JP2007074171A - Radio transmitter, radio receiver, and method for them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve data transmission efficiency by transmitting data at the optimal data transmission rate while simplifying processing of HARQ or the like. <P>SOLUTION: In a radio transmitter 100, a transmission system determination part 106 changes a modulation system into a system whose receiving capability is much higher under the consideration of current radio quality with a reception side when transmitting retransmission data, and determines to transmit data as different data from more antennas than that at the initial transmission time, and creates control information showing a method for connecting the changed modulation system and data to be transmitted from a plurality of antennas with one data, and transfers it to a reception system. Thus, it is possible to make transmission data quantity in the case of retransmission same as that in the case of initial transmission, and to simplify processing of HARQ or the like. Also, it is possible to transmit the data at the optimal data transmission rate. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wireless transmission device, a wireless reception device, and a method thereof used for a MIMO (Multi-Input Multi-Output) transmission method.

  In recent years, in mobile communication systems that are developing rapidly, the MIMO transmission system has attracted attention as a technique for increasing the transmission capacity. The MIMO transmission method is a method of transmitting different data from a plurality of transmitting antennas to a plurality of receiving antennas using the same time, frequency, and the like.

  This MIMO transmission scheme is characterized in that the radio quality between the transmitting and receiving apparatuses is good and the transmission capacity increases in proportion to the number of transmitting and receiving antennas if the number of receiving antennas is the same as the number of transmitting antennas. However, when the wireless quality between the transmitting and receiving apparatuses is poor, interference occurs between different data output from each transmitting antenna, and the receiving side cannot receive each data correctly, and conversely the data transmission efficiency is reduced. The problem occurs.

  Therefore, for example, Patent Document 1 discloses a method that does not reduce data transmission efficiency when the wireless quality between the transmitting and receiving apparatuses is poor. Hereinafter, the outline will be described with reference to FIG. FIG. 10 is a diagram for explaining a modulation scheme of data transmitted from each transmission / reception antenna at the time of initial transmission and retransmission between conventional multi-input / multi-output wireless transmission / reception apparatuses. FIG. 10 shows a case where both the transmission side and the reception side have two antennas.

  In FIG. 10, the wireless transmission device 1000 is configured to transmit one transmission interval TTI () at the time of initial transmission in accordance with the wireless quality with the wireless reception device 1001 indicated by the wireless quality signal periodically notified from the wireless reception device 1001. Within Transmit Time Interval), the wireless antenna 1001 transmits data 1011 from the transmission antenna 1003 and data 1012 from the transmission antenna 1004 using the 16QAM modulation method. This is a MIMO multiplexing scheme.

  On the other hand, when the wireless reception device 1001 cannot correctly receive the data 1011 transmitted from the transmission antenna 1003 of the transmission device 1001, the wireless reception device 1001 transmits a retransmission request signal (NACK) to the wireless transmission device 1000.

  Upon receiving the retransmission request signal, the wireless transmission device 1000 confirms the wireless quality with the wireless reception device 1001 at this time, and when the data is transmitted to the wireless reception device 1001 with the same modulation method (16QAM), the wireless reception device 1001 If it is determined that the possibility that the device 1001 can correctly receive is below a certain value, the same data 1021 and 1022 as the data 1011 are transmitted from the transmission antennas 1003 and 1004 to the wireless reception device 1001, respectively. This is a MIMO diversity method.

  According to this method, it is possible to improve the reception probability in the receiving apparatus and avoid further reduction in data transmission efficiency as compared with the case where data is transmitted from one transmission antenna due to the transmission / reception diversity effect.

  Moreover, in the above-mentioned Patent Document 1, as another method, a modulation scheme in which the wireless transmission device 1000 has a higher reception probability than 16QAM in accordance with the wireless quality between the wireless transmission device 1001 and the wireless reception device 1001 at the time of retransmission. A method of transmitting using a QPSK modulation scheme is disclosed.

