a terminal operation unit 201, a reference signal generation unit 202, and a transmission buffer 203 as main functional units.

  The terminal operation unit 201 has a function equivalent to a terminal generally used in a wireless communication system, such as reporting to the base station 100 a BSR indicating the size of data retained in the transmission buffer 203, Since the configuration and operation are well known, a description thereof will be omitted. BSR is reported in units of LCG (LCH Group) bundled with multiple LCHs. As will be described later, the base station 100 can calculate the data size that can be transmitted by the terminal 200 using the reported BSR.

  The reference signal generation unit 202 has a function of transmitting a reference signal for measuring uplink channel quality at the base station 100 to the base station 100 via the terminal operation unit 201 at a predetermined timing.

  The transmission buffer 203 has a function of storing packet data transmitted from the terminal 200 together with management information such as arrival time and packet size. The staying data includes, for example, data generated as wireless communication control information and data generated in a radio upper layer, and is generated for each LCH. This data is transmitted to the base station 100 via the terminal operation unit 201 using radio resources allocated by the scheduling information received from the base station 100.

1.2) Radio Resource Allocation Control Next, the operation of this embodiment will be described with reference to FIG. FIG. 5 shows a control procedure in which the scheduler 103 assigns (or does not assign) radio resources to the terminal 200.

  First, the scheduler 103 selects allocation PRB and MCS Index candidates (radio resource candidates) from the PUSCH estimated SINR (operation S301). Specifically, a PRB having the maximum TBS is selected from the assignable PRB groups. Since the LTE uplink radio access method is SC-FDMA (Single Carrier-Frequency Division Multiple Access), continuous PRBs are allocated. The MCS refers to the lookup table and selects an Index that can achieve the target error rate.

Next, as already described, scheduler 103 calculates TBS size (S_tb) from the selected radio resource candidates (PRB and MCS Index) (operation S302), and terminal 200 performs uplink transmission using this radio resource candidate. Is performed, it is determined according to the following equation (1) whether or not the transmission buffer size of the terminal 200 becomes 0 [bite] (operation S303).
S_Tb (u, t)-MacHead> S_Buff (u, t) [bites] (1)
Where u is the terminal number, t is the current time [ms], S_Tb (u, t) is the TBS calculated from the PRB and MCS Index candidates, MacHead is the expected size of the MAC header, S_Buff (u , t) represents the buffer size. MacHead is a fixed value parameter. S_Buff (u, t) is calculated according to the following equation (2) using the buffer size (S_BuffRep (u)) most recently reported from the terminal 200. When there are a plurality of LCGs, the total value of S_BuffRep (u) for each LCG is used as the estimated buffer size. Here, the number of established LCGs is 1, and S_Buff (u, t) = S_BuffRep (u).

  When the transmission buffer size of the terminal 200 becomes 0 (operation S303; YES), it means that there is a margin in the calculated TBS size (S_tb). Therefore, in order to improve transmission efficiency, the above equation (1) is used. The allocated PRBs are excluded within a satisfactory range, the MCS index is recalculated, and S_Tb (u, t) is also recalculated (operation S304). In this embodiment, the assigned PRB candidates are excluded in ascending order of PRB Index, but the exclusion method is not limited to this, and may be excluded in descending order of PRB Index, or the number of assigned PRBs is minimized. In this way, the PRSCH having a small PUSCH estimated SINR may be excluded. If the transmission buffer size does not become 0 (operation S303; NO), PRB reduction and MCS reselection operation S304 are skipped.

Subsequently, the scheduler 103 calculates a transmission efficiency index Eff according to the following equation (3) using the TBS size S_Tb and the transmission buffer size S_Buff calculated in the operation S302 or S304 (operation S305).
Eff (u, t) = S_Buff (u, t) / (S_Tb (u, t)-MacHead) (3)
It is determined according to the following equation (4) whether or not the transmission efficiency index Eff is greater than or equal to the transmission efficiency threshold value Th_Eff (operation S306).
Eff (u, t)> = Th_Eff (4)
Here, Eff (u, t) represents a transmission efficiency index, and Th_Eff represents a transmission efficiency threshold value.
S_Tb (u, t) is calculated from the latest radio resource candidate.

