JP2005168045A - Communications apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control transmission power with high precision for each slot in asymmetric communication. <P>SOLUTION: Request wave electric power measured with a request wave electric power measure circuit 105 is averaged over a plurality of slots with an equalization circuit 106, and electric power errors in requesting wave electric power of each of the slots are reduced. In an SIR measure circuit 108, SIR(n) of each of the slots is computed from the mean rate of the desired wave electric power of a plurality of the slots and the measurements of interference wave electric power of each of the slots. In a TPC-generating circuit 109, comparison between the SIR(n) of each of the slots and threshold is made, and transmission power control information is generated. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a communication device used in a wireless transmission system such as a car phone or a mobile phone.

  In a wireless transmission system such as a car phone or a cellular phone, in order to keep the SIR (Signal to Interference Ratio) constant and the BER (Bit Error Rate) below a predetermined value, Transmission power control according to the state of the transmission path is performed.

  The transmission power control method includes closed loop transmission power control and open loop transmission power control.

  In the closed loop transmission power control, the SIR corresponding to the reception quality is measured on the communication partner side for its own transmission signal, the transmission power is reduced when the measured SIR value is higher than the target SIR value, and the measured SIR value is the target. In this method, TPC (Transmit Power Control: transmission power control bit) that increases the transmission power when the SIR value is lower is transmitted on the reverse line, and the transmission power is controlled based on the contents of the TPC.

  On the other hand, the open loop transmission power control calculates the level lost in the radio section by subtracting the reception level from the transmission level of the known communication partner, and adds the reception level of the target communication partner to this lost level. This is a method for controlling the transmission power value.

  Here, in the future, it is expected that data communication in which the amount of downlink information is overwhelmingly larger than that in uplink will be mainstream, and the wireless communication system of asymmetric communication in which the amount of uplink and downlink data is asymmetrical Development is underway.

  However, until now, no method has been disclosed for controlling transmission power with high accuracy for each slot in a wireless communication system that performs asymmetric communication.

  The present invention has been made in view of this point, and an object of the present invention is to provide a communication apparatus capable of controlling transmission power with high accuracy for each slot in asymmetric communication.

  The communication apparatus of the present invention includes a signal including a plurality of transmission power control information and transmission data generated based on an SIR calculated from a signal of a plurality of time slots received by the communication partner in one time slot. A configuration having receiving means for receiving and transmission power control means for controlling the transmission power of each of the plurality of time slots based on each of the received plurality of transmission power control information is adopted.

  The communication system of the present invention is a communication system having at least two communication devices, wherein one communication device receives a signal from the other communication device for a plurality of time slots, and the reception device receives the signal. Transmission power control information generating means for generating each of a plurality of transmission power control information based on the SIR calculated from the signals of the plurality of time slots, a plurality of transmission power control information generated by the transmission power control information generating means, Transmission signal generating means for generating a transmission signal including transmission data in one time slot, and transmission means for transmitting the transmission signal generated by the transmission signal generating means to the communication partner, The communication device is configured to receive the transmission power of a plurality of time slots based on each of the reception unit that receives the transmission signal and each of the received transmission power control information. A configuration having a transmission power control means for controlling.

  According to the present invention, since it is possible to improve the measurement accuracy by reducing the power error of the desired wave power in each slot, it is possible to control the transmission power with high accuracy for each slot in asymmetric communication.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

(Embodiment 1)
In the first embodiment, a case of closed loop transmission power control will be described. FIG. 1 is a block diagram showing a configuration of a radio communication apparatus according to Embodiment 1 of the present invention.

  The duplexer 102 switches the path through which the signal passes during transmission and reception, outputs the signal received from the antenna 101 to the reception RF circuit 103, and outputs the transmission signal output from the transmission RF circuit 112 to the antenna 101. To do.

  The reception RF circuit 103 amplifies the reception signal, converts the frequency to baseband, and outputs it to the demodulation circuit 104. The demodulation circuit 104 demodulates the baseband signal and extracts the received data of the local station.

  The desired wave power measurement circuit 105 measures the received power (hereinafter referred to as “desired wave power”) of a known signal included in the output signal of the demodulation circuit 104 and outputs the measurement result to the averaging circuit 106. The averaging circuit 106 calculates an average value of desired wave powers in a plurality of slots, and outputs the average value to the SIR measurement circuit 108.