In this method using the QPSK modulation method, two transmission intervals TTI are required. However, since transmission is performed using a modulation method that matches the radio quality, data can be transmitted at an optimum data transmission rate, and data transmission efficiency can be improved. Can be improved.
JP 2003-244045 A

  However, in the first conventional example, the reception probability is improved by the transmission / reception diversity effect, but since the current gain due to the transmission / reception diversity effect cannot be recognized, efficient data transmission according to the current wireless quality is performed. There is a problem that can not be.

  In the second conventional example, since the data to be retransmitted straddles two transmission intervals TTI, the HARQ (Hybrid) that improves the gain by combining the data at the first transmission and the data at the time of retransmission. There is a problem that processing such as Automation Repeat Request is complicated.

  The present invention has been made in view of such a point, and while simplifying processing such as HARQ, the wireless transmission device and the wireless reception device can transmit data at an optimal data transmission rate and improve data transmission efficiency. It is an object to provide apparatus and methods thereof.

  In order to solve this problem, a wireless transmission device according to the present invention is a wireless transmission device that includes a plurality of transmission antennas and performs MIMO (Multi-Input Multi-Output) transmission, and manages the wireless quality of a communication partner device. A wireless quality management means for determining the transmission method in consideration of the current wireless quality of the communication partner device at the time of data transmission, and generating control information including the determined transmission method; and the control Modulation encoding means for encoding and modulating transmission data associated with information based on the transmission scheme determined by the transmission scheme determination means, and data output from the modulation encoding means for each of the plurality of transmission antennas Transmitting means to transmit to the communication partner apparatus, the transmission method determining means, at the time of transmission of retransmission data, in the transmission method determined at the first transmission, When the transmission probability is below a predetermined threshold, the transmission method is changed so that data transmitted from one antenna is divided and transmitted from a plurality of antennas at the time of initial transmission, and data transmitted from each transmission antenna is combined The antenna format information indicating is included in the control information.

  A radio reception apparatus according to the present invention includes a plurality of reception antennas and performs MIMO (Multi-Input Multi-Output) reception, wherein each of the plurality of reception antennas transmits from the radio transmission apparatus. Receiving means for receiving data; and demodulating and decoding means for demodulating / decoding data based on the control information and combining the data based on a combining method indicated by antenna format information included in the control information Take the configuration.

  A transmission method according to the present invention is a transmission method of a wireless transmission device that includes a plurality of transmission antennas and performs MIMO (Multi-Input Multi-Output) transmission, and is a wireless quality management step of managing the wireless quality of a communication counterpart device And at the time of data transmission, a transmission method is determined in consideration of the current radio quality of the communication partner device, and a transmission method determination step for generating control information including the determined transmission method is attached to the control information. A modulation and coding step for encoding and modulating transmission data based on the transmission method determined in the transmission method determining step, and the data encoded and modulated in the modulation and coding step from each of the plurality of transmission antennas A transmission step of transmitting to the counterpart device, wherein the transmission method determination step has a predetermined reception probability at the communication counterpart device in the transmission method determined at the time of initial transmission when transmitting retransmission data. If the value is less than or equal to the value, the antenna format information indicates how to combine the data transmitted from each transmitting antenna by changing the transmission method so that the data transmitted from one antenna is divided and transmitted from multiple antennas during the initial transmission. Is included in the control information.

  A reception method according to the present invention is a reception method of a radio reception apparatus that includes a plurality of reception antennas and performs MIMO (Multi-Input Multi-Output) reception, and communicates from each of the plurality of reception antennas by the transmission method. A receiving step for receiving data transmitted from the counterpart device, and demodulation decoding for demodulating and decoding the data based on the control information and combining the data based on the combining method indicated by the antenna format information included in the control information And a process comprising the steps.

  According to the present invention, in the retransmission data transmission, the modulation scheme is changed to a scheme with a higher reception probability and is transmitted as different data from a larger number of antennas than at the first transmission, so the amount of transmission data at the time of retransmission is reduced. It can be the same as the first transmission. Therefore, processing such as HARQ for combining the initial transmission data and the retransmission data can be simplified on the reception side. In addition, since a modulation / coding scheme according to the current radio quality can be selected, data can be transmitted at an optimum data transmission rate, and data transmission efficiency can be improved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the present embodiment, a case where each wireless transmission / reception apparatus is equipped with two transmission / reception antennas will be described.

