JP2002026747A - Wireless communication terminal device and transmission power control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize prevention of deterioration in reception quality and prevention of interference to other stations, by conducting transmission power control with high accuracy, even when the information quantity of a packet, sent the first time, changes from information quantity of a retransmitted packet. SOLUTION: A received quality measurement circuit 205 measures reception quality of a retransmitted packet. A TPC command generating circuit 210 sets the object value of the received quality which depends on the information quantity of the repeated packet; and a reception quality measurement circuit 205 compares the measured reception quality with a set object value, and decreases the transmission power, when the measured reception quality is larger than the object reception quality or to increase the transmission power, when the measured reception quality is smaller than the object reception quality as its control.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication terminal that combines an automatic retransmission request and transmission power control, and more particularly to a communication terminal used for packet communication.

[0002]

2. Description of the Related Art In conventional wireless communication, in order to realize high quality transmission, an error control technique for correcting an error which cannot be recovered by equalization or diversity or the like is used. Automatic retransmission request (Automatic Retransmission Request) is one of the error control techniques.
peat Request: ARQ (hereinafter ARQ).

In this ARQ system, a transmitting side and a receiving side are connected by a bidirectional transmission path, and an error is detected on the receiving side by an error detection code transmitted together with information data. In the ARQ scheme, the receiving side sends a positive acknowledgment signal (Positive Acknowledd) when there is no error in the received data.
gment: ACK, hereafter referred to as ACK) to the sender.
If an error in the received data is detected, a retransmission request signal (Negative Acknowledgment: NACK, hereinafter NACK)
To the sender. When sending a NACK to the transmitting side, it requests retransmission from the transmitting side.

There is an error control technique called a hybrid ARQ scheme as one of the ARQ schemes. This hybrid ARQ scheme is a scheme in which an ARQ scheme is combined with an error correction code. As the hybrid ARQ scheme, i) a scheme in which a transmission packet is configured using a code capable of error correction and error detection, and the same packet as the first packet is retransmitted when a NACK is received on the transmission side; ii) The first packet Transmits a packet containing information and an error detection code in the same manner as in the basic ARQ scheme, and when a NACK is received by the transmitting side, instead of retransmitting the information for the second time, an error correction code for the information is used. (This error correction code has the same length as the transmission data, and is also called an invertible code.) A method for correcting the error of the information transmitted the first time, and iii) The basic ARQ method is used for the first time. Similarly, when the information and the error detection code are transmitted and the NACK is received by the transmission side, the error correction coded information is retransmitted from the second time onward, and the error correction capability is improved at each retransmission. Iv) The first time, information and its error-corrected code are sent together, and if a NACK is received on the transmitting side, only the error-corrected code of the information is retransmitted, etc. It has been known. As a definition of a term, in the ARQ scheme, a unit of data to be transmitted or retransmitted is called a packet.

Here, data transmission using the iii) type ARQ scheme will be described. First, information data 2 to which an error detection code 1 and ARQ control information 3 are attached is transmitted from the transmission side as shown in FIG. The receiving side decodes the error detection code every time one packet is received, and detects the presence or absence of an error. If no error can be detected, the reception is determined to be normal and the ACK of the packet is transmitted to the transmission side. When an error is detected, the error packet is stored in a memory provided on the receiving side, and a NACK of the packet is transmitted to the transmitting side. The sending side is ACK
Is received, the packet following the packet corresponding to the ACK is transmitted. When the NACK is received, since this time is the second transmission, a packet obtained by performing error correction coding on the packet is retransmitted as a retransmission packet. When receiving the retransmission packet, the receiving side combines the packet stored in the memory with the retransmission packet and performs error correction.

[0006] In the conventional radio communication, transmission power control that adaptively changes transmission power on the transmission side so as to obtain an optimum reception level on the reception side and reduces the influence of interference with other stations is performed. Used.

In the transmission power control, the measurement of the reception quality and the increase / decrease of the transmission power are performed, for example, in one slot cycle. In this case, the magnitude of the measured reception quality (measured reception quality) and the target reception quality (target reception quality) are determined, and if the measured reception quality is high, an instruction to reduce the transmission power is sent to the transmission side, and the measurement is performed. If the reception quality is low, a command to increase the transmission power is sent to the transmission side. The transmitting side increases or decreases the transmission power accordingly.

[0008]

The above iii) type A
In the RQ scheme, when a packet including, for example, J-bit information data is transmitted in the first transmission, the information data is error-correction-coded at the time of retransmission, and a retransmission packet including K (> J) -bit information data is transmitted. Resent. This retransmission packet is compared with the first transmission packet by (K-
Since the amount of information is large by J) bits, the packet is transmitted with higher transmission power than the first transmitted packet. However, the target reception quality of the packet transmitted first time is set on the receiving side, so that the measured reception quality of the retransmission packet transmitted with the transmission power larger than that of the first transmission packet is higher than the target reception quality. Falsely determined to be large,
An incorrect command to lower the transmission power is sent to the transmitting side.
For this reason, there is a problem that a packet transmitted next to the retransmission packet is transmitted with transmission power lower than desired transmission power, and reception quality is degraded.

In the ARQ method of the above iv) type,
When transmitting L-bit information data and M-bit data obtained by performing error correction coding on the information data at the first transmission, only the M-bit data is retransmitted as a retransmission packet at the time of retransmission. Since the retransmission packet has a smaller information amount by L bits compared to the first transmission packet,
It is transmitted with a transmission power smaller than the first transmitted packet. However, since the target reception quality of the first transmitted packet is set on the receiving side, the measured reception quality of the retransmission packet transmitted with a smaller transmission power than the first transmission packet is higher than the target reception quality. Is erroneously determined to be too small, and an erroneous command to increase the transmission power is sent to the transmission side. For this reason, there is a problem that a packet transmitted next to the retransmission packet is transmitted with transmission power higher than desired transmission power, and interference with other stations increases.

As described above, when the information amount of the packet transmitted first and the information amount of the retransmitted packet are different, the reception quality of the retransmitted packet is erroneously determined. You. As a result, there is a problem that reception quality is degraded when an instruction to reduce transmission power is issued by mistake, and there is a problem that interference with other stations increases when an instruction to increase transmission power is made by mistake.

[0011] The present invention has been made in view of such a point, and even when the information amount of the first transmitted packet and the information amount of the retransmission packet change, the transmission power control is performed with high accuracy, and the reception quality is improved. And to prevent interference with other stations.

[0012]

According to the present invention, there is provided a radio communication terminal apparatus comprising: a measuring unit for measuring a reception quality of a retransmission packet;
Comparing the target value of the reception quality set in accordance with the information amount of the retransmission packet and the reception quality measured by the measuring means, if the measured reception quality is larger than the target reception quality, reduce the transmission power, When the measured reception quality is smaller than the target reception quality, a control unit that controls the transmission power so as to increase the transmission power is adopted.