  When the transmission efficiency index Eff is greater than or equal to the threshold value Th_Eff (operation S306; YES), allocation of radio resource candidates to the terminal 200 is determined, and information on the allocated radio resources is transmitted to the terminal 200 as scheduling information (operation S307). ).

When the transmission efficiency index Eff is not equal to or greater than the threshold Th_Eff (operation S306; NO), the scheduler 103 uses the information related to the arrival time of the transmission packet staying at the terminal 200 as the delay index D according to the following equation (5) Calculate (operation S308).
D (u, t) = t-t_Bsr (5)
Here, t is the current time [ms], and t_Bsr [ms] is the time when the base station 100 first receives a BSR indicating a data size larger than 1 byte from the terminal 200 after transmitting the scheduling information to the terminal 200. And However, if no BSR is received after the scheduling information is transmitted, t_Bsr is the latest time when the BSR is received.

Subsequently, the scheduler 103 determines whether or not the delay index D is greater than or equal to the allowable delay value Bud_D according to the following equation (6) (operation S309).
D (u, t)> = Bud_D (u) [ms] (6)
Here, D (u, t) represents a delay index, and Bud_D (u) represents an allowable delay value. In the case where there are a plurality of LCGs, Bud_D (u) is set to the minimum delay allowable value (Bud_D_Lcg (u, lg)) set for each LCG. lg represents the LCG number. However, LCGs whose buffer size is determined to be 0 are excluded from the target. Also, Bud_D_Lcg (u, lg) is the minimum value of the allowable delay value of LCH constituting LCG (referred to as Bud_D_Lch (u, l)). l represents the LCH number. It is assumed that Bud_D_Lch (u, l) is uniquely set in advance based on the QCI corresponding to LCH.

  When the delay index D is equal to or greater than the allowable delay value Bud_D (operation S309; YES), the scheduler 103 determines assignment of radio resource candidates to the terminal 200 and transmits information on the assigned radio resources to the terminal 200 as scheduling information. (Operation S307). When the delay index D is not equal to or greater than the allowable delay value Bud_D (operation S309; NO), no radio resource is allocated to the terminal 200.

  As described above, according to the present embodiment, when the expected transmission efficiency is low and there is a delay, radio resources are not allocated to the terminal 200. Transmission efficiency can be improved and system capacity can also be improved.

1.3) Modification In addition, in the present embodiment, the estimated buffer size (S_Buff (u, t)) is the buffer size (S_BuffRep (u)) reported from the terminal 200 as shown in Equation (2). However, the present invention is not limited to this. For example, the estimated total size of Transport Blocks for which scheduling information has been transmitted from the base station 100 and the terminal 200 has not transmitted PUSCH based on the scheduling information is used as the estimated buffer size (S_Buff (u, t)). Also good. Specifically, it can be calculated by the following equation (7).

上式（７）の右辺の第２項が推定合計サイズである。N_SchDelayはスケジューリング情報に基づいてPUSCHで送信しない最大subframe数を表す。従って、PUSCHを送信していない時刻は[t-N_SchDelay 〜 t-1]の範囲となる。スケジューリング情報を送信していない時刻t-iに関しては、S_Tb(u,t-i)を0biteとする。式（７）を用いることで、バッファサイズの推定精度が向上するので、伝送効率やシステム容量が更に改善する。

The second term on the right side of Equation (7) is the estimated total size. N_SchDelay represents the maximum number of subframes that are not transmitted on the PUSCH based on the scheduling information. Therefore, the time when PUSCH is not transmitted is in the range of [t-N_SchDelay to t-1]. For time ti when no scheduling information is transmitted, S_Tb (u, ti) is set to 0 bite. By using Equation (7), the accuracy of estimating the buffer size is improved, so that the transmission efficiency and system capacity are further improved.