(Embodiment 1)
FIG. 1 is a block diagram showing a configuration of a first wireless transmission / reception apparatus according to an embodiment of the present invention. 1 includes a transmission / reception antenna 101-1, 101-2, a transmission / reception unit 102, a modulation / encoding unit 103, and CRC addition. The first radio transmission / reception device 100 shown in FIG. Unit 104, buffer 105, transmission method determination unit 106, demodulation / decoding unit 107, signal analysis unit 108, radio quality management unit 109, retransmission management unit 110, and radio quality measurement signal generation unit 111. Then, the downlink data transmitted from the host device is wirelessly transmitted from the transmission / reception antennas 101-1 and 101-2 to the second wireless transmission / reception device (hereinafter also simply referred to as “wireless transmission device”) shown in FIG. An operation of transferring the uplink data received at 101-1 and 101-2 from the wireless reception apparatus shown in FIG.

  The transmission / reception antennas 101-1 and 101-2 transmit the downlink data transferred from the transmission / reception unit 102 to the wireless reception device shown in FIG. 2. In addition, the transmission / reception antennas 101-1 and 101-2 receive uplink data transmitted from the wireless reception device illustrated in FIG.

  The transmission / reception unit 102 transmits two different downlink data transferred from the modulation / encoding unit 103, a transmission scheme (modulation / coding scheme, antenna format) associated therewith shown in FIG. 8, retransmission control information (data identification number, The control information for notifying the number of times of retransmission) and the wireless quality measurement signal transferred from the wireless quality measurement signal generation unit 111 are spread and transferred to predetermined transmission / reception antennas 101-1 and 101-2. . Further, the uplink data transmitted from the transmitting and receiving antennas 101-1 and 101-2 is combined (reception diversity), despreading processing, and the like, and transferred to the demodulation and decoding unit 107.

  The modulation and encoding unit 103 modulates and encodes two different downlink data transferred from the CRC adding unit 104 according to the transmission method (included in the control information) notified from the transmission method determining unit 106, respectively. And transfer the data to the transmission / reception unit 102. Also, the modulation and coding unit 103 performs modulation and coding according to a predetermined transmission method on the control information notified of the transmission method and retransmission control information notified from the transmission method determining unit 106, and transmits and receives 102.

  The CRC adding unit 104 calculates the CRC of two different downlink data transferred from the transmission method determining unit 106 according to the antenna format information associated therewith, adds the calculated value to the downlink data, and the modulation and coding unit 103. When two different downlink data are originally one data according to the antenna format information, the CRC adding unit 104 calculates a CRC for the combination of the two data.

  The buffer 105 is a memory that stores the downlink data received from the host apparatus and the retransmission downlink data transferred from the retransmission management unit 110 in the transmission method determination unit 106.

