JP4354778B2 - COMMUNICATION SYSTEM, COMMUNICATION DEVICE, AND COMMUNICATION METHOD - Google Patents

Description

  The present invention relates to a communication system such as a cellular phone network, a communication device such as a base station device or a mobile station device included therein, and a communication method therefor.

  Due to the convenience of mobile phones, the number of users has been increasing in recent years, and accordingly, the infrastructure that supports mobile phone systems is also desired socially. Under such a social background, a mobile phone system adopting a so-called CDMA (Code Division Multiple Access) system instead of a conventional mobile phone system has been put into practical use due to high communication quality and the like.

  In this CDMA cellular phone system, a base station that divides a service area into a plurality of cells and performs communication mainly with a mobile station apparatus in an area (cover area) defined by each cell. A device is provided and a so-called cellular system is adopted, which differs from the conventional system in that a plurality of mobile station apparatuses communicate with a base station apparatus using the same frequency band.

Thus, as a result of a plurality of mobile station apparatuses communicating with a base station apparatus using the same frequency band, from the base station apparatus to one of the mobile station apparatuses belonging to the cover area of the base station apparatus The signal (downlink signal) transmitted in this manner interferes with the downlink signal for other mobile station apparatuses, causing communication quality degradation. The same applies to uplink signals.

  Therefore, in the CDMA cellular phone system, the base station apparatus and the mobile station apparatus control the signal transmission power to be the minimum power necessary to satisfy the required channel quality. In general, this control is performed by a method in which the signal reception side calculates the minimum necessary transmission power based on the communication state information such as the strength of the received signal and requests the transmission side for the calculated transmission power. Realized.

In recent years, there has been an increasing demand for higher data communication speed and prevention of data communication delay, and various error control techniques that satisfy this demand have been developed. One of them is packet combining type hybrid ARQ (Automatic Repeat Request, hereinafter abbreviated as “PSHARQ”). This PSHARQ is based on a technique of performing a request for retransmission of the packet by the ARQ method when an error that cannot be corrected by the error correction code occurs in the received packet while performing error correction by the error correction code for each packet. In addition, by holding packets received in the past (packets that could not be corrected), combining the retransmitted packets with the held packets improves the quality of the packets, Packet data can be taken out (Patent Document 1).
JP 2002-26747 A

  Here, in the CDMA communication system using the conventional PSHARQ method described in Patent Document 1, even when a retransmitted packet has a reception quality (before combining) of the retransmitted packet that is higher than a target, The transmission power is reduced, and control is performed to increase the transmission power when the reception quality is lower than the target. However, in such transmission power control, in the PSHARQ scheme, a previously received packet and a retransmitted packet are combined, and as a result, an unnecessarily high signal quality may be achieved. Since transmission with power exceeding the power is performed, problems such as a decrease in capacity (the number of users who can talk at the same time), a decrease in sector throughput, and an increase in power consumption may occur. .

  The present invention has been made in view of the above circumstances, and its object is to provide a communication system, a communication apparatus, and a communication method that can increase capacity, improve sector throughput, and prevent an increase in power consumption. One of them.

  The present invention for solving the problems of the conventional example is a communication system having a mobile station apparatus and a base station apparatus that communicate with each other, wherein at least one of the mobile station apparatus and the base station apparatus is the other Means for detecting an error in the received data received from the other device, and means for requesting the other device to retransmit the data portion corresponding to the portion of the received data in which the error is detected. Is characterized by comprising means for transmitting the data portion requested to be retransmitted from the one device to the one device with transmission power smaller than the transmission power when the data portion was transmitted in the past. .

  Further, the present invention for solving the problems of the conventional example is a communication device that communicates with another communication device, and retransmits based on received data received from the other communication device. A means for determining whether or not a request is required and, if the result of the determination indicates that retransmission is required, at least a portion of the received data that needs to be retransmitted is smaller than the transmission power that was transmitted in the past. And means for requesting the other communication device to retransmit with power.

