JP2003264873A - Wireless communication apparatus and retransmission method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wireless communication apparatus and a retransmission method realizing efficient use of a wireless resource upon receiving a retransmission request. <P>SOLUTION: An HS-DSCH quality estimate section 116 estimates a channel quality of a downlink shared channel, a retransmission quality estimate unit 117 estimates required quality having been deficient in preceding packet transmission, an MCS assignment section 118 assigns a coding rate and a modulation system at which an opposite station can obtain the quality equivalent to the required quality, so that the wireless communication apparatus 100 can efficiently use a wireless resource without receiving information of deficient quality from the opposite station even in the case of a retransmission request. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication apparatus and a retransmission method, and is suitable for application to, for example, a wireless communication apparatus and a retransmission method that adaptively change a modulation method and a coding rate according to channel quality. is there.

[0002]

2. Description of the Related Art Conventionally, as a higher-speed IMT-2000 packet transmission method, an HS for the purpose of speeding up a downstream peak transmission speed, low transmission delay, and high throughput, etc.
A method called DPA (High Speed Downlink Packet Access) is under study. As a technology that supports HSDPA, 3GPP (3rd Generation Partnersh)
ipProject) TR25.848 "Physical layer aspects
of UTRA High Speed Downlink Packet Access, TR2
5.858 "HSDPA Physical Layer Aspects" includes A
A transmission method called MC (Adaptive Modulation and Coding) is disclosed.

The AMC technique is a technique for adaptively and rapidly changing the modulation method and the error correction coding rate according to the fluctuation of the line quality. In the AMC technology, as the line quality is better, a higher speed modulation method is used and the error correction coding rate is increased to increase the transmission rate. Specifically, the mobile station (or base station) measures the downlink propagation quality for each mobile station at any time, and the base station determines the mobile station to which the information should be transmitted and the optimum transmission rate based on the measurement result. And transmit information. A modulation method (for example, QPSK (Quaternary Phase) is related to the transmission rate.
Shift Keying) and 16QAM (Quaternary Amplitude)
Modulation)), coding rate (for example, turbo coding is performed at 1/3, and the coding rate is changed by puncturing or repetition).
Is being considered.

As described above, when the AMC technique is used, the modulation method and the coding rate are adaptively determined based on the measurement result of the line transmitted from the mobile station.
The maximum amount of data that can satisfy a desired error rate can be transmitted according to the line status. As a result, both transmission efficiency and error rate can be achieved.

[0005]

By the way, in the AMC technique, when there is a large error in the measurement or estimation of the line quality or when the line quality fluctuates quickly with time, the desired quality can be obtained on the receiving side. Instead, the same data may need to be retransmitted. In this case, depending on the modulation method and coding rate at the time of retransmission, the number of times of retransmission increases or excessive resources are used for transmission, and there is a drawback that radio resources are wasted.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a wireless communication apparatus and a retransmission method capable of efficiently using wireless resources when a retransmission request is made.

[0007]

In order to solve such a problem, a wireless communication apparatus of the present invention has the following configuration.

(1) A radio communication apparatus adapted to retransmit retransmission data when a communication partner station requests retransmission, and a line quality detecting means for detecting a line quality with the partner station. , The quality of the restored data at the partner station such as modulation processing, coding processing, spreading processing, spreading code multiplexing processing or transmission power control processing according to the line quality obtained by the line quality detection means for the transmission data. A transmission signal processing unit that performs an influence process, a retransmission quality estimation unit that estimates the required quality of a retransmission signal by calculating the quality shortage of the transmission data that has undergone signal processing at the partner station, and a retransmission quality estimation unit. Allocation means for allocating the processing element of each processing that affects the quality of the restored data by the transmission signal processing means at the time of retransmission, based on the required quality obtained by Take.

According to this structure, the required quality of the retransmitted signal, which is the quality deficiency in the previous transmission, is estimated by the retransmission quality estimation means, and the modulation method, the coding rate, and the spreading factor according to the deficiency quality are assigned by the allocation means. , A spreading code multiplex number, transmission power, etc. are allocated to form a retransmission signal of a quality that compensates for the shortage. Thus, it becomes possible to transmit a retransmission signal that substantially satisfies the required quality required by the partner station without excess or deficiency, and as a result, the number of retransmissions does not increase or transmission is performed using excessive resources. , Will be able to use wireless resources efficiently. In addition, since the required quality at the time of retransmission is estimated by the retransmission quality estimation means, the required quality at the time of retransmission can be obtained without receiving the required quality from the partner station, and the wireless resource efficiency is further improved by this amount. Will be able to use.

(2) In the wireless communication device of the present invention, the retransmission quality estimation means has the line quality when the transmission data processed by the transmission signal processing means and transmitted is received by the partner station, and at the time of the transmission. A configuration is adopted in which the quality deficiency in the partner station is calculated based on the relationship with the processing element of each process assigned by the assigning means.

According to this structure, it is possible to easily estimate the quality shortage (required quality) at the time of retransmission based on the correspondence between the line quality information and the processing elements.

