JP5742654B2 - Wireless communication system - Google Patents

Description

  The present invention relates to a wireless communication system.

  A mobile communication system that performs transmission allocation using a scheduler, and the HSDPA system, which is standardized in 3GPP, has been partially put into practical use.

  Hereinafter, the HSDPA system for implementing the downlink high-speed transmission will be described as an example using a terminal configuration example and a base station configuration example.

1 to 5 are diagrams for explaining a conventional HSDPA system.
In the terminal shown in FIG. 1, for example, based on the pilot signal of the downlink signal received via the antenna 10, the radio unit 11, and the demodulation / decoding unit 12, the radio channel quality measurement / calculation unit 13 CQI: Channel Quality Indicator) is measured and calculated. As a specific example, the SIR is calculated by measuring the reception power and interference power of the pilot signal, and the CQI is calculated based on this. The CQI value is assembled into a signal for transmission by the radio channel quality indicator transmission unit 14, encoded and modulated by the encoding / modulation unit 15, and transmitted to the base station via the antenna 10 via the uplink radio channel. That is, the CQI value is reported to the base station.

  On the other hand, in the base station of FIG. 2, a signal carrying the CQI value sent from the terminal is received via the antenna 20, the radio unit 21, and the demodulation / decoding unit 22, and the radio channel quality indicator collection unit 23 The wireless channel quality index (CQI) is collected and notified to the scheduler 24. In the scheduler 24, for example, the priority of the terminal is calculated for each frequency band using the radio channel quality indicator (hereinafter abbreviated as CQI: Channel Quality Indicator) reported from the terminal, and the transmission parameter is set in descending order of priority. Then, the control signal generator 25 generates a control signal for transmission, and transmits it to the terminal via the encoder / modulator 27, the radio unit 28, and the antenna 20. The transmission data of the transmission data buffer 26 is transmitted to the terminal after transmitting the control signal.

FIG. 3 is a processing flow of scheduling.
Suppose now that there are terminals UE1 to UEn in the cell of the base station. In step S10, the CQI values (CQI1-CQIn) of the terminals UE1-UEn are received. In step S11, CQI1 to CQIn are stored. In step S12, TTI is initialized. TTI is an abbreviation for transmission time interval and indicates a transmission interval of data to a terminal. Here, it is used as a variable indicating the number of transmissions to the terminal. In step S13, TTI is incremented by one. In step S14, the priority Pk of the terminal UEk is calculated. In step S15, i = 0 and j = 1 are initialized. In step S16, the remaining radio resource Ri is calculated. When i = 0, since no radio resources have been allocated yet, Ri is all the radio resources of the system. In step S17, it is determined whether or not the remaining radio resource Ri is not smaller than zero. If the determination in step S17 is Yes, the process proceeds to step S21. When the determination in step S17 is No, in step S18, a terminal UEj having a priority (priority) Pk of the maximum value Pk_max is calculated from ni terminals. In step S19, a data transmission method (data length, modulation scheme, etc.) to the terminal UEj is selected. In step S20, i is increased by 1, j is increased by 1, and the process returns to step S16. In step S21, the transmission method selected in step S19 is modulated as a control signal and transmitted to the terminal. In step S22, the transmission data is modulated and transmitted to the terminal that transmitted the control signal, and the process returns to step S13.

  In addition, as a priority calculation method, there are the MAX CIR method that selects from the one with the highest CQI value, the PF (Proportional Fairness) method that selects from the one with the highest CQI, and selects the opportunities equally. It is used.

  By the way, in the 3GPP described above, the specification of an E3G (Evolved 3G) system is being studied as a next-generation mobile communication system. In this regard, the introduction of OFDMA in the downlink and SC-FDMA in the uplink is being studied as a multiple access method.

  In the E3G system, scheduling is performed in the same manner as the HSDPA system using a wider frequency band (for example, 4 times) than the conventional HSDPA. Further, terminals used in the E3G system have different bandwidths for uplink and downlink. Further, for example, in the case of downlink, the band that can be used by the terminal varies depending on the terminal such as 1.25 MHz, 2.5 MHz, 5 MHz, 10 MHz, and 20 MHz.

For this reason, scheduling limited to a specific band cannot be performed unlike HSDPA, and it is necessary to perform scheduling with a system band of 20 MHz in consideration of the used bandwidth.
In other words, as shown in FIG. 4, it is necessary to perform scheduling of the entire system with one scheduler.

