WO2009098981A1

WO2009098981A1 - Transmitter, receiver, base station device, mobile station device, and wireless communication system

Info

Publication number: WO2009098981A1
Application number: PCT/JP2009/051353
Authority: WO
Inventors: Yosuke Akimoto; Shohei Yamada; Seiji Sato
Original assignee: Sharp Kabushiki Kaisha
Priority date: 2008-02-04
Filing date: 2009-01-28
Publication date: 2009-08-13

Abstract

The communication efficiency and coding gain of HARQ retransmission in a MIMO communication system are maximally improved. A transmitter for transmitting an HARQ transmission signal sequence which is generated from a transport block which is the signal sequence passed to a physical layer by a MAC layer and which is matched to the transmission unit of the HARQ generates a plurality of HARQ transmission signal sequences on the basis of the same transport block and transmits the generated HARQ transmission signal sequences at the same time. Furthermore, the HARQ transmission signal sequences correspond to different redundancy versions.

Description

Transmitter, receiver, base station apparatus, mobile station apparatus, and radio communication system

The present invention relates to a technique for retransmitting a signal transmitted using a multiplexing technique by HARQ (Hybrid Automatic Repeat reQuest).

3GPP (3rd Generation Partnership Project) has evolved a communication system based on a network communication system based on W-CDMA (Wideband-Code Division Multiple Access) and GSM (Global System for Mobile Communications). It is. In 3GPP, the W-CDMA system is standardized as a third generation cellular mobile communication system, and services are started sequentially. In addition, HSPA (High-Speed Packet Access), which further increases the communication speed, has been standardized and the service has started. In 3GPP, the evolution of third-generation radio access technology (Evolved Universal Terrestrial Radio Access: hereinafter referred to as “E-UTRA”) is being studied.

As one of various technologies for realizing higher communication efficiency in mobile communication, there is a technology called MIMO (Multi-Input / Multi-Output) communication as described in Non-Patent Document 1. In this MIMO communication technique, a transmission-side apparatus is provided with a plurality of antennas, and communication data independent from each antenna is transmitted by radio waves called carriers. The receiving side apparatus receives this with a plurality of antennas, and uses a communication propagation path estimation technique or the like to convert a carrier wave including a plurality of different communication data transmitted from the transmitting side apparatus and synthesized in the communication propagation path, By separating and using each communication data, high communication efficiency is realized.

Meanwhile, a technique called HARQ (Hybrid Automatic Repeat reQuest) as described in Non-Patent Document 2 is also attracting attention as a highly efficient communication technique. In mobile communication, it is common to use error correction code technology that enables normal communication even if communication errors that may occur due to various factors on the communication propagation path occur. If a communication error exceeding the capability of the transmission occurs, communication data information cannot be normally transmitted from the transmission side apparatus to the reception side apparatus. In the HARQ communication technique, as shown in FIG. 31, a transmission signal sequence provided with error correction bits (parity bits) having a sufficient sequence length using a Turbo code or the like is stored in a buffer. The transmitting side apparatus reads the additional error correction information stepwise to the receiving side apparatus and transmits it, so that the error of the communication data including the error already received in the receiving side apparatus can be further corrected. become. Thereby, data communication can be performed efficiently.

E-UTRA is considering introducing MIMO communication technology and HARQ. In E-UTRA, the MIMO communication scheme is applied to the downlink. In the MIMO communication method, a plurality of signal sequences can be spatially multiplexed and transmitted. A unit of the spatially multiplexed signal sequence is called a stream, and a stream that can be transmitted between the base station device and the mobile station device. This number is called Rank. Since the rank can be calculated only by the mobile station apparatus that can know the downlink propagation path information, it is fed back from the mobile station apparatus to the base station apparatus, and the base station apparatus determines the number of downlink streams based on this information. Send a signal.

In addition, HARQ transmission is a unit transmitted for each initial transmission and retransmission generated based on HARQ from a transmission signal sequence (referred to as a transport block) transmitted from a MAC (Medium Access Control) layer to a physical layer. It is called a signal sequence and is transmitted as downlink data. The bit sequence transmitted as the HARQ transmission signal sequence is assigned a number (defined as a redundancy version or RV (Redundancy Version)) for each pattern, and this number is assigned to the downlink control channel immediately before transmission of the downlink data. By transmitting the information, it is possible to share information indicating which bit is selected between the transmission side device and the reception side device. Such a mechanism in the transmission side apparatus is called rate matching, and a mechanism for synthesizing bit sequences transmitted in stages in the reception side apparatus is called rate dematching. As for the above buffer, in E-UTRA, it is considered to use a buffer called a circular buffer in which the end of the buffer and the head are linked. As a result, when the bit sequence is read from the buffer, the bit sequence can be read sequentially from the beginning when the end is reached. One HARQ retransmission signal sequence is spatially multiplexed using one or more streams and transmitted to the receiver. A group of multiplexed signal sequences is called a multiplexed signal group. In the spatial multiplexing system, a group of streams matches this.

Regarding HARQ in E-UTRA, HARQ can execute multiple processes simultaneously. A plurality of buffers for storing transmission signal sequences are prepared for transmission and reception, and it is possible to transmit other transport blocks that are not related during the retransmission process. In E-UTRA, a HARQ process is executed for each transport block, a number identifying the process is signaled to the receiving side device, and which transmission sequence is retransmitted by using this number is transmitted to the transmitting side device and the receiving side. Can be shared by devices. This identifier is referred to as a process number, and is notified to the receiving side device through a control channel.

By combining the MIMO communication technology and the HARQ communication technology as described above, a plurality of transport blocks are made to correspond to a plurality of HARQ transmission signal sequences, and this HARQ transmission signal sequence is made to correspond to a multiplexed signal group and spatially multiplexed. You can send and receive. This concept is as shown in FIGS. 33A and 33B. Each of the N transport blocks is transmitted as N HARQ transmission signal sequences corresponding to the above-described HARQ. The receiver performs decoding processing from each HARQ transmission signal sequence to obtain N transport blocks. These detailed operations will be described with reference to FIGS. 34 and 35. FIG.

FIG. 34 and FIG. 35 are diagrams showing an example of the configuration of the transmission side apparatus and the reception side apparatus when the conventional MIMO communication technique and the HARQ communication technique are combined. First, the transmission side device performs error correction coding in the error correction coding unit 101 for each of a plurality of transport blocks transmitted from the higher layer to the reception side device, and the rate matching unit 102 performs the error correction coding on the reception side device. Select the error correction information data to be sent. That is, retransmission control by HARQ is performed in units of transport blocks. The encoded output signal of the rate matching unit 102 is defined as “encoded sequence”. These encoded sequences are scrambled (104) and modulated (105), respectively, and transmission layer mapping is performed (106). A sequence of signals to be subjected to processing such as scramble and modulation on a signal corresponding to HARQ, each sequence is called a “codeword”, and one codeword is one HARQ transmission. Corresponds to the signal sequence. The transmission layer mapping unit 106 generates a plurality of streams by performing serial / parallel conversion or the like according to the configuration of the stream for transmitting the plurality of transmission data from the modulation mapping unit 105 as necessary. Is transmitted to the receiving side device by spatial multiplexing.

In the downlink of E-UTRA, it is considered to use MIMO communication systems of ranks 1 to 4 and a maximum of two transport blocks, a maximum of two HARQ transmission signal sequences, and a maximum of two codewords corresponding thereto. Has been. And a rank can change the number of the ranks which can be utilized according to the condition of a propagation path at any time. The transport blocks from rank 1 to rank 4, the HARQ transmission signal sequence generated therefrom, and the correspondence between codewords and streams are as shown in FIGS. 32A to 32D.

The receiving side apparatus performs processing such as propagation path estimation, separation of streams multiplexed in space, demodulation processing, and the like on the received signals received through the plurality of antennas, and obtains a plurality of symbol sequences corresponding to each transmission stream. On the other hand, the reception layer inverse mapping unit 201 determines which antenna of the transmitting apparatus the stream is transmitted from, and reproduces a plurality of data series. This data sequence corresponds to the HARQ transmission signal sequence in the transmitter. Next, each HARQ transmission signal sequence is input to the inverse modulation mapping section 202, the descrambling section 203, and the rate dematching section 205. The signal input to the rate dematching unit 205 matches the encoded sequence at the transmitter. After HARQ combining is performed on the encoded sequence, error correction decoding (206) is performed to check whether there is an error in the received data for each transport block. The receiving side apparatus transmits an ACK (Positive Acknowledge) for a sequence in which received data has no error, and a NACK (Negative Acknowledge) for a series having an error in the transport block unit, respectively.