  Furthermore, the present invention for solving the problems of the above-described conventional example is a communication device that performs communication with another communication device, and means for receiving a request for transmission power from the other communication device; The transmission power is set based on the request from the other communication apparatus, and when the data retransmission request is received from the other communication apparatus, the transmission power for the retransmission is set as the object of the retransmission. Transmission power control means for setting the transmission power to be smaller than the transmission power when the data to be transmitted in the past, and transmission means for transmitting data to the other communication device with the set transmission power. It is a feature.

  Here, it further includes an information acquisition unit that acquires, as transmission related information, information related to a transmission process of the data to be retransmitted, and the transmission power control unit performs the retransmission based on the transmission related information. It is good also as determining and setting the transmission power for this.

  The transmission related information includes the past number of transmissions of the data to be retransmitted, the number of past retransmission requests for the data to be retransmitted, and the number of data to be retransmitted. It may include at least one of information on the number of users communicating at the time of transmission and the transmission speed of the data to be retransmitted.

  In addition, a communication method according to an aspect of the present invention uses a communication device that performs communication with another communication device, receives a request for transmission power from the other communication device, and receives the request from the other communication device. The transmission power is set on the basis of the request, and when the data re-transmission request is received from the other communication device, the transmission power for the re-transmission is set in the past for the data to be re-transmitted. The step of setting the transmission power to be smaller than the transmission power at the time of transmission and the step of transmitting data to the other communication device with the set transmission power are characterized in that they are executed.

  A first embodiment of the present invention will be described with reference to the drawings. The communication system according to the present embodiment includes a mobile phone 10 and a base station apparatus 30 as shown in FIG. The cellular phone 10 includes a data processing unit 11, an encoding unit 12, a spread modulation unit 13, a power control unit 14, an RF processing unit 15, a despread demodulation unit 16, a packet combining unit 17, and a decoding unit. 18, a channel quality calculation unit 19, and a downlink transmission power control information generation unit 20.

  In addition, the base station apparatus 30 includes a data processing unit 31, an encoding unit 32, a spread modulation unit 33, a power control unit 34, an RF processing unit 35, a despread demodulation unit 36, a decoding unit 38, a downlink unit, A line transmission power control information decoding unit 39, a retransmission control unit 40, and a transmission power control information correction unit 41 are included.

  The data processing unit 11 of the mobile phone 10 outputs user data to be transmitted to the encoding unit 12. The data processing unit 11 performs a predetermined process based on the reception data input from the decoding unit 18. The encoding unit 12 receives input of user data to be transmitted from the data processing unit 11, encodes the user data by a predetermined encoding method, and outputs the encoded user data to the spread modulation unit 13.

  The spread modulation unit 13 modulates the user data encoded by the encoding unit 12, performs spread modulation using the spread code, obtains a transmission signal, and outputs the transmission signal to the power control unit 14. The spread modulation unit 13 modulates the ACK / NACK signal input from the decoding unit 18 and the transmission power control information input from the downlink transmission power control information generation unit 20, and then performs spread modulation. A transmission signal is obtained and the transmission signal is output to the power control unit 14.

  The power control unit 14 adjusts the transmission power of the transmission signal obtained by the modulation and outputs it to the RF processing unit 15. The RF processing unit 15 transmits the transmission signal input from the power control unit 14 via an antenna. The RF processing unit 15 receives a signal arriving at the antenna and outputs the received signal to the despreading demodulation unit 16.

  The despread demodulator 16 despreads the received signal input from the RF processor 15, further demodulates the processing result, extracts the received data, and outputs the received data to the packet combiner 17. The received data extracted here is assumed to be a packet having a predetermined data format. Also, the despreading demodulator 16 detects the quality (SNR) of the received signal and outputs it to the line quality calculator 19.

  The packet combining unit 17 includes a storage unit (not shown). When nothing is recorded in the storage unit and the reception data is input from the despreading demodulation unit 16, the packet synthesis unit 17 outputs the reception data to the decoding unit 18. At the same time, it is stored in the storage unit. In addition, when the reception data is input from the despreading demodulation unit 16 when the storage unit stores the reception data received up to the previous time or the combined result of a plurality of reception data received up to the previous time, the received data Is combined with the data stored in the storage unit, the combined result is output to the decoding unit 18, and the data stored in the storage unit is overwritten with the combined result. Further, when the packet synthesizing unit 17 outputs a signal (ACK) indicating that the decoding unit 18 has succeeded in decoding, the packet synthesizing unit 17 discards the data stored in the storage unit. Here, the combining method is the same as the packet combining processing in normal PSHARQ, and therefore further detailed description is omitted.

