Base station apparatus, mobile communication system, and method of controlling transmission power

[0001] The present invention relates to a mobile communication system and a transmission power control method, and in particular, is a base station of a cellular mobile communication system to which a code division multiple access (hereinafter referred to as CDMA) system is applied. The present invention relates to an apparatus, a mobile communication system using the base station apparatus, and a transmission power control method.

PROBLEM TO BE SOLVED: To provide a CDMA type cellular mobile communication system in which a plurality of mobile terminals share the same frequency band to communicate with a base station device. Then, in this mobile communication system, when a certain mobile terminal and the base station device communicate with each other, the other mobile terminal becomes the base station device for the signal (desired signal) transmitted by the mobile terminal to the base station device. The transmitted signal (non-desired signal) becomes an interference, and this signal interferes with the communication between the desired mobile terminal and the base station device. The interference level increases in proportion to the reception level of the undesired signal wave received by the base station apparatus, and the reception level of the undesired signal is proportional to the transmission power transmitted from the undesired mobile terminal. Therefore, in a CDMA mobile communication system, in order to minimize the interference level, the base station device controls the transmission power from the mobile terminal, and the reception level at the base station device is always minimized. It is necessary to control the transmission power.

[0003] As a conventional technique relating to a transmission power control method for the above, a method called closed-loop power control is known. The base station device that executes this power control method measures the reception quality such as the signal-to-interference power ratio (SIR value) of the uplink channel, the received power, etc., compares it with the desired target value determined by the system, and compares it with the desired target value. Based on the result, a transmission power control signal indicating an instruction to increase or decrease the transmission power of the mobile terminal is created, and then this transmission power control signal is added to a frame of transmission data and transmitted to the mobile terminal. The mobile terminal that receives the transmission power control signal controls the transmission power according to the increase / decrease instruction. By repeating this control, the reception quality level in the base station apparatus can be converged to the target value.

[0004] Recently, attention has been paid to a method of removing interference due to cross-correlation of diffusion codes assigned to each mobile terminal, which occurs when a desired signal is detected by despreading from a code-multiplexed signal. As one of the methods, a multi-user reception type interference elimination device has been proposed.

[0005] In this multi-user reception method, all user signals are demodulated once in the first stage, an interference replica of each user is created, and an interference replica other than the user signal which is a desired wave signal is created from the received input signal. Is reduced to eliminate interference, and the user signal, which is the desired wave signal, is demodulated again using this signal in the next stage, so that the signal of the demodulation result of the second stage has a signal quality higher than that of the demodulation result of the first stage. It is to improve. Then, by using such a configuration in multiple stages and repeating a series of processes a plurality of times, interference can be eliminated.

[0006] As a conventional technique for controlling a transmission power of a base station apparatus having such an interference removing function, for example, a technique described in Japanese Patent Application Laid-Open No. 10-247894 is known.

[0007] In the transmission power control method according to the prior art, the SIR value of each user is measured using the received signal after passing through all the interference elimination receiving circuits composed of a plurality of stages, and the SIR value and the SIR value are preset. The target SIR value is compared with the target SIR value value by a comparison circuit, the result is added to the transmission frame as a transmission power control bit, and the transmission frame is transmitted to the mobile terminal.

[0008] However, the transmission power control method based on the above-mentioned conventional technique in the base station apparatus provided with the interference elimination function sufficiently brings out the interference elimination effect. It has a problem that it is not possible to control the transmission power in the above.

[0009] That is, the control of the transmission power using the SIR value of the signal that has passed through the interference elimination receiving circuit in the final stage has a large processing delay due to the interference elimination receiving circuit having a multi-stage configuration, so that the received signal is received by the antenna. It takes time to generate the transmission power control signal after that, and as a result, the transmission power control error becomes large. For this reason, the above-mentioned prior art cannot accurately control the transmission power of the mobile terminal, and when the transmission power becomes larger than desired for the receiving device, the amount of interference for other mobile terminals increases. The problem of doing this arises.