  Further, it is assumed that the downlink system bandwidth is 20 MHz and the terminal downlink bandwidth is 5 MHz. At this time, the frequency used at the time of operation is variable due to the balance with other terminals, and there are four possibilities. Therefore, in order for the scheduler of the base station to consider the bandwidth used by other terminals and to select an optimum band from a plurality of bands, as shown in FIG. Each time, CQI must be measured and calculated, and CQI reported to the base station.

  In other words, it is necessary to measure and calculate CQI four times that of HSDPA. In addition, the number of CQI reports to the base station is quadrupled. As a result, the uplink interference is also quadrupled.

In the E3G system, when scheduling the entire system with one scheduler,
・ Simply compared with the scheduler of the conventional HSDPA system, the number of terminals to be scheduled is simply several times (for example, 4 times) compared with the HSDPA system.
The transmission interval is 0.5 msec, which is 1/4 compared with 2 msec of the conventional HSDPA system. From the above two points, for example, a scheduling speed 16 times that of the conventional HSDPA system is required. In other words, the priority calculation time must be 1/16.

  On the other hand, the improvement in the processing performance of CPUs and DSPs that have been scheduled so far is based on 2010, the E3G service start target, even if Moore's Law (double the processing speed in 18 months) is taken into account. It is only about 4 times and not 16 times the above.

Therefore, it is essential to speed up the scheduling process.
Patent Document 1 discloses a technique for grouping and scheduling terminals that move at high speed. Furthermore, it specializes the bandwidth to be scheduled. These are considered to be based on 3GPP HSUPA (High Speed Uplink Packet Access).
However, it is described that scheduling is not performed for a terminal that is moving at a low speed or stopped.

  Patent Document 2 is an example using OFCDM (Orthogonal Frequency and Code Division Multiplexing). That is, a method of performing spreading and multiplexing in the frequency direction and the time direction is used.

  Patent Document 3 performs terminal grouping using the attenuation amount of transmission power, and since there is no description regarding the used frequency band, it is considered that conventional OFDM is used.

  In Patent Document 4, a base station detects a moving speed of a mobile station using a Doppler frequency and optimally selects a coding rate and a modulation method.

  In Patent Document 5, the transmission rate of communication between a mobile station and a base station is optimally determined based on information such as the Doppler frequency of the mobile station.

  Patent Document 6 groups subcarriers, acquires channel quality information for each group, and transmits and receives them.

JP 2006-060814 A JP 2005-318434 A Japanese Patent Laid-Open No. 2001-036950 Japanese Patent Laid-Open No. 2003-259437 JP 2005-260992 A JP 2005-160079

  The subject of this invention is providing the radio | wireless communications system which can speed up the processing speed of the scheduling process in a base station.

  The wireless communication system of the present invention is a wireless communication system in which a base station communicates with a plurality of terminals under control using a plurality of frequency bands, and a wireless channel obtained for each frequency band used by the terminal for communication with the base station. Based on the quality, grouping means for allocating the plurality of terminals into groups for each frequency band, scheduling means for scheduling the terminals divided into the groups in units of groups, and based on the scheduling results, The base station includes communication means for communicating with the terminal.

  According to the present invention, it is possible to reduce the number of scheduling target terminals per scheduler by grouping terminals for each frequency to be used and perform scheduling for each group, scheduling can be performed in parallel, and scheduling processing can be performed. Time can be shortened.

