WO2008053553A1

WO2008053553A1 - Wireless communication system

Info

Publication number: WO2008053553A1
Application number: PCT/JP2006/321899
Authority: WO
Inventors: Takayoshi Ode
Original assignee: Fujitsu Limited
Priority date: 2006-11-01
Filing date: 2006-11-01
Publication date: 2008-05-08
Also published as: JPWO2008053553A1; JP4801740B2

Abstract

Each of terminals, when receiving a signal from a base station, calculates and notifies a CQI of the received signal to the base station. The base station uses the notified CQI values to calculate a CQI threshold value, and notifies it to each terminal. Then, each of the terminals, when determining/calculating a CQI value of a downlink channel, compares it with the notified CQI threshold value. If the calculated CQI value is smaller than the CQI threshold value, then the terminal halts the notification of CQI value to the base station. The base station receives reports of CQI values only from terminals at which the CQI values are greater than the CQI threshold value, and implements a scheduling only for these terminals so as to have communication only with these terminals.

Description

Specification

Wireless communication system

Technical field

[0001] The present invention relates to a wireless communication system.

Background art

[0002] 3GPP has been standardized! / And the HSDPA system has been partially put into practical use. The HSDPA system is a mobile communication system that performs transmission assignment using a scheduler.

1 to 3 illustrate a conventional HSDPA system.

[0003] An HSDPA system for implementing downlink high-speed transmission will be described as an example using the conceptual diagram of FIG. 1, the terminal configuration example of FIG. 2, and the base station configuration example of FIG.

At the terminal, for example, a radio channel quality index (hereinafter abbreviated as CQI: Channel Quality Indicator) is calculated based on the received downlink pilot signal. Specifically, the SIR is calculated by measuring the received power and interference power of the pilot signal, and the CQI is calculated based on this. The result is encoded and modulated, and transmitted to the base station via the uplink radio line. In other words, CQI is reported to the base station. In FIG. 2, the signal of the base station power received by the antenna 10 is decoded by the radio unit 11 and the demodulation / decoding unit 12, and the CQI of the received data is calculated by the CQI measurement 'calculation unit 13. The CQ control unit 14 converts the calculated CQI into a predetermined format, and the CQI transmission unit 15 configures the CQI into transmission data, which is modulated by the encoding / modulation unit 16 and the radio unit 17 and then transmitted to the antenna. Sent from 10 to the base station.

[0004] On the other hand, in the scheduler provided in the base station, for example, the priority order of the terminal is calculated using a radio channel quality indicator (hereinafter abbreviated as CQI: Channel Quality Indicator) reported from the terminal, and the priority order is high. Select a transmission parameter from, and perform transmission. In FIG. 3, terminal power CQI information received by antenna 20 is decoded by radio section 21 and demodulation-decoding section 22 and detected by CQI section 23. Based on the contents of the CQI detected by the CQI unit 23, the scheduler 24 also schedules downlink communication with the base station power to the terminal and has control information necessary for the terminal to receive a signal from the base station. Control signal creation The control unit 25 generates the control signal and transmits the control signal to the terminal via the encoding / modulating unit 27, the radio unit 28, and the antenna 20. After transmitting the control signal, transmission data such as user data stored in the transmission data buffer 26 is similarly transmitted to the terminal.

[0005] As shown in FIG. 1, the scheduler assigns priority to terminals UE1 to 6 based on CQI values obtained from terminals UE1 to UE6 (here, values of 1 to 30 are assumed). Is calculated, the terminal UE to be transmitted is selected according to the priority order, and the downlink signal is transmitted. In this case, since there are six terminals, it is necessary to calculate the priority order six times.

[0006] As priority calculation methods, the MAX CIR method, which selects from those with the highest CQI values, or the PF (Proportional Fairness) method, which selects the ones with the highest CQI and equal opportunities Etc. are 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 and uplink SC-FDMA schemes in the downlink as multi-access schemes is being considered!

[0008] In addition, the E3G system uses a wider frequency band (eg, 4 times) than the conventional HSDPA, and performs scheduling in the same manner as the HSDPA system. When the frequency bandwidth is doubled, the number of scheduling target terminals in E3 G downlink transmission is simply several times (for example, 4 times) compared to the HSDPA system. In addition, transmission intervals of 0.5 msec, which is 1/4 compared with 2 msec for conventional HSDPA systems, are being studied.

[0009] From the above two points, for example, the E3G system requires a scheduling speed 16 times that of the conventional HSDPA. In other words, the priority calculation time must be 1/16.

On the other hand, the improvement in processing performance of CPUs and DSPs that perform scheduling before the start of E3G service is based on Moore's Law (processing speed doubled in 18 months) based on the E3G service start target 2010. Even if it is considered, it is only about 4 times, and not 16 times the above. Therefore, in order to realize an E3G system, high-speed scheduling is essential.

[0010] Furthermore, considering the reporting of CQI to base stations

• The number of CQI reports increases as the number of terminals increases. • The specification bandwidth is four times that of conventional HSDPA systems, so multiple CQIs need to be measured and reported.