(3) In the wireless communication device of the present invention, the retransmission quality estimation means includes the line quality when the transmission data processed by the transmission signal processing means and transmitted is received by the partner station, and the transmission signal processing. The quality deficiency in the partner station of the signal-processed transmission data is calculated based on the channel quality that is the basis of the signal processing by the means.

According to this structure, based on the line quality which is the basis for allocating the processing element by the transmission signal processing means at the time of the previous transmission and the line quality when the signal is actually received by the partner station. Therefore, it becomes possible to easily estimate the quality shortage (required quality) at the time of retransmission.

(4) In the wireless communication device of the present invention, the channel quality detecting means receives the channel quality report value of the common pilot channel obtained by the partner station from the partner station and extracts it, and the common pilot channel of the common pilot channel. Downlink shared channel quality estimation means for estimating the channel quality of the downlink shared channel from the channel quality report value is employed.

According to this configuration, the channel quality of the downlink shared channel can be satisfactorily detected by using only the actually used channel without separately providing a new channel. As a result, the processes (1) to (3) can be satisfactorily performed without increasing the number of channels.

(5) In the wireless communication device of the present invention, the line quality detecting means estimates the line quality of the downlink shared channel on which the transmission data is transmitted, based on the transmission power of the dedicated physical channel transmitted by the local station. Adopt a configuration that does.

According to this structure, the downlink shared channel (H
Since the line quality of SDPA (including HS-DSCH) is estimated, the processes (1) to (3) can be performed without receiving information about the line quality from the partner station.

(6) The radio communication apparatus of the present invention deletes the received data up to the previous time with respect to the partner station when the required quality of the retransmitted signal estimated by the retransmitted quality estimating means is not less than a predetermined value. A configuration including means for transmitting an instruction signal is adopted.

According to this structure, when the packet data of too bad quality has been received by the previous time, the demodulated data of sufficient quality can be obtained even if they are combined due to the packet data. However, if the required quality estimated by the retransmission quality estimation means is equal to or higher than a predetermined value (that is, if the reception quality up to the previous time is equal to or lower than the predetermined value), A signal for instructing to delete the received packet data stored on the other side is transmitted, and the packet data is redone from the first transmission. As a result, the number of retransmissions can be effectively reduced.

(7) In the radio communication device of the present invention, when the processing of the transmission signal processing means is not changed at the time of retransmission, the transmission of the retransmission data is stopped until the quality value obtained by the line quality detecting means becomes a value of a predetermined value or more. The transmission timing control means for transmitting the retransmission data when the predetermined channel quality is obtained is adopted.

According to this structure, for example, the transmission rate of the retransmission signal is regulated, and the transmission signal processing means can perform processing according to the shortage on the retransmission data according to the line quality. Even in a situation where it is not possible, it is possible to give data of the required quality to the partner station without increasing the number of unnecessary retransmissions or delaying retransmissions uselessly.

(8) The resending method of the present invention is a resending method for resending resending data when a resending request is made from the communicating station, and detects the line quality with the destining station. At the partner station, which performs the channel quality detection step and the transmission data, such as modulation processing, coding processing, spreading processing, spreading code multiplexing processing, or transmission power control processing according to the channel quality obtained in the channel quality detection step. And a retransmission quality estimation step for estimating the required quality of the retransmission signal by calculating a quality shortage at the partner station of the signal-processed transmission data Then, the transmission signal processing step is repeated at the time of retransmission, and the quality of the restored data at the transmission signal processing step at the time of retransmission is adjusted so that the required quality obtained at the retransmission quality estimation step is satisfied. To include a and allocation step of allocating the processing element of each processing giving sound.

According to this method, in the retransmission quality estimation step, the required quality of the retransmitted signal, which is the quality deficiency in the previous transmission, is estimated, and in the allocation step, the modulation scheme, the coding rate, and the spreading factor according to the deficiency quality. , A spreading code multiplex number, transmission power, etc. are allocated to form a retransmission signal of a quality that compensates for the shortage. Thus, it becomes possible to transmit a retransmission signal that substantially satisfies the required quality required by the partner station without excess or deficiency, and as a result, the number of retransmissions does not increase or transmission is performed using excessive resources. , Will be able to use wireless resources efficiently. In addition, since the required quality at the time of retransmission is estimated in the retransmission quality estimation step, the required quality at the time of retransmission can be obtained without the partner station sending the required quality, and the wireless resource efficiency is further improved by this amount. Will be able to use.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION The essence of the present invention is to estimate the lack of received data quality at the partner station, based on the line quality information obtained at the partner station and the transmission power value at the partner station. The modulation scheme, the coding rate, the spreading rate, the spreading code multiplex number, the transmission power, and the like are assigned so that the quality of the retransmitted signal corresponds to this shortage. This allows
As a retransmitted signal, it becomes possible to efficiently use radio resources without transmitting data with excessive quality or increasing the number of retransmissions.

