JP3902775B2 - Implementation apparatus for mobile communication system and recording medium recording its processing program - Google Patents

Description

  The present invention relates to a mobile communication system transmission power control method and apparatus for controlling transmission power between a base station and a mobile terminal of a mobile communication system. In particular, a mobile communication system (CDMA / TDD) of a TDD-SS (Time Division Duplex-Spread Spectrum) system or a mobile station of a mobile communication system (CDMA / FDD) of a FDD-SS (Frequency Division Duplex-Spread Spectrum) system The present invention relates to a mobile communication system transmission power control method and apparatus for controlling transmission power according to fluctuations in signals received between terminals.

  Conventionally, in a FDD-SS mobile communication system (CDMA / FDD), when data is transmitted and received by radio communication between a base station and a mobile terminal, an uplink and a base that transmit signals from the mobile terminal to the base station A different carrier frequency is used in the downlink for transmitting a signal from the station to the mobile terminal.

  Signals transmitted and received between the base station and the mobile terminal are attenuated by an obstacle existing between the distance between the base station and the mobile terminal or between the base station and the mobile terminal, and interference between the direct wave and the reflected wave. It fluctuates due to fading caused by etc. In the FDD-SS mobile communication system, transmission power is controlled by a closed loop in order to correct fluctuation due to fading. For example, in the IS-95 standard, uplink transmission power control of a CDMA / FDD system that controls transmission power of a terminal is applied.

  When transmission power control is performed on a transmission path between a mobile terminal and a base station regardless of the CDMA / FDD and CDMA / TDD systems, there are the following problems. That is, when the attenuation of the transmission path temporarily increases due to fading with a certain mobile station, the base station controls the transmission power so that the mobile station transmits a signal with a very large power. This interferes with communication with other mobile stations. Conversely, when the transmission power of the mobile station becomes excessively large, it interferes with the communication between other base stations and the base station.

  Further, in a CDMA / FDD mobile communication system, uplink transmission power is controlled by a mobile terminal based on uplink power control information obtained at the base station, and downlink transmission is performed at the base station based on downlink power control information obtained at the mobile terminal. Since the transmission power is controlled by a closed loop for controlling the power, there is a problem that a delay occurs in the control of the transmission power.

  A main object of the present invention is to provide a transmission power control method and apparatus for a CDMA mobile communication system capable of preventing waste of transmission power and interference with other stations.

  Another object of the present invention is to provide a transmission power control method and apparatus for a CDMA mobile communication system capable of correcting a change in a signal generated on an uplink or a downlink at high speed.

  In the present invention, in order to control the power of the signal transmitted between the base station and the mobile station, one of the base station / mobile station detects a change in the signal generated in the downlink or uplink, From the detected signal change, power control information for correcting the signal change occurring in the uplink or downlink is generated and notified to the other. The transmission power transmitted on the uplink or downlink is corrected according to the notified power control information. At this time, the transmission power value to be corrected is compared with a predetermined allowable correction value, and the transmission power value is lower than the predetermined allowable value. If it is larger, the transmission is temporarily stopped, and the transmission power is corrected when the transmission power value is equal to or less than a predetermined allowable value. This concept is particularly useful when a data packet signal is transmitted between the base station and the mobile station. This concept is different from voice service in packet mobile communication. When the transmission power of a packet signal is required to exceed a predetermined value and interferes with others, the transmission is temporarily stopped and transmitted after a predetermined delay. However, this is based on the knowledge of the present inventors that communication efficiency is not impaired, and rather the overall communication efficiency can be increased.

  In order to achieve the above object, typical aspects of the present invention are as follows.

  (1) In the mobile communication system transmission power control method, the transmission power value to be corrected is compared with the maximum allowable correction value, and transmission is temporarily stopped when the transmission power value to be corrected is larger than the maximum allowable correction value. The transmission power is corrected when the generated power control information is equal to or less than the maximum allowable correction value.

  As described above, according to the mobile communication system transmission power control method, when the generated power control information is larger than the maximum allowable correction value, transmission is temporarily stopped, and the power control information is less than the maximum allowable correction value. Since transmission is performed at this time, waste of transmission power can be prevented.