It is FIG. (1) explaining the conventional HSDPA system. It is FIG. (2) explaining the conventional HSDPA system. It is FIG. (3) explaining the conventional HSDPA system. It is FIG. (4) explaining the conventional HSDPA system. It is FIG. (5) explaining the conventional HSDPA system. It is a sequence diagram which shows the flow of the process of embodiment of this invention. It is explanatory drawing in the case of grouping using the simplest line quality of each zone | band at the time of line setting according to this invention. It is a figure which shows the measurement image of the radio channel quality for every use band. It is FIG. (1) explaining the grouping and scheduling method of a terminal. It is FIG. (2) explaining the grouping and scheduling method of a terminal. It is a figure which shows the image of the method of grouping and scheduling in case the use bandwidth of a terminal differs from FIG. It is FIG. (1) explaining hierarchical grouping. It is FIG. (2) explaining hierarchical grouping. It is an example of the grouping table which a base station has when a terminal is grouped. It is a figure explaining the other method of grouping. It is an example of the grouping table which a base station corresponds to the grouping of FIG. It is FIG. (1) which shows the example of a process at the time of allocating a terminal to a group, respectively. It is FIG. (2) which shows the example of a process at the time of allocating a terminal to a group, respectively. It is FIG. (3) which shows the example of a process at the time of allocating a terminal to a group, respectively. It is FIG. (4) which shows the example of a process at the time of allocating a terminal to a group, respectively. It is FIG. (5) which shows the example of a process at the time of allocating a terminal to a group, respectively. It is a figure which shows the principle structure of the terminal of this invention. It is a figure which shows the principle structure of the base station of this invention. It is the structural example applied when measuring the CQI by using the structure of FIG. 22 as radio channel quality. FIG. 24 is a configuration example applied when measuring the CQI with the configuration of FIG. 23 as radio channel quality. It is a 2nd structural example of the base station of embodiment of this invention. It is a figure which shows the 3rd structural example of the base station of embodiment of this invention. It is a figure which shows the 2nd structural example of the terminal of embodiment of this invention corresponding to FIG. It is a figure which shows the 4th structural example of the base station of embodiment of this invention. It is a figure which shows the 5th structural example of the base station of embodiment of this invention.

Hereinafter, description will be given by taking downlink transmission as an example.
FIG. 6 is a sequence diagram showing a flow of processing according to the embodiment of the present invention.

In FIG. 6, the terminal measures the radio channel quality for each frequency band (1). That is, for each frequency band, the SIR is calculated from the received data, and the CQI value is obtained based on this. The measured radio channel quality is notified to the base station (2). The base station determines the frequency band to be used by the terminal from the received radio channel quality information (3), and classifies all terminals that have transmitted the radio channel quality into groups (4). When the grouping setting is completed, the base station notifies each terminal of the terminal group to which the terminal belongs (5). The terminal that has received the terminal group notification sets the use frequency band and the terminal group (6). The wireless channel quality is measured in the use frequency band set in the terminal (7), and the measurement result is notified to the base station (8). The base station performs scheduling for each frequency band used based on the notified radio channel quality. That is, a terminal to be transmitted is selected based on the priority order of the terminals, and a transmission method is selected. Based on this result, control information for the terminal to receive is created (9). The terminal is notified of transmission control information (10), and then transmits data (11).

  In this way, in the OFDMA system or the MC-CDMA system, terminals are grouped according to a bandwidth and a usable frequency that can be used by the terminals. The grouping may be performed at the time of setting the wireless line, or may be grouped at a fixed period after the wireless line is set. In addition to the usable bandwidth of the terminal, information for grouping may include line quality for each band, line use status (load) for each band, and the like.

  FIG. 7 is an explanatory diagram when grouping is performed using the simplest line quality of each band at the time of line setting according to the present invention.

  Specifically, consider a case where the maximum bandwidth that a terminal can use is 5 MHz, and the system bandwidth is 20 MHz. At the time of line setup, the terminal measures the radio channel quality and calculates the radio channel quality index for each of the system bandwidth 20MHz divided by the maximum usable bandwidth 5MHz (1) and notifies the base station (2). The base station (or the radio network controller) determines the use frequency based on this information and the usable bandwidth of the terminal (3), and divides the terminal for each use bandwidth and use frequency and performs grouping (4). ). The use frequency may be determined in consideration of the line load between the frequencies that can be accommodated.

  FIG. 7 is almost the same as FIG. 6, but the used frequency band and the terminal group are set at the time of line setting. In a steady state, each terminal measures the radio channel quality of the used frequency band of its own terminal and reports Scheduling is started at the base station based on the received radio channel quality and communication is started. Since the operation in the steady state is the same as that in FIG.

FIG. 8 is a diagram showing a measurement image of the radio channel quality for each used band.
As described above, the terminal whose terminal group is determined measures the channel quality only for the determined use frequency, calculates the CQI, and reports to the base station.

Thereby, the number of CQI reports can be reduced and uplink interference can be reduced.
The base station that has received the CQI classifies the CQI for each group of the terminals, and performs scheduling for each terminal group (for each used frequency band). As a result, the number of scheduling target terminals decreases, so that the priority calculation processing amount of the terminals in scheduling can be reduced, and the processing speed can be increased. In addition, since scheduling is performed for each terminal group, the processing can be further speeded up by operating a plurality of schedulers in parallel.