According to this configuration, the target value of the reception quality is set according to the information amount of the retransmission packet, and the reception quality of the received packet is determined based on the set target value, so that the information amount of the packet changes. Even in this case, transmission power control can be performed with high accuracy.

[0014] The wireless communication terminal of the present invention employs a configuration in the above-mentioned wireless communication terminal, which comprises a setting means for setting a target value of the reception quality in accordance with the information amount of the retransmission packet.

According to this configuration, even when the information amount of the packet changes, transmission power control can be accurately performed.

In the wireless communication terminal device according to the present invention, in the above wireless communication terminal device, when the information amount of the retransmission packet increases as compared with the information amount of the previously transmitted packet, the setting means may set a target of reception quality. A configuration is adopted in which the value is set higher than the target value of the previously transmitted packet.

According to this configuration, even when the information amount of the retransmission packet increases, transmission power control can be performed with high accuracy.

In the wireless communication terminal device according to the present invention, in the above wireless communication terminal device, the setting means may include a target of reception quality when the information amount of the retransmitted packet is smaller than the information amount of the previously transmitted packet. A configuration is adopted in which the value is set lower than the target value of the previously transmitted packet.

According to this configuration, even when the information amount of the retransmission packet decreases, the transmission power control can be performed with high accuracy.

The wireless communication terminal according to the present invention, in the above wireless communication terminal, comprises a transmission power control signal generating means for generating a transmission power control signal for instructing an increase or decrease of transmission power, and a transmission power control signal generated by said transmission power control means. Wireless transmission means for wirelessly transmitting the power control signal to the base station apparatus as the communication partner.

The radio base station apparatus according to the present invention includes a transmission power control means for performing radio communication with the radio communication terminal apparatus and controlling transmission power in accordance with a transmission power control signal wirelessly transmitted from the radio communication terminal apparatus. Take.

According to these configurations, the transmission power control can be accurately performed in the base station apparatus even when the information amount of the packet changes.

The radio base station apparatus according to the present invention comprises: setting means for setting a target value of the reception quality of the retransmission packet according to the information amount of the retransmission packet; and setting the target value set by the setting means to the radio communication terminal apparatus. Notification means for notifying
Is adopted.

According to this configuration, even if the information amount of the retransmission packet increases, the transmission power control can be performed with high accuracy, and the processing amount of the communication terminal device can be reduced.

According to the transmission power control method of the present invention, the reception quality of a retransmission packet is measured, and a reception quality target value set according to the information amount of the retransmission packet is compared with the reception quality measured by the measuring means. If the measured reception quality is higher than the target reception quality, the transmission power is reduced, and if the measured reception quality is lower than the target reception quality, the transmission power is increased.

According to this method, transmission power control can be accurately performed even when the amount of information of a packet changes.

[0027]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The gist of the present invention is that when the information amount of a packet transmitted first and the information amount of a retransmitted packet of the packet are different, the retransmitted packet is changed according to the information amount of the retransmitted packet. Set the target reception quality, reduce the transmission power if the measured reception quality of the retransmitted packet is higher than the target reception quality, and increase the transmission power if the measured reception quality is lower than the target reception quality Is to control the transmission power with higher accuracy.

(Embodiment 1) FIG. 1 is a block diagram showing a configuration of a base station apparatus according to Embodiment 1 of the present invention.
FIG. 1 shows an example in which a CRC code is used as an error detection code and a convolutional code is used as an error correction code. In this base station apparatus, a signal received by antenna 101 is sent to reception RF circuit 103 through duplexer 102 for using the same antenna for transmission and reception. In the reception RF circuit 103, the reception signal is amplified and frequency-converted to an intermediate frequency or a baseband frequency.

The frequency-converted signal is supplied to the demodulation circuit 104
Is demodulated. The demodulation result is sent to the separation circuit 105,
Separation circuit 105 receives the received data and a transmission power control command (hereinafter, “TPC”) for instructing an increase or decrease of the transmission power.
Command) and a control signal indicating ACK or NACK (hereinafter, referred to as “retransmission control signal”). The transmission power control circuit 110 determines whether the TPC command indicates an increase or a decrease in the transmission power,
The amplification factor of the transmission RF circuit 111 is controlled based on the determination result.

Retransmission control circuit 106 determines whether or not to retransmit a packet according to a retransmission control signal, and controls multiplexing circuit 107 according to the determination. That is, when the retransmission control signal is NACK, it is determined that the packet is to be retransmitted, and the same transmission data as the previous transmission and the CRC code corresponding to the transmission data are assigned to the transmission packet. Conversely, when the retransmission control signal is ACK, it is determined that a new packet is to be transmitted, and new transmission data and a CRC code corresponding to the transmission data are assigned to the transmission packet.

The retransmission control circuit 106 controls the encoding circuit 108 according to the decision whether to retransmit the packet. That is, the retransmission control circuit 106 is provided with a table (not shown) indicating the correspondence between the number of packet transmissions and the coding rate of the convolutional code.
Knows the number of transmissions from the number of times NACK has been received, and refers to this table to control the encoding circuit 108 to perform convolutional coding at an encoding rate corresponding to the number of transmissions. The number of packet transmissions and the coding rate of the convolutional code correspond to increase the coding rate as the number of retransmissions increases. Here, it is assumed that convolutional coding is not performed at the time of the first transmission and convolutional coding is performed with N being a natural number of 2 or more and a coding rate of 1 / N at the time of the Nth transmission. . Further, retransmission control circuit 106 generates ARQ control information indicating the number of packet transmissions and the like, and outputs the generated ARQ control information to multiplexing circuit 107.

The multiplexing circuit 107 transmits transmission data and a CRC code (error detection code) under the control of the retransmission control circuit 106.
And ARQ control information are assigned to the transmission packet. The coding circuit 108 performs convolutional coding on the transmission packet output from the multiplexing circuit 107 at a coding rate according to the control of the retransmission control circuit 106. The convolutionally encoded transmission packet is modulated by the modulation circuit 109 and sent to the transmission RF circuit 111. The transmission RF circuit 111 amplifies the transmission packet at an amplification factor according to the control of the transmission power control circuit 110. This transmission packet is transmitted from the antenna 101 through the duplexer 102.

FIG. 2 is a block diagram showing a configuration of a communication terminal apparatus that performs radio communication with the base station apparatus according to Embodiment 1 of the present invention.

The packet received by the antenna 201 is
Duplexer 20 for using the same antenna for transmission and reception
2 to the receiving RF circuit 203, where it is amplified and further frequency-converted to an intermediate frequency or baseband frequency. The frequency-converted packet is output to the reception quality measurement circuit 205, the memory 206, and the combining circuit 207.