• Since the terminal has multiple bandwidths available, it is necessary to measure and report multiple bandwidth CQIs based on the bandwidth used and system bandwidth

The problem arises.

[0011] As described above, since the number of CQI measurement 'reports increases as compared with the conventional HSDPA system, there is a problem that radio interference in uplink communication increases.

Patent Document 1: Japanese Patent Laid-Open No. 2005-110070

Non-Patent Document 1: R2- 052897, "Qualcomm proposal for E- UTRAN Architecture and Pro tocols, Qualcomm Europe, 7-11, Nov, 2005

Disclosure of the invention

[0012] An object of the present invention is to provide a wireless communication system that can perform communication scheduling between a base station and a terminal at high speed.

In the wireless communication system of the present invention, in the wireless communication system in which the base station schedules communication procedures with the terminal and communicates with the terminal, the base station acquires the wireless channel quality of the downlink measured and calculated by the terminal, A downlink threshold value calculating means for calculating a first threshold value of the radio channel quality; and a transmitting means for transmitting the first threshold value calculated by the downlink threshold value calculating means to each terminal. Measures the downlink radio signal quality of the downlink radio channel quality measurement means for calculating, the storage means for storing the first threshold transmitted by the base station, and the downlink obtained by the measurement * calculation When the wireless channel quality is greater than the first threshold, the wireless channel quality is notified to the base station, and the wireless channel quality is If the threshold is less than the Control means for stopping communication, and the base station performs downlink communication scheduling by excluding terminals that cannot transmit the radio channel quality as scheduling targets.

Brief Description of Drawings

FIG. 1 is a diagram (part 1) for explaining a conventional HSDPA system.

FIG. 2 is a diagram (part 2) for explaining a conventional HSDPA system. FIG. 3 is a diagram (part 3) for explaining a conventional HSDPA system.

FIG. 4 is a first principle diagram of the present invention.

FIG. 5 is a block diagram of a terminal according to the present invention.

FIG. 6 is a block diagram of a base station according to the present invention.

[7] FIG. 7 is a sequence diagram for explaining the operation of the first principle.

FIG. 8 is a diagram (part 1) for explaining a second principle of the present invention.

FIG. 9 is a diagram (part 2) for explaining the second principle of the present invention.

FIG. 10 is a diagram (part 3) for explaining the second principle of the present invention.

FIG. 11 is a diagram (part 1) for explaining a third principle of the present invention.

FIG. 12 is a diagram (part 2) for explaining the third principle of the present invention.

FIG. 13 is a diagram (part 3) for explaining the third principle of the present invention.

FIG. 14 is a diagram (part 1) illustrating the fourth principle of the present invention.

FIG. 15 is a diagram (part 2) for explaining the fourth principle of the present invention.

FIG. 16 is a diagram (part 3) for explaining the fourth principle of the present invention.

圆 17] It is a figure explaining the effect of the present invention.

[18] A first configuration example of a terminal according to the present invention.

FIG. 19 is a first configuration example of a base station according to the present invention.

[20] This is a modification of the first configuration example of the base station of the present invention.

圆 21] A second configuration example of the terminal of the present invention.

[22] A second configuration example of the base station of the present invention.

[23] A third configuration example of the terminal of the present invention.

[24] A third configuration example of the base station of the present invention.

[25] A fourth configuration example of the base station of the present invention.

[26] This is a fifth configuration example of the base station of the present invention.

[27] This is a fourth configuration example of the terminal corresponding to the configuration of the base station in FIG. [28] A fourth configuration example of a terminal according to the present invention.

[29] A fifth configuration example of the terminal of the present invention.

[30] This is a sixth configuration example of the terminal of the present invention. FIG. 31 is a seventh configuration example of the terminal according to the present invention.

FIG. 32 is a sixth configuration example of the base station of the present invention.

FIG. 33 is an eighth configuration example of the terminal of the present invention corresponding to FIG. 31.

FIG. 34 is a seventh configuration example of the base station of the present invention.

FIG. 35 is a ninth configuration example of the terminal of the present invention corresponding to FIG. 33.

BEST MODE FOR CARRYING OUT THE INVENTION

In the embodiment of the present invention, the apparent number of terminals is reduced in order to speed up the scheduler operation.

In the following, the HSDPA system is described as an example.

FIG. 4 is a first principle diagram of the present invention. FIG. 5 is a block diagram of the terminal of the present invention.

FIG. 6 is a block diagram of the base station of the present invention. 5 and FIG. 6, the same reference numerals are assigned to the components corresponding to FIG. 2 and FIG.

[0016] Based on the radio channel quality indicator (CQI value) of the terminal selected at a certain time by the scheduler 24 of the base station, the radio channel quality indicator report threshold (hereinafter abbreviated as CQI threshold) is set as the radio channel quality indicator report threshold. The creation unit 46 calculates the value. This result (CQI threshold; threshold = 18 in FIG. 4) is encoded and modulated by the encoding / modulating unit 27, converted to a radio frequency by the radio unit 28, and the base station via the antenna 20. To each terminal in communication. When transmitting, it may be encoded, modulated and transmitted together with the transmission data, or may be encoded and transmitted separately using different radio channels.