  FIG. 9 and FIG. 10 are diagrams explaining terminal grouping and scheduling methods.

  9 and 10 show a case where the system band is 20 MHz and the terminal use bandwidth is 5 MHz, and the terminals UE100 to UE139 are grouped into four groups. The group 1 uses the frequency band 1 and performs scheduling using the scheduler 1 of the four provided schedulers. Similarly, band 2 and scheduler 2 are assigned to group 2, band 3 and scheduler 3 are assigned to group 3, and band 4 and scheduler 4 are assigned to group 4. This image is shown in FIG. Scheduling of each group is performed every 0.5 ms because the data transmission interval is 0.5 ms.

Thus, when a plurality of schedulers are provided , one scheduler is assigned to each terminal group. That is, for example, group 1 performs scheduling using scheduler 1, and group 2 performs scheduling using scheduler 2. These scheduling can be performed in parallel as shown in FIG.

  FIG. 11 is a diagram illustrating an image of a grouping and scheduling method when the used bandwidth of the terminal is different from that in FIG.

  FIG. 11 shows a case where the bandwidth used by the terminal is 10 MHz. The band 1 and the band 2 are used, the scheduling 5 is performed by the scheduler 5, the band 3 and the band 4 are used, and the scheduler 6 is used for scheduling. Grouped into group 6.

12 and 13 are diagrams for explaining hierarchical grouping.
As described above, the bandwidth that can be used by the terminal varies depending on the performance of the terminal. For this reason, a method of grouping with usable bandwidth can be considered. In the case of FIG. 12, terminals UE160 to UE169 that can use 20 MHz are classified into group 7 and scheduled by scheduler 7 using all of bands 1 to 4. On the other hand, the terminals UE140 to UE149 and UE150 to 159 having a use bandwidth of 10 MHz are scheduled by the scheduler 6 using the bands 5 and 3 and the bands 3 and 4 using the bands 1 and 2, respectively. Group 6. The UEs UE 100 to 109, UEs 110 to 119, UEs 120 to 129, and UEs 130 to 139 having a usage band of 5 MHz are scheduled by the scheduler 2 using the band 1 and the group 1 scheduled by the scheduler 1 and the band 2, respectively. Group 2 using band 3 and group 3 scheduled by scheduler 3 and group 4 using band 4 and scheduled by scheduler 4.

  As shown in FIGS. 13A and 13B, it is assumed that all usable bands are used. For example, a group having a wide usable band such as a usable band of 20 MHz is set as an upper group, and can be used, for example. A narrow loop such as a band of 5 MHz is set as a lower group. At this time, scheduling is performed from the upper group to the lower group.

  As shown in FIG. 13A, group 7 is first scheduled every 0.5 ms, which is the transmission time of each data, and then groups 5 and 6 are finally assigned to groups 1-4. Scheduled. FIG. 13B describes an image of hierarchical scheduling. Scheduling is performed sequentially and hierarchically from the scheduler 7. In schedulers 5 and 6, two schedulers operate in parallel, and in schedulers 1 to 4, four schedulers operate in parallel.

FIG. 14 is an example of a grouping table that the base station has when terminals are grouped.
Corresponding to each terminal group number, the center frequency of the used band of each group, the bandwidth, and the identification number of the terminal belonging to each group are registered.

FIG. 15 is a diagram for explaining another method of grouping.
The required transmission speed differs depending on the data to be transmitted. Therefore, the required bandwidth differs depending on the data. In other words, depending on QoS, there may be a case where the use bandwidth needs to be wide or a case where the use bandwidth can be narrowed. Furthermore, even if the required transmission rate cannot be satisfied, transmission can be considered if transmission is possible by narrowing the bandwidth in consideration of other terminals. For this reason, when the usable bandwidth of a certain terminal is 20 MHz, it is possible not only to belong to a terminal group with a used bandwidth of 20 MHz but also to belong to a terminal group with a narrower bandwidth such as 10 MHz or 5 MHz. is there. Therefore, the terminal groups are hierarchized in the order of the used bandwidth. In FIG. 15, a terminal having a 20 MHz bandwidth can communicate at 10 MHz or 5 MHz. In addition, a terminal with a 10 MHz bandwidth can communicate at 5 MHz. Terminals UE 160 to UE 169 having a usage band of 20 MHz use bands 1 to 4 and are grouped so as to belong to all groups 1 to 6 in addition to belonging to group 7 scheduled by scheduler 7. Therefore, when the terminals UE160 to UE169 cannot use the 20 MHz band, the terminals UE160 to UE169 are allocated to either the group 5 or 6 of the 10 MHz band, or the groups 1 to 4 of the 5 MHz band when the 10 MHz band cannot be used. The possibility that the UEs 160 to 169 cannot communicate is reduced. Similarly, terminals UE140 to 149 and UE150 to 159 having a use band of 10 MHz are also allocated to groups 1 to 4 so that communication in the 5 MHz band can be performed when communication in the 10 MHz band is not possible. . Terminals UE100 to 109, UE110 to 119, UE120 to 129, and UE130 to 139 having a usage band of 5 MHz do not have a usage band of 5 MHz or less, and therefore belong to only groups 1 to 4, respectively.