  (2) In a mobile communication system transmission power control method for controlling the power of a signal transmitted between a base station and a mobile terminal, a change in the signal generated in the downlink from the base station to the mobile terminal is detected. And generating power control information for correcting a change in the signal generated on the uplink from the detected change in signal, and a signal transmitted on the uplink from the mobile terminal to the base station based on the generated power control information. The transmission power is corrected, and the power control information with the corrected transmission power is transmitted from the mobile terminal to the base station together with the transmission signal with the corrected transmission power.

  This is a power control method that is particularly effective for the CDMA / TDD system because it is estimated that the detected change in the downlink signal also occurs in the uplink. There is an advantage that it is possible to correct a change in signal generated in the uplink from the mobile terminal to the base station at high speed.

  According to the present invention, it is possible to realize a CDMA mobile communication system capable of preventing waste of transmission power and interference with other stations.

  In the CDMA / TDD mobile communication system, a first embodiment for controlling transmission power when communication is performed between a base station and a mobile terminal will be described.

  FIG. 1 is a block diagram showing a schematic configuration diagram of a mobile communication system according to the present embodiment. The CDMA / TDD mobile communication system of this embodiment includes a base station 100 and a mobile terminal 110, and communicates via a communication line 120. The communication line 120 includes an uplink 121 and a downlink 122, and a guard time 123 for preventing interference between lines is set between the uplink 121 and the downlink 122. The carrier frequency 124 of the communication line 120 is fc. The base station assigns the communication line 120 to the uplink 121 and the downlink 122 in a time division manner. Base station 100 and mobile terminal 110 are connected by uplink 121 and downlink 122.

  Base station 100 includes a downlink transmission power setting section 101, a downlink power control information comparison section 102, a downlink power control information generation section 103, and a power control information reception section 104.

  Downlink transmission power setting section 101 sets transmission power transmitted by base station 100 on downlink 122 according to the comparison result of downlink power control information comparison section 102.

  The downlink power control information comparison unit 102 compares whether the downlink 122 power control information generated by the downlink power control information generation unit 103 is larger than the maximum allowable correction value of the base station 100.

  Downlink power control information generating section 103 generates power control information for downlink 122 using signal (fading) information on uplink 121 and power control information transmitted from mobile terminal 110. Since the signal on the uplink 121 is corrected by the mobile terminal 110, the downlink power control information generation unit 103 calculates the value before correction of the signal on the uplink 121 using the power control information transmitted from the mobile terminal 110. Then, power control information for the downlink 122 is generated.

  The power control information receiving unit 104 receives power control information transmitted from the mobile terminal 110.

  The mobile terminal 110 includes an uplink transmission power setting unit 111, an uplink power control information comparison unit 112, an uplink power control information generation unit 113, and a power control information transmission unit 114.

  Uplink transmission power setting section 111 sets the transmission power of uplink 121 according to the comparison result of uplink power control information comparison section 112. The set transmission power of the uplink 121 is transmitted from the mobile terminal 110 via the uplink 121.

  The uplink power control information comparison unit 112 compares whether the uplink 121 power control information generated by the uplink power control information generation unit 113 is greater than the maximum allowable correction value of the mobile terminal 110.

  Uplink power control information generation section 113 generates uplink 121 power control information using signal (fading) information on downlink 122.

  The power control information transmission unit 114 transmits the power control information of the uplink 121 set by the uplink transmission power setting unit 111 to the base station 100.

  FIG. 2 is a block diagram illustrating a schematic configuration of the base station 100. The base station 100 includes a CPU 201, a memory 202, a display device 203, an input / output device 204, a digital signal processor (DSP) 205, a mobile communication switching center interface unit 206, an antenna 210, and a pilot channel modulator 211. A response channel modulator 212, a transmission channel modulator 213, reserved channel matched filters 214 to 215, transmission channel matched filters 216 to 217, a pseudo-noise code generator (PN code generator) 218, and an adder 220 to 221, multipliers 230 to 231, and a TDD switch 240.