For the transport block for which ACK has been transmitted from the reception side device, the transmission side device ends transmission there, and then repeats the above operation for the transport block passed from the upper layer to the reception side device. Send. For the transport block in which NACK is transmitted from the receiving side device, according to the instruction of the scheduler unit in the MAC layer, as shown in FIG. 31, the rate matching unit centering on the error correction information data not transmitted in the previous transmission Select and transmit to the receiving side apparatus using the same HARQ transmission signal sequence / stream. The encoded bit pattern of the transport block retransmitted here is identified by the receiving side device using the redundancy version transmitted by the control channel as described above, and the error correction information data transmitted from the transmitting side device is received at the previous reception. Is combined with the received data and error correction decoding processing is performed again. As a result, if the reception side apparatus can remove the reception error of the transport block that has been previously received in error, it transmits an ACK to the transmission side apparatus, and if the reception error still cannot be removed, the transmission side again A NACK is transmitted to the apparatus, and the next error correction information data is requested to the transmission side apparatus. The transmission side device and the reception side device repeat the above operation for a predetermined maximum number of retransmissions until the reception error of each transport block can be eliminated.

In the above technique, there may be a problem when performing transport block retransmission given by an upper layer. This problem is specifically when two or more transport blocks are transmitted, and transmission of the transport block (this is assumed to be A) fails, but the rest (this is assumed to be B) is successful. This occurs when a newly generated transport block to be transmitted at the retransmission timing does not occur. Although the transport block A is retransmitted based on the control by HARQ, since there is no data to be transmitted using the stream that has transmitted the transport block B, it is necessary to define how to handle this.

In response to this problem, Non-Patent Document 3 states that no data is sent when there is no transmission of a transport block that uses a multiplexed signal group 1 and a corresponding codeword (this is called NULL). is suggesting. Specifically, if the index indicating the size of the transport block (transport block size, TBS: Transport Block Size) transmitted with the control channel is transmitted as 0 along with the transmission of the downlink data, it is received that NULL is transmitted. The machine processes. This will be described by taking rank 4 transmission in E-UTRA shown in FIG. 32D as an example. As shown in FIG. 36, using multiplexed signal group 1 and codeword 1 corresponding thereto in the first transmission, The HARQ transmission signal sequence 1 corresponding to the first transport block is transmitted, and the HARQ transmission signal sequence 2 corresponding to the second transport block is transmitted using the multiplexed signal group 2 and the codeword corresponding thereto. . If an error occurs only in the second transport block, in the second transmission, nothing is transmitted in the codeword 1 that transmitted the first transport block and the stream corresponding thereto, and the second transport block Only the block is retransmitted as in the first transmission.

Further, in Non-Patent Document 4, in order to solve the above problem, a new rank form capable of transmitting the same number of bits is defined, and only one transport block in which a reception error has occurred is transmitted. is suggesting. This will be explained by taking the transmission of rank 4 of E-UTRA shown in FIG. 32D as an example. As shown in FIG. 37, the first transmission uses the multiplexed signal group 1 and the codeword 1 corresponding thereto. HARQ transmission signal sequence 1 corresponding to one transport block is transmitted, and HARQ transmission signal sequence 2 corresponding to the second transport block is transmitted using multiplexed signal group 2 and codeword 2 corresponding thereto. When an error occurs only in the first transport block, the HARQ transmission signal sequence corresponding to the second transport block is retransmitted using transmission mapping that can transmit one HARQ transmission signal sequence in two streams. As a result, only the second transport block can be retransmitted using the same band as the first transmission.
JPO Home Page "Reference Room" "Other Reference Information" "Standard Technology Collection" "FY2016 MIMO (Multi Input Multi Output) Related Technologies" "1-1-1-1 MIMO System Model" [http: //www.jpo .go.jp / shiryou / s_sonota / hyoujun_gijutsu / mimo / 1-1-1.pdf] JPO Home Page "Reference Room" "Other Reference Information" "Standard Technology Collection" "FY2016 MIMO (Multi Input Multi Output) Related Technology" "2-4-2-1 Hybrid-ARQ" [http: //www.jpo .go.jp / shiryou / s_sonota / hyoujun_gijutsu / mimo / 2-2-4-2.pdf] "Efficient support of transmission using codeword DTX", 3GPP TSG RAN WG1 # 51, R1-074743, November 2007 "Extending Code to Layer Mapping for Efficient Support of Retransmissions", 3GPP TSG RAN WG1 # 51, R1-074455, November 2007

However, the conventional techniques described in

Non-Patent Documents

3 and 4 are used in the situation where one transport block is retransmitted and the other transport block is not transmitted as described above. Nothing will be sent in the stream corresponding to the codeword that is not. That is, there is a problem in that the communication efficiency is lowered because the multiplexing that uses the maximum capacity of the communication path is not performed. In the prior art, as shown in FIGS. 33A and 33B, a stream used for HARQ retransmission of a specific transport block is fixed, and an available and unused stream cannot be effectively used.

Furthermore, if limited to E-UTRA, in the method of Non-Patent Document 2, there are two representations of the signal transmission scheme corresponding to rank 2, and in order to identify this with the receiver, the transmitter Therefore, it is necessary to transmit information for identification, and it is not preferable that the control information increases in wireless communication with a limited bandwidth.

The present invention has been made in view of such circumstances, and by effectively using a stream having no transport block to be transmitted, and enabling flexible retransmission of transport blocks, MIMO communication can be performed. It is an object of the present invention to provide a technique for maximizing the communication efficiency and error rate characteristics of HARQ retransmission at the time of system.

(1) In order to achieve the above object, the present invention has taken the following measures. That is, the transmitter of the present invention is a transmitter that transmits a HARQ transmission signal sequence that is generated from a transport block that is a signal sequence passed to the physical layer by the MAC layer and matches a transmission unit by HARQ, A plurality of HARQ transmission signal sequences are generated based on the same transport block, and the generated plurality of HARQ transmission signal sequences are transmitted simultaneously.

Thus, since a plurality of HARQ transmission signal sequences are generated based on the same transport block, for example, the communication efficiency of HARQ retransmission at the time of MIMO communication is maximized and the coding gain is maximized. Thus, communication quality can be improved.

(2) Further, the transmitter of the present invention is characterized in that each of the plurality of HARQ transmission signal sequences corresponds to a different redundancy version.

Thus, since each of the plurality of HARQ transmission signal sequences corresponds to a different redundancy version, it is possible to improve HARQ characteristics.

(3) Moreover, the transmitter of the present invention is a transmitter that includes a plurality of antennas, performs spatial multiplexing of a plurality of signal sequences by a MIMO communication method, and retransmits a transport block based on HARQ. Based on HARQ, the HARQ transmission signal sequence is multiplexed by a MIMO communication method using a selection / distribution unit that generates a larger number of HARQ transmission signal sequences than the number of transport blocks and the plurality of antennas. And a transmitter for re-transmission.

In this way, since more HARQ transmission signal sequences than the number of transport blocks based on HARQ are generated, for example, the communication efficiency of HARQ retransmission at the time of MIMO communication is maximized, and the coding gain is maximized. By improving the communication quality, communication quality can be improved.

(4) Further, in the transmitter of the present invention, the selection / distribution unit has failed to receive one of the transmission signal sequences from the destination communication apparatus, and has successfully received the other transmission signal sequences. If there is no new transport block that is different from the sequence to be retransmitted and the HARQ transmission signal sequence that is generated from the transport block that has been failed to be received, the transport that has been successfully received. A feature is that transmission is performed using multiple resources used by the HARQ transmission signal sequence generated from the block.

Thus, there is a notification from the destination communication device that reception of one of the transmission signal sequences has failed and reception of the other transmission signal sequences has been successful, and a new transport different from the sequence to be retransmitted. In the case where there is no block, the HARQ transmission signal sequence generated from the transport block assumed to have failed to receive, and the multiple resources used by the HARQ transmission signal sequence generated from the transport block assumed to have been successfully received are used. Therefore, retransmission using a stream that cannot be used in the conventional method can be performed. As a result, it is possible to realize efficient retransmission that effectively uses the free physical resources.

(5) Further, in the transmitter of the present invention, the selection / distribution unit failed to receive any one of the transmission signal sequences from the destination communication apparatus and succeeded in receiving the other transmission signal sequences. When there is no new transport block that is different from the sequence to be retransmitted and the HARQ transmission signal sequence generated from the transport block that has been failed to be received is It is characterized in that transmission is performed using all the multiple resources including the multiple resources used by the HARQ transmission signal sequence corresponding to the port block.

Thus, there is a notification from the destination communication device that reception of one of the transmission signal sequences has failed and reception of the other transmission signal sequences has been successful, and a new transport different from the sequence to be retransmitted. In the case where there is no block, the HARQ transmission signal sequence generated from the transport block assumed to have failed to receive includes multiple resources used by the HARQ transmission signal sequence corresponding to the transport block assumed to be successfully received. Since all multiplex resources are used for transmission, retransmission using a stream that cannot be used in the conventional method can be performed. As a result, it is possible to realize efficient retransmission that effectively uses the free physical resources.

(6) In addition, the receiver of the present invention is a receiver that receives a HARQ transmission signal sequence that is generated from a transport block that is a signal sequence passed to the physical layer by the MAC layer and matches a transmission unit by HARQ. Thus, based on the received HARQ transmission signal sequence, a smaller number of transport blocks than the number of HARQ transmission signal sequences are restored.

Thus, based on the received HARQ transmission signal sequence, a smaller number of transport blocks than the number of HARQ transmission signal sequences are restored, so that, for example, the communication efficiency of HARQ retransmission during MIMO communication is maximized. The coding gain can be maximized and the communication quality can be improved.