  In the scheduling, the scheduling is performed in order from the upper layer group (for example, 20 MHz) to the lower layer group (for example, 5 MHz). As a result, the number of scheduling target terminals in the group can be reduced, and the priority order calculation process can be reduced, so that scheduling can be speeded up.

  FIG. 16 is an example of a grouping table of the base station corresponding to the grouping of FIG.

  Corresponding to the terminal group numbers 1 to 7, the center frequency of the used band of each group, the bandwidth, and the identification number of the terminal belonging to each group are registered.

  The same applies to the case of FIG. 14, but when a plurality of schedulers are provided, the same number of groups are provided. A scheduler is provided for each group, and the scheduling speed can be increased by operating each scheduler in parallel in a hierarchical manner as described above. Further, instead of providing a plurality of schedulers, one scheduler capable of parallel operation may be used.

  FIG. 17 to FIG. 21 are diagrams illustrating an example of a processing flow when terminals are allocated to groups.

  In the example of the process of FIG. 17, in step S30, the maximum usable bandwidth of the target terminal is confirmed. In step S31, a CQI for each band is received from the terminal. In step S32, a use band is selected from the maximum value of CQI. In step S33, a terminal group corresponding to the selected band is selected.

  In the example of FIG. 18, in step S35, the maximum usable bandwidth of the target terminal is confirmed, and in step S36, CQI for each band is received from the terminal. In step S37, a use band is selected from the CQI and the use status of each band, and in step S38, a terminal group is selected. The usage status of each band is the number of terminals already allocated to each band. If the number of terminals allocated to a certain band increases too much, the frequency selected by the scheduler decreases and the transmission speed decreases. In this case, the CQI is not the maximum band but the CQI is the second largest band. Perform processing such as selection.

  In the example of FIG. 19, in step S40, the maximum usable bandwidth of the target terminal is confirmed. In step S41, the bandwidth and CQI for each band are received from the terminal. In step S42, the used bandwidth and the used bandwidth are selected from the maximum value of CQI. In step S43, a terminal group is selected. In FIG. 19, it is assumed that the terminal can use a plurality of used bands. For example, when the system band is 20 MHz and the terminal use band is 10 MHz, the terminal can use 10 MHz and 5 MHz as the use bandwidth. Therefore, the terminal measures CQI of two bands of 10 MHz width and four bands of 5 MHz width, and the base station selects a use band from this measurement result.

  In the example of FIG. 20, for example, a case is considered where QoS GBR (Guaranteed Bit Rate) is set. That is, consider a case where a service that defines the minimum transmission rate is set. For example, it is assumed that a transmission rate that can be transmitted with a bandwidth of 5 MHz, a modulation scheme QPSK, and a coding rate of 1/3 is 3 Mbps. At this time, if the GBR of a certain terminal is 5 Mbps, the bandwidth needs to be 10 MHz in order to satisfy GBR. Therefore, terminals are allocated to a group having a used bandwidth of 10 MHz. As a modulation method, there are multi-value modulation methods such as 16QAM and 64QAM in addition to QPSK, and the coding rate can be made variable or the MIMO function can be used.

  In step S45, the maximum usable bandwidth of the target terminal is confirmed. In step S46, the QoS of the transmission data to the target terminal is confirmed. In step S47, the required bandwidth is calculated. In step S48, a CQI for each bandwidth of the necessary bandwidth is received from the terminal. In step S49, the used bandwidth is selected from the maximum value of CQI, the usable bandwidth, and the required bandwidth, and in step S50, a terminal group is selected.