The memory 206 stores a received packet output from the reception RF circuit 203 under the control of a CRC determination circuit 208 described later. The combining circuit 207 refers to the ARQ control information included in the received packet to determine the number of times the received packet has been transmitted, and reads out the packet stored in the memory 206 according to the determined number of transmissions. The packets are combined, and error correction processing is performed on the combined packets. That is, if the received packet is the first transmitted packet, it is not combined with the packet stored in the memory 206, and if the received packet is the second transmitted packet or later, the received packet is stored in the memory 206. Each packet that has been transmitted up to the previous time is read out and combined with the packet output from the reception RF circuit 203. As a result, the retransmitted packets are combined, and the combined packets are subjected to error correction, so that the error rate characteristics during error correction (decoding) are improved. The synthesizing circuit 20
7 is provided with a table indicating the correspondence between the number of packet transmissions and the coding rate of the convolutional code, and performs error correction with reference to this table. Since this table is the same as that provided in the retransmission control circuit 106, it is possible to perform error correction corresponding to the convolutional coding performed in the base station apparatus.

The reception quality measuring circuit 205 measures the SIR (Signal-to-Interference Ratio) to check the reception quality of the received signal output from the reception RF circuit 203. The measured SIR is TP
It is sent to the C command generation circuit 210. As a method of examining the reception quality, in addition to the method of examining the SIR, for example, a reception electric field strength, a desired signal reception power, a reception signal power to interference power + noise power ratio (Signal-to-Interference plus No.
ise Ratio (hereinafter abbreviated as SINR).

The CRC determining circuit 208 is composed of the combining circuit 207
A CRC (Cyclic Redundancy Check) is performed on the output error-corrected packet, and it is determined whether or not the data has an error. If an error is detected (CRC = NG), the NG signal is stored in the memory 206.
And to the retransmission control circuit 209. When an error is detected, the memory 2 stores the received packet.
06 is controlled. Conversely, when no error is detected (when CRC = OK), the reception data is obtained and an OK signal is output to the memory 206 and the retransmission control circuit 209. In addition, when no error is detected, the memory 206 is controlled so that a received packet that has been successfully received is deleted.

The retransmission control circuit 209 is provided with a CRC determination circuit 2
The ARQ control information included in the packet determined in step 08 is extracted and output to the TPC command generation circuit 210.
Further, when the NG signal is output from the CRC determination circuit 208, the retransmission control circuit 209 generates a NACK and outputs it to the frame configuration circuit 211. Conversely, when the OK signal is output, the retransmission control circuit 209 generates an ACK and generates the ACK. Output to 211.
As described above, the ACK and the NACK are collectively referred to as a retransmission control signal.

TPC command generation circuit 210 sets a target SIR based on the ARQ control information output from retransmission control circuit 209, and compares the set target SIR with the measurement SIR measured by reception quality measurement circuit 205. To generate a TPC command. TPC command generation circuit 2
10 will be described in detail later.

The frame configuration circuit 211 receives the retransmission control signal from the retransmission control circuit 209 and the TPC command generation circuit 2
The TPC command from 10 and transmission data form a frame. The signal having the frame configuration is modulated by the modulation circuit 212, amplified by the transmission RF circuit 213, and frequency-converted. This transmission signal is transmitted from antenna 201 through duplexer 202.

Next, the operation of the base station apparatus and the communication terminal apparatus having the above configurations will be described. Here, first,
Packet P1 is transmitted and received without error, and then P
2 is transmitted and erroneously received, P2 'which is a retransmission packet of P2 is retransmitted, and P2' is received without error, and P3 is transmitted. P1 to P3, which are the first transmitted (not retransmitted) packets
Is processed in the same manner, and a case where P2 is transmitted will be described as an example. An error is detected in P2 in the communication terminal apparatus, NACK is transmitted to the base station apparatus, and a retransmission packet P2 'is transmitted.

In the base station apparatus, the transmission data, CRC code and ARQ control information are assigned to the packet in the multiplexing circuit 107 to form a transmission packet P2. Since this transmission packet P2 is a packet transmitted for the first time, it is output to the modulation circuit 109 as it is without being subjected to convolutional coding in the encoding circuit 108, and is modulated.
The signal is amplified by the circuit 111 and transmitted from the antenna 101 through the duplexer 102.

In the communication terminal apparatus, the packet P 2 received from the antenna 201 is
The signal is sent to the F circuit 203, where it is amplified and further frequency-converted to an intermediate frequency or a baseband frequency. The frequency-converted packet is received by the reception quality measurement circuit 205,
The data is output to the memory 206 and the synthesis circuit 207.

The packet output to the synthesizing circuit 207 is output as it is to the CRC judging circuit 208, and the CRC judging circuit 208 makes a CRC judgment. In this example, since P2 is incorrect, an NG signal is output to the memory 206 and the retransmission control circuit 209. The reception RF circuit 2 is stored in the memory 206.
03 is stored.

In the reception quality measuring circuit 205, the SIR of the received packet P2 is measured.
It is output to the PC command generation circuit 210. In the retransmission control circuit 209, NACK is generated according to the NG signal from the CRC determination circuit 208, and output to the frame configuration circuit 211.

In the TPC command generation circuit 210, a target SIR is set according to the ARQ control information output from the retransmission control circuit 209, and the set target SIR is set.
A TPC command is generated based on the measurement SIR output from the reception quality measurement circuit 205. For example, it is assumed here that a TPC command for lowering the transmission power is generated. The generated TPC command is output to the frame configuration circuit 211. In the frame configuration circuit 211,
NACK from the retransmission control circuit 209, a TPC command from the TPC command generation circuit 210, and transmission data form a frame. The signal having the frame configuration is modulated by the modulation circuit 212, amplified by the transmission RF circuit 213, and frequency-converted. This transmission signal is transmitted from antenna 201 through duplexer 202.

In the base station apparatus again, the antenna 101
Are transmitted to the reception RF circuit 103 through the duplexer 102. In the reception RF circuit 103, the reception signal is amplified and frequency-converted to an intermediate frequency or a baseband frequency.

The frequency-converted signal is supplied to the demodulation circuit 104
Is demodulated. The demodulation result is sent to the separation circuit 105,
The received data, TPC command, N
ACK and ACK. The transmission power control circuit 110 determines that the TPC command instructs an increase in the transmission power, and performs control to increase the amplification factor of the transmission RF circuit 111 by a predetermined amount.