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

(Embodiment 1) In FIG. 1, reference numeral 100 generally indicates a wireless communication apparatus according to Embodiment 1 of the present invention. The wireless communication device 100 is adapted to adaptively change the modulation method and the coding rate according to the line quality and the amount of transmission data by using the AMC technology.
In the case of this embodiment, a case will be described where the radio communication device 100 is provided in a base station in a mobile communication system, but the radio communication device 100 may be provided in a communication terminal.

The wireless communication device 100 includes a buffer 101,
Transmission frame creation unit 102, coding unit 103, modulation unit 1
04, spreading section 105, transmission radio section 106, antenna A
N, reception radio section 111, despreading section 112, demodulation section 11
3, decoding unit 114, report value extraction unit 115, HS-DS
CH quality estimation unit 116, retransmission quality estimator 117, MC
S (Modulation and Coding Scheme) assigning section 118
And a scheduling unit 120. Here, in order to be able to handle transmission data for a plurality of communication partner stations, the respective units 101 to 106, 111 to 118 other than the transmission radio unit 106, the antenna AN, the reception radio unit 111 and the scheduling unit 120 are respectively There are multiple.

First, the transmission system of the wireless communication device 100 will be described. The wireless communication device 100 temporarily stores transmission data for each user in the buffer 101, frames the stored transmission data by the transmission frame creation unit 102, and then sends the frames to the encoding unit 103.

In radio communication apparatus 100, coding section 103 codes the transmission data, and modulation section 104 modulates the coded transmission data. Here, the coding unit 103 and the modulation unit 104 function as transmission signal processing means, and respectively perform error correction coding processing and modulation according to the allocation result (coding rate and modulation method) in the MCS allocation unit 118 as allocation means. Processing is performed.

The coding rate is, for example, 1/3, and the coding rate is changed by puncturing or repeating the parity part. The modulation method is selected from QPSK and 16QAM, for example. To do. The determination of the transmission rate (coding rate and modulation method) here is based on the previously acquired line quality. MC
The processing of the S allocation unit 118 will be described in detail later.
The modulated transmission data is output to spreading section 105.

Spreading section 105 spreads the modulated transmission data addressed to each partner station using different spreading codes for each partner station. The spread transmission data is transmitted by the transmission wireless unit 106.
Is output to the antenna AN, and is subjected to predetermined wireless processing such as up-conversion, and then wirelessly transmitted from the antenna AN.

Next, the receiving system of the wireless communication device 100 will be described. The wireless communication device 100 has an antenna 109,
A signal wirelessly transmitted from the partner station is received and output to the reception wireless unit 111. In the reception wireless unit 111, the antenna 1
The signal received in 05 is subjected to predetermined wireless processing such as down conversion. The output signal (baseband signal) of reception radio section 111 is output to despreading section 112.

The despreading unit 112 despreads the received signal using the spreading code, and the demodulation unit 113 demodulates the despread received signal. The demodulated received signal is output to decoding section 114. The decoding unit 114 decodes the demodulated received signal. The decrypted information is output to the report value extraction unit 115.

The report value extraction unit 115 extracts a report value for each partner station from the decrypted information. Among the extracted report values, the report value indicating the channel quality is sent to the HS-DSCH quality estimating unit 116 and the scheduling unit 120. Here, the reported value is, for example, CIR (Carrier to Interfere) of CPICH (common pilot channel) measured by a communication terminal which is a communication partner station.
nce ratio) and SIR (Signal to Interference Rati)
o), TFRC (Transport Format and
Information such as (Resource Combination). Even if the value is not the reported value, as described in the second embodiment,
Dedicated channels with transmit power control (eg DP
It is also possible to know the line quality by the transmission power of CH (Dedicated Physical Channel).

Further, the report value extracting section 115 receives ACK (ACKnowledgment) / NACK (Ne
gative ACKnowledgment: negative acknowledgment) information is extracted and sent to the scheduling unit 120.

The scheduling section 120 recognizes the retransmission request by the NACK signal, determines the scheduling according to the traffic condition and channel quality at the time of retransmission, and controls so that the retransmission is performed by this scheduling. Specifically, the buffer 1 is set according to the determined scheduling.
The retransmission data is output from 01. In addition, the scheduling unit 120 notifies the MCS allocating unit 118 and the retransmission quality estimator 117 of the transmission timing.

HS-DSCH as channel quality detecting means
The quality estimation unit 116 estimates the channel quality with the partner station of the HS-DSCH, which is a channel for transmitting data packets, based on the channel quality of the CPICH input from the report value extraction unit 115. Specifically, CPICH and HS-DSCH have different transmission qualities and the like, and therefore the line quality is naturally different. In the HS-DSCH quality estimation unit 116,
Based on the difference and ratio of this transmission power, H
Estimate the channel quality of S-DSCH. The HS-DSCH quality estimation unit 116 transmits the estimation result to the retransmission quality estimator 117.
And the MCS allocation unit 118.

The MCS allocating unit 118 uses the HS-DSC.
The coding rate and the modulation scheme are assigned based on the estimation result obtained by the H quality estimation unit 116 and the estimation result obtained by the retransmission quality estimator 117.