  The decoding unit 18 attempts decoding based on the data (received data or the combined result of the received data) input from the packet combining unit 17. Specifically, using the error correction / detection code added at the time of encoding, the data part has no error, or has been corrected even if there is an error (that is, transmitted on the base station device 30 side) If the data transmitted on the base station apparatus 30 side is determined to be reproduced, the data portion is output as received data. In addition, when the data transmitted on the base station device 30 side can be reproduced, the decoding unit 18 outputs an ACK signal to the spread modulation unit 13 and cannot reproduce the data transmitted on the base station device 30 side. If NACK signal is received, the NACK signal is output to the spread modulation section 13.

  The channel quality calculation unit 19 generates information indicating the channel quality (aerial quality) based on the received signal quality (SNR) information input from the despreading demodulation unit 16 and generates a downlink transmission power control information generation unit. 20 is output. The downlink transmission power control information generation unit 20 estimates the antenna power to be transmitted by the base station device 30 based on the information indicating the channel quality input from the channel quality calculation unit 19, and based on the estimation result, A signal requesting the antenna power of the estimation result is generated as transmission power control information and output to the spread modulation unit 13

  The data processing unit 31 of the base station device 30 outputs data to be transmitted to the encoding unit 32. The data processing unit 31 performs predetermined processing based on the reception data input from the decoding unit 38.

  The encoding unit 32 receives input of data to be transmitted from the data processing unit 31, encodes the data by a predetermined encoding method, generates and holds packet data, and inputs from the retransmission control unit 40 In accordance with the instruction, the packet data is sequentially output to the spread modulation unit 33, or the previously transmitted packet data is output to the spread modulation unit 33 again.

  Specifically, the encoding unit 32 includes a storage unit (not shown) that can temporarily store the generated packet data, and stores the previously output packet data (referred to as the i-th packet data for distinction). Section (which may be a first-in first-out (FIFO) type buffer). Basically, when receiving an instruction to transmit the next packet data from the retransmission control unit 40 described later, the encoding unit 32 outputs the i + 1th packet data to the spread modulation unit 33 and overwrites the storage unit And store. When the instruction to retransmit the previous packet is input from the retransmission control unit 40, the encoding unit 32 stores the same packet data (in this case, the same as the last output) stored in the current storage unit. i + 1-th packet data) is output to the spread modulation unit 33.

  The spread modulation unit 33 modulates the data encoded by the encoding unit 32, performs spread modulation using the spread code, obtains a transmission signal, and outputs the transmission signal to the power control unit 34.

  The power control unit 34 adjusts the transmission power of the transmission signal obtained by the modulation based on the corrected transmission power control information output from the transmission power control information correction unit 41 and outputs the transmission power to the RF processing unit 35. The RF processing unit 35 transmits the transmission signal input from the power control unit 34 via the antenna. The RF processing unit 35 receives a signal arriving at the antenna and outputs the received signal to the despreading demodulation unit 36.

  The despread demodulator 36 despreads the received signal input from the RF processor 35 and further demodulates the processing result. Here, if the data obtained as a result of the despreading process is the data of the transmission power control signal, the despreading demodulation unit 36 outputs the data to the downlink transmission power control information decoding unit 39, and also performs the despreading process. As a result, if the obtained data is ACK or NACK data, the data is output to the retransmission control unit 40, and if it is other data, it is output to the decoding unit 38.

  The decoding unit 38 performs a decoding process based on the data input from the despreading demodulation unit 36, and outputs received data obtained as a result of the decoding to the data processing unit 31.

  When the transmission power control signal data is input, the downlink transmission power control information decoding unit 39 decodes the data, generates transmission power control information (so-called antenna power request value data), and transmits the transmission power control information. Output to the correction unit 41. The retransmission control unit 40 receives the input of ACK or NACK data and decodes the data. If the data is ACK, the retransmission control unit 40 outputs an instruction to the encoding unit 32 to output the next packet data. If it is NACK, an instruction to resend the previous packet is output to the encoding unit 32. In addition, when the retransmission control unit 40 outputs an instruction to retransmit the previous packet to at least the encoding unit 32, the retransmission control unit 40 confirms that the retransmission processing is being performed to the transmission power control information correction unit 41. A signal (retransmission processing signal) is output.