[0010] On the other hand, in order to further reduce the processing delay until the SIR value is measured, a method of controlling the transmission power using the SIR value of the signal passing through the interference elimination circuit of the first stage is also conceivable. In this method, the processing delay by the interference elimination circuit can be reduced, and the time from receiving the received signal to measuring the SIR value can be shortened. Therefore, in this method, the delay of the transmission power control using the SIR value is also reduced, and the error of the transmission power control can be reduced.

[0011] However, in this method, the interference elimination effect is not sufficiently reflected in the SIR value for failure, and when the transmission power is controlled by this SIR value, the transmission power of the mobile terminal is further reduced as a system. However, there is a problem that the transmission power cannot be reduced. Further, this method has a problem that the accuracy of the control itself is poor because the transmission power is controlled by using a signal in which the interference elimination effect is not sufficiently working.

[0012] An object of the present invention is a base station apparatus and a mobile communication system capable of solving the above-mentioned problems of the prior art, improving the interference removing effect, and controlling the transmission power with less processing delay. And to provide a transmission power control method.

[0013] According to the present invention, the object is composed of a plurality of mobile terminals and a plurality of base station devices including an interference elimination receiving unit having a plurality of stages of interference elimination receiving circuits. In the base station device in the mobile communication system in which the interference elimination receiving circuit of each stage in the base station apparatus performs interference elimination processing, the received signal is based on the reception signal whose interference is eliminated by the interference elimination receiving circuit in the previous stage of the interference elimination receiving unit. Based on the means for calculating the corrected SIR value based on the SIR value which is the signal-to-interference power ratio measured in 1 and the SIR value of the received signal whose interference is removed by the interference elimination receiving circuit in the subsequent stage, and the calculated corrected SIR value. A means for estimating the transmission power control SIR value, a means for generating a transmission power control signal using the estimated transmission power control SIR value, and a means for controlling the transmission power of the mobile terminal. This is achieved by providing a transmission power control means that adds a control signal to the downlink frame.

[0014] Further, the purpose is that the corrected SIR value is the SIR value of the received signal whose interference is removed by the interference elimination receiving circuit in the subsequent stage, and the reception signal whose interference is removed by the interference elimination receiving circuit in the previous stage from the rear SIR value. It is achieved by subtracting the front-stage SIR value, which is the SIR value of, or by integrating and averaging the value obtained by subtracting the front-stage SIR value from the rear-stage SIR value at a specific cycle.

[0015] Further, the object is that the SIR value for transmission power control is a value calculated by subtracting the corrected SIR value from the SIR value in the previous stage, and the transmission power control signal is for transmission power control. Because it is a value created based on the result of comparing the SIR value and the target SIR value, and the SIR value in the previous stage is the first stage to the last stage of the interference elimination receiving unit having the interference elimination receiving circuit in the plurality of stages. This is achieved by the SIR value measured based on the received signal that has been de-interfered by any one of the de-interference receiving circuits up to the front.

[0016] Further, the object is composed of a plurality of mobile terminals and a plurality of base station devices including an interference elimination receiving unit having a plurality of stages of interference elimination receiving circuits, and interference elimination of each stage in the base station apparatus. In a base station device in a mobile communication system in which the receiving circuit performs interference elimination processing, the SIR value is a signal-to-interference power ratio measured based on the received signal interference-removed by the interference elimination receiving circuit in the previous stage of the interference elimination receiving unit. A means for calculating the corrected SIR value based on the SIR value of the received signal whose interference is removed by the interference elimination receiving circuit in the subsequent stage, and a means for estimating the correction target SIR value based on the calculated corrected SIR value. It is provided with a means for generating a transmission power control signal using the corrected correction target SIR value and a transmission power control means for adding the generated transmission power control signal to the downlink frame in order to control the transmission power of the mobile terminal. Achieved by.