In this embodiment, the estimated buffer size and the TBS are used as the transmission efficiency index Eff as shown in the equation (3). However, the present invention is not limited to this. For example, only the estimated buffer size is used. The following equation (8) used may be applied for simplification.
Eff (u, t) = S_Buff (u, t) (8)

In this embodiment, the delay index is calculated using the time t_Bsr at which the BSR is received as shown in the equation (5). However, the present invention is not limited to this, and for example, a buffer The following equation (9) using the estimated data transmission time may be used.
D (u, t) = t -t_Bsr + S_Buff (u, t) / Rate_Ave (u, t) (9)
The third term (S_Buff (u, t) / Rate_Ave (u, t)) on the right side of Equation (9) is the estimated transmission time. Rate_Ave (u, t) represents the average transmission rate per subframe of the terminal u and is updated using the following equation (10).
Rate_Ave (u, t) [bites / ms] = (1-w_TBS) * Rate_Ave (u, t-1) + w_TBS * S_Tb (u, t) (10)
Here, w_TBS represents a weighting coefficient. Note that S_Tb (u, t) at the time of no allocation is set to 0, and Rate_Ave (u, t) is updated.

  Furthermore, in Expression (5) and Expression (9), t_Bsr is calculated using the time when the BSR is received, but the present invention is not limited to this. For example, if the buffer status report information from the terminal 200 includes a representative value of the arrival time of the packet, that value may be used.

Further, in this embodiment, the delay tolerance value Bud_D (u) is calculated from each LCG tolerance value (Bud_D_Lcg (u, lg)) or the minimum value of each LCH tolerance value (Bud_D_Lch (u, l)). Although set, the present invention is not limited to this. For example, the QCI having the highest priority may be used as a reference.

2. Second Embodiment In the first embodiment described above, whether or not radio resources can be allocated to the terminal 200 is determined using the transmission efficiency index Eff and the delay index D. However, in the second embodiment of the present invention, the load index PRB is further determined. The usage is used to determine whether or not radio resource allocation is possible.

2.1) Configuration Referring to FIG. 5, the load measuring unit 111 is added to the base station 100, which is different from the sixteenth embodiment.

  The scheduler 103 has the same function as that of the first embodiment, but also uses a load index Load measured by the load measuring unit 111 in addition to the delay index D and the transmission efficiency index Eff when determining availability.

  The load measuring unit 111 has a function of calculating a load index Load for determining the load. In this embodiment, the load index Load is a PRB usage rate (PRB usage) based on the PUSCH allocation information.

2.2) Radio Resource Allocation Control FIG. 6 shows a control procedure in which the scheduler 103 allocates radio resources to the terminal 200. Referring to FIG. 6, the operation S401 and S402 are inserted between the operations S304 and S305, which is different from the first embodiment. That is, in order to improve transmission efficiency, the scheduler 103 excludes the assigned PRB within a range that satisfies the above-described equation (1), recalculates the MCS Index (operation S304), and then the load measuring unit 111 loads the load index Load. (Operation S401), it is determined according to the following equation (11) whether or not the load index Load is equal to or greater than the load threshold Th_Load.
Load (t)> = Th_Load (11)
Here, Load (t) represents a load index, and Th_Load represents a load threshold value. In this embodiment, Load (t) is a PRB usage rate (PRB usage) at time t.

  If the load index Load is greater than or equal to the load threshold Th_Load (operation S402; YES), the scheduler 103 proceeds to operation S305 as in the first embodiment. If the load index Load is not equal to or greater than the load threshold value Th_Load (operation S402; NO), the scheduler 103 does not execute the operations S305-S306 and S308-S309, and the radio resource to the terminal 200 as described above. Candidate assignment is determined, and information on radio resources to be assigned is transmitted to terminal 200 as scheduling information (operation S307).

  According to this embodiment, when the cell load is low, there is no restriction on radio resource allocation to the terminal 200. Therefore, when there is a sufficient load with respect to the system capacity, priority is given to the throughput of each terminal.

  Further, in this embodiment, PRB usage is used as the load index Load (t), but the present invention is not limited to this, for example, the number of terminals connected to the cell and the estimated buffer size of all terminals (S_Buff The total value of (u, t)) may be used.

3. Third Embodiment A third embodiment of the present invention is LTE downlink radio resource allocation control, in which the transmission buffer size / maximum payload size is used as the transmission efficiency index Eff, and the packet party approximate time is used as the delay D. To do.

3.1) Configuration Referring to FIG. 7, similarly to the first embodiment shown in FIG. 3, the base station 100 performs wireless communication with the terminal 200 existing in the local station communication area through a wireless channel. The device is connected to a network (not shown) and can perform data communication with other base stations. Although not shown, the base station 100 can be connected to a plurality of terminals, and a plurality of base stations can exist.