  The transmission power control information correction unit 41 corrects the transmission power control information input from the downlink transmission power control information decoding unit 39 as it is while the retransmission processing signal is not input from the retransmission control unit 40. It outputs to the electric power control part 34 as control information. Further, the transmission power control information correction unit 41 receives the transmission power control information input from the downlink transmission power control information decoding unit 39 in a predetermined method while the retransmission processing signal is input from the retransmission control unit 40. The transmission power control information after correction is output to the power control unit 34.

  Here, the transmission power control information correction method in the transmission power control information correction unit 41 is as follows. In the present embodiment, transmission power control information correction section 41 determines a correction amount based on information related to data transmission processing (hereinafter referred to as transmission-related information) and the like, and from downlink transmission power control information decoding section 39. The transmission power request value represented by the input transmission power control information is reduced and corrected based on the correction amount. Here, the reduction correction method may be a method of subtracting the correction amount from the required value or multiplying the required value by the correction amount. In the former case, the correction amount is defined as a power reduction amount, and in the latter case, the correction amount is defined as a power reduction rate.

  The transmission related information includes, for example, (1) information on the data rate (transmission speed of transmission data), (2) the number of past retransmissions, or (3) the number of receptions of a past retransmission request (NACK). is there. Hereinafter, the case where the transmission power control information correction unit 41 performs correction based on (1) data rate information will be specifically described. Here, the information regarding the data rate can be, for example, the data transmission / reception amount of the base station device 30. Here, as an example, when the service type (data rate) of the i-th user is Di, information on the data rate as transmission related information is

すなわち、各ユーザのデータレートの総和として表されるものとする。ここでは、現在基地局装置３０との通信を行っているユーザがｎ人いるものとしている。

That is, it is expressed as the sum of the data rates of each user. Here, it is assumed that there are n users currently communicating with the base station device 30.

  Then, the transmission power control information correction unit 41 determines the correction amount of the transmission power based on a predetermined table as shown in FIG. Here, if the sum of the data rates as transmission-related information is between the first threshold value A and the second threshold value B, the correction amount is α, the second threshold value B, and the third threshold value. A correction amount is β if it is between the threshold value C and the correction amount is γ if it is between the third threshold value C and the fourth threshold value D. The correction amount is divided in stages according to the threshold value. Note that A <B <C <D.

Here, when the correction amounts α to γ are defined as the power reduction amount, α <β <γ is set. Then, the correction amount determined based on the table is subtracted from the transmission power request value P represented by the transmission power control information input from the downlink transmission power control information decoding unit 39, and the subtraction result is transmitted after correction. It is output as power control information.
Here, as the data rate information, the sum of the data rates in communication with each user is actually calculated. However, as a simple method instead of this, the data rate can be expressed approximately by the number of users. Good.

  Also, a case will be described in which the transmission power control information correction unit 41 performs correction based on (2) the number of past retransmissions. In this case, the transmission power control information correction unit 41 acquires information on the number of retransmissions indicating the number of retransmissions of the packet that the base station device 30 is currently transmitting, and uses the information on the number of retransmissions as the information on the number of retransmissions. Based on this, the correction amount is determined. The determination of the correction amount in this case can also be performed with reference to a table as shown in FIG. 3, for example. Here, if the number of retransmissions is “1” (that is, the first retransmission), the correction amount is α, and if it is “2” (that is, the second retransmission), the correction amount is β, “3” or more (that is, (The third and subsequent retransmissions) represents an example in which the correction amount is γ. In this way, the correction amount may be the same after a certain number of times.

  Here, the acquisition of the number of retransmissions includes, for example, a counter that counts the number of consecutive NACK receptions on the base station device 30 side (a counter that is reset to “0” when ACK is received and incremented when NACK is received), The count value of the counter may be acquired, or the number of retransmission requests, such as the number of consecutive NACK transmissions, is counted on the mobile phone 10 side, and the count value is transmitted to the base station device 30 side. The station device 30 may receive and acquire the count value.