[0017] Further, the purpose is that the corrected SIR value is the SIR value of the received signal whose interference is removed by the interference elimination receiving circuit in the subsequent stage, and the reception signal whose interference is removed by the interference elimination receiving circuit in the previous stage from the rear SIR value. It is achieved by subtracting the front-stage SIR value, which is the SIR value of, or by integrating and averaging the value obtained by subtracting the front-stage SIR value from the rear-stage SIR value at a specific cycle.

[0018] Further, the object is that the correction target SIR value is a value calculated by subtracting the correction SIR value from the target SIR value, and the transmission power control signal is corrected with the previous stage SIR value. Achieved by comparing with the target SIR value and creating based on the result, and by making the averaging cycle shorter than the transmit power control cycle between the base station apparatus and the base station control station. To.

[0019] Further, the object is composed of a plurality of mobile terminals and a plurality of base station devices including an interference elimination receiving unit having a plurality of stages of interference elimination receiving circuits, and interference elimination of each stage in the base station apparatus. This is achieved by using a base station device including the above-mentioned means as the base station device in a mobile communication system in which the receiving circuit performs interference elimination processing.

[0020] Further, the object is that in the mobile communication system described above, the base station apparatus comprises a means for calculating a corrected SIR value and a means for calculating a transmission power control SIR value by a CPU and software memory. Further, it is achieved by configuring the means for calculating the correction target SIR value by the CPU and the software memory.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of a mobile communication system and a transmission power control method according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing a configuration of a mobile communication system to which the present invention is applied, FIG. 2 is a block diagram showing a configuration of a mobile terminal and a radio base station apparatus, and FIG. 3 is a first embodiment of the present invention. A block diagram showing a detailed configuration of a radio base station device according to a form, FIG. 4 is a block diagram showing a configuration of a transmission power control SIR estimation unit, and FIG. 5 is a configuration of a correction SIR calculation means and a transmission power control SIR estimation means. FIG. 6 is a diagram for explaining the configuration of the SIR table memory of the transmission power control SIR estimation unit, and FIG. 7 is a flowchart for explaining the processing operation for estimating the transmission power control SIR. In FIGS. 1 to 5, 100 is a radio base station device, 101 to 10n is a mobile terminal, 10, 17, 40, 41 are antennas, 11 is a receiving radio module, 12 is an interference elimination receiver, 13, 13a to 13n, 43 is the decoding unit, 14 is the SIR measurement unit, 15 is the SIR estimation unit for transmission power control, 16 is the transmission power control signal creation unit, 18 is the transmission radio module, 19 is the adder circuit, 20a to 20n is the diffusion circuit, 21a. ~ 21n is the frame creation section, 22 and 46 are the coding section, 42 is the synchronous detection section, 44 is the transmission power control section, 45 is the variable gain amplifier, 47 is the comparison section, 48 is the addition section, and 120a ~ 120n is the interference removal section. Receive circuit, 150 is SIR measurement unit IF, 151 is SIR table memory, 152 is CPU, 154 is transmission power control signal creation unit IF, 200 is software memory, 250 is SIR estimation processing unit, 251 is correction SIR calculation means, 252 Is an SIR estimation means for transmitting power control.

As shown in FIG. 1, a mobile communication system to which the present invention is applied includes a radio base station device 100 and a plurality of mobile terminals 101 to 10n. Although FIG. 1 shows only one radio base station device and a plurality of mobile terminals in the service area (cell) of this radio base station device, an actual mobile communication system has a large number of radio bases. The station equipment is arranged so as to be able to communicate with a large number of mobile terminals in each cell, and each of the radio base station equipment is public via a base station control station and an exchange control station (not shown). It is connected to the communication network.

[0024] Now, in the cellular mobile communication system shown in FIG. 1, a case where mobile terminals 101 to 10n exist in the same cell and the base station apparatus 100 communicates with the mobile terminal 101 will be considered. The radio base station device 100 communicates with the mobile terminal 101, but also communicates with other mobile terminals 102 to 10n. In this case, for communication between the radio base station device 100 and the mobile terminal 101, the transmission signals of the other mobile terminals 102 to 10n become interference sources in CDMA.