  The base station 100 includes a base station operation unit 101, a reference signal generation unit 121, a channel quality estimation unit 122, a scheduler 123, and a transmission buffer 124 as main functional units. Since the base station operation unit 101 has the same function as that of the first embodiment, the description thereof is omitted.

  The reference signal generation unit 121 has a function of transmitting a reference signal for the terminal 200 to measure the channel quality to the terminal 200 via the base station operation unit 101 at a predetermined timing. Channel quality estimation section 122 has a function of estimating SINR of the downlink data channel (PDSCH) from CQI included in CSI reported from terminal 200.

  The scheduler 123 calculates a radio resource candidate such as PRB and MCS Index to be allocated to the terminal 200 using the estimated SINR of PDSCH and the buffer information of the transmission buffer 124, and determines radio transmission efficiency using the buffer information. A transmission efficiency index Eff and a delay index D for determining the transmission delay of the staying packet, a function for determining whether or not radio resource candidates can be allocated using the transmission efficiency index Eff and the delay index D, and A function of generating a Transport Block and transmitting data in the transmission buffer 124 to the terminal 200 via the base station operation unit 101. The transmission buffer 124 has a function of storing packet data transmitted from the base station 100 together with management information such as arrival time and packet size.

  Next, the terminal 200 will be described. The terminal 200 includes a terminal operation unit 201 and a channel quality measurement unit 211 as main functional units. Since the terminal operation unit 201 has the same function as that of the first embodiment, the description thereof is omitted.

  The channel quality measurement unit 211 measures the channel quality such as SINR from the reference signal received from the base station 100, quantizes it as CSI, and at the timing instructed from the base station 100 via the terminal operation unit 201 It has a function to report to 100.

3.2) Radio Resource Allocation Control FIG. 8 shows a control procedure in which the scheduler 123 allocates (or does not allocate) radio resources for transmitting data to the terminal 200.

  First, the scheduler 123 selects allocation PRB and MCS Index candidates from the estimated SINR of PDSCH (operation S501). As in the first embodiment, the PRB having the maximum TBS is selected as an allocation candidate from among the assignable PRB groups. Since the LTE downlink radio access system is OFDMA (Orthogonal Frequency Division Multiple Access), discontinuous PRBs can be assigned.

Next, as in the first embodiment, the TBS size is calculated from the selected radio resource candidate (operation S502), and whether or not the buffer size of the transmission buffer 124 becomes 0 when transmission is performed using the radio resource candidate. The determination is made according to the above-described equation (1) (operation S503). In the present embodiment, the buffer size (S_Buff (u, t)) in equation (1) is calculated according to the following equation (12).
S_Buff (u, t) = S_BuffSum (u) (12)
Here, S_BuffSum (u) is the total value of the buffer sizes of all LCHs of the terminal 200 in the transmission buffer 124. In the downlink, the buffer size can be measured for each LCH.

  When the transmission buffer size becomes 0 (operation S503; YES), similarly to the first embodiment, the assigned PRB is excluded within the range satisfying the expression (1), and the MCS Index and TBS are recalculated (operation S504). . In this embodiment, the PDSCH is excluded from PRBs having a small estimated SINR so that the number of assigned PRBs is minimized. When the transmission buffer size does not become 0 (operation S503; NO), the operation S504 is skipped.

  Subsequently, similarly to the first embodiment, the scheduler 123 calculates a transmission efficiency index Eff using the S_Tb and the transmission buffer size S_Buff calculated in the above operation S502 or S504 (operation S505), and the transmission efficiency index Eff. Is equal to or greater than the transmission efficiency threshold value Th_Eff according to equation (4) (operation S506). When the transmission efficiency index Eff is greater than or equal to the transmission efficiency threshold Th_Eff (operation S506; YES), the scheduler 123 determines assignment of radio resource candidates to the terminal 200, assigns PRB and MCS Index, and sets Transport Block. Generate (operation S507).