(7) Further, the receiver of the present invention includes a plurality of antennas, receives a plurality of HARQ transmission signal sequences spatially multiplexed by the MIMO communication scheme, and receives a HARQ transmission signal sequence retransmitted based on HARQ. A receiver that receives a plurality of HARQ transmission signal sequences retransmitted in a MIMO communication scheme using the plurality of antennas, and a HARQ transmission signal sequence that has already received the received HARQ transmission signal sequence And a switching unit that switches to a processing unit that decodes the same transport block.

In this way, since the received HARQ transmission signal sequence is switched to a processing unit that decodes the HARQ transmission signal sequence that has already been received and that has the same transport block, the HARQ transmission based on the received HARQ transmission signal sequence It is possible to restore fewer transport blocks than the number of signal sequences, to maximize the communication efficiency of HARQ retransmission during MIMO communication, to maximize the coding gain, and to improve the communication quality.

(8) In addition, the receiver of the present invention includes a plurality of antennas, receives a plurality of HARQ transmission signal sequences spatially multiplexed by the MIMO communication scheme, and receives a HARQ transmission signal sequence retransmitted based on HARQ. A receiver that receives a plurality of HARQ transmission signal sequences retransmitted in a MIMO communication scheme using the plurality of antennas, and the same transport among the plurality of received HARQ transmission signal sequences The block corresponding to the block is characterized by comprising a switching unit that combines them and switches to a processing unit that decodes the HARQ transmission signal sequence that has already been received and that has the same transport block.

As described above, among the plurality of received HARQ transmission signal sequences, those corresponding to the same transport block are combined, and among the already received HARQ transmission signal sequences, the same transport block is decoded. Therefore, based on the received HARQ transmission signal sequence, it is possible to restore fewer transport blocks than the number of HARQ transmission signal sequences, and maximize the communication efficiency of HARQ retransmission during MIMO communication. It is possible to maximize the coding gain and improve the communication quality.

(9) In the receiver of the present invention, the switching unit determines a transmission signal sequence corresponding to each HARQ transmission signal sequence based on a transmission bit pattern specified by a transmission source communication device. It is said.

In this way, the transmission signal sequence corresponding to each HARQ transmission signal sequence is determined based on the transmission bit pattern specified by the transmission source communication apparatus. For example, when the transmission signal sequence cannot be identified by the process number Also, it is possible to identify which transmission signal sequence is the retransmitted data. As a result, extra control bits for this identification can be reduced.

(10) In the receiver of the present invention, the switching unit determines a transmission signal sequence to which each HARQ transmission signal sequence corresponds based on the size of the transmission signal sequence designated by the transmission source communication apparatus. It is characterized by that.

As described above, the transmission signal sequence corresponding to each HARQ transmission signal sequence is determined based on the size of the transmission signal sequence specified by the transmission source communication apparatus. For example, the transmission signal sequence is identified by the process number. Even if it is not possible, it is possible to identify which transmission signal sequence is the retransmitted data. As a result, extra control bits for this identification can be reduced.

(11) Further, the receiver of the present invention is characterized in that ACK / NACK corresponding to the number of transmission signal sequences transmitted from the transmission source communication device is returned.

As described above, since the ACK / NACK corresponding to the number of transmission signal sequences transmitted from the transmission source communication device is returned, only the necessary number of ACK / NACKs can be transmitted. As a result, communication efficiency can be improved.

(12) Further, the base station apparatus of the present invention is characterized by including any of the transmitters described above.

According to this base station apparatus, since HARQ transmission signal sequences corresponding to HARQ more than the number of transmission signal sequences are generated, for example, the communication efficiency of HARQ retransmission at the time of MIMO communication is maximized and encoded. Communication quality can be improved by maximizing the gain.

(13) Further, the mobile station apparatus of the present invention is characterized by including any of the receivers described above.

According to this mobile station apparatus, based on the received HARQ transmission signal sequences corresponding to a plurality of HARQ, the transmission signal sequences processed in a smaller number of higher layers than the number of the HARQ transmission signal sequences are restored. The communication quality can be improved by maximizing the communication gain of HARQ retransmission at the time of MIMO communication and maximizing the coding gain.

(14) Further, the radio communication system of the present invention is characterized by comprising the above base station apparatus and the above mobile station apparatus.

According to this wireless communication system, since more HARQ transmission signal sequences corresponding to HARQ than the number of transmission signal sequences are generated, for example, the communication efficiency of HARQ retransmission at the time of MIMO communication is maximized and encoded. Communication quality can be improved by maximizing the gain.

According to the present invention, the communication quality can be improved by maximizing the coding gain by utilizing the communication efficiency of HARQ retransmission at the time of MIMO communication to the maximum.

It is a figure which shows the concept of this invention. It is a figure which shows the concept of this invention. It is a block diagram which shows the example of 1 structure of the transmitter with which the base station apparatus which concerns on 1st Embodiment is provided. It is a block diagram which shows the example of 1 structure of the receiver with which the mobile station apparatus which concerns on 1st Embodiment is provided. It is a sequence chart which shows the resending process of HARQ. It is a figure which shows the operation example of a transmitter. It is a figure which shows the operation example of a receiver. It is a figure which shows the operation example of a transmitter. It is a figure which shows the operation example of a receiver. It is a block diagram which shows the example of 1 structure of the transmitter with which the base station apparatus which concerns on 2nd Embodiment is provided. It is a block diagram which shows one structural example of the receiver with which the mobile station apparatus which concerns on 2nd Embodiment is provided. It is a sequence chart which shows the resending process of HARQ. It is a figure which shows the operation example of a transmitter. It is a figure which shows the operation example of a receiver. It is a figure which shows a circular buffer which holds the transmission data series provided in the rate matching part, and a mode that the data of a redundancy version are read from the buffer. It is a figure which shows a circular buffer which holds the transmission data series provided in the rate matching part, and a mode that the data of a redundancy version are read from the buffer. It is a figure which shows the operation example of a transmitter. It is a figure which shows the operation example of a receiver. It is a figure which shows a circular buffer which holds the transmission data series provided in the rate matching part, and a mode that the data of a redundancy version are read from the buffer. It is a figure which shows a circular buffer which holds the transmission data series provided in the rate matching part, and a mode that the data of a redundancy version are read from the buffer. It is a sequence chart which shows the resending process of HARQ. It is a figure which shows the operation example of a transmitter. It is a figure which shows the operation example of a receiver. It is a figure which shows the operation example of a transmitter. It is a figure which shows the operation example of a receiver. It is a figure which shows a circular buffer which holds the transmission data series provided in the rate matching part, and a mode that the data of a redundancy version are read from the buffer. It is a figure which shows a circular buffer which holds the transmission data series provided in the rate matching part, and a mode that the data of a redundancy version are read from the buffer. It is a sequence chart which shows the resending process of HARQ. It is a sequence chart which shows the resending process of HARQ. It is a block diagram which shows the example of 1 structure of the transmitter with which the base station apparatus which concerns on 6th Embodiment is provided. It is a block diagram which shows the example of 1 structure of the receiver with which the mobile station apparatus which concerns on 6th Embodiment is provided. It is a sequence chart which shows the resending process of HARQ. The figure which shows a mode that the retransmission process which has arrange | positioned the transport block 2 to both the 1st encoding sequence and HARQ transmission signal sequence and the 2nd encoding sequence and HARQ transmission signal sequence in the MAC layer of a base station apparatus. is there. It is a figure which shows a mode that it is judged which transport block was transmitted in the receiver by the process number transmitted by the control channel. It is a figure which shows the transmission signal series which provided the error correction bit (parity bit) stored in a buffer. It is a figure which shows the correspondence of the transmission signal series of rank 1, and a stream. It is a figure which shows the correspondence of the transmission signal series of rank 2, and a stream. It is a figure which shows the correspondence of the transmission signal series of rank 3, and a stream. It is a figure which shows the correspondence of the transmission signal series of rank 4, and a stream. It is a figure which shows the concept of combining a MIMO communication technique and a HARQ communication technique, making a plurality of transport blocks correspond to a plurality of HARQ transmission signal sequences, and spatially multiplexing and transmitting / receiving this HARQ transmission signal sequence. It is a figure which shows the concept of combining a MIMO communication technique and a HARQ communication technique, making a plurality of transport blocks correspond to a plurality of HARQ transmission signal sequences, and spatially multiplexing and transmitting / receiving this HARQ transmission signal sequence. It is a figure which shows an example of a structure of the transmission side apparatus at the time of combining the conventional MIMO communication technique and HARQ communication technique. It is a figure which shows an example of a structure of the receiving side apparatus at the time of combining the conventional MIMO communication technique and HARQ communication technique. It is a figure which shows an example of the transmission of rank 4 in E-UTRA. It is a figure which shows an example of transmission of rank 4 of E-UTRA.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Encoding part 102 Rate matching part 103 Selection / allocation part 104 Scramble part 105 Modulation mapping part 106 Transmission layer mapping part 107 Scheduler part 201 Reception layer reverse mapping part 202 Inverse modulation mapping part 203 Inverse scrambling part 204 Switching part 205 Rate data Matching unit 206 Error correction decoding unit 601 Serial / parallel (S / P) conversion unit 602 Parallel / serial (P / S) conversion unit 1001 Circular buffer 1002 Systematic bit 1003 Parity bit

1A and 1B are diagrams showing the concept of the present invention. The transmitter generates a plurality of HARQ transmission signal sequences from one transport block, and multiplexes and transmits the generated plurality of HARQ transmission signal sequences. The receiver recovers one transport block from a plurality of HARQ transmission signal sequences. When there is no transport block to be transmitted at the transmitter, the transport block to be retransmitted is efficiently retransmitted using an empty HARQ transmission signal sequence / stream. In addition, the process of associating the HARQ transmission signal sequence with a plurality of multiplexed signal groups is logically supported, and includes processing performed on each signal sequence such as scrambling in the process. It is also included in the scope of the present invention that it is not included. Here, a specific operation of a transmitter that associates one transport block with a plurality of HARQ transmission signal sequences and a specific operation of a receiver that associates a plurality of HARQ transmission signal sequences with one transport block An example will be described.