In the terminal, the received signal is converted into a baseband signal by the radio unit 31, demodulated by the demodulator / decoder unit 12, and after decoding, the received power and interference power of the received signal (eg, pilot signal) are converted. The radio channel quality is measured and the CQI is calculated by measuring the radio channel quality indicator 'calculating unit 13.

[0018] This result is compared with the report threshold (hereinafter abbreviated as CQI threshold) similarly demodulated and decoded and stored in the radio channel quality indicator report threshold storage unit 34. Do not report C QI values. Further, the wireless channel quality indicator measurement 'calculation unit 13 is set so as not to calculate the CQI value for a certain period. If the threshold is exceeded, the CQI value is reported.

[0019] Thereby, the base station reduces the number of received CQI values. Reported CQI values decrease As a result, the priority order calculation time can be shortened. For example, in Figure 4, setting the CQI threshold value to 18 results in three terminals reporting CQI values. By setting only the terminal that has reported the CQI value to the scheduling target, the base station can reduce the number of targets for calculating priority in scheduling and reduce the calculation time. In the case of Figure 4, the number of priority calculations is only three.

FIG. 7 is a sequence diagram for explaining the operation of the first principle.

In FIG. 7, the base station transmits a radio channel quality measurement signal (pilot signal) to the terminal (1). The terminal measures the downlink radio channel quality, calculates the radio channel quality index (C QI) (2), and notifies the base station of the radio channel quality index (CQI) (3). When the base station receives all the terminal power wireless communication quality indicators under its control, the base station calculates the threshold of the wireless channel quality indicator (CQI) by taking the average of these or using the scheduler scheduling result. (Four). Then, the wireless channel quality index threshold (CQI) is notified to each terminal (5). This completes the setting of the threshold value for each terminal.

[0021] When a threshold is set for each terminal, the terminal shifts to a steady state. The terminal measures the radio channel quality and calculates the radio channel quality index (CQI) (6). The terminal compares the calculated wireless channel quality indicator with a threshold value, and determines whether or not the terminal is capable of reporting the wireless channel quality indicator to the base station (7). If it is determined not to report, the terminal is not subject to scheduling by the base station, and the base station power is not sent to its own terminal, so the terminal enters a dormant state. That is, the base station is not notified of the radio channel quality index (CQI) (8), and the base station excludes the terminal from scheduling (9). Therefore, transmission control information and data are not transmitted from the base station to the terminal (10), (11). When it is determined that the radio channel quality indicator is to be reported, the radio channel quality indicator is notified to the base station. Upon receiving the report, the base station selects a terminal that performs scheduling for downlink communication for the reporting terminal, notifies the selected terminal of transmission control information, and then transmits the transmission control information to the selected terminal. Send the data to the terminal.

8 to 10 are diagrams for explaining the second principle of the present invention.

When the CQI value falls below the threshold, the terminal power is also excluded from the scheduling target for the base station. I values may be reported. This specific CQI value is either transmitted from the base station to the terminal in advance or set as a wireless communication system.

[0023] As shown in FIG. 8, the terminal actively requests the base station that the scheduling target should be intended for the base station, so that the base station does not have to schedule the terminal. The base station itself, which is not good at power, can manage which terminal power is excluded from S scheduling!

FIG. 9 is a sequence diagram (part 1) showing the operation of the second principle.

The processing in the threshold setting state is the same as the first principle. When the threshold value of the radio channel quality index (CQI) is set for each terminal, each terminal enters a steady state. In the steady state, the terminal measures and calculates CQI, compares the calculated CQI value with a threshold value, and determines whether or not it is capable of reporting the CQI value to the base station (7). If the calculated CQI value is smaller than the threshold, the base station is notified of a message requesting it to be scheduled (8). When the base station receives the CQI value to be scheduled and a specific message from the subordinate terminal, it confirms which terminal to schedule (9) and performs scheduling (10). As a result of scheduling, transmission control information and data are transmitted to the scheduling target terminal. Transmission control information and data are not transmitted to terminals that are not scheduled (11), (12).

FIG. 10 is a sequence diagram (part 2) illustrating the operation of the second principle.

The processing in the threshold setting state is the same as the first principle. When the threshold value of the radio channel quality index (CQI) is set for each terminal, each terminal enters a steady state. In the steady state, the terminal measures and calculates CQI, compares the calculated CQI value with a threshold value, and determines whether or not it is capable of reporting the CQI value to the base station (7). If the calculated CQI value is smaller than the threshold value, the base station is notified of a CQI that has a predetermined meaning to be excluded from scheduling (8). When the base station receives a CQI value with a specific CQI value to be scheduled from a subordinate terminal, it confirms which terminal to schedule (9) and performs scheduling (10). As a result of scheduling, transmission control information and data are transmitted to the scheduling target terminal. Transmission control information and data are not transmitted to terminals that are not scheduled (11), (12). FIG. 11 to FIG. 13 are diagrams for explaining the third principle of the present invention.