Retransmission quality estimator 117 assigns information (coding rate, modulation method) from MCS assigning section 118.
And the required quality required at the time of retransmission is estimated based on the HS-DSCH estimation result when the data packet transmitted by signal processing from the HS-DSCH section 116 with this allocation information is received by the partner station. .

In the case of this embodiment, retransmission quality estimator 117 and MCS allocation section 118 are configured as shown in FIG. The MCS allocation unit 118 is composed of an allocation quality calculation unit 118B and an MCS determination unit 118A. Further, the MCS determination unit 118A is composed of a threshold value determination unit 118D and an allocation table 118C.

The allocation quality calculation unit 118B has an HS
-The newest HS-DS from DSCH quality calculator 116
The channel quality information of CH is input, and the required quality at the time of retransmission estimated by the retransmission quality estimator 117 is also input. Here, as will be described below, retransmission quality estimator 1
The required quality output from 17 is the required quality required at the time of retransmission, and in the case of this embodiment, it is a value representing the lack of quality transmitted up to the previous time as a percentage.

The allocation quality calculation unit 118B uses the HS-
Current HS-DSCH from DSCH quality estimator 116
Based on the line quality and the lack of quality required for retransmission,
Calculate quality for allocation. For example, if 70% of the quality required for decoding at the partner station was received in the previous transmission, the retransmission quality estimator 117 obtains an estimation result that the remaining 30% quality is required for retransmission. To be

In the allocation quality calculation unit 118B, the MC
A virtual HS-DS such that the S determination unit 118A determines the coding rate and the modulation scheme corresponding to 30% or more.
Calculate the channel estimate for CH. That is, the MCS determination unit 1
In order to allocate a quality of 30% or more by 18A, the MCS determination unit 118A is required to assign (10
The channel estimation value of 0/30) times may be input. That is, assuming that the estimated value of the HS-DSCH quality estimation unit 116 is X, the required quality at the time of retransmission obtained by the retransmission quality estimator 117 is Y%, and the value output from the allocation quality calculation unit 118B is Z, Z = X × (100 / Y).

The threshold value judging section 118D has a plurality of threshold values, and judges the value calculated by the allocation quality calculating section 118B as a threshold value. Allocation table 118C
Is a ROM (Read Only Memor) in which the line quality is used as an address, and each address is associated with a modulation method and a coding rate.
y). In other words, if the current table quality has a certain value in the allocation table 118C, by assigning this modulation method and this coding rate, the restored data of the quality required by the partner station will be obtained. The correlation between the modulation scheme and the coding rate is stored.

FIG. 3 shows an example of the relationship between the threshold value judging section 118D and the allocation table 118C. The threshold value determination unit 118D has five threshold values Th1 to Th5, and performs threshold value determination on the calculated value obtained by the allocation quality calculation unit 118B. As a result, for example, the calculated value is Th
If it is 1 or more and less than Th2, the allocation table 11
8C allocates QPSK and a coding rate of 1/4. When the calculated value is Th4 or more and less than Th5,
16 QPSK and 1/2 according to allocation table 118C
Code rates are assigned. Incidentally, the threshold Th1
If less than, no transmission is done.

The retransmission quality estimator 117 is composed of a required quality calculation unit 117A and a required quality storage unit 117B. The required quality calculation unit 117A includes the MCS allocation unit 1
From the coding rate and modulation scheme assigned by 18, and the line quality of HS-DSCH from the report value measured at the time of transmitting by assigning the coding rate and modulation scheme,
Estimate the required quality that was lacking in the actual transmission. In this estimation processing, if the required quality calculation unit 117A stores information about which coding rate and modulation method are used for a certain channel quality and how much reception quality is obtained at the partner station, It can be easily realized.

The retransmission quality estimator 117 stores in the required quality storage unit 117B the reception quality (required quality) calculated by the required quality calculation unit 117A, which is insufficient until the previous transmission. The required quality storage unit 117B,
The most recently stored required quality is sent to the allocation quality calculation unit 118B. Further, at the second or more retransmission, the required quality at the previous retransmission stored in the required quality storage unit 117B is sent to the required quality calculation unit 117A. That is,
In the required quality calculation unit 117A, at the time of the first retransmission, how much the required quality of 100% is calculated from the coding rate and modulation scheme information from the allocation table 118C and the channel quality information from the HS-DSCH quality estimation unit 116. Whether or not there is a shortage is calculated, and at the time of the second and subsequent retransmissions, how much further quality shortfall is calculated with respect to the previous shortfall.

Thus, the HS-DSCH quality estimation unit 11
6, MCS allocation section 118 and retransmission quality estimator 11
7, first, at the time of the first transmission of certain packet data, the HS-DSCH line quality estimated by the HS-DSCH quality estimating unit 116 is directly input to the MCS determining unit 118A via the allocation quality calculating unit 118B. It Then, the MCS determination unit 118A allocates the coding rate and the modulation scheme according to the channel quality.