  CPU 201 for controlling the operation of the entire base station, memory 202 for loading a control program for controlling the operation of the entire base station, display device 203 for displaying the operating state of the base station, instructions for operations to the base station, etc. An input / output device 204 that performs input / output processing, a DSP 205 that controls communication processing with the mobile terminal 110, and a mobile communication switching center interface unit 206 that is connected to the mobile communication switching center are connected via a bus.

  Since the base station 100 communicates with the mobile terminal 110 by TDD-SS, a pilot channel, a reservation channel, a response channel, and a transmission using the same carrier frequency 124 are used between the base station 100 and the mobile terminal 110. A channel is formed. This state will be described later with reference to FIG.

  The DSP 205 includes a downlink transmission power setting unit 101, a downlink power control information comparison unit 102, a downlink power control information generation unit 103, and a power control information reception unit 104. The DSP 205 also includes a pilot channel modulator 211, a response channel modulator 212, a transmission channel modulator 213, reserved channel matched filters 214 to 215, transmission channel matched filters 216 to 217, and a PN code generator 218. Are connected to the TDD switch 240.

  The pilot channel modulator 211 is a modulator that modulates a pilot channel that transmits a pilot signal, and the response channel modulator 212 modulates a response channel that transmits a response packet in response to a reservation packet received from the mobile terminal 110. The transmission channel modulator 213 is a modulator that modulates a plurality of transmission channels that transmit data packets. The modulated pilot signal, the modulated response packet, and the modulated data packet are superimposed by the adders 220 and 221 and transmitted from the antenna 210 to the mobile terminal 110 via the multiplier 230 and the TDD switch 240.

  The reserved channel matched filters 214 to 215 are filters that receive reserved packets transmitted from the mobile terminal 110, and the transmission channel matched filters 216 to 217 are filters that receive data packets transmitted from the mobile terminal 110. The received reservation packet and data packet are processed by the DSP 205.

  The PN code generator 218 is a code generator that generates a PN code used in each of the pilot channel, reserved channel, response channel, and transmission channel.

  The TDD switch 240 is a switch that switches transmission / reception timings of the uplink 121 and the downlink 122 according to the TDD timing output by the DSP 205.

  The power control information transmitted from the mobile terminal 110 is input to the power control information receiving unit 104 of the DSP 205 via the reservation / transmission channel matched filters 214 to 215 and 216 to 217. The power control signal set by the downlink transmission power setting unit 101 of the DSP 205 is input to the pilot channel modulator 211, the response channel modulator 212, and the transmission channel modulator 213.

  FIG. 3 is a block diagram illustrating a schematic configuration of the mobile terminal 110. The mobile terminal 110 includes a CPU 301, a memory 302, a display device 303, an input / output device 304, a DSP 305, an antenna 310, a reserved channel modulator 311, a transmission channel modulator 312, and a pilot channel demodulator 313. A response channel demodulator 314, a transmission channel demodulator 315, a pseudo noise code generator (PN code generator) 316, a fading-to-power controller 317, an adder 320, multipliers 330 and 331, and a TDD switch. 340.

  In addition, a CPU 301 that controls the operation of the entire device, a memory 302 that loads a control program, a display device 303 that displays an operation state, an input / output device 304 that performs input / output processing of data to be transmitted and received, and a mobile terminal 110 The DSP 305 that controls the communication processing is connected via a bus.

  The DSP 305 includes an uplink transmission power setting unit 111, an uplink power control information comparison unit 112, an uplink power control information generation unit 113, and a power control information transmission unit 114.

  The DSP 305 further includes a reserved channel modulator 311, a transmission channel modulator 312, a pilot channel demodulator 313, a response channel demodulator 314, a transmission channel demodulator 315, a PN code generator 316, and a fading pair. The power control unit 317 and the TDD switch 340 are connected via a bus.