In Fig. 11, when a terminal reports a special CQI value and excludes it from scheduling, the terminal can receive CQI values of other base stations and other frequency bands and Measure the received field strength. Furthermore, depending on the result, a handover process is performed.

FIG. 12 is a sequence diagram (part 1) illustrating the operation of the third principle.

In FIG. 12, the operation is almost the same as in FIG. 9, but in a steady state, the terminal requests the base station to exclude its own terminal from scheduling, and then uses other base stations and other frequency bands. Go to measure CQI values and received field strength (13).

FIG. 13 is a sequence diagram (part 2) illustrating the operation of the third principle.

In Fig. 13, in the steady state, the terminal itself judges whether or not it is necessary to measure the CQI of another band or other base station power (7). During measurement, it is determined that transmission (up and down) with the base station needs to be stopped. Along with this, by notifying the base station that it is not subject to scheduling (8), the transmission from the base station is stopped and the CQI of another band or another base station is measured (13). When there is a need to measure the CQI of another band or another base station, for example, when it is determined that a handover is necessary, or when it is desired to confirm the possibility of performing higher-speed transmission. .

[0029] In the above description, downlink has been described, but the present invention can also be applied to uplink. In this case, a threshold is set for the CQI value measured and calculated at the base station.

FIG. 14 to FIG. 16 are diagrams for explaining the fourth principle of the present invention.

In Fig. 14, this is notified to the terminals that are not scheduled. Furthermore, it requests the terminals that are not subject to scheduling not to report CQI values to the base station. The terminal that has received the notification measures and calculates CQI values and received electric field strengths of other base stations and other frequency bands while it is not subject to scheduling. Further, depending on the result, a handover process is performed.

FIG. 15 and FIG. 16 are sequence diagrams showing the operation of the fourth principle. Fig. 15 shows the exchange between the first base station and the terminal. When the target is not subject to force scheduling, which is almost the same as in Fig. 12, a CQI report stop request is sent from the base station. Since the terminal stops reporting CQI values to the base station based on the CQI report stop request, the amount of uplink radio resources used can be reduced. When CQI value reporting to the first base station is stopped, CQI from other bands or other base stations is measured.

FIG. 16 is a sequence diagram showing exchanges between other base stations and terminals.

The sequence for measuring the CQI of another base station (second base station) is the same as in FIG. 15. However, if the second base station etc. is not subject to scheduling, another base station Go to CQI measurement (3rd base station) etc.

In the above description, the description is limited to CQI. However, reception field strength, propagation environment, radio channel quality, and reception quality (SIR, CIR, etc.) may be used. Radio channel quality is a collective term for these.

FIG. 17 is a diagram for explaining the effect of the present invention.

[0034] As described above, by reducing the number of CQI reports, the expected number of terminals to be scheduled is reduced, so that priority calculation processing is also reduced, and the processing speed can be increased.

FIG. 17 is a diagram showing a result of simulating the number of scheduling priority calculations, with the vertical axis representing the number of calculations and the horizontal axis representing the threshold value (offset from the CQI average value).

Suppose that the top four terminals are selected in the order of CQI values from 32 terminals with uniform CQI values. At this time, the number of calculations required for selection is 3.2 × 10 ⁶ times. In other words, 10 ⁵ trials were performed in the simulation to uniformly assign the values of 1 to 30 to the CQI values of 32 terminals, and the resulting priority calculation count was 3.2 X 10 ⁶ times. Become.

[0036] At this time, if the average value of the CQI values of 32 terminals is set as the CQI threshold value, and terminals below the threshold value are excluded from scheduling targets, the scheduling target terminals are 16 terminals, and the number of calculations required for terminal selection is 1.6. X 10 ⁶ and halved. Therefore, the scheduling process can be performed at high speed.

Similarly, as the threshold value is increased from the average value, the number of scheduling objects decreases, so the number of calculations decreases. Also, as the threshold value is reduced, the schedule Since the number of Euling objects increases, the number of calculations increases. It is preferable to set the threshold value so that there is no shortage of terminals to be selected and no selection error occurs! Considering the case where terminals with the strictest conditions report CQI at the same time, the conventional method reports 32 terminals at the same time. Interference is reduced by 3dB. By controlling the CQI reports of the terminal in this way, the number of CQI reports using the uplink radio channel is reduced, and as a result, uplink interference is reduced.

FIG. 18 is a first configuration example of the terminal according to the present invention. FIG. 19 is a first configuration example of the base station of the present invention. FIG. 20 is a modification of the first configuration example of the base station of the present invention. In FIG. 18, components corresponding to those in FIG. 19 and 20, the same reference numerals are assigned to the components corresponding to those in FIG.

In the terminal configuration of FIG. 18, the data received by antenna 10, radio unit 11, and demodulation / decoding unit 12 is input to CQI measurement / calculation unit 13 to calculate a CQI value. The calculated CQI value is converted into a value of 1 to 30 in the CQI control unit 14. Also, the calculated CQI value is compared with the threshold value stored in the CQI threshold value storage unit 34, and it is determined whether or not to transmit the CQI value to the base station. If it is decided to transmit, the calculated CQI value is assembled into a CQI value report format in the CQI transmission unit 15, and is transmitted via the encoding / modulation unit 16, the radio unit 17, and the antenna 10. Sent.