When the transmission efficiency index Eff is not equal to or greater than the transmission efficiency threshold value Th_Eff (operation S506; NO), the scheduler 123 uses information related to the arrival time of the packet staying in the transmission buffer, as in the first embodiment. The delay index D is calculated according to the following equation (13) (operation S508),
D (u, t) = t -t_MaxPri_Arrival (u) (13)
It is determined whether or not the delay index D is greater than or equal to the allowable delay value St_D (operation S509).
Here, t_MaxPri_Arrival represents the earliest arrival time among LCH transmission waiting packets with the highest QCI priority, and St_D (u) is the delay set for the LCH selected in t_MaxPri_Arrival (u) The allowable value.

  If the delay index D is equal to or greater than the allowable delay value St_D (operation S509; YES), the allocation of the above-described radio resource candidates is determined and a transport block is generated (operation S507). If the delay index D is not equal to or greater than the allowable delay value St_D (operation S509; NO), the scheduler 123 does not execute the operation S507 and does not allocate radio resources to the terminal 200.

4). Other Embodiments Although several embodiments of the present invention have been described above, the present invention is not limited to the above embodiments.

  The present invention may be applied to a system composed of a plurality of devices, or may be applied to a single device. Furthermore, the present invention can also be applied to a case where a program that realizes the functions described in the above embodiments is supplied from a system or remotely and the processing of the operation procedure described in the embodiments is executed. Therefore, in order to realize the functions of the present invention in the base station, a program installed in the base station and executed by a processor in the base station, a medium storing the program, and a server for downloading the program are also included in the scope of the present invention. include.