  The reservation channel modulator 311 is a modulator that modulates a reservation channel for transmitting a reservation packet for reserving a transmission channel by informing the base station 100 that there is a data packet to be transmitted. The transmission channel modulator 312 A modulator that modulates a plurality of transmission channels that transmit data packets. The modulated reservation packet and data packet are superimposed by the adder 320 and transmitted from the antenna 310 to the base station 100 via the multiplier 330, the fading-to-power control unit 317, and the TDD switch 340.

  The pilot channel demodulator 313 is a demodulator that demodulates the transmitted pilot signal, and the signal strength of the received pilot signal and the TDD timing indicated by the pilot signal are input to the DSP 305. The response channel demodulator 314 is a demodulator that demodulates the transmitted response packet, and the transmission channel demodulator 315 is a demodulator that demodulates the transmitted data packet.

  The PN code generator 316 is a code generator that generates a plurality of PN codes used in each of the pilot channel, reserved channel, response channel, and transmission channel.

  The fading-to-power control unit 317 is a control unit that controls transmission power based on the fading information obtained by the DSP 305. The TDD switch 340 is configured to control the uplink 121 and the downlink 122 according to the TDD timing output by the DSP 305. This switch switches transmission / reception timing.

  FIG. 4 schematically shows an outline of data transmission in the CDMA / TDD mobile communication system. In FIG. 4, 401 to 403 are reservation packets, 411 to 413 are response packets, 421 to 423 are data packets, and 431 and 432 are pilot signals. The reservation packets 401 to 403, the response packets 411 to 413, the data packets 421 to 423, and the pilot signals 431 and 432 are spread spectrum with a reservation code, a response code, an uplink / downlink transmission code, and a pilot code, respectively, and the uplink 121 And the downlink 122 are transmitted at the same carrier frequency 124. A communication line using the carrier frequency 124 is divided into an uplink 121 and a downlink 122 by time division.

  The mobile terminal 110 having a data transmission request transmits reservation packets 401 to 403 to the base station 100 using the uplink 121. The base station 100 that has received the reservation packets 401 to 403 determines a transmission channel to be assigned to each mobile terminal, and then transmits response packets 411 to 413 to the mobile terminal 110 using the downlink 122. The mobile terminal 110 that has received the response packets 411 to 413 transmits the data packets 421 to 423 to the base station 100 through the assigned transmission channel. Pilot signals 431 and 432 are transmitted only for the time allocated to downlink 122.

  FIG. 5 shows a processing procedure for transmission power control of the base station 100. Base station 100 sets transmission power of downlink 122 based on the power control information transmitted from mobile terminal 110 and the signal strength (fading information) of uplink 121.

  The reserved channel or transmission channel signals are input from the reserved channel matched filters 214 to 215 or the transmission channel matched filters 216 to 217 (step 501). The downlink power control information generation unit 103 extracts the signal strength for each bit of the input signal (step 502), and the power control information of the mobile terminal 110 received by the extracted signal strength and the power control information reception unit 104. Are used to estimate the fading of the uplink 121 (step 503).

  That is, since the signal of the uplink 121 has already been corrected by the mobile terminal 110, the reserved channel or transmission of the input uplink 121 using the information related to fading in the power control information transmitted from the mobile terminal 110 is transmitted. After the signal strength of the channel is returned to the signal strength before the correction in the mobile terminal 110, the fading of the uplink 121 is estimated.

  The downlink power control information generation unit 103 further calculates a required power (transmission power) necessary for correcting the fading estimated in step 503 (step 504).

  The downlink power control information comparison unit 102 compares the required power value calculated by the downlink power control information generation unit 103 with the maximum allowable correction value that is the maximum value of the transmission power that can be corrected by the base station 100 (step). 505). If the required power value is larger than the maximum allowable correction value in step 505, transmission is not performed in this slot, the process is stopped until the next slot (step 506), and the same process as in step 502 is performed in the next slot. I do. If the required power value is equal to or less than the maximum allowable correction value in step 505, the downlink transmission power setting unit 101 sets the transmission power of the downlink 122 according to the required power value (step 507).

  FIG. 6 shows a processing procedure for transmission power control of the mobile terminal 110. The mobile terminal 110 receives the pilot signal transmitted from the base station 100, sets the transmission power of the uplink 121, and transmits the power control information used to control the transmission power to the base station 100.