Therefore, the wireless base station apparatus 100 controls the transmission power of each mobile terminal communicating with each other so that the transmission signal from each mobile terminal does not interfere with other mobile terminals. Control the transmission power from the terminal to the minimum required. The outline of this control will be described with reference to FIG. 2 together with the configuration of the mobile terminal and the radio base station device.

[0026] The mobile terminal 101 includes a coding unit 46 that encodes a signal to be transmitted, a transmission power control unit 44, a variable gain amplifier 45 whose gain is controlled by the transmission power control unit 44, and the amplifier. The antenna 40 that transmits the signal from 45 to the radio base station device 100, the antenna 41 that receives the signal from the radio base station device 100, and the received signal are detected and the transmission power control signal and the signal to the own terminal are separated. It is configured to include a synchronous detection unit 42 for decoding and a decoding unit 43 for decoding a signal to the own terminal. Further, the radio base station apparatus 100 includes an antenna 10 that receives transmission signals from all the mobile terminals communicating in the cell, and an interference removing unit 12 that removes interference from the reception signals of the antenna 1 with respect to individual mobile terminals. , The decoding circuit 13 that decodes the signal from each mobile terminal, the SIR measuring unit 14 that measures the SIR of the signal from each mobile terminal after interference removal, and the measured SIR value and the target SIR value. A comparison unit 47 that compares and generates a transmission power control signal, a coding unit 22 that encodes a signal transmitted to a mobile terminal, and an addition unit 48 that synthesizes a signal transmitted to the mobile terminal and a transmission power control signal. It is configured with an antenna 17 that transmits a synthesized signal to a mobile terminal.

[0027] Next, in the mobile terminal 101 and the wireless base station device 100 configured as described above, these operations will be described assuming that the wireless base station device 100 controls the transmission power from the mobile terminal 101. To do.

[0028] The transmission signal transmitted from the antenna 40 of the mobile terminal 101 and the transmission signal from the other mobile terminals 102 to 10n are received by the antenna 10 of the radio base station apparatus 100 and sent to the interference removing unit 12. .. The interference elimination receiving unit 12 removes the interference power of the mobile terminals 102 to 10n from the received signal and detects the received data of the mobile terminal 101. The received signal from the detected mobile terminal 101 is sent to the SIR measuring unit 14 and the decoding unit 13. The received signal input to the decoding unit 13 is demodulated and used as received data. On the other hand, the SIR measuring unit 14 to which the same received signal is input measures the SIR of the received signal and transfers the SIR value to the comparison unit 47. The comparison unit 47 compares the measured SIR value with the target SIR value of the mobile terminal 101, and based on the result, outputs a transmission power control signal having the meaning of an increase instruction or a decrease instruction of the transmission power. Generate and transfer to the addition unit 48.

[0029] The data transmitted to the mobile terminal is encoded by the coding unit 22 and transferred to the addition unit 48. The addition unit 48 adds the transmission power control signal input from the comparison unit 47 to the transmission signal input from the coding unit 22. The transmission signal to which the transmission power control signal is added is transmitted via the antenna 17.

[0030] The mobile terminal 101 receives the signal transmitted from the radio base station device 100 by the antenna 41, and sends the received signal to the synchronous detection unit 42. The synchronous detection unit 42 synchronously detects the received signal and separates the transmission power control signal from the received signal. The received signal from which the transmission power control signal is separated is transferred to the decoding unit 43, demodulated, and used as received data. On the other hand, the transmission power control signal is transferred to the transmission power control unit 44. If the result of decoding the content of the transmission power control signal is an instruction to increase the transmission power, the transmission power control unit 44 is appropriate so that the power increase instructed by the radio base station device 100 to the variable gain amplifier 45 is obtained. If the result of decoding is an instruction to reduce the transmission power, the gain control is performed so that the power of the variable gain amplifier 45 is reduced.