5. Supplementary Notes Part or all of the above-described embodiments and examples may be described as the following supplementary notes, but are not limited thereto.
(Appendix 1)
A wireless communication device in a wireless communication system,
Index calculation means for calculating the relative size of the actual data size to the transmittable data size on the radio link with the terminal as a transmission efficiency index;
Radio resource allocation determination means for determining allocation of radio resources for transmission of the actual data based on at least the transmission efficiency index;
A wireless communication apparatus comprising:
(Appendix 2)
The wireless communication apparatus according to appendix 1, wherein the wireless resource allocation determination unit allocates the wireless resource if the transmission efficiency index is equal to or greater than a predetermined value.
(Appendix 3)
The radio communication apparatus according to appendix 1 or 2, wherein the radio resource allocation determination unit does not allocate the radio resource as long as a transmission delay is allowed if the transmission efficiency index is smaller than a predetermined value.
(Appendix 4)
The wireless communication apparatus according to any one of appendices 1-3, wherein the predetermined data size is calculated based on at least the quality of the wireless link.
(Appendix 5)
The radio communication apparatus according to any one of appendices 1-4, wherein the radio resource allocation determination unit further performs allocation determination of the radio resource based on a load state of the radio link.
(Appendix 6)
The wireless communication apparatus according to appendix 5, wherein the wireless resource allocation determination unit allocates the wireless resource if the load state is smaller than a predetermined value.
(Appendix 7)
The load state is any one of a wireless band usage rate of the wireless link, the number of connected terminals, or a total value of data sizes retained in the connected terminals. A wireless communication device according to 1.
(Appendix 8)
A wireless resource allocation method in a wireless communication device connected to a terminal,
Calculate the relative size of the actual data size to the transmittable data size on the wireless link with the terminal as a transmission efficiency index,
Radio resource allocation determination means performs allocation determination of radio resources for transmission of the actual data based on at least the transmission efficiency index.
A radio resource allocation method characterized by the above.
(Appendix 9)
The radio resource allocation method according to appendix 8, wherein the radio resource allocation determination unit allocates the radio resource when the transmission efficiency index is equal to or greater than a predetermined value.
(Appendix 10)
The radio resource allocation method according to appendix 8 or 9, wherein the radio resource allocation determination unit does not allocate the radio resource as long as a transmission delay is allowed if the transmission efficiency index is smaller than a predetermined value. .
(Appendix 11)
The radio resource allocation method according to any one of appendices 8-10, wherein the predetermined data size is calculated based on at least the quality of the radio link.
(Appendix 12)
The radio resource allocation method according to any one of appendix 8-11, wherein the radio resource allocation determination unit further performs allocation determination of the radio resource based on a load state of the radio link.
(Appendix 13)
13. The radio resource allocation method according to appendix 12, wherein the radio resource allocation determination unit allocates the radio resource if the load state is smaller than a predetermined value.
(Appendix 14)
The load state is any one of the wireless link usage rate of the wireless link, the number of connected terminals, or the total value of the data size retained in the connected terminals. The radio | wireless resource allocation method as described in.
(Appendix 15)
A wireless communication system in which a base station and a terminal perform wireless communication,
The base station calculates index relative to the actual data size relative to the transmittable data size on the radio link with the terminal as a transmission efficiency index;
A radio communication system comprising: radio resource allocation determination means for determining allocation of radio resources for transmission of the actual data based on at least the transmission efficiency index.
(Appendix 16)
The wireless communication system according to supplementary note 15, wherein the wireless resource allocation determination unit allocates the wireless resource when the transmission efficiency index is equal to or greater than a predetermined value.
(Appendix 17)
The radio resource allocation determination unit does not allocate the radio resource as long as a transmission delay is allowed if the transmission efficiency index is smaller than a predetermined value. Wireless communication system.
(Appendix 18)
18. The wireless communication system according to any one of appendices 15-17, wherein the predetermined data size is calculated based on at least the quality of the wireless link.
(Appendix 19)
The radio communication system according to any one of appendices 15-18, wherein the radio resource allocation determination unit further performs allocation determination of the radio resource based on a load state of the radio link.
(Appendix 20)
The radio communication system according to appendix 19, wherein the radio resource allocation determination unit allocates the radio resource if the load state is smaller than a predetermined value.
(Appendix 21)
The load state is any one of the radio link usage rate of the radio link, the number of connected terminals, or the total value of the data size retained in the connected terminals. The wireless communication system according to 1.
(Appendix 22)
A program for causing a computer to function as a wireless communication device in a wireless communication system,
A transmission size control function that calculates the relative size of the actual data size to the transmittable data size on the wireless link with the terminal as a transmission efficiency index;
A radio resource allocation determination function for determining allocation of radio resources for transmission of the actual data based on at least the transmission efficiency index;
Is realized by the computer.
(Appendix 26)
A radio resource allocation method for a base station to perform radio communication with a terminal in a communication area,
Obtaining the size and arrival time of staying data to be transmitted in the wireless communication;
Calculating a transmission efficiency index using the size of the staying data;
Calculating a delay index using the arrival time of the residence data;
A radio resource allocation method comprising: a radio resource allocation step for determining whether to perform radio resource allocation to the terminal based on the transmission efficiency index and the delay index.
(Appendix 27)
Radio resource allocation to the terminal is performed in the radio resource allocation step when the transmission efficiency index is greater than or equal to a threshold value of transmission efficiency, or when the delay index is greater than or equal to an allowable delay value. The radio resource allocation method according to appendix 26.
(Appendix 28)
27. The radio resource allocation method according to appendix 26, wherein the transmission efficiency index is a size of the staying data with respect to a transmittable data size.
(Appendix 29)
27. The radio resource allocation method according to supplementary note 26, wherein the transmission efficiency index is a size of the staying data.
(Appendix 30)
Further comprising obtaining communication channel quality information of the terminal;
29. The radio resource allocation method according to appendix 28, wherein the transmittable data size is calculated using at least the channel quality information.
(Appendix 31)
27. The radio resource allocation method according to supplementary note 26, wherein the delay index is calculated using a report time of the size of the staying data.
(Appendix 32)
27. The radio resource allocation method according to appendix 26, wherein the delay index is calculated using an arrival time of the staying data.
(Appendix 33)
The radio resource allocation method according to appendix 7, wherein the delay threshold is set based on a QoS of the staying data.
(Appendix 34)
Further comprising measuring a load index of wireless communication between the base station and the terminal,
27. The radio resource allocation method according to appendix 26, wherein, in the radio resource allocation step, execution of radio resource allocation to the terminal is determined based on a load index in addition to the transmission efficiency index and the delay index.
(Appendix 35)
35. The radio resource allocation method according to claim 34, wherein, when the load index is smaller than a load threshold value, radio resource allocation to the terminal is performed in the radio resource allocation step.
(Appendix 36)
35. The radio resource allocation method according to supplementary note 34, wherein the load index is a usage rate of a frequency block which is a radio band allocation unit.
(Appendix 37)
35. The radio resource allocation method according to supplementary note 34, wherein the load index is the number of terminals connected to the base station.
(Appendix 38)
35. The radio resource allocation method according to claim 34, wherein the load index is a total value of the staying data sizes of terminals connected to the base station.
(Appendix 39)
27. The radio resource allocation method according to supplementary note 26, wherein the radio communication is uplink data communication.
(Appendix 40)
27. The radio resource allocation method according to supplementary note 26, wherein the radio communication is downlink data communication.
(Appendix 41)
A wireless communication system for a base station to perform wireless communication with a terminal in a communication area,
The base station is
Means for acquiring the size and arrival time of staying data to be transmitted by the wireless communication;
Means for calculating a transmission efficiency index using the size of the staying data;
Means for calculating a delay index using the arrival time of the staying data;
Means for allocating radio resources based on the transmission efficiency index and the delay index, for determining implementation of radio resource allocation to the terminal;
A wireless communication system comprising:
(Appendix 42)
A base station that performs wireless communication with a terminal in a communication area,
Means for acquiring the size and arrival time of staying data to be transmitted by the wireless communication;
Means for calculating a transmission efficiency index using the size of the staying data;
Means for calculating a delay index using the arrival time of the staying data;
Means for allocating radio resources based on the transmission efficiency index and the delay index, for determining implementation of radio resource allocation to the terminal;
A base station comprising:
(Appendix 43)
A program for realizing a radio resource allocation control function in a base station computer that performs radio communication with a terminal in a communication area,
A function of acquiring the size and arrival time of the staying data to be transmitted by the wireless communication;
A function of calculating a transmission efficiency index using the size of the staying data;
A function of calculating a delay index using the arrival time of the staying data;
A radio resource allocating function for determining execution of radio resource allocation to the terminal based on the transmission efficiency index and the delay index;
Is implemented on the computer.