  Furthermore, the transmission power control information correction unit 41 may determine the correction amount based on the total number of NACK receptions during communication, that is, (3) the number of receptions of past retransmission requests (NACKs). Also in this case, a counter that counts the number of times NACK is received or transmitted is provided in at least one of the base station device 30 or the mobile phone 10 side, and the transmission power control information correction unit 41 acquires the count value of this counter. The correction amount is determined with reference to a predetermined table. Note that not only the NACK reception count but also the ACK reception rate in the packet transmission count may be used. In this case, the table for determining the correction amount is, for example, as shown in FIG.

  The system of the present embodiment is configured as described above, and operates as follows. That is, as shown in FIG. 5, the base station apparatus 30 transmits a transmission signal including a data packet (S1), and the mobile phone 10 side receives the transmission signal. Then, the mobile phone 10 demodulates the transmission signal and tries to extract data from the packet that is the decoding result (S2). If the data cannot be extracted, the mobile phone 10 holds the packet and transmits a signal requesting retransmission of the packet (S3). Further, the cellular phone 10 generates downlink transmission power control information from the quality (SNR) of the signal received from the base station device 30 and transmits it together with the retransmission request signal (S3).

  The base station apparatus 30 accepts downlink transmission power control information and tentatively determines downlink transmission power based on this information (S4). The determination result of the transmission power amount here is the same result as the conventional transmission power control. In this embodiment, since a signal requesting retransmission is received here, information on the communication state such as information on the data rate as described above is acquired, and the correction amount is determined based on the information. The downlink transmission power determined temporarily is reduced and corrected based on the determined correction amount (S5). Then, the same data packet as that transmitted in the process S1 is transmitted with the transmission power after the reduction correction (S6).

  That is, the base station apparatus 30 of the present embodiment transmits a packet (data portion) requested to be retransmitted with a transmission power smaller than the transmission power when the packet was transmitted in the past. Here, normally, the transmission power is set based on a request from the mobile phone 10, and when a request for retransmission of data is received from the mobile phone 10, the transmission power for the retransmission is changed to the retransmission. The transmission power is set to be smaller than the transmission power when the data to be transmitted is transmitted in the past.

  Thereafter, the cellular phone 10 combines the packets and extracts the data (S7), and if it can be extracted, sends out an ACK (S8). Also in this case, the mobile phone 10 may generate downlink transmission power control information from the strength of the signal received from the base station device 30 and transmit it together with the retransmission request signal.

  The base station device 30 receives the ACK and determines the transmission power for the transmission of the next packet (S9). Since the next packet is not a retransmission, the determined transmission power is set as it is, and the packet is transmitted with the transmission power (S10).

  In this example, transmission power is reduced and corrected at the time of retransmission, but information indicating a change tendency of downlink transmission power control information is acquired and transmission power is corrected based on the information indicating the change tendency. If it is determined whether or not to perform correction (here, whether or not to set transmission power smaller than the transmission power at the time of transmission in the past), and it is determined not to perform correction, downlink transmission power control information as requested You may make it perform electric power control based on. Specifically, in this example, the transmission power control information correction unit 41 compares the downlink transmission power control information input in the past (for example, the previous time) with the downlink transmission power control information input this time. However, when the downlink transmission power control information input this time is larger than the previous information, that is, when the requested transmission power tends to increase, a retransmission processing signal is transmitted from the retransmission control unit 40. Even if it is input, the downlink transmission power control information input this time may be output as it is as the downlink transmission power control information after correction without correction. According to this, for example, when the quality (SNR) of a signal received by the mobile phone 10 is deteriorated for some reason, the reduction correction is performed, and a sufficient signal cannot be received. Disappear.

  As described above, according to the present embodiment, in the system adopting the PSHARQ scheme, the transmission power amount of the retransmitted packet synthesized with respect to the packet received in the past is reduced and corrected, so that the signal quality more than necessary is obtained. Achievement is suppressed, capacity and sector throughput can be improved, and power consumption can be reduced.