  In the example of FIG. 21, it is considered that transmission characteristics deteriorate due to movement of the terminal. That is, the Doppler frequency is determined by the moving speed of the terminal, and the degree of deterioration of the transmission characteristics is determined by the Doppler frequency. Since the Doppler frequency increases as the use frequency increases, it is desirable to use a low frequency for communication with the terminal in order to cope with high-speed movement.

  Therefore, for example, when the system bandwidth is 20 MHz and the center frequency is f1 <f2 <f3 <f4 in FIG. 14, the high frequency bands (center frequencies f3, f4, f6) are for high-speed mobile terminals, and the lower one Frequency bands (f1, f2, f5) are intended for terminals moving at low speed or stationary.

  Prior to terminal grouping, the terminal moving speed is estimated by the terminal or base station. As an estimation method, for example, the moving speed is estimated by measuring the interval (fading pitch) of the drop in the received electric field strength due to fading. The result is compared with a threshold value of the moving speed, and when it is fast, it is determined that it is moving at high speed, and when it is slow, it is determined that it is moving at low speed or is stopped.

  In step S55, the moving speed of the target terminal is estimated. In step S56, high speed movement / low speed movement is determined. In step S57, the maximum usable bandwidth of the target terminal is confirmed. In step S58, a CQI for each required bandwidth is received from the terminal. In step S59, the moving speed, the usable bandwidth, and the CQI of each band are received. Then, a bandwidth and a use band are selected, and a terminal group is selected in step S60.

  FIG. 22 is a diagram showing a principle configuration of a terminal according to the present invention. FIG. 23 is a diagram showing a basic configuration of the base station of the present invention. In FIG. 22, the same reference numerals are assigned to the components corresponding to FIG. In FIG. 23, components corresponding to those in FIG.

  In downlink transmission of a wireless communication system using a plurality of bands such as OFDMA and MC-CDMA such as E3G, a terminal transmits a downlink control signal (for example, pilot) to the antenna 10, the radio unit 11, and the demodulation / decoding unit 12 when setting a line. The channel quality measuring unit 13 measures and calculates the radio channel quality of each band by measuring the received power, and the result is transmitted to the channel quality transmitting unit 14, the encoding / modulating unit 15, the radio The base station is notified using the uplink radio channel via the unit 16 and the antenna 10.

  In the base station that has received the radio channel quality of each band, the channel setting measurement result extraction unit 29 extracts the radio channel quality and the like for each band measured by the terminal, and provides them to the channel setting unit 30. The line setting unit 30 determines the band to be used by the terminal in consideration of the usable bandwidth of the terminal, the use state of the band, and the load while referring to the information on the terminal of the terminal group setting unit 31. The terminals are grouped according to the band, and the result is notified to the terminals via the terminal group setting signal creation unit 32.

  Upon receiving the notification, the terminal group setting information extraction unit 17 extracts this information, and the settings of the frequency band of the terminal group to which the terminal is assigned are set via the terminal setting control unit 18 to the radio units 11 and 16. To the line quality measuring unit 13. Thereafter, the line quality measurement unit 13 periodically measures the line quality of the used band, calculates the line quality index, and reports it to the base station via the uplink radio channel.

  The base station that has received the radio channel quality indicator from each terminal by the channel quality information collection / classification unit 23 classifies the radio channel quality indicator for each group to which the terminal belongs, and uses the schedulers 24-1 to 24-n. The transmission priority is calculated for each group based on the radio channel quality indicator. At this time, each scheduler 24-1 to 24-n selects a scheduler in charge of the terminal group to which the terminal that has transmitted the line quality information belongs, and calculates the transmission priority. In FIG. 23, only two schedulers are shown, but in general, n schedulers can be provided, and it is effective to provide as many as the number of terminal groups.

  Based on the priority calculation result, a terminal to be transmitted is selected, and a transmission method (for example, transmission data amount, modulation scheme, coding rate, etc.) is selected. Based on the result, the control signal generator 25- In 1 to 25-n, a transmission control signal is created and transmitted to a terminal that transmits data. Subsequent to the transmission control signal, transmission data is encoded based on the determined transmission method, and is transmitted to the terminal after modulation. Note that the transmission method is selected in consideration of the usable bandwidth of the terminal and the usable modulation scheme. Furthermore, the transmission method selection process is simplified by limiting the modulation schemes that can be used for each group (each scheduler).