The transmission data to be transmitted from the mobile terminal 101 is encoded by the coding unit 46 and input to the variable gain amplifier 45. The variable gain amplifier 45 increases or decreases the transmission signal to the power controlled by the transmission power control unit 44, transfers the transmission signal to the antenna 40, and transmits the transmission signal via the antenna 40.

Next, the details of the radio base station apparatus 100 and its operation will be described with reference to FIG.

The radio base station apparatus 100 includes antennas 10 and 17 for reception and transmission, a receiving radio module 11 that performs high / intermediate frequency reception processing, an interference elimination receiving unit 12 having an interference removing function, and an interference removing receiving unit 12. Multi-stage interference elimination receiving circuits 120a to 120n, detection / decoding units 13a to 13n that detect / decode received signals, SIR measurement unit 14 that measures uplink channel SIR, and SIR for transmission power control. SIR estimation unit 15 for transmission power control to be estimated, transmission power control signal creation unit 16 to create a transmission power control signal by comparing the transmission power control SIR with the target SIR, and a coding unit to perform transmission data coding processing. 22a ~ 22n, frame creation unit 21a ~ 21n that creates transmission frames, diffusion circuit 20a ~ 20n that spreads transmission frames, adder circuit 19 that adds transmission signals for multiple mobile terminals, high / intermediate frequency It is configured to include a transmission radio module 18 that performs transmission processing.

[0034] As described above, the signal transmitted from the mobile terminal is received by the antenna 10, and the receiving radio module 11 demodulates the baseband signal and performs reception processing at a high / intermediate frequency. The received signal output from the receiving wireless module 11 is input to the interference removing receiving circuit 120a of the first stage of the interference removing receiving unit 12. The interference elimination receiving circuits 120a to 120n demodulate the received signal in which the transmission signals of a plurality of mobile terminals are multiplexed for each mobile terminal to create an interference replica of each mobile terminal, and then the original input signal is input. The interference wave is removed from the received signal by subtracting the interference replicas other than the desired wave signal. The received signal from which the interference replica has been reduced is input to the interference elimination receiving circuit in the next stage and processed in the same manner as in the previous stage. By repeating this operation a plurality of times, the signal quality of the demodulation result of the final stage is improved rather than the demodulation result of the first stage.

[0035] The signals output from the interference elimination receiving circuit 120n in the final stage are input to the detection / decoding units 13a to 13n, respectively, and are subjected to error correction control processing such as demodulation and Viterbi decoding, and then received data. Used as.

[0036] On the other hand, the signals 23a to 23n of each user output from the interference elimination receiving circuit 120a of the first stage are input to the uplink channel SIR measuring unit 14 through the respective signal lines. The SIR measurement unit 14 measures the SIR of the received signal input via the signal lines 23a to 23n of the first stage, and inputs the measured SIR value to the transmission power control SIR estimation unit 15 through the signal lines 25a to 25n. To do. Similarly, the signal output from the interference elimination receiving circuit 120n in the final stage is also input to the uplink channel SIR measurement unit 14, the SIR value is measured by the SIR measurement unit 14, and the SIR value is the SIR estimation for transmission power control. It is input to the part 15.

As shown in FIG. 4, the transmission power control SIR estimation unit 15 stores the SIR values received from the SIR measurement unit IF150 and the uplink SIR measurement unit 14, which are interfaces with the uplink SIR measurement unit 14. SIR table memory 151, transmission power control signal creation unit IF154 that is an interface with transmission power control signal creation unit 16, software memory 200 that stores a program that estimates transmission power control SIR, control of each functional block It is configured to include a CPU 152 having a function of executing an SIR estimation program for transmission power control, and an internal bus 155 connecting the above-mentioned functional units to each other. As shown in FIG. 5, the CPU 152 and the software memory 200 realize the correction SIR calculation means 251 and the transmission power control SIR estimation means 252, which constitute the SIR estimation processing unit 250. The memory 200 in this case may be physically one or a plurality of memories.