  In the description so far, the case where the base station apparatus 30 determines the transmission power reduction correction amount has been described, but instead, the mobile phone 10 may reduce and correct the transmission power request amount. Therefore, such an example will be described below as a second embodiment.

  The communication system according to the second embodiment of the present invention includes the mobile phone 10 and the base station apparatus 30 as in the communication system according to the first embodiment shown in FIG. However, the processing of the downlink transmission power control information generation unit 20 of the mobile phone 10 is different, and the base station device 30 includes a data processing unit 31, an encoding unit 32, a spread modulation unit 33, as shown in FIG. A power control unit 34, an RF processing unit 35, a despreading demodulation unit 36, a decoding unit 38, a downlink transmission power control information decoding unit 39, and a retransmission control unit 40, and a transmission power control information correction unit The difference is that 41 is not provided. In the following, differences from these first embodiments will be mainly described.

  The downlink transmission power control information generation unit 20 of the mobile phone 10 according to the present embodiment estimates the antenna power to be transmitted by the base station device 30 based on the information indicating the channel quality input from the channel quality calculation unit 19. Then, based on the estimation result, a signal requesting the antenna power of the estimation result is generated as transmission power control information. Further, downlink transmission power control information generation section 20 of the present embodiment receives the ACK / NACK signal output from decoding section 18 and generates the above-mentioned generation when decoding section 18 outputs an ACK signal. The transmitted transmission power control information is output to the spread modulation unit 13 as it is. When the decoding unit 18 outputs a NACK signal (that is, when packet retransmission is requested), the generated transmission power control information is corrected by a predetermined method, and the corrected transmission power control is performed. Information is output to the spread modulation unit 13.

  Here, the transmission power control information correction method in the downlink transmission power control information generation unit 20 is the same as the transmission power control information correction method in the transmission power control information correction unit 41 of the first embodiment, A correction amount is determined based on information related to data transmission processing (hereinafter referred to as transmission-related information) and the transmission power request value represented by the transmission power control information is reduced and corrected based on the correction amount. Become. Here, the reduction correction method may be a method of subtracting the correction amount from the required value or multiplying the required value by the correction amount. In the former case, the correction amount is defined as a power reduction amount, and in the latter case, the correction amount is defined as a power reduction rate.

  The transmission related information includes, for example, (1) information on the data rate (transmission speed of transmission data), (2) the number of past retransmissions, or (3) the number of receptions of a past retransmission request (NACK). Some points are the same as in the first embodiment.

  The system of the present embodiment is configured as described above, and operates as follows. That is, as shown in FIG. 7, the base station device 30 transmits a transmission signal including a data packet (S11), and the mobile phone 10 side receives this transmission signal. Then, the cellular phone 10 demodulates the transmission signal and tries to extract data from the packet obtained by decoding (S12). If the data cannot be extracted here, the cellular phone 10 holds the packet and generates a signal requesting retransmission of the packet.

  In addition, since the mobile phone 10 generates transmission power control information from the quality (SNR) of the signal received from the base station device 30 (S13) and requests retransmission of the packet here, the mobile phone 10 A correction amount is determined based on information on the communication state such as information on the data rate acquired from the station device 30 side, and the generated transmission power control information is corrected with the determined correction amount (S14). Then, a signal representing the corrected transmission power control information is transmitted together with the retransmission request signal (S15).

  The base station apparatus 30 accepts the downlink transmission power control information, determines the downlink transmission power based on this information (S16), and determines the same data packet as that transmitted in the process S11 (the mobile phone). (Transmission power that has been reduced and corrected on the 10 side) (S17).

  Thereafter, the cellular phone 10 combines the packets and extracts data (S18). If the data can be extracted, the mobile phone 10 transmits ACK. At this time, the generated transmission power control information (S19) is transmitted without being corrected.

  Also in this case, the downlink transmission power control information generation unit 20 has a required amount of transmission power such that the transmission power control information before correction generated this time is larger than the transmission power control information before correction up to the previous time. If there is a tendency to increase, correction may not be performed even when packet retransmission is requested.