  The transmission method determination unit 106 receives the downlink data received from the host device, the user identification number (identifying the reception device) notified along with the downlink data, the data type (real time (RT) system, non-real time system ( NRT) is stored in the buffer 105 in accordance with the identification). Then, the transmission method determination unit 106 acquires the wireless quality information from the user identification number from the wireless quality table (see FIG. 6) of the wireless quality management unit 109, and the wireless quality information, data type, and retransmission count information (wireless transmission). This indicates the number of times that the downlink data is transmitted from apparatus 100 to radio receiving apparatus 200. The downlink data to be transmitted is selected in accordance with the number of retransmissions of downlink data received from the host apparatus. When the selected downlink data is the first transmission, the transmission method determination unit 106 determines the transmission method (modulation / coding rate / antenna format) and the amount of data to be transmitted according to the radio quality information, the data type, and the like. . Then, the transmission method determination unit 106 notifies the retransmission management unit 110 of the retransmission management table registration request and the accompanying user identification number, data type, and selected downlink data (only for the determined data amount). The data identification number and the number of retransmission information are acquired. In addition, when the selected downlink data is retransmission, there is a transmission method in which the transmission method determination unit 106 can transmit the same amount of data as the first transmission according to radio quality information, data type, retransmission number information, and the like. If there is, determine the transmission method according to them, if not, select the transmission method with the highest reception possibility that can transmit the same amount of data (using all transmission antennas), Increase the amount of transmission power to be allocated as much as possible. Then, the transmission method determination unit 106 notifies the retransmission management unit 110 of a retransmission management table update request and accompanying user identification number, data identification number, and retransmission number information. (In each TTI, when resources such as antenna, power, and spreading code remain, selection of downlink data to be transmitted and transmission method determination are repeated.) Further, the transmission method determination unit 106 transmits the CRC addition unit 104 to the CRC addition unit 104. Then, the selected downlink data (when transmitting with two antennas according to the antenna format information, it is separated into two different downlink data) and the accompanying antenna format information are transferred, and the modulation and coding section 103 In contrast, the control information for notifying the transmission method and retransmission control information (data identification information, retransmission count information) is transferred.

  The demodulation / decoding unit 107 demodulates / decodes the uplink data transferred from the transmission / reception unit 102 in accordance with a predetermined transmission method and transfers the uplink data to the signal analysis unit 108.

  The signal analysis unit 108 analyzes the contents of the uplink data transferred from the demodulation / decoding unit 107. When ACK or NACK is received, the signal analysis unit 108 notifies the retransmission management unit 110 of the ACK (or NACK) notification signal and the user identification number and data identification number of the ACK (or NACK) accompanying the ACK (or NACK) notification signal. . When receiving the radio quality signal, the signal analysis unit 108 notifies the radio quality management unit 109 of the radio quality signal notification signal and the user identification number and radio quality information of the radio quality signal accompanying the radio quality signal notification signal. Further, when receiving the uplink data generated by the receiving device, the signal analysis unit 108 transfers the uplink data to the higher-level device.

  When the radio quality notification signal is notified from the signal analysis unit 108, the radio quality management unit 109 stores the user identification number and radio quality information associated with the radio quality notification signal in the radio quality table as shown in FIG. Write. Here, if an entry with the same user identification number has already been written, only the wireless quality information is rewritten. When the wireless quality management unit 109 refers to the wireless quality table using the user identification number as a key from the transmission method determination unit 106, the wireless quality management unit 109 notifies the transmission method determination unit 106 of the wireless quality information corresponding to the user identification number. .

  When the retransmission management table registration request is notified from the transmission method determination unit 106, the retransmission management unit 110 determines a data identification number for identification from other downlink data, and the user identification associated with the retransmission management table registration request The number, data type, and downlink data are written in the retransmission management table as shown in FIG. In addition, when a retransmission management table update request is notified from the transmission method determination unit 106, the retransmission management unit 110 sends an entry in the retransmission management table corresponding to the user identification number and data identification number associated with the retransmission management table update request. The retransmission number information is updated to the notified retransmission number information. In addition, when the ACK notification signal is notified from the signal analysis unit 108, the retransmission management unit 110 deletes the entry in the retransmission management table corresponding to the user identification number and data identification number associated with the ACK signal. On the other hand, when the NACK notification signal is notified from the signal analysis unit 108, the retransmission management unit 110 extracts an entry in the retransmission management table corresponding to the user identification number and data identification number associated with the NACK notification signal, and identifies the user identification. The number, data type, data identification number, retransmission count information (increment by 1), and downlink data to be retransmitted are transferred to the buffer 105.

  FIG. 2 is a block diagram showing a configuration of a second wireless transmission / reception apparatus according to an embodiment of the present invention. The second wireless transmission / reception apparatus 200 shown in FIG. 2 includes transmission / reception antennas 201-1 and 201-2, a transmission / reception unit 202, a demodulation / decoding unit 203, a CRC determination unit 204, an application processing unit 205, and wireless quality measurement. Unit 206, retransmission management unit 207, buffer 208, and modulation and coding unit 209, and captures the downlink data received by the transmission / reception antennas 201-1 and 201-2 from the wireless transmission device shown in FIG. 1. Then, an operation for wirelessly transmitting uplink data addressed to the higher-level device from the transmission / reception antennas 201-1 and 201-2 to the wireless transmission device shown in FIG.