(First embodiment)
First, a radio communication system according to the first embodiment of the present invention will be described. This wireless communication system includes a base station device and a mobile station device. FIG. 2 is a block diagram illustrating a configuration example of a transmitter included in the base station apparatus according to the present embodiment, and FIG. 3 is a block diagram illustrating a configuration example of a receiver included in the mobile station apparatus according to the present embodiment. FIG. As shown in FIG. 2, the transmitter 10 includes an encoding unit 101, a rate matching unit 102, a selection / distribution unit 103, a scramble unit 104, a modulation mapping unit 105, a transmission layer mapping unit 106, and a scheduler unit 107. Yes. Also, as shown in FIG. 3, the receiver 20 includes a reception layer inverse mapping unit 201, an inverse modulation mapping unit 202, a descrambling unit 203, a switching unit 204, a rate dematching unit 205, an error correction decoding unit 206, a control A unit 207 is provided. In the present embodiment, transmission processing at the base station device and reception processing at the mobile station device will be described taking transmission signals from the base station device to the mobile station device as an example. In this embodiment, the processing of the transmitter that generates a plurality of HARQ transmission signal sequences corresponding to one transport block is performed by the selection / distribution unit 103, and the HARQ transmission signal sequence described above is scrambled by 104. It corresponds to the signal after the signal input to. The processing of the receiver corresponding to the opposite is performed by the switching unit 204.

The transmitter 10 is provided with N transport blocks from the upper layer. The encoding unit 101 receives this as an input, adds a parity bit for error correction and error detection, and outputs the result. The rate matching unit 102 receives this as input, selects and aggregates bits according to the transmission band, and outputs an encoded sequence. Retransmission control using HARQ is performed for each transport block. Also, control information necessary for this is notified to the receiving side using another control information transmission channel. The serially connected encoding unit 101 and rate matching unit 102 are physically or logically provided in parallel.

The selection / distribution unit 103 receives the output signals from the N rate matching units 102 according to the control signal of the scheduler unit 107 controlled by the MAC layer, and selects the output signals to the N output terminals. Sort and output. The selection / distribution unit 103 outputs N HARQ transmission signal sequences, but an output from one rate matching unit 102 may correspond to zero or a plurality of HARQ transmission signal sequences.

The scrambler 104 receives one output signal of the selection / distribution unit 103, that is, the HARQ transmission signal sequence, scrambles it, and outputs it to the modulation mapping unit 105. The scramble process is realized by taking an exclusive OR with a predetermined sequence. Modulation mapping section 105 performs processing corresponding to the modulation method such as symbolization and complex number expression on the input bit string from scramble section 104, and outputs this as a symbol string. The scrambler 104 and the modulation mapping unit 105 connected in series are physically or logically provided in parallel with the selection / distribution unit 103. The transmission layer mapping unit 106 converts the N input signal sequences from the modulation mapping unit 105 into the number of streams that can be communicated by MIMO (M is the number of streams) and outputs the number of streams.

The scheduler unit 107 is configured to include downlink scheduling, uplink scheduling, control data creation, and control data reception functions. Further, the scheduling information is included in the control information and notified to the receiver. The received user data and control data are processed or output to a higher layer.

In downlink scheduling, user data is transmitted to each downlink channel from channel state information notified from the mobile station apparatus, ACK / NACK information of downlink data, data information of each user notified from higher layers, and the like. And scheduling for mapping control data.

In uplink scheduling, scheduling for mapping user data to each uplink channel is performed based on the uplink channel estimation result and the resource allocation request from the mobile station.

In the control data creation, an ACK / NACK signal is created as control data for correctness of uplink received data. Also, uplink and downlink scheduling information is created as control data. The scheduling unit instructs the encoding unit and the rate matching unit to perform the number of HARQ retransmission signal sequences and control after encoding.

The receiver 20 receives a number (M) of symbol series signals corresponding to the number of streams received and demodulated by the MIMO scheme. In reception layer inverse mapping section 201, processing reverse to that of transmission layer mapping section 106 is performed, processing for returning the input stream to the HARQ transmission signal sequence is performed, and N HARQ transmission signals corresponding to the transmitter are performed. A series is output. The inverse modulation mapping unit 202 receives one HARQ transmission signal sequence output from the reception layer inverse mapping unit 201, demodulates symbols in accordance with the processing of the modulation mapping unit 105, and outputs a bit sequence. The descrambling unit 203 performs processing reverse to that of the scrambler 104 and outputs this bit string. The inverse modulation mapping unit 202 and the descrambling unit 203 connected in series are physically or logically provided in parallel with the reception layer inverse mapping unit 201.

The outputs of the N descrambling units 203 are input to the switching unit 204, and are distributed and output for each HARQ processing unit, that is, for each corresponding transport block, under the control of the control unit 207. The operation of the control unit 207 is determined based on information indicating which transport block corresponds to the HARQ transmission signal sequence transmitted by the downlink control channel. This distribution is performed based on a control signal sent simultaneously with the downlink signal. Here, this output signal is an encoded sequence corresponding to the transmitter. When encoded sequences corresponding to the same transport block are provided from the descrambling unit 203, these are collectively output as one signal. The output of the switching unit 204 is input to the rate dematching unit 205, and the transmitted signals including retransmission are combined and output to the error correction decoding unit 206. The error correction decoding unit 206 performs error correction / error detection processing, removes the parity bits, and outputs a signal sequence corresponding to the transmitted transport block.

Next, the HARQ retransmission process performed using the transmitter shown in FIG. 2 and the receiver shown in FIG. 3 will be described using the sequence chart shown in FIG. In this example, the number M of HARQ transmission signal sequences is “2”. FIG. 4 shows the number of transmission signal sequences (501), the signal flow (502) corresponding to the first HARQ transmission signal sequence, and the second HARQ transmission signal in communication between the base station apparatus and mobile station apparatus in this embodiment. Signal flow (503) corresponding to the sequence, specific sequence chart (504), and specific signal flows of the base station apparatus and mobile station apparatus in each subframe (S551a, S552a, S553a, S554a, S555a) )It is shown.

In FIG. 4, in # Subframe1, the mobile station apparatus calculates channel information using a signal transmitted from the base station apparatus, and information (rank) of the number of streams applied to the downlink signal is transmitted from the mobile station apparatus to the base station apparatus. To give feedback. Here, since the number of streams 4 is desired, rank 4 is transmitted (S551a).

In # Subframe2, the base station apparatus determines the number of streams based on the rank information notified from the mobile station apparatus, and corresponds to two transport blocks using four streams using two HARQ transmission signal sequences. The downlink data is transmitted and received by the mobile station apparatus (S552a). Here, information identifying the signal sequence (process number) and selection pattern information (redundancy version, RV) of the transmission signal bit sequence selected by the rate matching unit are transmitted simultaneously on the downlink control channel. The process number and RV in the encoded sequence 1 are 1 and 0, respectively, and the process number and RV in the encoded sequence 2 are 2 and 0, respectively.

An example of the operation of the transmitter at this time is shown in FIG. 5, and an example of the operation of the receiver is shown in FIG. In the transmitter 10, the selection / distribution unit 103 operates to associate the encoded sequence 1 with the HARQ transmission signal sequence 1 and associate the encoded sequence 2 with the HARQ transmission signal sequence 2. The transmission layer mapping unit 106 creates four streams from two HARQ transmission signal sequences by the serial / parallel (S / P) conversion unit 601 from the HARQ transmission signal sequences modulated by the modulation mapping unit 105. In the receiver, the reception layer inverse mapping unit 201 corresponds to two HARQ transmission signal sequences from four streams by a parallel / serial (P / S) conversion unit 602. Based on the control signal from control section 207, switching section 204 associates HARQ transmission signal sequence 1 with encoded sequence 1 and HARQ transmission signal sequence 2 with encoded sequence 2, and outputs them to rate dematching section 205. To do. The control unit 207 determines a corresponding distribution method based on the process number notified by the control channel.