  In the terminal, the transmission control signal transmitted from the base station is extracted by the control signal extraction unit 19, the content of the signal is decoded, and settings necessary for data reception are performed in the demodulation / decoding unit 12. After setting, it receives data sent from the base station.

As described above, the following processing can be performed by grouping the bands using the terminals.
1) The radio channel quality is measured only for the used band, and the radio channel quality index is calculated and reported to the base station.
2) Scheduling is performed for each group, and calculation of priority order, selection of a transmission terminal, and transmission method are determined.

The above has the following effects.
It is possible to reduce the measurement of the radio channel quality with respect to the unused band. That is, the process is simplified. In addition, the number of radio channel quality indicators reported to the base station can be reduced. As a result, transmission processing at the terminal can be reduced and the number of reports can be reduced, so that radio wave interference on the uplink can be reduced.

  In addition, since scheduling is performed for each group, the number of scheduling target terminals can be reduced, and processing time for priority order calculation and the like can be shortened. Furthermore, since scheduling is performed for each group, parallel operation of scheduling is possible, and processing time for priority calculation and the like can be shortened.

  In the base station configuration example of FIG. 23, the line setting unit 30 and the terminal group setting unit 31 surrounded by a dotted line may be provided in a radio network controller (RNC) that is a higher-level device of the base station.

  In the above description, the terminal grouping is performed at the time of line setting. However, the grouping may be changed at any time, for example, to change the grouping at regular intervals or to adjust the number of terminals accommodated in the corresponding band (that is, load). In this case, for example, processing is performed as shown in FIG.

  FIG. 24 is a configuration example applied when measuring the CQI with the configuration of FIG. 22 as the radio channel quality. FIG. 25 is a configuration example applied when measuring the CQI with the configuration of FIG. 23 as the radio channel quality.

  The CQI measurement / calculation unit in FIG. 24 measures and calculates CQI only for the frequency band used by the own terminal group after it is determined which terminal group the own terminal belongs to. The setting for that is performed by the terminal setting control part 18. The CQI collection / classification unit 23 in FIG. 25 collects CQI measurement and calculation values related to the used frequency band of the terminal group to which the terminal belongs from the terminal, and the obtained CQI value is obtained from the corresponding terminal group. Passed to the scheduler responsible for scheduling.

FIG. 26 is a second configuration example of the base station according to the embodiment of the present invention.
In FIG. 26, the same reference numerals are assigned to the components corresponding to FIG.

  In the above configuration example, grouping was performed in consideration of the available bandwidth of the terminal. Here, for example, a case is considered where the usable bandwidth of the terminal is 20 MHz and one divided band is 5 MHz. This terminal belongs to a group with a used bandwidth of 20 MHz. However, depending on the data to be transmitted, there is a possibility that the required transmission rate is such that the bandwidth of 20 MHz may not be used. In this case, setting the used bandwidth to 20 MHz is inefficient. However, in a group where the bandwidth used is fixed, 20 MHz is used.

  Therefore, for example, it is assumed that a group with an available bandwidth of 20 MHz, a group with a bandwidth of 10 MHz, and a group with a bandwidth of 5 MHz overlap. In addition, since it is possible to belong to different groups with different use center frequencies, in this case, they belong to seven groups. At this time, when a wide bandwidth is used, scheduling must be performed in order from the widest bandwidth to be used when selecting a terminal to transmit. Therefore, the use of a wide band can be facilitated by hierarchizing from a group with a wide use bandwidth to a narrow group. In addition, when using a wide band, it is desirable to select a continuous band, but using the layer as described above facilitates the use of a continuous band.

  Such a hierarchical grouping can be realized by providing one hierarchical scheduler 24a capable of parallel calculation, instead of assigning different schedulers to each terminal group.

  FIG. 27 is a diagram illustrating a third configuration example of the base station according to the embodiment of the present invention. FIG. 28 is a diagram illustrating a second configuration example of the terminal according to the embodiment of the present invention corresponding to FIG. In FIG. 27, components corresponding to those in FIG. 28, components corresponding to those in FIG. 22 are denoted by the same reference numerals.

  Here, although uplink transmission will be described as an example, a use frequency band may be selected using uplink radio channel quality in downlink transmission.

  The terminal performance information creation unit 53 creates terminal performance information based on the terminal performance stored in the terminal performance storage unit 52, and the uplink control signal creation unit 54 creates the terminal according to the usable bandwidth information that is the terminal performance. The transmitted control signal (eg pilot signal) is transmitted to the base station.