In the retransmission control circuit 106, the separation circuit 105
In accordance with the output NACK, multiplexing circuit 107 is controlled to transmit the same transmission data as the previous transmission.
ARQ indicating that the packet is the first retransmission, etc.
Control information is generated and output to multiplexing circuit 107. In the multiplexing circuit 107, the same transmission data as in the previous transmission and the CRC code and ARQ control information corresponding to the transmission data are assigned to the packet to make a retransmission packet P2 '. This P2 'is output to the encoding circuit 108. P2 'is 2
Since this is the second transmission, the encoding circuit 108 performs convolutional encoding at an encoding rate of 1/2 under the control of the retransmission control circuit 106. Therefore, P2 'has almost twice the number of code bits (information amount) as compared with P2. P2 'is output to the transmission RF circuit 111. P2 'is transmitted at a transmission power that is approximately twice the transmission power of P2 so that the transmission rate is not reduced by the transmission RF circuit 111, and transmitted from the antenna 101 through the duplexer 102.

In the communication terminal again, the packet P2 'received from the antenna 201 is sent to the receiving RF circuit 203 through the duplexer 202, where it is amplified and further frequency-converted to an intermediate frequency or a baseband frequency. The frequency-converted packet is received by the reception quality measurement circuit 2
05, the memory 206, and the synthesis circuit 207.

When the combining circuit 207 checks that the packet P2 'is a retransmission packet based on the ARQ control information included in the packet, the combining circuit 207 combines the packet P2' with the first transmitted packet P2 read from the memory 206. , And the combined signal is error-corrected. This error-corrected packet is subjected to CRC determination by the CRC determination circuit 208. In this example, since P2 'has no error, received data is obtained and an OK signal is output to the memory 206 and the retransmission control circuit 209.

The reception quality measurement circuit 205 measures the SIR of the received packet P2 ', and outputs the measured SIR to the TPC command generation circuit 210. The retransmission control circuit 209 generates an ACK according to the OK signal from the CRC determination circuit 208 and outputs the ACK to the frame configuration circuit 211.

The TPC command generation circuit 210 sets a target SIR based on the ARQ control information output from the retransmission control circuit 209, and sets the target SIR.
R and the measurement SIR output from the reception quality measurement circuit 205
The TPC command is generated based on For example, it is assumed here that a TPC command for lowering the transmission power is generated. The generated TPC command is output to the frame configuration circuit 211. In the frame configuration circuit 211, the ACK from the retransmission control circuit 209, the TPC command from the TPC command generation circuit 210, and the transmission data are framed. The signal thus framed is modulated by the modulation circuit 212 and transmitted by the transmission RF circuit 213.
Is amplified and frequency-converted. This transmission signal is transmitted from antenna 201 through duplexer 202.

Here, the setting of the target SIR in the TPC command generation circuit 210 will be described. The target SIR of the first transmitted packet is set in the TPC command generation circuit 210 in advance. Each time the TPC command generation circuit 210 receives a packet,
The number of transmissions of the received packet is known by referring to the ARQ control information output from the retransmission control circuit 209, and a target SIR is set according to the number of transmissions. That is, as a result of referring to the ARQ control information, if the packet received this time is the first transmission packet, the target SIR of the previously transmitted first packet is set as it is, and the packet is received this time. If the packet is the second transmission packet (retransmission packet), since the retransmission packet is transmitted with approximately twice the transmission power of the first transmission packet, the target SIR is also the packet transmitted in the first transmission. Approximately twice the target SIR. When the packet received this time is the third transmission packet (retransmission packet), the target SIR is also transmitted at three times the transmission power of the first transmission. Set to three times the target SIR of the transmitted packet. Hereinafter, similarly, the number of transmissions is checked based on the ARQ control information, and a target SIR according to the number of transmissions is set.

As a definition of terms, a target SIR of a packet transmitted for the first time is referred to as a “first target SIR”,
The target SIR of the packet transmitted for the second time is referred to as “second target SIR”.

Here, generation of a TPC command in the TPC command generation circuit 210 will be described with reference to FIG. FIG. 3 shows an example of measuring the SIR of the packets P1 to P3. In the TPC command generation circuit 210, the target SIR set as described above and the reception quality measurement circuit 2
A TPC command is set based on the measurement SIR output from the step S05. This figure shows an example in which a TPC command is generated every time one packet is received.

Upon receiving packet P1, communication terminal apparatus according to the present embodiment performs error detection and performs SIR
Is measured and compared with the first target SIR. In this example,
Since there is no error in P1 and the measured SIR is smaller than the first target SIR, an ACK and a command to increase the transmission power are sent to the base station device. The base station apparatus transmits the ACK and the transmission power control circuit 110 according to the instruction to increase the transmission power.
To increase the transmission power and transmit P2. The communication terminal device
When packet P2 is received, error detection is performed and S
Measure the IR and compare it to the first target SIR. In this example, since P2 is erroneously received and the measured SIR is larger than the first target SIR, a NACK and a command to reduce the transmission power are sent to the base station apparatus. The base station device is NA
A retransmission packet P2 'obtained by convolutionally encoding P2 at an encoding rate of 1/2 in accordance with CK and a command to lower the transmission power is retransmitted. Therefore, P2 'contains twice as many code bits as P2, and the amount of information is about twice. When receiving the packet P2 'transmitted in this way, the communication terminal device performs error correction by combining the packet P2' and P2, and performs error detection on the data after error correction. Since P2 'is the second retransmitted packet, the measured SIR is compared with the second target SIR. In this example, there is no error in the data after error correction, and the measured SIR is smaller than the second target SIR. Therefore, an ACK and an instruction to increase the transmission power are sent to the base station apparatus. The base station apparatus increases the transmission power according to the ACK and the instruction to increase the transmission power, and transmits the next packet P3. Upon receiving the packet P3, the communication terminal apparatus performs error detection, measures the SIR, and compares the measured SIR with the target SIR. In this example, P3 is incorrect,
Since the measured SIR is large compared to the target SIR, NAC
K and a command to reduce the transmission power are sent to the base station apparatus.

As described above, by setting the target SIR according to the information amount of the retransmitted packet, even if the information amount of the retransmitted packet changes as compared with the information amount of the first transmitted packet. , The reception quality of the packet can be correctly determined.

As described above, according to the present embodiment, the target SIR is appropriately changed and set according to the information amount of the retransmission packet, and the reception quality of the packet received with the set target SIR is determined. Therefore, even when the information amount of the transmission packet changes, transmission power control can be performed with high accuracy.