In # Subframe3, decoding processing is performed on the HARQ retransmission signal sequence received by the mobile station apparatus in # Subframe2, and ACK or NACK is transmitted according to the presence or absence of the error (S553a). Here, since no error has occurred in HARQ retransmission signal sequence 1, the mobile station apparatus transmits ACK to the base station apparatus. Since the occurrence of an error is detected for HARQ retransmission signal sequence 2, the mobile station apparatus transmits NACK to the base station apparatus.

In # Subframe4, the base station apparatus performs retransmission processing in response to ACK / NACK transmitted from the mobile station apparatus in # Subframe3. At this time, the buffer in the base station apparatus is already empty, there is no transport block transferred from the upper layer, and only the sequence for which transmission failed may be retransmitted. The base station apparatus determines the number of streams based on the rank information notified from the mobile station apparatus in # Subframe1, and uses four streams using two HARQ transmission signal sequences to download one stream block corresponding to one transport block. Link data is transmitted and received by the mobile station apparatus (S554a). Here, the process number and the redundancy version are transmitted simultaneously on the downlink control channel. The process number and RV in the encoded sequence 1 are 2, 0, respectively, and the process number and RV in the encoded sequence 2 are 2, 0, respectively. That is, the HARQ

transmission signal sequences

1 and 2 indicate that the sequences transmitted in the HARQ transmission signal sequence 2 in # Subframe2 are retransmitted in parallel.

FIG. 7 shows an example of the operation of the transmitter at this time, and FIG. 8 shows an example of the operation of the receiver. In transmitter 10, selection / distribution section 103 associates encoded sequence 2 with HARQ transmission signal sequence 1 and HARQ transmission signal sequence 2, and does not associate encoded sequence 1 with each HARQ transmission signal sequence. In the receiver 20, the switching unit 204 determines a corresponding distribution method from the process number notified by the control channel, associates the HARQ transmission signal sequence 1 and the HARQ transmission signal sequence 2 with the encoded sequence 2, and outputs these signals. Is output to the rate dematching unit 205.

In FIG. 4, in #Subframe 5, decoding processing is performed on the HARQ retransmission signal sequence received by the mobile station apparatus in #Subframe 4, and ACK or NACK is transmitted according to the presence or absence of the error (S555a). Here, since no error has occurred for one transmission signal sequence, only one ACK / NACK transmission is required. Here, since no error is detected in the received signal, the mobile station apparatus transmits ACK to the base station apparatus.

As described above, according to the first embodiment, when retransmission occurs in a situation where there is no transport block to be newly transmitted, retransmission using a stream that cannot be used in the conventional method can be performed. It is possible to realize an efficient retransmission that effectively uses the free physical resources. In the present invention, the selection / distribution unit 103 is provided in the preceding stage of the scrambler 104. However, this can be provided in the preceding stage of the modulation mapping unit 105. A configuration including the operation of the allocating unit 103 may be taken. The position where the switching unit 204 is provided in the receiver is also changed according to the position of the selection / distribution unit 103 of the transmitter.

(Second Embodiment)
Next, a radio communication system according to the second embodiment of the present invention will be described. This wireless communication system includes a base station device and a mobile station device. FIG. 9 is a block diagram illustrating a configuration example of a transmitter included in the base station apparatus according to the present embodiment, and FIG. 10 is a block diagram illustrating a configuration example of a receiver included in the mobile station apparatus according to the present embodiment. FIG. The difference between the transmitter illustrated in FIG. 2 and the receiver illustrated in FIG. 3 is a rate matching unit 102, a selection / distribution unit 103, a switching unit 204, and a rate dematching unit 205. In this embodiment, the processing of the transmitter that generates a plurality of HARQ transmission signal sequences corresponding to one transport block is performed by the selection / distribution unit 103, and the HARQ transmission signal sequence described above is scrambled by 104. It corresponds to the subsequent output. The processing of the receiver corresponding to the opposite is performed by the switching unit 204.

The rate matching unit 102 in the transmitter shown in FIG. 9 receives information bits to which parity bits for error correction and error detection are added. Here, selection and aggregation of bits according to the transmission band are performed and output, and the output bit sequence corresponds to the supported redundancy version. Here, four redundancy versions (0, 1, 2, and 3) correspond, and in the above bit selection and aggregation, four different sequences are created for each output sequence and are output. The redundancy version for identifying this bit sequence is notified to the reception side using another control information transmission channel together with other information necessary for decoding. The output signals (total L) of the N rate matching units 102 are input to the selection / distribution unit 103, and the selection / distribution unit 103 selects one of the input signals to be transmitted under the control of the scheduler unit 107, Sort to N output terminals.

The switching unit 204 in the receiver 91 shown in FIG. 10 receives the HARQ transmission signal sequence that is the output signal of the N descrambling units 203 as an input, and distributes each HARQ processing unit, that is, for each corresponding transport block. To the rate dematching unit 205. For this reason, a plurality of codewords having the same or different RV may be simultaneously input to one rate dematching unit 205, and these are combined and output to the error correction decoding unit 206.

Next, the HARQ retransmission process performed using the transmitter shown in FIG. 9 and the receiver shown in FIG. 10 will be described using the sequence chart of FIG.

In #Subframe 1, the mobile station apparatus calculates channel information using a signal transmitted from the base station apparatus, and feeds back information (rank) of the number of streams applied to the downlink signal from the mobile station apparatus to the base station apparatus. Here, since the number of streams 4 is desired, rank 4 is transmitted (S551b).

In # Subframe2, the base station apparatus determines the number of streams based on the rank information notified from the mobile station apparatus, and corresponds to two transport blocks using four streams using two HARQ transmission signal sequences. The downlink data is transmitted and received by the mobile station apparatus (S552b). Here, the process number and the redundancy version are transmitted simultaneously on the downlink control channel. The process number and RV in the encoded sequence 1 are 1 and 0, respectively, and the process number and RV in the encoded sequence 2 are 2 and 0, respectively.

FIG. 12 shows a detailed operation example of the transmitter at this time, and FIG. 13 shows an operation example of the receiver. 14A and 14B are diagrams illustrating a circular buffer 1001 that holds transmission data sequences provided in the rate matching unit 102 and a state in which data of redundancy version 0 is read from the buffer. In the transmitter 90 shown in FIG. 12, the rate matching unit 102 holds the signal sequence with the parity bit added in the circular buffer 1001, and changes the information amount that can be transmitted on the physical channel from the start position according to the redundancy version. Read the corresponding number of bits. Here, the rate matching unit 102 corresponds to four redundancy versions, and performs four outputs corresponding to each.

The selection / distribution unit 103 receives a total of eight signals output from the two rate matching units 102. Here, RV0 signal in encoded sequence 1 is made to correspond to HARQ transmission signal sequence 1, and RV0 signal in encoded sequence 2 is made to correspond to HARQ transmission signal sequence 2. The transmission layer mapping unit uses the serial / parallel (S / P) conversion unit 601 to create four streams from the two HARQ transmission signal sequences from the HARQ transmission signal sequence modulated by the modulation mapping unit 105. In the receiver, the reception layer inverse mapping unit 201 causes the parallel / serial (P / S) conversion unit 602 to associate four streams with two HARQ transmission signal sequences. Based on the control signal from control section 207, switching section 204 associates HARQ transmission signal sequence 1 with RV0 of encoded sequence 1 and HARQ transmission signal sequence 2 with RV0 of encoded sequence 2, and performs rate dematching. The data is output to the unit 205. The control unit 207 determines a corresponding distribution method from the process number notified by the control channel.

In # Subframe3, decoding processing is performed on the HARQ retransmission signal sequence received by the mobile station apparatus in # Subframe2, and ACK or NACK is transmitted according to the presence or absence of the error (S553b). Here, since no error has occurred in HARQ retransmission signal sequence 1, the mobile station apparatus transmits ACK to the base station apparatus. Since the occurrence of an error is detected for HARQ retransmission signal sequence 2, the mobile station apparatus transmits NACK to the base station apparatus.

In # Subframe4, the base station apparatus performs retransmission processing in response to ACK / NACK transmitted from the mobile station apparatus in # Subframe3. At this time, the buffer in the base station apparatus is already empty, there is no transport block transferred from the upper layer, and only the sequence for which transmission failed may be retransmitted. The base station apparatus determines the number of streams based on the rank information notified from the mobile station apparatus in # Subframe1, and uses two HARQ transmission signal sequences and four streams to correspond to one transport block. The downlink data is transmitted and received by the mobile station device (S554b). Here, the process number and redundancy version information are transmitted simultaneously on the downlink control channel. The process number and RV in the encoded sequence 1 are 2 and 1, respectively, and the process number and RV in the encoded sequence 2 are 2 and 2, respectively. That is, the HARQ

transmission signal sequences

1 and 2 indicate that transport blocks corresponding to the encoded sequence 2 transmitted in #Subframe 2 are retransmitted in parallel.