  The pilot signal transmitted from the base station 100 is received by the pilot channel demodulator 313 and input to the DSP 305 (step 601). Uplink power control information generation section 113 extracts the signal strength of the input pilot signal (step 602), and a time slot period that is a specific time for transmitting the received pilot signal or a packet that is a specific time for transmitting the packet For the period, the extracted signal strength is integrated (step 603), and the value of shadowing attenuation, which is the attenuation of the pilot signal due to the distance or the attenuation of the pilot signal due to the obstacle, is calculated from the integrated value (step 604). A correction value for correcting the attenuation calculated in step 604 is calculated (step 605).

  Further, uplink power control information generation section 113 estimates fading occurring in the pilot signal from the signal strength of each bit of the pilot signal extracted in step 602 (step 606), and a correction value for correcting the estimated fading. Is calculated (step 607).

  In the uplink power control information comparison unit 112, the transmission power value necessary for fading correction calculated by the uplink power control information generation unit 113 and the maximum allowable correction value that is the maximum value of the transmission power that can be corrected by the mobile terminal 110. Are compared (step 608). When the required power value calculated by the uplink power control information generation unit 113 is larger than the maximum allowable correction value, the transmission is not performed in this slot, and the process is stopped until the next slot (step 609). The same processing is performed from step 602 in the slot. When the required power value is less than or equal to the maximum allowable correction value, the uplink transmission power setting unit 111 sets the maximum required power calculated by the uplink power control information generation unit 113 from a plurality of preset transmission power levels. A near transmit power level is selected (step 610). Then, according to the distance calculated in step 605 or the correction value for correcting attenuation due to shadowing and the transmission power level selected in step 610, the transmission power of uplink 121 is set (step 611).

  Further, uplink power control information generation section 113 obtains the value of C / I (Carrier / Interference) from the integrated value of the slot or packet period of the pilot signal obtained in step 603 (step 612), and power control information transmission section 114 transmits the transmission power setting value set in step 611 and the C / I obtained in step 612 to the base station 100 as power control information (step 613).

  Next, another embodiment in which the present invention is applied to a CDMA / FDD mobile communication system will be described with reference to FIGS.

  The CDMA / FDD mobile communication system includes a base station 700 and a mobile terminal 710, and the base station 700 and the mobile terminal by an uplink 721 formed by the uplink carrier frequency 724 and a downlink 722 formed by the downlink carrier frequency 725. 710 is connected. Further, a guard frequency 723 is set in the uplink / downlink carrier frequency to prevent interference.

  Base station 700 transmits a pilot signal on downlink 722, mobile terminal 710 receives the pilot signal, and downlink power control information generator 712 measures the reception strength of the pilot signal on downlink 722 to propagate the propagation path. The downlink power control information for controlling the transmission power of the downlink 722 is generated. Downlink power control information transmission section 711 transmits the generated downlink power control information to base station 700 via uplink 721.

  The downlink power control information receiving unit 701 of the base station 700 receives the downlink power control information transmitted from the mobile terminal 710 and passes it to the downlink transmission power setting unit 702. Downlink transmission power setting section 702 sets the transmission power of downlink 722 using the received downlink power control information.

  Also, when the uplink power control information generation section 703 of the base station 700 receives the signal on the uplink 721 transmitted from the mobile terminal 710, the uplink power control information generation section 703 measures the state such as fading of the signal on the uplink 721 and the uplink 721 Uplink power control information for controlling the transmission power of is generated. Uplink power control information transmission section 704 transmits the generated uplink power control information to mobile terminal 710 via downlink 722.

  The uplink power control information receiving unit 714 of the mobile terminal 710 receives the uplink power control information transmitted from the base station 700 and passes it to the uplink transmission power setting unit 713. The uplink transmission power setting unit 713 sets the transmission power of the uplink 721 using the received uplink power control information.