On the other hand, at the time of the first retransmission, the required quality calculation unit 117A determines from the coding rate and the modulation method assigned at the time of the first transmission and the line quality when the other station receives the first packet data. Calculate the quality shortfall in. Then, the shortage is stored in the required quality storage unit 117B as the required quality for the first retransmission.
Then, upon receiving a signal notifying the timing of retransmission from the scheduling unit 120, the required quality storage unit 117B assigns the stored required quality to the allocation quality calculation unit 118B.
Send to. The allocation quality calculation unit 118B uses the HS-
The latest HS estimated by the DSCH quality estimation unit 116
-A virtual channel quality to which a coding rate and a modulation scheme corresponding to the required quality are assigned is calculated from the channel quality of DSCH and the required quality required for retransmission. MC
The S determination unit 118A allocates the coding rate and the modulation scheme according to the virtual channel quality, and transmits the retransmission packet data that has been signal-processed with the coding rate and the modulation scheme.

Further, in the second and subsequent retransmissions, the required quality calculating unit 117A determines that the coding rate and the modulation scheme assigned in the previous retransmission and the line when the partner station receives the packet data from the previous retransmission. From the quality and the required quality for the previous retransmission stored in the required quality storage unit 117B, the shortage of the reception quality at the partner station for this retransmission is calculated. Subsequent processing is the same as that at the time of the first retransmission, so the description thereof will be omitted.

In this way, according to the HS-DSCH quality estimation section 116, the MCS allocation section 118 and the retransmission quality estimator 117, the CPICH sent from the partner station is transmitted.
It is possible to accurately estimate the quality deficiency (required quality) at the partner station, which is required at the time of retransmission, from only the quality information of 1, and to transmit the retransmitted packet data corresponding to this required quality.

Next, the operation of the radio communication device 100 will be described with reference to FIGS. 1 and 4. In FIG. 4, FIG.
A case will be described where a base station having the wireless communication device 100 configured as described above is communicating with a communication terminal. Further, FIG. 4 illustrates a case where the reception quality at the communication terminal does not satisfy the required quality and a retransmission request is made.

First, at time tm1, the communication terminal transmits line quality information (eg CIR of CPICH) to the base station,
When the base station receives this line quality information at time tb1,
Based on the line quality information, the transmission data is modulated and encoded by the modulation method and the coding rate such that the line quality at the communication terminal becomes the required quality or higher, and the data packet is transmitted at time tb2.

The mobile station transmits this data packet at time tm2.
When the error is detected after decoding, the line quality information and the NACK signal are transmitted at time tm3. Incidentally, although the communication terminal actually sends the line quality information regardless of the NACK signal, it is assumed here that the line quality information is sent at the same time in order to simplify the description.

When the base station receives the channel quality information and the NACK signal at the time point tb3, it enters the process of retransmitting the same data as the data transmitted at the time point tb2. At this time, the wireless communication device 100 of the base station, from the coding rate and the modulation scheme assigned to the data packet transmitted at time tb2, and the line quality at the time of receiving the data packet reported from the partner station at time tb3, The quality shortage in the previous transmission (transmission at time tb2) is calculated.

Incidentally, this shortage may be calculated based on the difference between the line quality received from the partner station at time tb1 and the line quality received at time tb3.

Radio communication apparatus 100 waits for the allocation of the coding rate and the modulation scheme for the retransmitted data until the timing of retransmitting by scheduling. Then, at the timing of retransmission, based on the reception quality information reported from the mobile station immediately before that, it is possible to transmit to the mobile station the quality shortage in the previous transmission (transmission at time tb2) in the current line state. The retransmitted data is signal-processed with a different coding rate and modulation method, and the retransmitted data packet is transmitted at time tb4.

When the communication terminal receives this retransmitted data packet at time tm4, it can obtain the received data of the required quality by combining this data packet with the previously received data packet and demodulating it.

According to the above configuration, the HS-DSCH quality estimation section 116 estimates the channel quality of the downlink shared channel, and the retransmission quality estimator 117 estimates the required quality which is insufficient in the previous packet transmission. And MC
Since the S allocating unit 118 allocates the coding rate and the modulation method such that the quality equivalent to the required quality can be obtained in the partner station, even if a retransmission request is made, information about insufficient quality from the partner station is obtained. It is possible to realize the wireless communication device 100 that can efficiently use wireless resources without receiving the.

In this embodiment, the coding section 103 and the modulation section 104 are described as an example of the transmission signal processing means for performing the processing that affects the quality of the restored data at the partner station. Other processes that affect the quality of the restored data include the spreading factor by the spreading unit 105, the number of spread code multiplexing, the transmission power by the transmission wireless unit 106, and the like. Therefore, the present invention is not limited to controlling the allocation of the coding rate and the modulation method according to the quality deficiency, but controls the allocation of the spreading rate, the number of spread code multiplexes, and the transmission power according to the quality deficiency. Also, the same effect as that of the above-described embodiment can be obtained. This also applies to the embodiments described later.