FIG. 15 shows a detailed operation example of the transmitter at this time, and FIG. 16 shows an operation example of the receiver. FIGS. 17A and 17B are diagrams illustrating a circular buffer 1001 that holds transmission data series provided in the rate matching unit 102 and a state in which data of redundancy version 0 is read from the buffer. In the transmitter, since the first rate matching unit 102 has successfully transmitted, the buffer is empty. For this reason, all the extracted data is empty. The second rate matching unit 102 holds the signal sequence to which the parity bit is added in the circular buffer 1001, and reads data according to the number of bits that can be transmitted on the physical channel from the start position corresponding to the redundancy version. The rate matching unit 102 corresponds to four redundancy versions, and performs four outputs corresponding to each. The selection / distribution unit 103 receives a total of eight signals output from the two rate matching units 102 as inputs. Here, the RV1 signal in the encoded sequence 2 is made to correspond to the HARQ transmission signal sequence 1, and the RV2 signal in the encoded sequence 2 is made to correspond to the HARQ transmission signal sequence 2.

The receiver 91 determines which transport block is transmitted based on the process number transmitted on the control channel. Here, since the HARQ

transmission signal sequences

1 and 2 both receive the signal having the process number 2, it can be determined that these are one transport block. HARQ transmission signal sequence 1 is associated with RV 1 of encoded sequence 2, and HARQ transmission signal sequence 2 is associated with RV 2 of encoded sequence 2, and output to rate dematching section 205.

In FIG. 11, in # Subframe5, decoding processing is performed on the HARQ retransmission signal sequence received by the mobile station apparatus in # Subframe4, and ACK or NACK is transmitted depending on the presence or absence of the error (S555b). Here, since no error has occurred for one transmission signal sequence, only one ACK / NACK transmission is required. Here, since no error is detected in the received signal, the mobile station apparatus transmits ACK to the base station apparatus.

As described above, according to the second embodiment, when retransmission occurs in a situation where there is no transport block to be newly transmitted, retransmission using a stream that cannot be used in the conventional method can be performed. It is possible to realize an efficient retransmission that effectively uses the free physical resources. Furthermore, in the present embodiment, since different redundancy versions of data can be transmitted in different streams, it is possible to realize efficient retransmission with higher coding gain.

(Third embodiment)
Next, a radio communication system according to the third embodiment of the present invention will be described. This wireless communication system includes a base station device and a mobile station device. The difference from the second embodiment is that the number of streams in which two codes can be used is different, the first HARQ transmission signal sequence can be transmitted using one stream, and the second HARQ transmission signal sequence Is assumed to be rank 3 communication capable of transmission using two streams. The transmitter in this embodiment is the same as the transmitter shown in FIG. 9 in the second embodiment, and the receiver in this embodiment is the same as the receiver shown in FIG. 10 in the second embodiment. It is the same. In this embodiment, the processing of the transmitter that generates a plurality of HARQ transmission signal sequences corresponding to one transport block is performed by the selection / distribution unit 103, and the HARQ transmission signal sequence described above is scrambled by 104. It corresponds to the subsequent output. The processing of the receiver corresponding to the opposite is performed by the switching unit 204. In the third embodiment, the HARQ retransmission process performed using the transmitter shown in FIG. 9 and the receiver shown in FIG. 10 will be described using the sequence chart of FIG.

In #Subframe 1, the mobile station apparatus calculates channel information using a signal transmitted from the base station apparatus, and feeds back information (rank) of the number of streams applied to the downlink signal from the mobile station apparatus to the base station apparatus. Here, since the number of streams 3 is desired, rank 3 is transmitted (S551c).

In # Subframe2, the base station apparatus determines the number of streams based on the rank information notified from the mobile station apparatus, and corresponds to two transport blocks using three streams using two HARQ transmission signal sequences. The downlink data is transmitted and received by the mobile station apparatus (S552c). Here, the process number and the redundancy version are transmitted simultaneously on the downlink control channel. The process number and RV in the encoded sequence 1 are 1 and 0, respectively, and the process number and RV in the encoded sequence 2 are 2 and 0, respectively.

FIG. 19 shows a detailed operation example of the transmitter at this time, and FIG. 20 shows an operation example of the receiver. In the transmitter 90, the rate matching unit 102 corresponds to four redundancy versions, and performs four outputs corresponding to each. The selection / distribution unit 103 receives a total of eight signals output from the two rate matching units 102. Here, under the control of scheduler section 107, RV0 signal in coded sequence 1 is made to correspond to HARQ transmission signal sequence 1, and RV0 signal in coded sequence 2 is made to correspond to HARQ transmission signal sequence 2. For the HARQ transmission signal sequence modulated by the modulation mapping unit 105, the transmission layer mapping unit creates only three signals corresponding to the HARQ transmission signal sequence 2 by the serial / parallel (S / P) conversion unit 601, and creates three streams. To do.

In the receiver 91, the reception layer inverse mapping unit 201 causes the parallel / serial (P / S) conversion unit 602 to associate the three streams with the two HARQ transmission signal sequences. Switching section 204 determines the corresponding allocation method from the process number notified by the control channel, and converts HARQ transmission signal sequence 1 to RV0 of encoded sequence 1 and HARQ transmission signal sequence 2 to RV0 of encoded sequence 2. Corresponding to each of them, it is output to the rate dematching unit 205.

FIG. 18 is a sequence chart showing the HARQ retransmission process. In FIG. 18, in # Subframe3, decoding processing is performed on the HARQ retransmission signal sequence received by the mobile station apparatus in # Subframe2, and ACK or NACK is transmitted according to the presence or absence of the error (S553c). Here, since no error has occurred in HARQ retransmission signal sequence 1, the mobile station apparatus transmits ACK to the base station apparatus. Since the occurrence of an error is detected for HARQ retransmission signal sequence 2, the mobile station apparatus transmits NACK to the base station apparatus.

In # Subframe4, the base station apparatus performs retransmission processing in response to ACK / NACK transmitted from the mobile station apparatus in # Subframe3. At this time, the buffer in the base station apparatus is already empty, there is no transport block transferred from the upper layer, and only the sequence for which transmission failed may be retransmitted. The base station apparatus determines the number of streams based on the rank information notified from the mobile station apparatus in # Subframe1, and uses three streams using two HARQ transmission signal sequences to correspond to one transport block. Data is transmitted and received by the mobile station device (S554c). Here, information for identifying a signal sequence (process number) and redundancy version information are transmitted simultaneously on the downlink control channel. The process number and RV in the encoded sequence 1 are 2 and 1, respectively, and the process number and RV in the encoded sequence 2 are 2 and 2, respectively. That is, in the encoded

sequences

1 and 2, the transport block corresponding to the encoded sequence 2 transmitted in #Subframe 2 is retransmitted in parallel.

FIG. 21 shows a detailed operation example of the transmitter at this time, and FIG. 22 shows an operation example of the receiver. FIG. 23A and FIG. 23B are diagrams showing a circular buffer 1001 that holds a transmission data sequence provided in the rate matching unit 102 and a state in which redundancy version 0 data is read from the buffer. In the transmitter 90, since the first rate matching unit 102 has successfully transmitted, the buffer is empty. For this reason, all the extracted data is empty. The second rate matching unit 102 holds the signal sequence to which the parity bit is added in the circular buffer 1001, and controls the scheduler unit 107 according to the number of bits that can be transmitted from the start position according to the redundancy version. Read the data.

The rate matching unit 102 is compatible with four redundancy versions, and performs four outputs corresponding to each. The selection / distribution unit 103 receives a total of eight signals output from the two rate matching units 102. Here, the RV1 signal in the encoded sequence 2 is made to correspond to the HARQ transmission signal sequence 1, and the RV2 signal in the encoded sequence 2 is made to correspond to the HARQ transmission signal sequence 2. However, since the HARQ transmission signal sequence 1 has half the number of streams that can be used compared to the HARQ transmission signal sequence 2, the number of bits that can be transmitted is reduced by half. That is, here, only the first half of the sequence output from rate matching section 102 is used as HARQ transmission signal sequence 1.

In receiver 91, switching unit 204 associates HARQ transmission signal sequence 1 with RV1 of encoded sequence 2 and HARQ transmission signal sequence 2 with RV2 of encoded sequence 2 based on the control signal of control unit 207, and Output to the dematching unit 205. The control unit 207 determines a corresponding distribution method from the process number notified by the control channel.

In #Subframe 5, decoding processing is performed on the HARQ retransmission signal sequence received by the mobile station apparatus in #Subframe 4, and ACK or NACK is transmitted according to the presence or absence of the error (S555c). Here, since no error has occurred for one transmission signal sequence, only one ACK / NACK transmission is required. Here, since no error is detected in the received signal, the mobile station apparatus transmits ACK to the base station apparatus.

As described above, according to the third embodiment, when retransmission occurs in a state where there is no transport block to be newly transmitted, it is possible to perform retransmission using a stream that cannot be used in the conventional method. It is possible to realize efficient retransmission that effectively utilizes the available resources. Furthermore, in this embodiment, it is possible to transmit different redundancy versions of data in different streams, and furthermore, encoding by enabling retransmission when the number of transmittable bits is reduced by changing the HARQ transmission signal sequence Efficient retransmission with high gain can be realized.