In the base station of FIG. 19, the antenna 20, the radio unit 21, and the demodulation / decoding unit 22 receive the CQI report, and the CQI unit 23 extracts the reported CQI value. The extracted CQI value is given to the scheduler 24 and used for scheduling. The result of scheduling is given to the SCQI threshold value generator 46 to calculate the CQI threshold value. The CQI threshold value is sent to the terminal via the encoding / modulation unit 27, the radio unit 28, and the antenna 20. When the CQI threshold is set for each terminal, the CQI value is reported again from the terminal, so scheduling is performed only for the terminal that has reported the CQI value, and communication is performed to the terminal selected by the scheduling. A control signal and transmission data for performing transmission are transmitted.

In the base station of FIG. 20, the antenna 20, the radio unit 21, and the demodulation / decoding unit 22 receive the CQI report, and the CQI unit 23 extracts the reported CQI value. The extracted CQI value is Given to KEGUYURA 24, used for scheduling. On the other hand, the CQI unit 23 averages the reported CQI values and gives them to the CQI threshold value creating unit 46, which calculates the C QI threshold value. The CQI threshold value is sent to the terminal via the encoding / modulation unit 27, the radio unit 28, and the antenna 20. When the CQI threshold is set for each terminal, the CQI value is also reported again for the terminal power, so the control signal and transmission data are transmitted only for the terminal that has reported the CQI value. .

FIG. 21 is a second configuration example of the terminal according to the present invention. FIG. 22 is a second configuration example of the base station of the present invention. In FIG. 21, the components corresponding to those in FIG. In FIG. 22, the same reference numerals are assigned to the components corresponding to FIG.

In the terminal configuration of FIG. 21, the data received by antenna 10, radio unit 11, and demodulation / decoding unit 12 is input to CQI measurement / calculation unit 13, where a CQI value is calculated. The calculated CQI value is converted into a value of 1 to 30 in the CQI control unit 14. Also, the calculated CQI value is multiplied by a weighting value based on QoS (Quality Of Service) held when the base station and the terminal communicate, and the multiplication result is stored in the CQI threshold storage unit 34. It is compared with the threshold value, and it is determined whether or not to transmit the CQI value to the base station. QoS indicates, for example, the required transmission rate and allowable transmission delay time of data to be transmitted and received, and the required data transmission interval. Increase the weighting value for data that requires high-speed transmission, and decrease the weighting for data that requires low-speed transmission. This makes it possible to set a threshold that takes into account the data transmission rate. When it is decided to transmit, the calculated CQI value is assembled into a CQI value report format in the CQI transmission unit 15 and transmitted via the encoding / modulation unit 16, the radio unit 17, and the antenna 10. Is done.

In the base station of FIG. 22, the antenna 20, radio section 21, and demodulation / decoding section 22 receive the CQI report, and the CQI section 23 extracts the reported CQI value. The extracted CQI value is given to the scheduler 24 as it is and used for scheduling. The average value of the extracted CQI values is given to the CQI transmission threshold value creation unit 46, the scheduling result is given to the C QI threshold value creation unit 46, and the QoS for each terminal stored in the base station is also C The value is given to the QI threshold creation unit 46, and the CQI threshold is calculated. QoS is used because some terminals communicate data that requires high-speed transmission. Because. The CQI threshold value is sent to the terminal via the encoding / modulation unit 27, the radio unit 28, and the antenna 20. When the CQI threshold is set for each terminal, the CQI value is reported again from the terminal. Therefore, only the terminal that has reported the CQI value transmits a control signal and transmission data for communication.

FIG. 23 is a third configuration example of the terminal according to the present invention. In FIG. 23, components corresponding to those in FIG.

In the terminal configuration of FIG. 23, data received by the antenna 10, the radio unit 11, and the demodulation / decoding unit 12 is input to the CQI measurement / calculation unit 13, and a CQI value is calculated. The calculated CQI value is converted into a value of 1 to 30 in the CQI control unit 14. Also, the calculated CQI value is multiplied by the QoS (Quality Of Service) weighted value held when the base station and the terminal communicate, and the multiplication result is stored in the CQI threshold storage unit 34. It is compared with the threshold value to determine whether or not to transmit the CQI value to the base station. When it is decided to transmit, the calculated CQI value is assembled into a CQI value report format in the CQI transmission unit 15 and transmitted via the encoding / modulation unit 16, the radio unit 17, and the antenna 10. Is done. If it is decided not to transmit the CQI value, the transmission control signal transmitting unit 40 generates a message requesting that the CQI value is excluded from the scheduling target, and transmits it to the base station.

FIG. 24 is a third configuration example of the base station of the present invention. In FIG. 24, components corresponding to those in FIG.