In this embodiment, a case has been described where the communication terminal apparatus knows the number of packet transmissions with reference to the ARQ control information and sets the target SIR according to the number of transmissions. Is not limited to this. That is, in the base station apparatus, ARQ
The number of packet transmissions is known by referring to the control information, a target SIR is set according to the number of transmissions, and the set target SIR is notified to the communication terminal. The communication terminal is notified by the base station. The reception quality of the packet may be determined based on the target SIR. in this case,
In the base station apparatus, retransmission control circuit 106 sets a target SIR according to the number of retransmissions, and sets the set target SIR to ARQ.
It is included in the control information and sent to the communication terminal device. Note that the method of setting the target SIR is the same as the method of setting the target SIR in the TPC command generation circuit 210. In the communication terminal device, the TPC command generation circuit 210 knows the target SIR by referring to the ARQ control information, and generates a TPC command based on the target SIR.

Also, in the present embodiment, the TPC is appropriately performed in the communication terminal apparatus according to the information amount of the transmission packet.
Although the case where the command is generated has been described, the present invention is not limited to this, and the TPC command may be generated appropriately in the base station apparatus according to the information amount of the transmission packet. Hereinafter, a case will be described where a TPC command is appropriately generated in the base station apparatus according to the information amount of a transmission packet. In this case, the hybrid ARQ scheme is applied to the system in which the communication terminal is used as a packet transmitting side.

In the communication terminal device, transmission data and CR
A transmission packet to which the C code and the ARQ control information are assigned is transmitted to the base station device. The base station device measures the SIR of the packet received from the antenna. Also,
The target SIR is determined by the target SI
As in the case where R is set, the number of transmissions of the received packet is known based on the ARQ control information, and is set appropriately according to the number of transmissions. Then, the TPC command is generated by comparing the target SIR thus set and the measured SIR. The base station device transmits the TPC command generated in this way to the communication terminal device, and the communication terminal device controls uplink transmission power based on the transmitted TPC command.

As described above, the target SIR is appropriately changed and set in the base station apparatus according to the information amount of the retransmission packet, and the reception quality of the packet received with the set target SIR is determined, so that the transmission is performed with high accuracy. It is also possible to perform power control.

(Embodiment 2) In Embodiment 1, when performing packet communication on the downlink, in a hybrid ARQ in which the amount of information of the first transmitted packet and that of the retransmission packet are different, the transmission power of the closed loop The example of performing the control has been described. This embodiment is an example of performing uplink open-loop transmission power control in a hybrid ARQ in which the amount of information of a packet to be transmitted first and the amount of information of a retransmission packet are different when performing packet communication on the downlink. Hereinafter, the present embodiment will be described with reference to FIGS. FIG. 4 is a block diagram showing a configuration of a base station apparatus according to Embodiment 2 of the present invention.
FIG. 5 is a block diagram showing a configuration of a communication terminal device according to Embodiment 2 of the present invention. 4, the same parts as those in FIG. 1 are denoted by the same reference numerals, and the detailed description will be omitted.

First, the base station apparatus according to the present embodiment will be described using FIG. FIG. 4 shows an example in which a CRC code is used as an error detection code and a convolutional code is used as an error correction code. In this base station apparatus, a signal received by antenna 101 is sent to reception RF circuit 103 through duplexer 102 for using the same antenna for transmission and reception. In the reception RF circuit 103, the reception signal is amplified,
The frequency is converted to an intermediate frequency or a baseband frequency.

The frequency-converted signal is supplied to the demodulation circuit 104
Is demodulated. The demodulation result is sent to the separation circuit 105,
Separation circuit 105 separates the data into reception data and a retransmission control signal. The retransmission control circuit 106 determines whether or not to retransmit the packet according to the retransmission control signal, and controls the multiplexing circuit 107 according to the determination. The multiplexing circuit 107 allocates transmission data, a CRC code (error detection code), and ARQ control information to a transmission packet under the control of the retransmission control circuit 106. The coding circuit 108 performs convolutional coding on the transmission packet output from the multiplexing circuit 107 at a coding rate according to the control of the retransmission control circuit 106. The convolutionally encoded transmission packet is modulated by the modulation circuit 109 and sent to the transmission RF circuit 111. Transmission RF circuit 111
Amplifies a transmission packet and performs frequency conversion. This transmission packet is transmitted from the antenna 101 through the duplexer 102.

Next, the configuration of the communication terminal apparatus according to the present embodiment will be described with reference to FIG. Antenna 40
1 is received by the receiving RF circuit 4 through the duplexer 402 for using the same antenna for transmission and reception.
03, where it is amplified and frequency converted to an intermediate or baseband frequency. The frequency-converted packet is received by the reception quality measurement circuit 405 and the memory 40.
6 and output to the synthesis circuit 407.

The memory 406 stores a received packet output from the reception RF circuit 403 when an NG signal is input from a CRC determination circuit 408 described later. The combining circuit 407 refers to the ARQ control information included in the received packet to check how many times the received packet has been transmitted, and according to the determined number of transmissions, the memory 406
Is read and combined, and error correction processing is performed on the combined packet. That is, when the received packet is the first transmitted packet, the packet is not combined with the packet stored in the memory 406, and
In the case of a packet transmitted after the first time, the memory 40
6 is read out and combined with the packet output from the reception RF circuit 403. As a result, the retransmitted packets are combined, and the combined packets are subjected to error correction, so that the error rate characteristics during error correction (decoding) are improved.
The combining circuit 407 is provided with a table indicating the correspondence between the number of packet transmissions and the coding rate of the convolutional code, and performs error correction with reference to this table. Since this table is the same as that provided in the retransmission control circuit 106, it is possible to perform error correction corresponding to the convolutional coding performed in the base station apparatus.

The reception quality measurement circuit 405 measures the SIR (received signal to interference power ratio) in order to check the reception quality of the reception signal output from the reception RF circuit 403. The measured SIR is sent to the transmission power determination circuit 410.
As a method of examining the reception quality, in addition to the method of examining the SIR, for example, there is a method of measuring a reception electric field strength, a desired wave reception power, a ratio of reception signal power to interference power + noise power, or the like.

The CRC judging circuit 408 includes a synthesizing circuit 407
A CRC (Cyclic Redundancy Check) is performed on the output error-corrected packet, and it is determined whether or not the data has an error. If an error is detected (CRC = NG), the NG signal is stored in the memory 406.
And to the retransmission control circuit 409. On the other hand, when no error is detected (when CRC = OK), received data is obtained and an OK signal is output to the memory 406 and the retransmission control circuit 409.

The retransmission control circuit 409 controls the CRC judgment circuit 4
The ARQ control information included in the packet determined in step 08 is extracted and output to the transmission power determination circuit 410. Also,
The retransmission control circuit 409 determines that the CRC
When a signal is output, a NACK is generated and output to the frame configuration circuit 411. Conversely, when an OK signal is output, AACK is output.
CK is generated and output to the frame configuration circuit 411.