(Fourth embodiment)
Next, a radio communication system according to the fourth embodiment of the present invention is described. This wireless communication system includes a base station device and a mobile station device. The difference from the first embodiment is that the size of the transport block notified from the transmission side (transport block size: TBS (Transport Block Size)) in the information for identifying the transport block in the receiver. It is a point using. Specifically, an encoded sequence designated as TBS = 0 corresponds to the same transport block as the other HARQ transmission signal sequence. In this embodiment, the processing of the transmitter that generates a plurality of HARQ transmission signal sequences corresponding to one transport block is performed by the selection / distribution unit 103, and the HARQ transmission signal sequence described above is scrambled by 104. It corresponds to the subsequent output. The processing of the receiver corresponding to the opposite is performed by the switching unit 204. The configurations of the transmitter and the receiver for implementing this are the same as those in the second embodiment, and are shown in FIGS. 9 and 10, respectively.

In the fourth embodiment, the HARQ retransmission process performed using the transmitter shown in FIG. 9 and the receiver shown in FIG. 10 will be described using the sequence chart of FIG. In FIG. 24, in # Subframe1, the mobile station apparatus calculates channel information using a signal transmitted from the base station apparatus, and information (rank) of the number of streams applied to the downlink signal is transmitted from the mobile station apparatus to the base station apparatus. To give feedback. Here, since the number of streams 4 is desired, rank 4 is transmitted (S551d).

In # Subframe2, the base station apparatus determines the number of streams based on the rank information notified from the mobile station apparatus, and corresponds to two transport blocks using four streams using two HARQ transmission signal sequences. The downlink data is transmitted and received by the mobile station apparatus (S552d). Here, the process number, redundancy version, and transport block size are transmitted simultaneously on the downlink control channel. The process number and RV and TBS in the HARQ transmission signal sequence 1 are 1, 0 and 100, respectively, and the process number and RV in the HARQ transmission signal sequence 2 are 2, 0 and
100.

In # Subframe3, decoding processing is performed on the HARQ retransmission signal sequence received by the mobile station apparatus in # Subframe2, and ACK or NACK is transmitted according to the presence or absence of the error (S553d). Here, since no error has occurred in HARQ retransmission signal sequence 1, the mobile station apparatus transmits ACK to the base station apparatus. Since the occurrence of an error is detected for HARQ retransmission signal sequence 2, the mobile station apparatus transmits NACK to the base station apparatus.

In # Subframe4, the base station apparatus performs retransmission processing in response to ACK / NACK transmitted from the mobile station apparatus in # Subframe3. At this time, the buffer in the base station apparatus is already empty, there is no transport block transferred from the upper layer, and only the sequence for which transmission failed may be retransmitted. The base station apparatus determines the number of streams based on the rank information notified from the mobile station apparatus in # Subframe1, and uses four streams using two HARQ transmission signal sequences to download one stream block corresponding to one transport block. The link data is transmitted and received by the mobile station apparatus (S554d). Here, the process number, redundancy version, and transport block size information are simultaneously transmitted on the downlink control channel. The process number and RV and TBS in the HARQ transmission signal sequence 1 are 2, 1, and 0, respectively, and the process number and RV in the HARQ transmission signal sequence 2 are 2, 2, and 100, respectively. Here, although the HARQ transmission signal sequence 1 is specified as TBS = 0, this value indicates the same transport block as the other HARQ transmission signal sequence. That is, this represents that the transport block corresponding to the encoded sequence 2 transmitted in # Subframe2 is retransmitted in parallel.

In receiver 91, switching section 204 associates HARQ transmission signal sequence 1 with RV 1 of encoded sequence 2 and HARQ transmission signal sequence 2 with RV 2 of encoded sequence 2 based on the control signal of control section 207, respectively. Output to the matching unit 205. The control unit 207 determines a corresponding distribution method based on the transport block size notified by the control channel.

In # Subframe5, decoding processing is performed on the HARQ retransmission signal sequence received by the mobile station apparatus in # Subframe4, and ACK or NACK is transmitted according to the presence or absence of the error (S555d). Here, since no error has occurred for one transmission signal sequence, only one ACK / NACK transmission is required. Here, since no error is detected in the received signal, the mobile station apparatus transmits ACK to the base station apparatus.

As described above, according to the fourth embodiment, when retransmission occurs in a situation where there is no transport block to be newly transmitted, retransmission using a stream that cannot be used in the conventional method can be performed. It is possible to realize an efficient retransmission that effectively uses the free physical resources. Further, in this embodiment, even when the transport block cannot be identified by the process number, it is possible to identify which transport block is the retransmitted data by looking at the transport block size. Extra control bits can be reduced.

(Fifth embodiment)
Next, a radio communication system according to the fifth embodiment of the present invention is described. This wireless communication system includes a base station device and a mobile station device. The difference from the first embodiment is that the redundancy version notified from the transmission side is used for the information for identifying the transport block in the receiver. Specifically, an encoded sequence designated as RV = 0 corresponds to the same transport block as the other HARQ transmission signal sequence. In this embodiment, the processing of the transmitter that generates a plurality of HARQ transmission signal sequences corresponding to one transport block is performed by the selection / distribution unit 103, and the HARQ transmission signal sequence described above is scrambled. This corresponds to the output after the unit 104. The processing of the receiver corresponding to the opposite is performed by the switching unit 204. The configurations of the transmitter and the receiver for implementing this are the same as those in the second embodiment, and are shown in FIGS. 9 and 10, respectively.

In the fifth embodiment, the HARQ retransmission process performed using the transmitter shown in FIG. 9 and the receiver shown in FIG. 10 will be described using the sequence chart of FIG. In FIG. 25, in # Subframe1, the mobile station apparatus calculates channel information using a signal transmitted from the base station apparatus, and obtains information on the number of streams (rank) applied to the downlink signal from the mobile station apparatus to the base station. Feedback to the device. Here, since the number of streams 4 is desired, rank 4 is transmitted (S551e).

In # Subframe2, the base station apparatus determines the number of streams based on the rank information notified from the mobile station apparatus, and supports two transport blocks using four streams using two HARQ transmission signal sequences. The downlink data is transmitted and received by the mobile station apparatus (S552e). Here, the process number and the redundancy version are transmitted simultaneously on the downlink control channel. The process number and RV in the HARQ transmission signal sequence 1 are 2 and 1, respectively, and the process number and RV in the HARQ transmission signal sequence 2 are 2 and 1, respectively.

In # Subframe3, decoding processing is performed on the HARQ retransmission signal sequence received by the mobile station apparatus in # Subframe2, and ACK or NACK is transmitted according to the presence or absence of the error (S553e). Here, since no error has occurred in HARQ retransmission signal sequence 1, the mobile station apparatus transmits ACK to the base station apparatus. Since the occurrence of an error is detected for HARQ retransmission signal sequence 2, the mobile station apparatus transmits NACK to the base station apparatus.

In # Subframe4, the base station apparatus performs retransmission processing in response to ACK / NACK transmitted from the mobile station apparatus in # Subframe3. At this time, the buffer in the base station apparatus is already empty, there is no transport block transferred from the upper layer, and only the sequence for which transmission failed may be retransmitted. The base station apparatus determines the number of streams based on the rank information notified from the mobile station apparatus in # Subframe1, and corresponds to one transport block using four streams using two HARQ transmission signal sequences. The downlink data is transmitted and received by the mobile station apparatus (S554e).

Here, the process number and redundancy version information are transmitted simultaneously on the downlink control channel. The process number and RV in the HARQ transmission signal sequence 1 are 2, 0, respectively, and the process number and RV in the HARQ transmission signal sequence 2 are 2, 2 respectively. Here, although the HARQ transmission signal sequence 1 is designated as RV = 0, this value indicates the same transport block as the other HARQ transmission signal sequence. At this time, it is assumed that the redundancy version of the HARQ transmission signal sequence 1 is determined by a rule determined in advance from the redundancy version of the HARQ transmission signal sequence 2. Here, for simplicity, it is assumed that RV = 2 which is the same as that of the HARQ transmission signal sequence 2 is used. That is, this represents that the transport block corresponding to the encoded sequence 2 transmitted in # Subframe2 is retransmitted in parallel.

In the receiver 91, the switching unit 204 associates the HARQ transmission signal sequence 1 with the RV2 of the encoded sequence 2 and the HARQ transmission signal sequence 2 with the RV2 of the encoded sequence 2 based on the control signal of the control unit 207, respectively. Output to the matching unit 205. The control unit 207 determines a corresponding distribution method based on the redundancy version notified by the control channel.

In # Subframe5, the HARQ retransmission signal sequence received by the mobile station apparatus in # Subframe4 is subjected to decoding processing, and ACK or NACK is transmitted depending on the presence or absence of the error (S555e). Here, since no error has occurred for one transmission signal sequence, only one ACK / NACK transmission is required. Here, since no error is detected in the received signal, the mobile station apparatus transmits ACK to the base station apparatus.

As described above, according to the fifth embodiment, when retransmission occurs in a situation where there is no transport block to be newly transmitted, it is possible to perform retransmission using a stream that cannot be used in the conventional method. It is possible to realize an efficient retransmission that effectively uses the free physical resources. Further, in this embodiment, even when the transport block cannot be identified by the process number, it is possible to identify which transport block is the retransmitted data by looking at the redundancy version. Extra control bits can be reduced.