  Here, when the known signal sequence is long and the interference signal can be suppressed, and when the slots are close to each other and the received power due to fading is small, the desired wave power in each slot is almost equal. Therefore, by calculating the average value of the desired wave power of each slot, it is possible to improve the measurement accuracy of the desired wave power.

  The interference wave power measurement circuit 107 measures the power of the interference wave output from the demodulation circuit 104 and outputs the measurement result to the SIR measurement circuit 108.

  The SIR measurement circuit 108 calculates SIR (n) (n is a slot number) of each slot from the average value of desired wave power of a plurality of slots and the measured value of interference wave power of each slot, and outputs it to the TPC generation circuit 109. .

  The TPC generation circuit 109 compares the SIR (n) of each slot with a threshold value, generates transmission power control information instructing to increase the transmission power in a slot where the SIR (n) is lower than the threshold value, and generates SIR ( Transmission power control information for instructing to reduce the transmission power is generated in a slot in which n) is higher than the threshold. Then, the TPC generation circuit 109 outputs the generated transmission power control information of each slot to the multiplexing circuit 110.

  Multiplexer 110 multiplexes a plurality of transmission power control information into one slot of transmission data and outputs the multiplexed data to modulation circuit 111. The modulation circuit 111 modulates the output signal of the multiplexing circuit 110 and outputs it to the transmission RF circuit 112. The transmission RF circuit 112 converts the frequency of the output signal of the modulation circuit 111, amplifies the transmission power, and wirelessly transmits from the antenna 101 via the duplexer 102.

  FIG. 2 is a block diagram illustrating a configuration of a wireless communication device that is a communication partner of the wireless communication device of FIG.

  Duplexer 202 switches the path through which the signal passes during transmission and reception, outputs the signal received from antenna 201 to reception RF circuit 203, and outputs the transmission signal output from transmission RF circuit 208 to antenna 201. To do.

  The reception RF circuit 203 amplifies the reception signal, converts the frequency to baseband, and outputs the result to the demodulation circuit 204. The demodulation circuit 204 demodulates the baseband signal and outputs it to the separation circuit 205. Separation circuit 205 separates the output signal of demodulation circuit 204 into reception data and transmission power control information.

  A CL (Closed Loop) transmission power control circuit 206 controls increase / decrease in transmission power in the transmission RF circuit 208 based on the transmission power control information separated by the separation circuit 205.

  The modulation circuit 207 modulates the transmission data and outputs it to the transmission RF circuit 208. The transmission RF circuit 208 converts the frequency of the output signal of the modulation circuit 207, amplifies the transmission power based on the control of the CL transmission power control circuit 206, and wirelessly transmits from the antenna 201 via the duplexer 202.

  In this way, by averaging the desired wave power over a plurality of slots and performing the closed-loop transmission power control using the average value, the power error of the desired wave power in each slot is reduced and the measurement accuracy is improved. Therefore, the transmission power can be controlled with high accuracy for each slot in the closed-loop transmission power control of asymmetric communication.

(Embodiment 2)
In the second embodiment, a case of open-loop transmission power control provided with an outer loop that controls reference power for transmission power control will be described. FIG. 3 is a block diagram showing a configuration of a wireless communication apparatus according to Embodiment 2 of the present invention. In the wireless communication device shown in FIG. 3, the same reference numerals as those in FIG. 1 are given to the components having the same operations as those of the wireless communication device shown in FIG.

  3 employs a configuration in which an error correction decoding circuit 301, a CRC determination circuit 302, and a transmission power determination circuit 303 are added to the wireless communication apparatus shown in FIG.

The error correction decoding circuit 301 performs error correction decoding processing on the output signal of the demodulation circuit 104 and extracts received data. The CRC determination circuit 302 performs CRC determination on the output signal of the demodulation circuit 104. The transmission power determination circuit 303 calculates the transmission reference power value SIR _t of the communication partner using the CRC determination value output from the CRC determination circuit 302 as an indicator of reception quality.