[0038] When the SIR value (referred to as the first stage SIR value) of the signal from the first-stage interference elimination receiving circuit 120a is input from the uplink channel SIR measuring unit 14 to the SIR measuring unit IF150 through the signal lines 23a to 23n, the SIR measuring unit IF150 Interrupts the CPU 152, and the CPU 152 stores the first-stage SIR value in a predetermined location of the SIR table memory 151, and executes the transmission power SIR estimation program stored in the software memory 200. Next, the CPU 152 estimates and estimates the transmission power control SIR value using the past correction ΔSIR stored in the SIR table memory 151 and the current first-stage SIR value during execution of the transmission power SIR estimation program. The SIR value is output to the transmission power control signal creation unit 16 via the transmission power control signal creation unit IF154.

[0039] Further, when the SIR value of the signal from the interference elimination receiving circuit 120n in the subsequent stage (referred to as the SIR value in the latter stage) is input from the uplink channel SIR measurement unit 14 to the SIR measurement unit IF150 via the signal lines 26a to 26n. The SIR measurement unit IF150 interrupts the CPU 152 in the same manner as described above, and the CPU 152 stores the subsequent SIR value in a predetermined location of the SIR table memory 151 in response to the interruption. In this case, the CPU 152 does not estimate the transmission power control SIR.

The estimated transmission power control SIR value is input to the transmission power control signal creation unit 16 via the signal lines 27a to 27n. The transmission power control signal creation unit 16 compares the input transmission power control SIR value with the target SIR values 17a to 17n given in advance to the mobile terminal, and the transmission power control SIR value is higher than the target SIR. If it is large, a transmission power control signal is created to instruct the mobile terminal to decrease the transmission power, and conversely, if the estimated SIR value is smaller than the target SIR value, the mobile terminal is instructed to increase the transmission power. Create a transmit power control signal.

[0041] The frame creation units 21a to 21n input from the transmission power control signal creation unit 16 to the transmission data addressed to each mobile terminal that has undergone error control processing such as convolutional coding and interleaving by the coding units 22a to 22n. The transmitted power control signal is added to a predetermined location defined by the system to form a frame. The diffusion circuits 20a to 20n perform spectrum diffusion processing with parameters corresponding to mobile terminals. The addition circuit 19 adds the transmission signals in order to multiplex and transmit the signals to the mobile terminal. The signal output from the adder circuit 19 is subjected to high frequency modulation processing by the transmission wireless module 18 and transmitted from the antenna 17.

Next, the SIR table configuration stored in the SIR table memory 151 shown in FIG. 4 and the estimation method of the transmission power control SIR will be described.

[0043] The SIR table is configured as shown in FIG. The example shown in FIG. 6 shows only a table for one user, and the SIR table is composed of three items: the first-stage SIR value, the second-stage SIR value, and the correction ΔSIR value. The SIR value measured from the signal of the first-stage interference elimination receiving circuit 120a is stored in the first-stage SIR value item, and the SIR value measured from the signal of the second-stage interference elimination receiving circuit 120n is stored in the second-stage SIR value item. To do. In the item of the correction ΔSIR value, the correction value used when estimating the transmission power control SIR is stored. In the case of the example shown in FIG. 6, this correction value is the result of subtracting the front-stage SIR value from the rear-stage SIR value, and these values are stored for each slot unit time in the wireless frame.

Next, the processing operation of the method of estimating the transmission power control SIR value will be described with reference to the flow shown in FIG. 7. This process is performed by the CPU 152 when the transmission power control SIR estimation program is started by an interrupt from the SIR measuring unit IF150 to the CPU 152.

(1) If there is a request to start the transmission power control SIR estimation process at the slot time t, whether the received data of the request is the first stage SIR value (t) or the second stage SIR value (t). Is determined (step 201).

(2) When it is determined in the determination in step 201 that the request is the first stage SIR value (t), the transmission power control SIR value (t) is estimated. This estimation calculates TPC_SIR (t), which is the transmission power control SIR, by subtracting the correction ΔSIR (t-1) calculated in the past from the received first-stage SIR value (t) as shown in Eq. (1). It is done by doing.