  The present invention is applicable to a wireless communication system such as a mobile communication system.

100 base station 101 base station operation unit 102 reference signal measurement unit 103 scheduler 111 load measurement unit 121 reference signal generation unit 122 channel quality estimation unit 123 scheduler 124 transmission buffer 200 terminal 201 terminal operation unit 202 reference signal generation unit 203 transmission buffer 211 channel Quality measurement department

Claims (9)

A wireless communication device in a wireless communication system,
Index calculation means for calculating the relative size of the actual data size to the transmittable data size on the radio link with the terminal as a transmission efficiency index;
Radio resource allocation determination means for determining allocation of radio resources for transmission of the actual data based on at least the transmission efficiency index;
A wireless communication apparatus comprising:   The radio communication apparatus according to claim 1, wherein the radio resource allocation determination unit allocates the radio resource when the transmission efficiency index is equal to or greater than a predetermined value. The indicator calculating means calculates a transmission delay of the actual data;
The radio communication apparatus according to claim 1 or 2, wherein the radio resource allocation determination unit does not allocate the radio resource as long as the transmission delay is allowed if the transmission efficiency index is smaller than a predetermined value. .   The radio communication apparatus according to claim 1, wherein the transmittable data size is calculated based on at least the quality of the radio link.   5. The radio communication apparatus according to claim 1, wherein the radio resource allocation determination unit further performs allocation determination of the radio resource based on a load state of the radio link.   6. The radio communication apparatus according to claim 5, wherein the radio resource allocation determination unit allocates the radio resource if the load state is smaller than a predetermined value.   6. The load state is any one of a radio band usage rate of the radio link, the number of connected terminals, or a total value of data sizes retained in the connected terminals. 7. A wireless communication device according to 6. A wireless resource allocation method in a wireless communication device connected to a terminal,
Calculate the relative size of the actual data size to the transmittable data size on the wireless link with the terminal as a transmission efficiency index,
Radio resource allocation determination means performs allocation determination of radio resources for transmission of the actual data based on at least the transmission efficiency index.
A radio resource allocation method characterized by the above. A wireless communication system in which a base station and a terminal perform wireless communication,
Based on at least the transmission efficiency index, the index calculation means for the base station to calculate the relative size of the actual data size to the transmittable data size on the radio link with the terminal as a transmission efficiency index, A radio communication system comprising: radio resource allocation determining means for determining allocation of radio resources for transmission of actual data.

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