  Also by this, the base station apparatus 30 transmits the packet (data part) requested to be retransmitted with transmission power smaller than the transmission power when the packet was transmitted in the past. Here, normally, the mobile phone 10 requests transmission power that has been reduced and corrected when requesting retransmission of data, the base station device 30 sets transmission power based on the request, and performs the retransmission The transmission power is set to be smaller than the transmission power when the target data has been transmitted in the past.

  Therefore, also in this embodiment, in the system adopting the PSHARQ scheme, the transmission power amount of the retransmission packet combined with the packet received in the past is reduced and corrected, and the signal quality more than necessary is achieved. Can be suppressed, capacity and sector throughput can be improved, and power consumption can be reduced.

  Furthermore, the communication device of the present invention is not limited to the mobile phone and the base station device as described above. Further, although an example has been described here in which the mobile phone side requests retransmission of a packet to the base station apparatus (that is, in the downlink), the opposite process, that is, similar processing can be performed in the uplink.

1 is a configuration block diagram illustrating an example of a communication system according to an embodiment of the present invention. It is explanatory drawing showing the example of the table used for determination of correction amount. It is explanatory drawing showing another example of the table used for determination of correction amount. It is explanatory drawing showing the further another example of the table used for determination of correction amount. It is a flowchart showing the operation example of the communication system which concerns on the 1st Embodiment of this invention. It is a block diagram showing the example of the base station apparatus as a communication apparatus which concerns on the 2nd Embodiment of this invention. It is a flowchart showing the operation example of the communication system which concerns on the 2nd Embodiment of this invention.

Explanation of symbols

10 mobile phone, 11, 31 data processing unit, 12, 32 encoding unit, 13, 33 spreading modulation unit, 14, 34 power control unit, 15, 35 RF processing unit, 16, 36 despreading demodulation unit, 17 packet synthesis , 18, 38 decoding unit, 19 channel quality calculation unit, 20 downlink transmission power control information generation unit, 39 downlink transmission power control information decoding unit, 40 retransmission control unit, 41 transmission power information correction unit.

Claims (6)

A communication system having a mobile station apparatus and a base station apparatus that communicate with each other,
Means for detecting an error in received data received by the mobile station device from the base station device;
Means for requesting the base station apparatus to retransmit the data portion corresponding to the portion in which the error is detected in the received data,
The total sum of the base station apparatus, the requested data portion the retransmission from the mobile station device, a communication speed of the mobile station apparatus, the communication speed of the other mobile station apparatus communicating with the base station apparatus with the transmission power is determined based on, have a means for transmitting to the mobile station apparatus,
The transmission power determined based on the sum is smaller than the transmission power at the time of transmission of the data portion, and decreases as the sum increases . A base station device that communicates with a plurality of mobile station devices,
Receiving means for receiving a request for data retransmission from one of the plurality of mobile station apparatuses;
The transmission power of the retransmission, the communication speed of the mobile station device, based on the total sum of the communication speed of the other mobile station apparatus determines the transmission power, and transmission power control means for setting,
Transmission means for transmitting the data with transmission power set by the transmission power control means ,
The transmission power that is determined based on the sum is smaller than the transmission power at the time of transmission of the data, the sum decreases as increases, the base station apparatus you wherein a. Further comprising information acquisition means for acquiring, as transmission related information, information related to the transmission processing of the data to be retransmitted;
The base station apparatus according to claim 2, wherein the transmission power control means determines and sets transmission power for the retransmission based on the transmission related information.   The base station apparatus according to claim 3, wherein the transmission related information includes a past transmission count of the data to be retransmitted.   The base station apparatus according to claim 3 or 4, wherein the transmission related information includes a past number of retransmission requests for the data to be retransmitted. A communication method between a mobile station apparatus and a base station apparatus that communicate with each other,
The mobile station device detecting an error in received data received from a base station device;
Requesting the base station device to retransmit a data portion corresponding to a portion in which an error is detected in the received data, the mobile station device;
The total sum of the base station apparatus, the requested data portion the retransmission from the mobile station device, a communication speed of the mobile station apparatus, the communication speed of the other mobile station apparatus communicating with the base station apparatus with the transmission power is determined based on, and a step of transmitting to the mobile station apparatus,
The transmission power is determined based on the sum, the data portion smaller than the transmission power at the time of transmission of small and that communication method as the sum increases.

Images