[0047] TPC_SIR (t) = First stage SIR (t) -Correction ΔSIR (t-1) ...... (1) However, in the above, the initial value of the correction ΔSIR value is set to zero and the calculation is started (step). 202).

(3) The calculated transmission power control SIR (t) is output to the transmission power control signal creation unit 16, and the received first-stage SIR value (t) is the row of slot No. t of the first-stage SIR term of the SIR table. Store in and end the process (steps 203, 204).

(4) On the other hand, if it is determined in step 201 that the request is the latter-stage SIR value (t), the subsequent-stage SIR value (t) is set to the slot No. t of the latter-stage SIR term of the SIR table. Store in the line of. Then, the correction ΔSIR (t) is calculated and stored in the row of the slot No. t of the correction ΔSIR term of the SIR table to end the process (steps 205 and 206).

[0050] In the above-described processing, the corrected ΔSIR value is the result of subtracting the front-stage SIR value from the rear-stage SIR value. May be obtained and the average value may be used as the correction value. The averaging cycle in this case is set shorter than the control cycle of the transmission power between the base station apparatus and the base station control station.

FIG. 8 is a block diagram showing a detailed configuration of a radio base station apparatus according to a second embodiment of the present invention, FIG. 9 is a block diagram showing a configuration of a target SIR correction unit, and FIG. 10 is a correction SIR calculation means. The figure explaining the configuration with the correction target SIR estimation means, FIG. 11 is a flowchart explaining the processing operation for estimating the correction target SIR, and then, with reference to these figures, about the second embodiment of the present invention. explain. In FIGS. 8 to 10, 30 is the target SIR correction unit, 300 is the SIR measurement unit IF, 301 is the SIR table memory, 302 is the CPU, 304 is the transmission power control signal creation unit IF, 306 is the control unit IF, and 400 is the software. The memory, 450 is the SIR estimation processing unit, 451 is the correction SIR calculation means, 452 is the transmission power control SIR estimation means, and the other symbols are the same as in FIG.

[0052] A characteristic configuration of the radio base station apparatus 100 according to the second embodiment of the present invention shown in FIG. 8 is that the one described with reference to FIG. 3 includes a target SIR correction unit 30.

In the radio base station apparatus shown in FIG. 8, the first-stage SIR value measured by the uplink channel SIR measuring unit 14 is input to the target SIR correction unit 30 via the signal lines 25a to 25n, and the second-stage SIR value is also input to the target SIR correction unit 30. Is input to the target SIR correction unit 30 via the signal lines 26a to 26n. As shown in FIG. 9, the target SIR correction unit 30 connects the SIR measurement unit IF300, the SIR table memory 301, the control unit IF306, the CPU302, the software memory 400, the transmission power control signal creation unit 304, and these functional blocks. It is configured with an internal bus 305. The CPU 302 and the software memory 400 realize the correction SIR calculation means 451 and the correction target SIR estimation means 452 shown in FIG. 10, and constitute the SIR estimation processing unit 450. The memory 400 in this case may be physically one or a plurality.

[0054] The SIR table memory 301 stores the same SIR table as described above with reference to FIG. A correction target SIR estimation program is stored in the software memory 400, and this program executes processing according to the flow shown in FIG. The correction target SIR estimation program performs almost the same processing as the flowchart of the transmission power SIR estimation program described with reference to FIG. 7, except that the processing in step 402 is different. The process of estimating the correction target SIR in step 402 is a process of calculating the correction target SIR estimated value by subtracting the correction ΔSIR from the target SIR received by the control unit IF306. The obtained correction target SIR value is output to the transmission power control signal creation unit 16 by the transmission power control signal creation unit IF304 in step 403.

The transmission power control signal creation unit 16 compares the first-stage SIR value input from the uplink channel SIR measurement unit 14 via the signal lines 25a to 25n with the correction target SIR value input from the target SIR correction unit 30. Then, a transmission power control signal is created from the result and output to the frame creation units 21a to 21n.