The transmission power determination circuit 410 uses the T
Similarly to the PC command generation circuit 210, a target SIR is set based on the ARQ control information, and the set target SIR is set.
Is compared with the measurement SIR measured by the reception quality measurement circuit 405, and the transmission power of the transmission RF circuit 414 described later is determined so that the measurement SIR approaches the target SIR. That is, the magnitude of the downlink measured SIR measured by the reception quality measurement circuit 405 and the target SIR are determined, and if the measured SIR is large, the transmission power is reduced, and if the measured reception quality is small, the transmission power is increased. Determine the power. The transmission power control circuit 413 controls the transmission power of the transmission RF circuit 414 with reference to the transmission power determined by the transmission power determination circuit 410.

The frame forming circuit 411 forms a frame of the retransmission control signal from the retransmission control circuit 409 and the transmission data. The signal thus framed is modulated by the modulation circuit 412, amplified by the transmission RF circuit 414 at an amplification factor according to the control of the transmission power control circuit 413, and frequency-converted. This transmission signal is transmitted from antenna 401 through duplexer 402.

Next, the operation of the base station apparatus and the communication terminal apparatus having the above configuration will be described. In the base station device,
In the multiplexing circuit 107, the transmission data, CRC code and A
The RQ control information and the RQ control information are allocated to the packet to become a transmission packet. This transmission packet is convolutionally coded by the coding circuit 108 at a coding rate according to the control of the retransmission control circuit 106, modulated by the modulation circuit 109, amplified by the transmission RF circuit 111, and transmitted through the duplexer 102 to the antenna 1.
Sent from 01. Note that, in the case of the first transmission, the transmission packet is output to the modulation circuit 109 without being subjected to convolutional coding in the coding circuit 108.

In the communication terminal apparatus, the packet received from antenna 401 is sent to reception RF circuit 403 through duplexer 402, where it is amplified and further frequency-converted to an intermediate frequency or baseband frequency. The frequency-converted packet is output to the reception quality measurement circuit 405, the memory 406, and the combining circuit 407.

The reception quality measurement circuit 405 measures the SIR of the received packet, and outputs the measured SIR to the transmission power determination circuit 410. The retransmission control circuit 409 generates a retransmission control signal according to the OK signal or the NG signal from the CRC determination circuit 408,
11 is output. In the retransmission control circuit, ARQ control information included in the packet determined by the CRC determination circuit 208 is extracted and sent to the transmission power determination circuit 410.

In transmission power determination circuit 410, a target SIR is set according to the ARQ control information output from retransmission control circuit 409, and the set target SIR and the measured SIR output from reception quality measurement circuit 405 are determined. The transmission power of the transmission RF circuit 414 is determined based on In the frame configuration circuit 411, a retransmission control signal from the retransmission control circuit 409 and transmission data are configured in a frame. The signal thus framed is modulated by the modulation circuit 412 and transmitted by the transmission RF circuit 414 to the transmission power control circuit 413.
Is amplified and frequency-converted according to the above control. This transmission signal is transmitted from antenna 401 through duplexer 402.

As described above, according to the present embodiment, the target SIR is appropriately changed and set according to the information amount of the retransmission packet, and the reception quality of the packet received with the set target SIR is determined. Therefore, even when the information amount of the transmission packet changes, it is possible to accurately perform downlink transmission power control.

(Embodiment 3) In each of the above embodiments, the target SIR is appropriately changed and set according to the information amount of the packet, so that the first transmitted packet and the retransmitted packet in the hybrid ARQ are Even when the information amount is different, the reception quality of the received packet is correctly determined, and the transmission power control is performed with high accuracy. When performing packet communication on the uplink, a method for correctly performing transmission power control in the hybrid ARQ is to appropriately change the target reception power of the base station apparatus in uplink open-loop transmission power control according to the information amount of the packet. It is also conceivable to set by setting. Hereinafter, the present embodiment will be described with reference to FIGS. FIG. 6 is a block diagram showing a configuration of a communication terminal apparatus according to Embodiment 3 of the present invention, and FIG. 7 is a block diagram showing a configuration of a base station apparatus according to Embodiment 3 of the present invention.

First, a communication terminal apparatus according to the present embodiment will be described with reference to FIG. The signal received by the antenna 601 is sent to the reception RF circuit 603 through the duplexer 602 for using the same antenna for transmission and reception. In the reception RF circuit 603, the reception signal is amplified and frequency-converted to an intermediate frequency or a baseband frequency.
The frequency-converted signal is output to the demodulation circuit 604 and the propagation loss measurement circuit 606.

The demodulation circuit 604 demodulates a data portion included in the signal whose frequency has been converted by the reception RF circuit 603. Separation circuit 605 separates the demodulation result into reception data and a retransmission control signal, and separates the retransmission control signal
8 is output. On the other hand, the propagation loss measuring circuit 606 extracts a common known signal from the reception signal output from the reception RF circuit 603, and measures the propagation loss of the extracted common known signal. The measured propagation loss is sent to the transmission power determination circuit 607.

Retransmission control circuit 608 determines whether or not to retransmit a packet according to a retransmission control signal, and controls multiplexing circuit 609 according to the determination. That is, when the retransmission control signal is NACK, it is determined that the packet is to be retransmitted, and the same transmission data as in the previous transmission and the CRC code corresponding to the transmission data are assigned to the transmission packet. Conversely, if the retransmission control signal is ACK, it is determined that a new packet is to be transmitted, and new transmission data and C corresponding to the transmission data are determined.
An RC code is assigned to a transmission packet.

[0083] Further, retransmission control circuit 608 controls encoding circuit 610 in accordance with the decision whether or not to retransmit the packet. That is, the retransmission control circuit 608 is provided with a table (not shown) indicating the correspondence between the number of packet transmissions and the coding rate of the convolutional code.
Knows the number of transmissions based on the number of times NACK has been received, and refers to this table to control the encoding circuit 610 to perform convolutional coding according to the number of transmissions. The number of packet transmissions and the coding rate of the convolutional code correspond to increase the coding rate as the number of retransmissions increases. Here, it is assumed that convolutional coding is not performed at the time of the first transmission and convolutional coding is performed with N being a natural number of 2 or more and a coding rate of 1 / N at the time of the Nth transmission. . Further, retransmission control circuit 608 generates ARQ control information indicating the number of packet transmissions and the like, and outputs it to transmission power determination circuit 607 and multiplexing circuit 609.

The transmission power determination circuit 607 knows the information amount of the transmission packet to be transmitted this time based on the ARQ control information output from the retransmission control circuit 608, and sets the target of the base station apparatus in accordance with the information amount of the transmission packet. The reception power is set, and the set target reception power and the propagation loss measuring circuit 60 are set.
6 based on the propagation loss measured in step 6
The transmission power of the circuit 613 is determined. Transmission power control circuit 6
Reference numeral 12 controls the transmission power of the transmission RF circuit 613 with reference to the transmission power determined by the transmission power determination circuit 607.