In the base station of FIG. 24, the antenna 20, the radio unit 21, and the demodulation / decoding unit 22 receive the CQI report, and the CQI unit 23 extracts the reported CQI value. The extracted CQI value is given to the downlink scheduler 24 as it is and used for downlink scheduling. The result of scheduling is given to the CQI threshold creation unit 46, and the CQI threshold is calculated. That is, the CQI values of k terminals selected by scheduling are given to the CQI value creating unit, and a CQI threshold is created based on the smallest CQI value (for example, α is set to the minimum CQI of the k CQI values). The result is a threshold value). The CQI threshold value is sent to the terminal via the encoding / modulation unit 27, the radio unit 28, and the antenna 20. When a CQI threshold is set for each terminal, the C QI value is reported again from the terminal, so that only the terminal that has reported the CQI value can communicate. The control signal and transmission data are transmitted.

[0047] Here, an out-of-target notification extraction unit 41 that extracts a message sent from a terminal or a specific CQI value is provided. When the non-target extraction unit 41 detects a message or a specific CQI value requested from the terminal to be excluded from the scheduling target, it gives it to the downlink scheduler 24 and removes the terminal from the downlink scheduling target. This information is also given to the uplink scheduler 43. The uplink CQI measurement 'calculation unit 42 calculates the CQI value of the uplink signal from the terminal, and gives the calculation result to the uplink scheduler 43. When the uplink scheduler 43 receives a notification that the terminal is not scheduled, the uplink scheduler 43 notifies the uplink CQI measurement 'calculation unit 42 of this, and stops measuring and calculating the CQI of the terminal. Further, the uplink control signal generator 44 transmits uplink control signals necessary for uplink communication to the terminals according to the scheduling of the uplink scheduler 43. The signal also stops sending.

FIG. 25 is a fourth configuration example of the base station of the present invention. In FIG. 25, components corresponding to those in FIG. 24 are given the same reference numerals.

In the base station of FIG. 25, the antenna 20, the radio unit 21, and the demodulation / decoding unit 22 receive the uplink signal from the terminal, and the uplink CQ decision / calculation unit 42 calculates the CQI. This is given to the upstream scheduler 43. Further, the calculated uplink CQI value is given to the uplink CQI threshold value creation unit 50, and this threshold value is given to the uplink scheduler 43. When the uplink scheduler 43 determines that the CQI value of the terminal is smaller than the threshold and is not subject to the terminal power schedule, the uplink scheduler 43 notifies the uplink CQI measurement 'calculation unit 42 of this, and measures the CQI of the terminal, Stop calculation. The uplink control signal generator 44 transmits a control signal necessary for uplink communication to the terminal in accordance with the scheduling of the uplink scheduler 43. For terminals that are not scheduled for uplink, The control signal also stops sending.

[0049] FIG. 26 is a fifth configuration example of the base station of the present invention. FIG. 27 is a fourth configuration example of the terminal corresponding to the configuration of the base station in FIG. In FIG. 26, components corresponding to those in FIG. 25 are given the same reference numerals. In FIG. 27, components corresponding to those in FIG.

[0050] In FIG. 26, there is newly provided a non-scheduled notification signal creation unit 51. ing. The non-scheduled notification signal creation unit 51 notifies the terminals that have not been scheduled by the uplink scheduler 43 not to transmit control signals such as pilot signals and uplink transmission data to the base station for a certain period of time. Generate a notification signal

To the terminal.

In the terminal in FIG. 27, when the non-scheduled notification signal extraction unit 53 detects the non-scheduling target notification from the base station, the pilot signal generation unit 54 is stopped for a certain period, and transmission of transmission data is also performed. Stop for a certain period.

FIG. 28 is a fourth configuration example of the terminal according to the present invention. FIG. 29 is a fifth configuration example of the terminal of the present invention. 28 and 29, the same reference numerals are assigned to the components corresponding to FIG.

In FIG. 28, a timer 60 is newly provided as compared with FIG. The timer 60 counts a predetermined time and notifies the CQI control unit 14 when the time is up. The CQI control unit 14 compares the measured CQI value with the CQI threshold value, and even when the timer 60 has timed out even in a terminal that is in a CQI transmission stop state, the CQI control unit 14 measures and calculates the CQI value, The CQI measurement / calculation unit 13 and the CQI transmission unit 15 are controlled to transmit. As a result, even if a terminal becomes a CQI non-reporting terminal and is not subject to scheduling, the CQI value is again notified to the base station after a certain period of time. And communication can be resumed. The timer setting time is determined in consideration of the number of terminals accommodated in the base station, the CQI value of the terminal to be stopped, the QoS of the data, and the like.

FIG. 29 shows a configuration in which QoS is also used for CQI value transmission determination of CQI control unit 14 in FIG. If it is determined from the QoS settings that the terminal is transmitting / receiving high-speed transmission data, the timer 60 time-up time is set short, and the time during which the terminal stops communication with the base station is set. Shorten and give priority to data transmission / reception.

FIG. 30 is a sixth configuration example of the terminal according to the present invention. In FIG. 30, the same reference numerals are assigned to the components corresponding to those in FIG.