Further, in the above embodiment, the line quality when the transmission data processed by the transmission signal processing means (encoding unit 103, modulation unit 104) and transmitted is received by the partner station, and its transmission. The quality deficiency in the partner station is calculated based on the relationship with the processing elements (coding rate, modulation method) of each processing assigned by the assigning means (MCS assigning unit 118). Is not limited to this, and the quality deficiency may be calculated as follows.

That is, the transmission signal processing means (encoding unit 103 and modulation unit 104 in the case of the embodiment) signal-processed and transmitted, and the line quality when the transmission data is received by the partner station, and the transmission signal. Processing means (in the case of the embodiment,
The quality deficiency in the partner station of the signal-processed transmission data may be calculated based on the channel quality that is the basis of the signal processing by the encoding unit 103 and the modulation unit 104).

In this embodiment, the deficiency quality is a value in which the deficiency is expressed as a percentage. However, the present invention is not limited to this, and the same thing can be obtained even if the deficiency value itself is used. Is feasible.

Further, in this embodiment, as the MCS determining section 118A, a ROM (Read Only Memory) in which a modulation scheme based on channel quality and a coding rate are associated with each other is used, but the present invention is applicable to this. The configuration is not particularly limited as long as the modulation scheme and the coding rate are determined based on the line quality.

(Second Embodiment) In FIG. 5, in which parts corresponding to those in FIG.
3 shows a wireless communication device according to a second embodiment of the present invention. The wireless communication device 200 is the wireless communication device 100 of the first embodiment.
Estimates the required quality of the retransmitted signal based on the CPICH channel quality information received from the partner station, while estimating the required quality of the retransmitted signal based on the transmission power value of the DPCH transmitted to the partner station. Has been done.

Generally, the transmission power of the DPCH is controlled based on the line quality so that the poorer the line quality is, the larger the transmission power becomes. Focusing on this point, in this embodiment, by estimating the channel quality of the DSCH based on the transmission power of the DPCH, the quality shortage is obtained without receiving the reception quality information from the partner station. There is.

Practically, in the radio communication device 200, the transmission power information detecting section 201 detects the transmission power of DPCH, and H
The S-DSCH quality estimation unit 202 estimates the HS-DSCH channel quality based on the transmission power of the DPCH. Specifically, it is estimated that the higher the transmission power of DPCH, the worse the line quality of HS-DSCH. The HS-DSCH quality estimation unit 202 uses the estimated channel quality information as the MCS allocation unit 20.
4 and retransmission quality estimator 203.

Next, the retransmission operation of radio communication apparatus 200 will be explained using FIG. In the wireless communication device 200, first, in step ST1, the HS-DSCH quality estimating unit 202 detects the DPC detected by the transmission power information detecting unit 201.
HS-DSCH with the other station based on H transmission power
Then, the MCS allocating section 204 estimates combinations of coding rates and modulation schemes that can be allocated based on this channel quality. Then, in the subsequent step ST2, the modulation coding rate and the modulation method are assigned.

Specifically, when the transmission power of the DPCH is low, it is determined that the HS-DSCH channel quality is good, and a modulation method with a large number of multivalues and a high rate coding rate are assigned. On the other hand, when the transmission power of DPCH is high, it is determined that the line quality of HS-DSCH is poor, and a modulation method with a low multilevel number and a low rate coding rate are assigned.

Next, in step ST3, the MCS allocating section 204 stores the required quality at the partner station when the packet data is transmitted with the coding rate and the modulation method estimated to be allocatable in step ST1. For example, step S
If the line quality is 5 [dB] at T1 and the required quality at the partner station when the packet data is transmitted with the assigned coding rate and modulation scheme is 3 [dB], this 3
Save [dB].

At step ST4, the HS-DSC is again used.
The H quality estimation unit 202 estimates the channel quality of the HS-DSCH with the partner station based on the transmission power of the DPCH detected by the transmission power information detection unit 201, and stores this. The wireless communication device 200 transmits packet data with the modulation scheme and coding rate assigned in step ST2 almost at the same time as the processing in step ST4.

In step ST5, the scheduling section 120 performs reception determination processing based on the ACK / NACK signal sent from the partner station, and when the ACK signal is received, the packet data transmission processing is completed. On the other hand, when the NACK signal is received, the process proceeds to step ST6 and the packet data is retransmitted.

At step ST6, the MCS allocation unit 2
04 estimates the reception quality required for retransmission, that is, the required quality that is lacking in the previous transmission, from the required quality stored in step ST3 and the line quality for transmission stored in step ST4. Here, considering why there was a retransmission request in step ST5, even though an appropriate transmission rate was allocated in step ST1 in accordance with the channel quality, in step ST4, the coding rate and the modulation method were allocated, and then in step ST4. It is considered that there is a time lag before the actual packet transmission of and the line quality fluctuated (to the worse) during that time. In consideration of this, in the wireless communication device 200,
In step ST6, it is estimated that the value obtained by subtracting the estimated line quality at the time of actual transmission stored in step ST4 from the required quality stored in step ST3 is the reception quality (deficiency) required by the partner station at the time of retransmission.