(Sixth embodiment)
Next, a radio communication system according to the sixth embodiment of the present invention is described. This wireless communication system includes a base station device and a mobile station device. FIG. 26 is a block diagram illustrating a configuration example of a transmitter included in the base station apparatus according to the present embodiment, and FIG. 27 is a block diagram illustrating a configuration example of a receiver included in the mobile station apparatus according to the present embodiment. It is. The difference between the transmitter shown in FIG. 26 and the transmitter shown in FIG. 9 is that the transport block transmitted in each stream is controlled in the MAC layer without using the selection / distribution unit 103 in FIG. It is to be. In the present embodiment, the processing of the transmitter that generates a plurality of HARQ transmission signal sequences corresponding to one transport block is already prepared at the stage of arranging the transport block, and after the output of the rate matching unit 102 Thus, a plurality of HARQ transmission signal sequences corresponding to one transport block are obtained. The processing of the receiver corresponding to the opposite is performed by the switching unit 204. The operation of the receiver shown in FIG. 10 is the same as that of the second embodiment.

The HARQ retransmission process performed using the transmitter shown in FIG. 26 and the receiver shown in FIG. 27 will be described using the sequence chart of FIG. In FIG. 28, in # Subframe1, the mobile station apparatus calculates channel information using a signal transmitted from the base station apparatus, and information on the number of streams (rank) applied to the downlink signal is transmitted from the mobile station apparatus to the base station apparatus. To give feedback. Here, since the number of streams 4 is desired, rank 4 is transmitted (S551f).

In # Subframe2, the base station apparatus determines the number of streams based on the rank information notified from the mobile station apparatus, and corresponds to two transport blocks using four streams using two HARQ transmission signal sequences. The downlink data is transmitted and received by the mobile station apparatus (S552f). Here, the process number and the redundancy version are transmitted simultaneously on the downlink control channel. The process number and RV in the encoded sequence 1 are 1 and 0, respectively, and the process number and RV in the encoded sequence 2 are 2 and 0, respectively (FIG. 26).

In # Subframe3, decoding processing is performed on the HARQ retransmission signal sequence received by the mobile station apparatus in # Subframe2, and ACK or NACK is transmitted depending on the presence or absence of the error (S553f). Here, since no error has occurred in HARQ retransmission signal sequence 1, the mobile station apparatus transmits ACK to the base station apparatus. Since the occurrence of an error is detected for HARQ retransmission signal sequence 2, the mobile station apparatus transmits NACK to the base station apparatus.

In # Subframe4, the base station apparatus performs retransmission processing in response to ACK / NACK transmitted from the mobile station apparatus in # Subframe3. At this time, since the transport block 1 has already been successfully transmitted, only the transport block 2 that has failed to be transmitted is transmitted. The base station apparatus determines the number of streams based on the rank information notified from the mobile station apparatus in # Subframe1, and retransmits the transport block 2 using two HARQ transmission signal sequences and four streams. . Here, as shown in FIG. 29, in the MAC layer of the base station apparatus, the transport block 2 is provided for both the first encoded sequence / HARQ transmission signal sequence and the second encoded sequence / HARQ transmission signal sequence. Perform resend processing. The rate mobile station apparatus receives this (S554f). Here, the process number and redundancy version information are transmitted simultaneously on the downlink control channel. The process number and RV in the encoded sequence 1 are 2 and 1, respectively, and the process number and RV in the encoded sequence 2 are 2 and 2, respectively. That is, the HARQ

transmission signal sequences

As shown in FIG. 30, the receiver 93 determines which transport block is transmitted based on the process number transmitted on the control channel. Here, since control unit 207 has received signals with process numbers 2 for both HARQ

transmission signal sequences

1 and 2, it can be determined that these are one transport block. The control unit 207 outputs, to the switching unit 204, a control signal that associates the HARQ transmission signal sequence 1 with the RV1 of the encoded sequence 2 and the HARQ transmission signal sequence 2 with the RV2 of the encoded sequence 2, and performs the control. 204 outputs to the rate dematching part 205, and synthesize | combines these received signals.

In #Subframe 5, decoding processing is performed on the HARQ retransmission signal sequence received by the mobile station apparatus in #Subframe 4, and ACK or NACK is transmitted depending on the presence or absence of the error (S555f). Here, since no error has occurred for one transmission signal sequence, only one ACK / NACK transmission is required. Here, since no error is detected in the received signal, the mobile station apparatus transmits ACK to the base station apparatus.

As described above, according to the sixth embodiment, when retransmission occurs in a situation where there is no transport block to be newly transmitted, retransmission using a stream that cannot be used in the conventional method can be performed. It is possible to realize an efficient retransmission that effectively uses the free physical resources. Furthermore, in this embodiment, since data of different redundancy versions can be transmitted in different streams, efficient retransmission with higher coding gain can be realized.

In the present embodiment, the process number notified from the transmitter is used as the information for identifying the transmitted transport block, but the procedure described in the fourth and fifth embodiments is used. Street, redundancy version or transport block size may be used. In the present embodiment, the retransmission process corresponding to rank 4 has been described. However, as in the third embodiment, the case of rank 3 can be similarly performed.

Each embodiment of the present invention has been described in detail with reference to the drawings, but the specific configuration is not limited to this embodiment, and the design and the like within the scope of the present invention are also claimed. Included in the range.

Claims

A transmitter that transmits a HARQ transmission signal sequence that is generated from a transport block that is a signal sequence passed to a physical layer by a MAC layer and matches a transmission unit by HARQ,
A transmitter that generates a plurality of HARQ transmission signal sequences based on the same transport block and transmits the generated plurality of HARQ transmission signal sequences simultaneously.
The transmitter according to claim 1, wherein each of the plurality of HARQ transmission signal sequences corresponds to a different redundancy version.
A transmitter that includes a plurality of antennas, spatially multiplexes and transmits a plurality of signal sequences according to a MIMO communication scheme, and retransmits a transport block based on HARQ,
A selection / distribution unit that generates a larger number of HARQ transmission signal sequences than the number of transport blocks based on HARQ;
A transmitter comprising: a transmission unit that multiplexes and retransmits the HARQ transmission signal sequence by a MIMO communication scheme using the plurality of antennas.
The selection / distribution unit receives a notification from the transmission destination communication apparatus that reception of one of the transmission signal sequences has failed and reception of another transmission signal sequence has been successful, and is different from the sequence to be retransmitted. In the case where there is no new transport block, the HARQ transmission signal sequence generated from the transport block assumed to have been successfully received is used by the HARQ transmission signal sequence generated from the transport block that is assumed to have failed to be received. 4. The transmitter according to claim 3, wherein transmission is performed using multiple resources.
The selection / distribution unit receives a notification from the transmission destination communication apparatus that reception of one of the transmission signal sequences has failed and reception of another transmission signal sequence has been successful, and is different from the sequence to be retransmitted. When there is no new transport block, the HARQ transmission signal sequence generated from the transport block that is considered to have failed to be received is used by the HARQ transmission signal sequence that corresponds to the transport block that is said to be successfully received. 4. The transmitter according to claim 3, wherein transmission is performed using all of the multiple resources including the multiple resources.
A receiver that receives a HARQ transmission signal sequence that is generated from a transport block that is a signal sequence passed to a physical layer by a MAC layer and matches a transmission unit by HARQ,
A receiver that restores fewer transport blocks than the number of HARQ transmission signal sequences based on a received HARQ transmission signal sequence.
A receiver that includes a plurality of antennas, receives a plurality of HARQ transmission signal sequences spatially multiplexed in a MIMO communication scheme, and receives a HARQ transmission signal sequence retransmitted based on HARQ,
A receiving unit that receives a plurality of HARQ transmission signal sequences retransmitted in a MIMO communication scheme using the plurality of antennas;
A receiver comprising: a switching unit that switches a received HARQ transmission signal sequence to a processing unit that decodes an HARQ transmission signal sequence that has already been received and that has the same transport block.
A receiver that includes a plurality of antennas, receives a plurality of HARQ transmission signal sequences spatially multiplexed in a MIMO communication scheme, and receives a HARQ transmission signal sequence retransmitted based on HARQ,
A receiving unit that receives a plurality of HARQ transmission signal sequences retransmitted in a MIMO communication scheme using the plurality of antennas;
Among the plurality of received HARQ transmission signal sequences, those corresponding to the same transport block are combined, and the processing unit that decodes the already received HARQ transmission signal sequence having the same transport block And a switching unit for switching.
9. The reception according to claim 7, wherein the switching unit determines a transmission signal sequence corresponding to each HARQ transmission signal sequence based on a transmission bit pattern specified by a transmission source communication apparatus. Machine.
The switching unit determines a transmission signal sequence to which each HARQ transmission signal sequence corresponds, based on a size of a transmission signal sequence specified by a transmission source communication apparatus. The listed receiver.
The receiver according to any one of claims 6 to 10, wherein an ACK / NACK corresponding to the number of transmission signal sequences transmitted from a transmission source communication device is returned.
A base station apparatus comprising the transmitter according to any one of claims 1 to 5.
A mobile station apparatus comprising the receiver according to any one of claims 6 to 11.
A wireless communication system comprising the base station device according to claim 12 and the mobile station device according to claim 13.