The multiplexing circuit 609 controls transmission data and a CRC code (error detection code) under the control of the retransmission control circuit 608.
And ARQ control information are assigned to the transmission packet. The encoding circuit 610 convolutionally encodes the transmission packet output from the multiplexing circuit 609 at an encoding rate according to the control of the retransmission control circuit 608. The transmission packet thus convolutionally coded is modulated by the modulation circuit 611 and sent to the transmission RF circuit 613. The transmission RF circuit 613 amplifies the transmission packet at an amplification factor according to the control of the transmission power control circuit 612. This transmission packet is transmitted from the antenna 601 through the duplexer 602.

Next, with reference to FIG. 7, a description will be given of a base station apparatus for performing wireless communication with the communication terminal apparatus according to the present embodiment. The packet received by the antenna 701 is sent to the reception RF circuit 703 through the duplexer 702, where it is amplified and further frequency-converted to an intermediate frequency or baseband frequency. The frequency-converted packet is output to the memory 704 and the combining circuit 705.

The memory 704 stores a received packet output from the reception RF circuit 703 under the control of a CRC determination circuit 706 described later. The combining circuit 705 refers to the ARQ control information included in the received packet to determine the number of times the received packet has been transmitted, and reads out the packet stored in the memory 704 according to the determined number of transmissions. The packets are combined, and error correction processing is performed on the combined packets. That is, if the received packet is the first transmitted packet, the received packet is not combined with the packet stored in the memory 704. If the received packet is the second transmitted packet, the received packet is stored in the memory 704. Each packet that has been transmitted up to the previous time is read and combined with the packet output from the reception RF circuit 703. As a result, the retransmitted packets are combined, and the combined packets are subjected to error correction, so that the error rate characteristics during error correction (decoding) are improved. Also, the combining circuit 70
5 is provided with a table indicating the correspondence between the number of packet transmissions and the coding rate of the convolutional code, and performs error correction with reference to this table. Since this table is the same as that provided in the retransmission control circuit 608, it is possible to perform error correction corresponding to the convolutional coding performed in the communication terminal device.

The CRC determination circuit 706 is composed of a synthesis circuit 705
A CRC check is performed on the output error-corrected packet to determine whether there is an error in the data.
If an error is detected (CRC = NG), N
The G signal is output to the memory 704 and the retransmission control circuit 707. Further, when an error is detected, the memory 704 is controlled to store the received packet. Conversely, when no error is detected (when CRC = OK), the reception data is obtained and an OK signal is output to the memory 704 and the retransmission control circuit 707. If no error is detected, the memory 704 is controlled so as to erase the received packet that has been successfully received.

The retransmission control circuit 707 has a CRC
When an NG signal is output from 06, a NACK is generated and output to the frame configuration circuit 708. Conversely, when an OK signal is output, an ACK is generated and output to the frame configuration circuit 708. As described above, the ACK and the NACK are collectively referred to as a retransmission control signal.

The frame forming circuit 708 forms a frame of the retransmission control signal from the retransmission control circuit 707 and the transmission data. The signal thus framed is modulated by the modulation circuit 709 and output to the multiplexing circuit 712.

The frame forming circuit 710 forms a frame of the common known signal. The signal thus framed is modulated by the modulation circuit 711 and output to the multiplexing circuit 712.

The multiplexing circuit 712 multiplexes the signal output from the modulation circuit 709 and the signal output from the modulation circuit 711 and outputs the multiplexed signal to the transmission RF circuit 713. Multiplexer 71
The multiplexed signal output from 2 is amplified by the transmission RF circuit 713, frequency-converted, and transmitted from the antenna 701 through the duplexer 702.

Next, the operation of the base station apparatus and the communication terminal apparatus having the above configurations will be described. In the communication terminal apparatus, the transmission data, the CRC code, and the ARQ control information are assigned to the packet in the multiplexing circuit 609 to become a transmission packet. This transmission packet is encoded by the encoding circuit 61
At 0, convolutional coding is performed at a coding rate according to the control of the retransmission control circuit 608, modulated by the modulation circuit 611, amplified by the transmission RF circuit 613, and transmitted from the antenna 601 through the duplexer 602. Note that, in the case of the first transmission, the transmission packet is output to the modulation circuit 611 without being subjected to convolutional encoding in the encoding circuit 610.

In the base station apparatus, the packet received from antenna 701 is sent to reception RF circuit 703 through duplexer 702, where it is amplified and further frequency-converted to an intermediate frequency or baseband frequency. The frequency-converted packet is stored in the memory 704 and the combining circuit 705.
Is output to

In the combining circuit 407, the CRC determining circuit 70
According to the control of No. 6, the previously transmitted packet output from the memory 704 and the currently transmitted packet are combined and output to the CRC determination circuit 706. The CRC determination circuit 706 performs a CRC determination on the packet synthesized by the synthesis circuit 706 and outputs either the OK signal or the NG signal to the retransmission control circuit 707. Retransmission control circuit 7
At 07, a retransmission control signal is generated according to the output of the CRC determination circuit, and the generated retransmission control signal is output to the frame configuration section 708.

In frame forming section 708, the transmission data and the retransmission control signal output from retransmission control circuit 707 are framed. The signal thus framed is modulated by the modulation circuit 709 and output to the multiplexing circuit 712. The frame forming circuit 710 forms a frame of the common known signal. The signal thus framed is modulated by the modulation circuit 711 and output to the multiplexing circuit 712. In the multiplexing circuit 712, the signal output from the modulation circuit 709 and the signal output from the modulation circuit 711 are multiplexed. This multiplexed signal is amplified by the transmission RF circuit 713, frequency-converted, and transmitted from the antenna 701 through the duplexer 702.

Again, in the communication terminal device, the antenna 601
Are transmitted to the reception RF circuit 603 through the duplexer 602, where they are amplified and further frequency-converted to an intermediate frequency or baseband frequency.
The frequency-converted packet is output to the demodulation circuit 604 and the propagation loss measuring circuit 606.

The demodulation circuit 604 includes a reception RF circuit 603
A data portion included in the frequency-converted signal is demodulated. The demodulated signal is separated by a separation circuit 605 into received data and a retransmission control signal. The retransmission control signal is output to retransmission control circuit 608.

On the other hand, the propagation loss measuring circuit 606 extracts a common known signal from the reception signal output from the reception RF circuit 603, and measures the propagation loss of the extracted common known signal. The measured propagation loss is determined by the transmission power determination circuit 60.
It is sent to 7.