In step ST7, the HS-DSCH quality estimation unit 202 determines the current HS-DSCH channel quality with the partner station based on the current transmission power of the DPCH. Then, MCS allocating section 204 estimates the assignable coding rate and modulation scheme based on this channel quality and the required quality required at the partner station at the time of retransmission estimated at step ST6. Then move to step ST2,
The coding rate and modulation scheme allocation processing estimated in step ST7 is performed on the retransmission data. As a result, it becomes possible to retransmit the retransmitted data with a quality that is more than sufficient without receiving any information from the partner station.

According to the above configuration, the channel quality of the HS-DSCH is estimated based on the transmission power of the DPCH, the modulation scheme and the coding rate are assigned, and the transmission power of the DPCH is transmitted even when a retransmission request is made. By estimating the lack of quality at the other station due to the previous packet transmission based on the above, the modulation scheme and coding rate are assigned so that the retransmitted signal has a quality that compensates for this lack of quality. Therefore, it is possible to realize the wireless communication device 200 that can efficiently use the wireless resources even when the retransmission request is received without receiving any information from the partner station.

In this embodiment, the case where the reception quality of the HS-DSCH at the partner station is estimated based on the transmission power of the DPCH and the modulation method and the coding rate are assigned has been described. The information for estimating the reception quality at is not limited to the transmission power, and for example, the reception quality of the packet data transmitted by the HS-DSCH at the partner station may be estimated based on the spreading rate or transmission rate of the DPCH. The reception quality of packet data at the partner station may be estimated based on information controlled according to the reception quality of the partner station.

(Third Embodiment) In FIG. 7 in which parts corresponding to those in FIG.
7 shows a wireless communication device according to a third embodiment of the present invention. The wireless communication device 300 according to the first embodiment is different from the wireless communication device 300 except that the wireless communication device 300 includes an initialization signaling generator 301.
It has the same configuration as 0.

When the required quality of the retransmission signal estimated by the retransmission quality estimator 117 is a predetermined value or more, the initialization signaling generator 301 deletes the packet data transmitted up to the previous time to the partner station. A signal instructing that is generated and sent to the transmission frame creation unit 102. The transmission frame creation unit 102 inserts an initialization signal at a predetermined position in the transmission frame.

As a result, the partner station that received the initialization signal deletes the packet data accumulated in the reception buffer. At the partner station that receives and demodulates the packet data from the wireless communication device 300 as described above, the packet data whose reception quality does not satisfy the required value is temporarily stored in the buffer, and the retransmitted packet data and the stored packet data are stored. The demodulated data satisfying the required quality is obtained by synthesizing and demodulating the packet data.

However, when the reception quality of the packet data received so far is too poor, it may not be possible to obtain demodulated data of sufficient quality even if the retransmitted signals are combined due to this packet data. is there. In consideration of this, in the present embodiment, when the retransmitted signal is required to have a required quality of a predetermined value or more, a signal instructing to delete the received packet data stored on the other side is transmitted, The packet data is re-executed from the first transmission.

According to the above configuration, in addition to the first embodiment, when the retransmission signal is required to have a quality equal to or higher than a predetermined value, a signal for instructing to delete the packet data stored in the partner station is transmitted to the partner station. By transmitting to the station, in addition to the effect of the first embodiment, it is possible to realize the wireless communication device 300 that can further reduce the number of retransmissions and can use the wireless resources more efficiently.

(Fourth Embodiment) In FIG. 8 in which parts corresponding to those in FIG.
The structure of the radio | wireless communication apparatus which concerns on Embodiment 4 of this invention is shown. The wireless communication device 400 includes a scheduling unit 401.
The wireless communication apparatus 100 has the same configuration as that of the wireless communication apparatus 100 according to the first embodiment, except that the scheduling processing of is different.

Radio communication apparatus 400 is constructed so that when applied to a system in which the transmission rate cannot be changed during retransmission, the partner station can obtain the required reception quality without increasing the number of retransmissions.

The scheduling unit 401 has the HS-D
The channel quality information of the HS-DSCH with the partner station estimated by the SCH quality estimation unit 116 is input, and
Information indicating the required quality of the retransmission signal is input from the retransmission quality estimator 117.

The scheduling section 401 uses the HS-DS.
The retransmission signal is transmitted when the channel quality estimated by the CH quality estimation unit 116 reaches a quality at which the required quality of the retransmission signal input from the retransmission quality estimator 117 can be transmitted. That is, the scheduling unit 401 of this embodiment performs scheduling with retransmission quality also taken into consideration. As a result, even if the transmission rate for retransmitted signals is regulated and the modulation method and coding rate for retransmitted data cannot be adaptively changed according to the channel quality, the other station can be retransmitted without increasing the number of retransmissions. Data of required reception quality can be given.

According to the above configuration, even if the transmission rate for the retransmission signal is regulated and the modulation scheme and the coding rate for the retransmission data cannot be adaptively changed according to the line quality, it is useless. It is possible to realize the wireless communication device 400 that can give the data of the required reception quality to the partner station without increasing the number of times of retransmission.