  The transmission / reception antennas 201-1 and 201-2 transfer downlink data transmitted from the wireless transmission device 100 to the transmission / reception unit 202. In addition, the transmission / reception antennas 201-1 and 201-2 transmit the uplink data transferred from the transmission / reception unit 202 to the wireless transmission device 100.

  The transmission / reception unit 202 separates the multiplexed downlink data and control information transferred from the transmission / reception antennas 201-1 and 201-2, and is transmitted by the transmission / reception antennas 101-1 and 101-2 of the wireless transmission device 100. The data is converted into a data format, subjected to despreading processing, and transferred to the demodulation / decoding unit 203. However, the radio quality measurement signal is transferred to the radio quality measurement unit 206 after despreading. Further, the transmission / reception unit 202 performs spreading processing on the uplink data (including radio quality signal, ACK, and NACK) transferred from the modulation / coding unit 209, and performs predetermined transmission / reception antennas 201-1, 201-. Forward to 2.

  The demodulation / decoding unit 203 demodulates / decodes the control information transferred from the transmission / reception unit 202 according to a predetermined transmission method. Then, the demodulation / decoding unit 203 demodulates the downlink data transferred from the transmission / reception unit 202 by the modulation method included in the control information, and when two different downlink data are originally one data from the antenna format information, Combine the two data. In the case of retransmission based on the number of retransmissions information included in the control information, the demodulation / decoding unit 203 notifies the retransmission management unit 207 of the retransmission data combination notification signal and the data identification number included in the control information. The storage data stored in the buffer 208 (downlink data transmitted until the previous time) is acquired. Then, the demodulation / decoding unit 203 combines the stored data and the retransmitted downlink data. In the case of the first transmission, composition is not performed. Subsequently, the demodulation / decoding unit 203 decodes the downlink data (the combined data in the case of retransmission) and transfers the decoded data to the CRC determination unit 204.

  The CRC determination unit 204 performs CRC determination of the downlink data transferred from the demodulation / decoding unit 203. When an error is detected, the CRC determination unit 204 transfers the NACK generation request signal and the accompanying data identification number and downlink data to the retransmission management unit 207. On the other hand, if no error is detected, the CRC determination unit 204 notifies the retransmission management unit 207 of the ACK generation request signal and the accompanying data identification number, and transfers the downlink data to the application processing unit 205.

  The application processing unit 205 performs processing on the further lower layer of the downlink data transferred from the CRC determination unit 204. Also, uplink data is generated and transferred to the modulation and coding unit 209.

  The radio quality measurement unit 206 measures the radio quality between the transmission device and the reception device (downlink) from the radio quality measurement signal transferred from the transmission / reception unit 202, generates a radio quality signal from the result, and modulates the radio quality signal. Transfer to the encoding unit 209.

  When the retransmission management unit 207 is notified of the retransmission data combination notification signal from the demodulation and decoding unit 203, the retransmission management unit 207 acquires the previously stored downlink data from the buffer 208 according to the data identification number attached to the retransmission data combination notification signal. Then, the stored data is transferred to the demodulation / decoding unit 203. In addition, when the NACK generation request signal is notified from the CRC determination unit 204, the retransmission management unit 207 transmits the downlink data that is also transferred to the buffer 208 according to the data identification number attached to the NACK generation request signal. Store. Then, retransmission management section 207 generates NACK and transfers the NACK to modulation and coding section 209. In addition, when ACK generation request signal is notified from CRC determination section 204, retransmission management section 207 generates ACK and transfers the ACK to modulation and coding section 209.

  The buffer 208 is a memory for storing the downlink data transferred to the retransmission management unit 207 because an error is detected.