Here, in general, when transmitting using a plurality of transmission slots, in order to distribute error bit positions and improve error correction capability, interleaving is performed so that transmission signals of all slots are randomly arranged. Has been given. In this case, the wireless communication apparatus transmits a signal indicating the transmission reference power value SIR _t to the communication partner, so that the reception power after error correction processing in all slots satisfies a predetermined quality. Can be controlled.

However, wireless communication device, only transmission reference power value SIR _t can not control according to the interference amount of each slot to a communication partner can not be reduced transmit power to interference level small slot Therefore, interference with other cells cannot be reduced.

Therefore, the transmission power determining circuit 303 of the wireless communication device adds the SIR (n) of each slot to the calculated transmission reference power value SIR _t, calculates a transmission reference power value SIR _t of each slot (n).

The multiplexing circuit 110 multiplexes information indicating the transmission reference power value SIR _t (n) on the transmission data and outputs the multiplexed data to the modulation circuit 111.

  FIG. 4 is a block diagram illustrating a configuration of a wireless communication device that is a communication partner of the wireless communication device of FIG. In the wireless communication apparatus shown in FIG. 4, the same components as those in FIG. 2 are denoted by the same reference numerals as those in FIG.

  Compared with the wireless communication apparatus shown in FIG. 2, the wireless communication apparatus shown in FIG. 4 has a desired wave power measurement circuit 401 and an OL (Open Loop) transmission power control circuit instead of the CL transmission power control circuit 206. 402 is added.

Separation circuit 205 separates the output signal of demodulation circuit 204 into reception data and transmission reference power value SIR _t (n).

  The desired wave power measurement circuit 401 measures the desired wave power S of the known signal included in the output signal of the demodulation circuit 204 and outputs the measurement result to the OL transmission power control circuit 402.

  The OL transmission power control circuit 402 calculates the transmission power T (n) of each slot according to the following equation (1), and controls increase / decrease of transmission power in the transmission RF circuit 208. However, Const in Equation (1) is a fixed value for gain adjustment.

T (n) = SIR _t (n) −S + Const (1)
In this way, by performing open loop transmission power control in consideration of the SIR of each slot in addition to the transmission reference power value, transmission power can be controlled with high accuracy for each slot in asymmetric communication.

1 is a block diagram showing a configuration of a wireless communication apparatus according to Embodiment 1 of the present invention. The block diagram which shows the structure of the radio | wireless communication apparatus used as the communicating party of the radio | wireless communication apparatus of FIG. FIG. 2 is a block diagram showing a configuration of a wireless communication apparatus according to Embodiment 2 of the present invention. The block diagram which shows the structure of the radio | wireless communication apparatus used as the communicating party of the radio | wireless communication apparatus of FIG.

Explanation of symbols

105 desired wave power measurement circuit 106 averaging circuit 107 interference wave power measurement circuit 108 SIR measurement circuit 109 TPC generation circuit 206 CL transmission power control circuit 301 error correction decoding circuit 302 CRC determination circuit 303 transmission power determination circuit 401 desired wave power measurement circuit 402 OL transmission power control circuit

Claims (6)

Receiving means for receiving, from a communication partner, a signal including a plurality of transmission power control information and transmission data generated based on SIR calculated from signals of a plurality of time slots received by the communication partner in one time slot;
And a transmission power control means for controlling transmission power of a plurality of time slots based on each of the received plurality of transmission power control information.   The communication apparatus according to claim 1, wherein the communication apparatus performs asymmetric communication with a communication partner.   The communication apparatus according to claim 1, wherein the transmission power control information is a TPC. A communication system having at least two communication devices,
One communication device is
Receiving means for receiving a signal from the other communication device for a plurality of time slots;
Transmission power control information generating means for generating each of a plurality of transmission power control information based on SIR calculated from signals of a plurality of time slots received by the receiving means;
Transmission signal generating means for generating a transmission signal including a plurality of transmission power control information and transmission data generated by the transmission power control information generating means in one time slot;
Transmission means for transmitting the transmission signal generated by the transmission signal generation means to the communication partner,
The other communication device
Receiving means for receiving the transmission signal;
And a transmission power control means for controlling transmission power of a plurality of time slots based on each of the received plurality of transmission power control information.   The communication system according to claim 4, wherein the two communication devices perform asymmetric communication with each other.   The communication system according to claim 4 or 5, wherein the transmission power control information is TPC.

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