  FIG. 8 shows a processing procedure of transmission power control of the base station 700 in another embodiment. In the base station 700, the transmission power of the downlink 722 is set by the downlink power control information transmitted from the mobile terminal 710, and the state such as signal fading on the uplink 721 is measured to generate the uplink power control information. To the mobile terminal 710.

  The downlink power control information receiving unit 701 receives downlink power control information transmitted from the mobile terminal 710 via the uplink 721 (step 801). The downlink transmission power calculation unit 705 calculates the required transmission power using the downlink power control information transmitted from the mobile terminal 710. In the downlink power control information comparison unit 706, the required power value necessary for correcting the transmission power generated by the downlink transmission power calculation unit 705 and the maximum allowable correction value that is the maximum value of the transmission power that can be corrected by the base station 700, Compare (step 802A).

  As a result of the comparison process 802A, when the required transmission power value calculated based on the downlink power control information is larger than the maximum allowable correction value of the base station 700, transmission of the signal is stopped (step 802B), and the next slot Alternatively, transmission is attempted during the packet period. After the transmission process is stopped, the processes after step 804 are performed. On the other hand, if the calculated required transmission power is less than or equal to the maximum allowable correction value, the downlink transmission power setting section 702 sets the transmission power according to the required power value (step 803).

  Uplink power control information generation section 703 inputs a signal on uplink 721 transmitted from mobile terminal 710 (step 804), and extracts the signal strength for each signal bit of input uplink 721 (step 805). Further, fading of the uplink 721 signal transmitted by the mobile terminal 710 is estimated from the extracted signal strength change for each bit, and uplink power control information is generated (step 806). The uplink power control information transmission unit 704 transmits the uplink power control information generated by the uplink power control information generation unit 703 to the mobile terminal 710 via the downlink 722 (step 807).

  FIG. 9 shows a processing procedure of transmission power control of the mobile terminal 710 in another embodiment. Based on the uplink power control information transmitted from the base station 700, the transmission power of the uplink 721 is set, the state of fading of the signal on the downlink 722 is measured to generate downlink power control information, and the base station 700 Send to.

  The mobile terminal 710 receives the pilot signal on the downlink 722 transmitted from the base station 700 (step 901). The uplink transmission power calculation unit 715 extracts a signal strength for each bit of the received pilot signal (step 902), and a time slot period that is a specific time for transmitting data or a packet that is a specific time for transmitting a packet For the period, the extracted signal strength is integrated (step 903). The uplink transmission power calculation unit 715 further calculates a shadowing attenuation value, which is the attenuation of the pilot signal due to the distance or the attenuation of the pilot signal due to the obstacle, from the value integrated in the slot or packet period (step 904).

  On the other hand, the uplink power control information receiving section 714 extracts uplink transmission power control information from the received signal (step 905). Uplink transmission power calculation section 715 transmits the uplink signal 721 using the pilot signal attenuation by the distance calculated in step 904 or the pilot signal attenuation by the obstacle and the power control information extracted in step 905. The required transmission power of the signal is calculated (step 906). The uplink power control information comparison unit 716 compares the transmission power value required for correction calculated by the uplink transmission power calculation unit with a maximum allowable correction value that is the maximum value of transmission power that can be corrected by the mobile terminal 710 ( Step 906A). In step 906A, when the required power value calculated by the uplink transmission power calculation unit 715 is compared with the maximum allowable correction value, and the required power value is larger than the maximum allowable correction value, the mobile terminal 710 The transmission process is stopped until the slot or packet time. If the required power value is equal to or smaller than the maximum allowable correction value in step 906A, the uplink transmission power setting unit 713 sets the calculated required power value as the transmission power of the uplink 721.

  Downlink power control information generation section 712 estimates fading of downlink 722 using the signal strength for each bit of the pilot signal extracted in step 902 and the distance or shadowing attenuation value calculated in step 904 ( The value of C / I is obtained from the integrated value of the slot or packet period of the pilot signal obtained by the processing of Step 908) and Step 903 (Step 909).

  The downlink power control information transmission unit 711 transmits the fading information estimated in step 908 and the C / I obtained in step 909 as downlink power control information using the uplink 721 (step 910). .