  The base station measures the received power of the control signal (example pilot signal) transmitted from the terminal at each band at the time of channel setting in the CQI measurement / calculation unit 50, and calculates the radio channel quality of each band. Then, the terminal performance information extraction unit 51 extracts the usable bandwidth of the terminal, gives this to the line setting unit 30, selects the group to which the corresponding terminal belongs, and notifies the terminal.

  Upon receiving the notification, the terminal group setting information extracting unit 17 extracts the group information, and the terminal setting control unit 18 performs device settings such as the wireless units 11 and 16 so that the terminal can receive the corresponding band. Uplink data transmission is performed using

  On the other hand, the base station measures and calculates the uplink radio channel quality by the CQI measurement / calculation unit 23 only for the band of the group to which the terminal belongs, and performs uplink scheduling based on the result. A terminal is selected based on the priority calculated by scheduling, an uplink transmission method is selected, and the selected terminal is notified. This notification is extracted by the control signal extraction unit 19 of the terminal and set in the demodulation / decoding unit 12.

  FIG. 29 is a diagram illustrating a fourth configuration example of the base station according to the embodiment of the present invention. 29, the same reference numerals are assigned to the components corresponding to FIG.

  In the above configuration, the terminal grouping is performed using the wireless channel quality of each band and the usable bandwidth of the terminal. Here, however, the terminal grouping is performed in consideration of QoS (Quality of Service) of data to be transmitted. Do. The QoS is determined in advance when the base station and the terminal communicate (for example, at the time of line setting). Since the base station knows the QoS when communicating with the terminal in advance, this information is used as the line setting unit 30. And input to the terminal group setting unit 31 to be considered when grouping terminals.

  FIG. 30 is a diagram illustrating a fifth configuration example of the base station according to the embodiment of the present invention. In FIG. 30, the same reference numerals are assigned to the components corresponding to FIG.

  In the above configuration, the terminal grouping is performed using the wireless channel quality of each band and the usable bandwidth of the terminal. Here, however, the grouping is performed in consideration of the moving speed of the terminal. In the base station, for example, the received power of the control signal (for example, pilot signal) or data transmitted from the terminal is measured by the moving speed measuring / calculating unit 40, and the moving speed of the terminal (or the terminal and the base station Relative speed) is calculated. When the terminal group setting unit 31 or the line setting unit 30 compares the measured / calculated terminal speed with the speed threshold stored in the terminal group setting unit 31 or the line setting unit 30, the terminal is set to a high speed. It is determined that the mobile terminal is moving, and the use bandwidth and use frequency are selected, and a group of terminals is selected. The speed threshold may be held outside the terminal group setting unit 31 or the line setting unit 30.

  As described above, according to the present invention, it is possible to reduce the number of scheduling target terminals per scheduler by grouping terminals for each used frequency and performing scheduling for each group, and scheduling can be performed in parallel. It can be implemented and the scheduling processing time can be shortened.

  In addition, since it is only necessary to measure the radio channel quality only for the used frequency band, the measurement processing can be reduced. Furthermore, since the number of reports of radio channel quality can be reduced, interference power can be reduced.

Claims (3)

In a wireless communication system that performs communication between a base station device and a terminal device using a plurality of frequency bands simultaneously,
An allocation unit that allocates radio resources to the terminal device in each of a plurality of frequency bands based on a communicable bandwidth as terminal performance;
A wireless communication system, comprising: a communication means for allowing the base station apparatus to communicate with the terminal apparatus using the allocated radio resources simultaneously . In a base station apparatus in a wireless communication system that performs communication between a base station apparatus and a terminal apparatus using a plurality of frequency bands simultaneously,
An allocation unit that allocates radio resources to the terminal device in each of a plurality of frequency bands based on a communicable bandwidth as terminal performance;
Notification means for notifying the terminal device of the allocation result;
A base station apparatus comprising: communication means for communicating with the terminal apparatus using the allocated radio resources simultaneously . In a terminal device in a wireless communication system that performs communication between a base station device and a terminal device using a plurality of frequency bands simultaneously,
The base station apparatus has communication means for communicating with the base station apparatus by simultaneously using radio resources allocated in each of a plurality of frequency bands based on a communicable bandwidth as terminal performance. Characteristic terminal device.