[0056] The radio base station apparatus according to the first and second embodiments of the present invention described above will be described as using the signals of the first-stage and final-stage interference elimination receiving circuits in the interference elimination receiving unit for SIR measurement. However, according to the present invention, instead of the signal of the interference elimination receiving circuit of the first stage, the signal of the interference elimination receiving circuit after the first stage or before the final stage can be used.

[0057] FIGS. 12 and 13 are block diagrams showing a detailed configuration of a radio base station apparatus according to a third and fourth embodiment of the present invention. The radio base station apparatus according to the third and fourth embodiments of the present invention is the signal of any one of the interference elimination receiving circuits from the first stage to the last stage in the radio base station equipment shown in FIGS. This is an example configured to measure SIR using. That is, in these examples, the signal from the second stage in the interference elimination receiving unit via the signal lines 28a and 28n and the signal of the interference elimination receiving circuit in the final stage are used for the measurement of SIR. ..

[0058] In the case of these examples, although the effect is slightly lower than the case of using the signals of the interference elimination receiving circuits of the first stage and the final stage, they can be sufficiently used.

[0059] According to each embodiment of the present invention described above, it is possible to solve the problems of the prior art, improve the interference removing effect, and control the transmission power with less processing delay. it can. As a result, according to the above-described embodiment of the present invention, the number of mobile terminals that can be connected at the same time can be efficiently increased, and the wireless resources of the entire system can be efficiently utilized.

[Effect of the Invention] As described above, according to the present invention, it is possible to improve the interference removing effect and control the transmission power with less processing delay.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a configuration of a mobile communication system to which the present invention is applied.

FIG. 2 is a block diagram showing a configuration of a mobile terminal and a wireless base station device.

FIG. 3 is a block diagram showing a detailed configuration of a radio base station apparatus according to the first embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of a transmission power control SIR estimation unit.

FIG. 5 is a diagram illustrating a configuration of a corrected SIR calculation means and a transmission power control SIR estimation means.

FIG. 6 is a diagram illustrating a configuration of a SIR table memory of a transmission power control SIR estimation unit.

FIG. 7 is a flowchart illustrating a processing operation for estimating a transmission power control SIR.

FIG. 8 is a block diagram showing a detailed configuration of a radio base station apparatus according to a second embodiment of the present invention.

FIG. 9 is a block diagram showing a configuration of a target SIR correction unit.

FIG. 10 is a diagram illustrating a configuration of a correction SIR calculation means and a correction target SIR estimation means.

FIG. 11 is a flowchart illustrating a processing operation for estimating a correction target SIR.

FIG. 12 is a block diagram showing a detailed configuration of a radio base station apparatus according to a third embodiment of the present invention.

FIG. 13 is a block diagram showing a detailed configuration of a radio base station apparatus according to a fourth embodiment of the present invention.

[Description of code] 100 Radio base station device 101 ~ 10n Mobile terminal 10, 17, 40, 41 Antenna 11 Reception radio module 12 Interference elimination reception unit 13, 13a ~ 13n, 43 Decoding unit 14 SIR measurement unit 15 Transmission power control SIR estimation unit 16 Transmission power control signal creation unit 18 Transmission wireless module 19 Addition circuit 20a ~ 20n Spread circuit 21a ~ 21n Frame creation unit 22, 46 Coding unit 30 Target SIR correction unit 42 Synchronous detection unit 44 Transmission power control unit 45 Variable gain amplifier 47 Comparison unit 48 Addition unit 120a to 120n Interference elimination reception circuit 150 SIR measurement unit IF151 SIR table memory 152, 302 CPU154 Transmission power control signal creation unit IF200, 400 Software memory 250, 450 SIR estimation processing unit 251, 451 correction SIR calculation means 252, 452 SIR estimation means for transmission power control 300 SIR measurement unit IF301 SIR table memory 304 Transmission power control signal creation unit IF306 Control unit IF