  As a setting method of the maximum allowable correction value in the comparison processing in the first embodiment and the second embodiment, the upper limit value is dynamically set according to the state of the communication path, for example, the speed of the mobile terminal. it can. It can also be set according to the difference in communication packet data rate and required service quality. Each transmission power control procedure described above can be programmed and implemented in a software format by the corresponding processing program unit.

  The present invention has been specifically described above based on the above embodiment, but the present invention is not limited to the above embodiment, and it is needless to say that various changes can be made without departing from the scope of the present invention.

It is a block diagram which shows schematic structure of the mobile communication system by one Embodiment of this invention. It is a block diagram which shows schematic structure of the base station 100 of the mobile communication system of this embodiment. It is a block diagram which shows schematic structure of the mobile terminal 110 of the mobile communication system of this embodiment. It is a model diagram which shows the outline | summary of the data transmission of the mobile communication system of this embodiment. It is a figure which shows the process sequence of the transmission power control of the base station 100 of the mobile communication system of this embodiment. It is a figure which shows the process sequence of the transmission power control of the mobile terminal 110 of the mobile communication system of this embodiment. It is a figure which shows the mobile communication system schematic structure by other embodiment of this invention. It is a figure which shows the process sequence of the transmission power control of the base station 700 of the mobile communication system by said other embodiment. It is a figure which shows the process sequence of the transmission power control of the mobile terminal 710 of the conventional mobile communication system by the said other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100,700 ... Base station, 110,710 ... Mobile terminal, 120 ... Communication line, 124 ... Carrier frequency, 201, 301 ... CPU, 202, 302 ... Memory, 203, 303 ... Display device, 204, 304 ... Input / output device 205, 305 DSP, 206, mobile switching center interface unit, 210, 310 antenna, 218, 316 PN code generator, 240 TDD switch, 317 fading power control unit, 340 TDD switch.

Claims (11)

A terminal device that performs wireless communication with a base station,
A transmission power control means for generating a control target value of necessary transmission power determined according to a propagation situation with the base station;
A comparison means for comparing the control target value of the required transmission power with an allowable maximum transmission power ;
And a means for stopping signal transmission to the base station when the control target value of the required transmission power is equal to or greater than the allowable maximum transmission power .   The terminal apparatus according to claim 1, wherein a propagation state with the base station is determined based on a reception state of a reception signal from the base station.   The terminal apparatus according to claim 1, wherein a propagation state with the base station relates to fading of a signal with the base station. 2. The terminal device according to claim 1, wherein the signal transmission is a data packet transmission. 2. The terminal device according to claim 1, wherein when the signal transmission is stopped, the transmission is stopped over a period of one slot or more. A base station that performs wireless communication with a plurality of terminals,
Transmission power control means for generating a control target value of the required transmission power to the terminal determined according to the propagation status between each terminal;
A comparison means for comparing the control target value of the required transmission power with an allowable maximum transmission power ;
And a means for stopping signal transmission to the terminal when the control target value of the required transmission power is equal to or greater than the allowable maximum transmission power .   The base station according to claim 6, wherein a propagation state between the terminal device and the terminal device is determined based on a reception state of a reception signal from the terminal device.   The base station according to claim 6, wherein a propagation state with the terminal device relates to fading of a signal with the terminal device. The base station according to claim 6, wherein the signal transmission is a data packet transmission. The base station according to claim 6, wherein when the signal transmission is stopped, the transmission is stopped over a period of one slot or more. A computer-readable recording medium storing a program for executing transmission power control of a mobile communication system for controlling power of a packet signal transmitted between a base station and a mobile terminal, the mobile station and the mobile station Provided in at least one of the stations,
The program includes program means for obtaining a required transmission power for correcting a change in signal strength generated on a line according to a propagation situation between a base station and a mobile terminal, and a maximum transmission power that can be allowed by the required transmission power. A computer means comprising: program means for temporarily stopping transmission when the transmission power becomes larger; and program means for performing transmission when the required transmission power is less than or equal to the allowable maximum transmission power. Possible recording media.

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