In the configuration of FIG. 30, when the terminal does not report CQI to the base station, the CQI control unit 14 uses the radio unit 1 to measure and calculate CQIs of other frequency bands or other base stations. I, set the detection frequency of the demodulation and decoding unit 12, and restart the CQI measurement and calculation unit for CQI measurement and calculation. In particular, when measuring and calculating the CQI of another frequency band or another base station, the original base station is notified of the power to notify the specific CQI value and a message to that effect. If it is determined that communication with the frequency band or the base station is possible as a result of measurement, calculation and comparison with the threshold value of another frequency band or another base station, the radio unit 17, The encoding / modulation unit 16 is controlled to communicate with the frequency band or the base station.

FIG. 31 is a seventh configuration example of the terminal of the present invention. In FIG. 31, the components corresponding to those in FIG.

In FIG. 31, a transmission control signal transmitter 65 is provided. The transmission control signal transmission unit 65 stops the transmission from the frequency band or the base station that is not subject to scheduling when the terminal measures or calculates the CQI of another frequency band or another base station. A stop request is transmitted to the base station.

FIG. 32 is a sixth configuration example of the base station of the present invention. FIG. 33 is an eighth example configuration of the terminal according to the present invention corresponding to FIG. In FIG. 32, components corresponding to those in FIG. 24 are denoted by the same reference numerals, and description thereof is omitted. In FIG. 33, components corresponding to those in FIG. 21 are denoted by the same reference numerals and description thereof is omitted.

In FIG. 32, the base station identifies a terminal that is not subject to scheduling in the downlink scheduler 43, and notifies the other cell CQ play request control signal creation unit 66 of the information on the terminal. The other cell CQ decision request control signal generator 66 measures and calculates the CQI of the other cell (other frequency band or other base station) for the notified terminal, and tries to communicate with the other cell. Send the requested notification to the terminal. The downlink scheduler 43 can also be incorporated in the upward scheduler.

FIG. 33 shows a terminal configuration corresponding to the configuration shown in FIG. 32, and includes another cell CQI measurement request signal extraction unit 67. Other cell CQ play request signal extraction unit 67 includes antenna 10, radio unit

II, Demodulator If the received data from the base station received by the decoder 12 includes a CQI measurement request signal for another cell, this is extracted. When the other cell CQI measurement request signal is extracted, the CQ controller 14 is instructed to measure and calculate the CQI of the other cell. The set frequencies of the radio units 11 and 17, the demodulation 'decoding unit 12 and the encoding / modulation unit 16 are changed.

[0059] FIG. 34 is a seventh configuration example of the base station of the present invention. FIG. 35 is a ninth configuration example of the terminal of the present invention corresponding to FIG. 34, components corresponding to those in FIG. 32 are denoted by the same reference numerals and description thereof is omitted. 35, components corresponding to those in FIGS. 28 and 31 are denoted by the same reference numerals, and description thereof is omitted.

In FIG. 34, another cell CQI measurement period setting unit 68 is provided. The other cell CQI measurement period setting unit 68 sets the CQI measurement period of the other cell in the request signal from the other cell CQ play request control signal creation unit 66 to the terminal and transmits it to the terminal. The downlink scheduler 43 sets the CQI measurement period of the other cell, and causes the terminal to measure the CQI of the other cell only during the limited period. During this period, control is performed so that communication is not performed between the base station and the terminal. The downlink scheduler 43 can also be incorporated in the uplink scheduler.

[0061] In FIG. 35, as in FIG. 33, the terminal is provided with the other cell CQI measurement request signal extraction unit 67. Here, the CQI measurement period of the other cell sent from the base station The other cell CQI measurement request signal power is also read, and the measurement period is set in the CQI control unit 14. The CQI control unit 14 recognizes the CQI measurement period of other cells based on the clock signal generated by the timer 60. The CQI of other cells is measured and calculated only during this measurement period.

[0062] As described above, according to the present invention, it is possible to reduce the number of apparent terminals to be scheduled, and thus it is possible to reduce the scheduling processing time. Also, terminals that are not subject to scheduling do not report downlink CQI using the uplink control channel, so that uplink interference can be reduced. Furthermore, CQI measurement of other cells can be performed by stopping communication with the base station of the terminal that is not scheduled. In addition, this makes it easy to hand over the terminal power not selected by scheduling to another cell and improve the throughput.

Claims

The scope of the claims

[1] In a wireless communication system in which a base station schedules communication with a terminal and communicates with the terminal,

The base station

A downlink threshold value calculating means for acquiring the downlink wireless channel quality measured and calculated by the terminal and calculating a threshold value of the wireless channel quality;

Transmission means for transmitting the threshold value calculated by the downlink threshold value calculation means to each terminal,

Downlink radio channel quality measurement and calculation means for measuring and calculating the radio communication quality of the downlink signal of the base station power,

Base station power storing means for storing the transmitted threshold value;

The downlink radio channel quality obtained by measurement and calculation is compared with the threshold, and when the radio channel quality is higher than the threshold, the radio channel quality is notified to the base station, and the radio channel quality is Control means for stopping transmission of the base station of the radio channel quality when the threshold value is below,

The base station performs downlink communication scheduling based on the radio channel quality.