The retransmission control circuit 608 determines whether or not to retransmit a packet according to the retransmission control signal, and controls the multiplexing circuit 609 and the encoding circuit 610 according to the determination. In the retransmission control circuit 608, ARQ control information indicating the number of times of packet transmission and the like is generated and output to the transmission power determination circuit 607 and the multiplexing circuit 609.

The transmission power determination circuit 607 knows the information amount of the transmission packet to be transmitted this time based on the ARQ control information output from the retransmission control circuit 608, and determines the target amount of the base station apparatus according to the information amount of the transmission packet. The reception power is set, and the transmission power of the transmission RF circuit 613 is determined based on the set target reception power and the propagation loss measured by the propagation loss measurement circuit 606. That is, when a packet is retransmitted, the coding rate increases and the amount of information of the packet increases. Therefore, the target reception power of the base station apparatus is set according to the information amount of the packet, and the transmission power is determined. Specifically, at the first retransmission, the information amount of the packet doubles, so the target reception power of the base station apparatus is also set to double, and the retransmission is performed at the set target reception power in consideration of the measured propagation loss. Determine the transmission power so that the packet is received. The transmission power control circuit 612 controls the transmission power of the transmission RF circuit 613 with reference to the transmission power determined by the transmission power determination circuit 607.

As described above, according to the present embodiment, the target reception power of the base station apparatus is appropriately changed and set according to the information amount of the retransmission packet, and the packet is received at the set target reception power. The transmission power is determined with reference to the propagation loss of the common known signal transmitted from the base station apparatus so that the transmission power control can be accurately performed even when the information amount of the transmission packet changes. Can be.

In each of the above embodiments, the AR
In the Q method, a method in which information data not subjected to error correction coding is transmitted the first time, and when a NACK is received on the transmission side, a method in which the information data is error corrected and coded in the second and subsequent times is retransmitted. Has been described as an example, but the present invention is not limited to this, and can be applied to all systems that transmit packets with different information amounts at the time of the first transmission and at the time of retransmission. For example, the first time, the information data and the data obtained by performing error correction coding on the information data are transmitted together, and when a NACK is received by the transmission side, only the data obtained by performing error correction coding on the information data is retransmitted. You may. Also in this case, the target SIR is appropriately set according to the information amount of the retransmission packet.
Is changed and set, and the reception quality of the packet received with the set target SIR is determined, so that the reception quality of the received packet can be correctly determined. Therefore, since transmission power control can be performed with high accuracy, deterioration of reception quality can be prevented and interference with other stations can be reduced.

Also, in each of the above embodiments, the case where the base station apparatus performs wireless communication with the communication terminal apparatus has been described. However, the present invention is not limited to this, and the case where communication is performed using another communication apparatus is described. Can also be applied.

[0105]

As described above, according to the present invention, the target value of the reception quality is set according to the information amount of the retransmission packet, and the reception quality of the packet received with the set target value is determined. Even when the information amount of the packet changes, transmission power control can be performed with high accuracy.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a base station apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a block diagram showing a configuration of a communication terminal apparatus that performs wireless communication with a base station apparatus according to Embodiment 1 of the present invention.

FIG. 3 is a diagram illustrating an S of a received packet according to the first embodiment of the present invention.
Diagram showing an example of IR measurement

FIG. 4 is a block diagram showing a configuration of a base station apparatus according to Embodiment 2 of the present invention.

FIG. 5 is a block diagram showing a configuration of a communication terminal apparatus that performs wireless communication with a base station apparatus according to Embodiment 2 of the present invention.

FIG. 6 is a block diagram showing a configuration of a communication terminal device according to Embodiment 3 of the present invention.

FIG. 7 is a block diagram showing a configuration of a base station apparatus that performs wireless communication with a communication terminal apparatus according to Embodiment 3 of the present invention.

FIG. 8 is a diagram illustrating a configuration example of a transmission packet used in a data transmission method using an ARQ scheme.

[Explanation of symbols]

 205, 405 reception quality measurement circuit 207, 407, 705 synthesis circuit 208, 408, 706 CRC determination circuit 209, 409, 707 retransmission control circuit 210 TPC command generation circuit 410, 607 transmission power determination circuit 606 propagation loss measurement circuit

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Junichi Aizawa 4-3-1 Tsunashima Higashi, Kohoku-ku, Yokohama-shi, Kanagawa F-term (reference) in Matsushita Communication Industrial Co., Ltd. 5K014 AA01 EA08 FA03 FA11 GA01 HA05 5K060 BB07 CC04 DD04 LL01 5K067 AA03 AA23 BB21 DD27 DD45 EE02 EE10 GG08 HH21 HH22 HH28

Claims (8)

[Claims] 1. A measuring means for measuring the reception quality of a retransmission packet, a target value of reception quality set according to the information amount of the retransmission packet is compared with the reception quality measured by the measurement means, and the measurement is performed. Control means for controlling the transmission power so as to reduce the transmission power when the reception quality is higher than the target reception quality and to increase the transmission power when the measured reception quality is lower than the target reception quality. A wireless communication terminal device characterized by the above-mentioned. 2. The wireless communication terminal device according to claim 1, further comprising a setting unit for setting a target value of the reception quality according to the information amount of the retransmission packet. 3. The method according to claim 2, wherein the setting unit sets the target value of the reception quality higher than the target value of the previously transmitted packet when the information amount of the retransmitted packet increases as compared with the information amount of the previously transmitted packet. The wireless communication terminal device according to claim 2, wherein the setting is performed. 4. The method according to claim 1, wherein the setting unit sets the target value of the reception quality lower than the target value of the previously transmitted packet when the information amount of the retransmitted packet is smaller than the information amount of the previously transmitted packet. The wireless communication terminal device according to claim 2, wherein the setting is performed. 5. A transmission power control signal generating means for generating a transmission power control signal for instructing an increase or a decrease in transmission power, and wirelessly transmitting the transmission power control signal generated by said transmission power control means to a base station apparatus as a communication partner. Wireless transmission means to
The wireless communication terminal device according to any one of claims 1 to 4, comprising: 6. A transmission power control means for performing wireless communication with the wireless communication terminal device according to claim 5, and controlling transmission power according to a transmission power control signal wirelessly transmitted from said wireless communication terminal device. Wireless base station device. 7. A wireless communication apparatus according to claim 1, wherein said setting means sets a target value of the reception quality of said retransmission packet in accordance with the information amount of said retransmission packet, and said target value set by said setting means. Notification means for notifying the terminal device;
A radio base station apparatus comprising: 8. The reception quality of the retransmission packet is measured, and a target value of the reception quality set according to the information amount of the retransmission packet is compared with the reception quality measured by the measuring means, and the measured reception quality is determined. A transmission power control method, wherein the transmission power is reduced when the reception quality is higher than the target reception quality, and the transmission power is increased when the measured reception quality is lower than the target reception quality.