Here, the description has been made only in the case where the transmission signal processing means cannot change the processing at the time of retransmission, but it may be used even in the case where it can be changed, and it is used in combination with the methods of the above-described first to third embodiments. May be. That is, if the scheduling is performed in consideration of the insufficient quality regarding the retransmission, the transmission efficiency can be further improved.

[0088]

As described above, according to the present invention,
The quality of the retransmitted signal corresponds to this lack by estimating the lack of received data quality at the partner station based on the line quality information obtained at the partner station and the transmission power value at the partner station. By assigning the modulation method, coding rate, spreading factor, number of spread code multiplexing, transmission power, etc. so that The signal can be transmitted. As a result,
It is possible to realize a wireless communication device and a retransmission method that can efficiently use wireless resources without increasing the number of retransmissions and transmitting data with excessive quality.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a wireless communication device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a detailed configuration of a retransmission quality estimator and an MCS allocation unit.

FIG. 3 is a diagram showing an example of a relationship between a threshold value determination unit and an allocation table.

FIG. 4 is a diagram for explaining the operation of the first embodiment.

FIG. 5 is a block diagram showing a configuration of a wireless communication device according to a second embodiment.

FIG. 6 is a flowchart for explaining the operation of the second embodiment.

FIG. 7 is a block diagram showing a configuration of a wireless communication device according to a third embodiment.

FIG. 8 is a block diagram showing a configuration of a wireless communication device according to a fourth embodiment.

[Explanation of symbols]

100, 200, 300, 400 Radio communication apparatus 101 Buffer 103 Coding section 104 Modulation section 115 Report value extraction section 116, 202 HS-DSCH estimation section 117, 203 Retransmission quality estimator 118, 204 MCS (Modulation and Coding Sche)
me) Allocation unit 120, 401 Scheduling unit 201 Transmission power information detection unit 301 Initialization signaling generator

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Claims (8)

[Claims] 1. A wireless communication device adapted to retransmit retransmission data when a retransmission request is made from a communication partner station, and line quality detecting means for detecting a line quality with the partner station. With respect to the transmission data, the quality of the restored data at the partner station such as modulation processing, coding processing, spreading processing, spread code multiplexing processing or transmission power control processing according to the line quality obtained by the line quality detection means A transmission signal processing means for performing an effecting process, a retransmission quality estimation means for estimating a required quality of a retransmission signal by calculating a quality shortage at the partner station of the signal-processed transmission data, and the retransmission quality Based on the required quality obtained by the estimation means, allocation means for allocating the processing elements of each processing that affects the quality of the restored data by the transmission signal processing means at the time of retransmission, Radio communication apparatus characterized by comprising. 2. The re-transmission quality estimating means assigns the line quality when the transmission data processed and transmitted by the transmission signal processing means is received by a partner station and the assigning means at the time of the transmission. The wireless communication device according to claim 1, wherein the quality deficiency in the partner station is calculated based on the relationship with the processing element of each process. 3. The retransmission quality estimation means is a basis of the channel quality when the transmission data processed by the transmission signal processing means and transmitted and received by the partner station and the signal processing by the transmission signal processing means. The wireless communication device according to claim 1, wherein a quality deficiency in the partner station of the signal-processed transmission data is calculated on the basis of the line quality. 4. The channel quality detecting means receives the channel quality report value of the common pilot channel obtained at the partner station from the partner station and extracts it, and downlinks from the channel quality report value of the common pilot channel. The wireless communication apparatus according to claim 1, further comprising downlink shared channel quality estimation means for estimating channel quality of the shared channel. 5. The channel quality detection means estimates channel quality of a downlink shared channel on which the transmission data is transmitted, based on transmission power of a dedicated physical channel transmitted by the local station. The wireless communication device according to claim 1. 6. A means for transmitting a signal for instructing a partner station to delete received data up to the previous time when the required quality of the retransmission signal estimated by the retransmission quality estimating means is equal to or more than a predetermined value. The wireless communication device according to claim 1, comprising: 7. If the processing of the transmission signal processing means is not changed at the time of retransmission, the transmission of the retransmission data is stopped until the quality value obtained by the line quality detecting means reaches a value of a predetermined value or more, and the predetermined line quality is maintained. The wireless communication apparatus according to claim 1, further comprising a transmission timing control unit that transmits the retransmitted data when obtained. 8. A resending method adapted to resend resending data when a resending request is made from a correspondent station, comprising: a channel quality detecting step of detecting a channel quality with the partner station; Affects the quality of restored data at the partner station such as modulation processing, coding processing, spreading processing, spreading code multiplexing processing, or transmission power control processing according to the channel quality obtained in the channel quality detection step for data. And a retransmission quality estimation step of estimating a required quality of a retransmission signal by calculating a quality shortage at the partner station of the signal-processed transmission data, and a transmission signal processing step at the time of retransmission. By repeating the signal processing step, the quality of the restored data in the transmission signal processing step at the time of retransmission is influenced so as to satisfy the required quality obtained in the retransmission quality estimation step. Retransmission method comprising the allocation step, the assigning the processing element of each processing giving.