[2] The radio communication system according to claim 1, wherein the scheduling of downlink communication based on the radio channel quality is performed by transmitting the radio channel quality and excluding the terminal from scheduling.

[3] The downlink threshold value calculation means of the previous base station calculates the threshold value by further adding service quality information set for data communication with the terminal,

The control means of the terminal further considers the service quality information set for data communication with the base station when determining whether or not to transmit the radio channel quality obtained by the measurement 'to the base station. The wireless communication system according to claim 1.

[4] The terminal further includes:

2. The wireless communication according to claim 1, wherein when the wireless channel quality is not transmitted to the base station, the base station is requested to exclude the terminal from being scheduled. System.

5. The radio communication system according to claim 4, wherein the signal requesting that the terminal is not subject to scheduling notifies a specific radio channel quality value determined in advance.

6. The radio communication system according to claim 1, wherein a terminal that is not subject to scheduling for downlink communication is also not subject to scheduling for uplink communication.

[7] In a wireless communication system in which a base station schedules communication with a terminal and communicates with the terminal,

The base station

An uplink radio channel quality measurement calculating means for measuring the radio channel quality of the uplink signal of the terminal power;

An uplink threshold value calculating means for calculating a threshold value of the uplink radio channel quality, and a terminal having an uplink radio channel quality higher than the threshold is set as an uplink communication scheduling target, and an uplink radio channel quality equal to or lower than the threshold value is determined. A wireless communication system, characterized in that said terminal is not subject to uplink communication scheduling.

[8] The base station notifies a terminal that is not subject to scheduling that it is not subject to scheduling, and the terminal that has received the notification does not transmit a pilot signal and uplink transmission data for a certain period of time. The wireless communication system according to claim 7.

[9] The terminal

A timer means for counting a predetermined time;

The radio communication system according to claim 1 or 7, wherein the terminal that is not subject to scheduling resumes transmission of radio channel quality to the base station when the timer means times out.

10. The radio communication system according to claim 9, wherein the time for the timer means to time out is set in consideration of the quality of service information set for the communication service between the base station and the terminal.

[11] The terminal measures / calculates the radio channel quality of another frequency band or downlink communication of another base station while not transmitting the radio channel quality to the base station. The wireless communication system according to claim 1.

[12] The terminal is characterized by requesting the base station to stop transmission of a downlink signal when measuring and calculating the downlink channel radio quality of another frequency band or another base station. The wireless communication system according to claim 11.

[13] When the terminal measures and calculates the radio channel quality of downlink communication of another frequency band or another base station, the base station notifies the radio channel quality of a specific value indicating the fact. 12. The wireless communication system according to claim 11, wherein

14. The base station instructs a terminal that has not been scheduled to measure and calculate another frequency band or the radio channel quality of the other base station. 11. The wireless communication system according to 11.

[15] The base station instructs the terminal that is not subject to scheduling to be in another frequency band or a period in which the measurement of the radio channel quality of other base stations is specified. The wireless communication system according to claim 14, wherein the base station and the terminal do not communicate during that period.

[16] In a terminal in a wireless communication system in which a base station schedules communication with a terminal and communicates with the terminal,

Base station power The stored storage means for storing the threshold value of the wireless communication quality is compared with the threshold value of the downlink wireless channel quality obtained by measurement and calculation, and the wireless channel quality is compared to the threshold value. A control means for notifying the base station of the radio channel quality when the radio channel quality is greater, and for stopping transmission of the radio channel quality to the base station when the radio channel quality is less than or equal to the first threshold;

A terminal comprising:

[17] In a base station in a wireless communication system in which a base station schedules communication with a terminal and communicates with the terminal,

A downlink threshold value calculating means for acquiring the downlink wireless channel quality measured and calculated by the terminal and calculating a threshold value of the wireless channel quality; Transmitting means for transmitting the threshold value calculated by the downlink threshold value calculating means to each terminal, and transmitting the radio channel quality based on a result of comparison between the threshold value and the measured and calculated radio channel quality. A base station that performs scheduling of downlink communication only for a terminal that has been updated.

A communication method in a wireless communication system in which a base station schedules communication with a terminal and communicates with the terminal,

The base station

Obtain the downlink radio channel quality measured and calculated by the terminal, calculate the first threshold of radio channel quality,

The threshold value calculated by the downlink threshold value calculation means is transmitted to each terminal,

The terminal

Measure and calculate the wireless communication quality of the downlink signal from the base station,

Stores the threshold value sent from the base station power,

The downlink radio channel quality obtained by measurement and calculation is compared with the threshold, and when the radio channel quality is higher than the threshold, the radio channel quality is notified to the base station, and the radio channel quality is When it is below the threshold, by stopping transmission of the radio channel quality to the base station, the base station transmits the radio channel quality V and schedules downlink communication with the terminal excluded from scheduling. I do

A communication method characterized by the above.