  Modulation / encoding section 209 modulates / encodes uplink data, radio quality signals, and ACK / NACK transferred from application processing section 205, radio quality measuring section 206, and retransmission management section 207, and transmits / receives section 202. Forward to.

  Next, operations of the wireless transmission device and the wireless reception device will be described with reference to FIGS. FIG. 3 is a flowchart for explaining the processing operation of the downlink data received from the host device by the wireless transmission device shown in FIG. FIG. 4 is a flowchart for explaining a processing operation when the wireless transmission device shown in FIG. 1 receives uplink data from the wireless reception device shown in FIG. FIG. 5 is a flowchart for explaining the processing operation when the wireless reception device shown in FIG. 2 receives downlink data from the wireless transmission device shown in FIG. FIG. 6 is a diagram illustrating a configuration example of a wireless quality table provided in the wireless quality management unit illustrated in FIG. FIG. 7 is a diagram illustrating a configuration example of a retransmission management table provided in the retransmission management unit illustrated in FIG. FIG. 8 is a diagram illustrating control information associated with data transmitted from the wireless transmission device illustrated in FIG. 1 to the wireless reception device illustrated in FIG. FIG. 9 is a diagram illustrating a modulation scheme of data transmitted from each transmission / reception antenna between the wireless transmission device illustrated in FIG. 1 and the wireless reception device illustrated in FIG. 2 at the time of initial transmission and retransmission.

  First, the reception processing operation of downlink data transmitted from the higher-level device by the wireless transmission device 100 will be described. The downlink data sent from the host device is accompanied by the user identification number (type of wireless reception device) as the destination, the data type of real-time data or non-real-time data, and other control data. ing. In step (hereinafter simply abbreviated as “ST”) 301 in FIG. 3, when the wireless transmission device 100 receives downlink data from the host device, the transmission method determination unit 106 first transmits the downlink data to the user identification number, The data is stored in the buffer 105 according to the data type.

  Subsequently, when the downlink data radio resources (transmission antenna, power, spreading code) are allocated (ST302: Yes), the transmission method determination unit 106 determines the data type and radio quality management of the downlink data to be transmitted. Based on the radio quality information that can be acquired from the radio quality table (see FIG. 6) of unit 109, the transmission scheme (modulation / coding rate / antenna format) and the amount of data to be transmitted are determined (ST303). The antenna format information is obtained by combining different data transmitted from the two transmission / reception antennas 101 and performing CRC calculation as one data, that is, at the time of retransmission, it is transmitted as one data at the first transmission. This is information for notifying the case where the data is divided into two and transmitted from the two transmission / reception antennas 101. For example, it can be expressed as 1-bit information, and it can be defined as ‘1’ when combining and calculating CRC, and ‘0’ in other cases.

  For example, at the first transmission, data A from antenna 1 and data B from antenna 2 are transmitted, antenna format information is set to '0', and at retransmission, data A-1 from antenna 1 and data A-2 from antenna 2 are transmitted. And the antenna format information is set to “1”. That is, at the time of the initial transmission in which two different data are simply transmitted, the antenna format information is “0”, and the original one is divided into two and transmitted from the two transmission / reception antennas 101. Only in the case of retransmission, the antenna format information is “1”.

  Then, the transmission method determination unit 106 notifies the retransmission management unit 110 of the retransmission management table registration request and the accompanying user identification number, data type, and selected downlink data (only for the determined data amount), Retransmission management section 110 stores it in the retransmission management table in association with the determined data identification number (ST304).

  Next, the transmission scheme determination unit 106 generates control information including the transmission scheme (modulation / coding scheme / antenna format) and retransmission control information (data identification number, retransmission count information) shown in FIG. In addition to notifying to unit 103, the antenna format information is attached to the downlink data and transferred to CRC adding unit 104 (ST305).

  Next, CRC adding section 104 calculates the CRC of the downlink data transferred from transmission method determining section 106 according to the antenna format information attached thereto. Here, when one piece of data is originally divided into two pieces of data according to the antenna format information, a CRC is calculated for a combination of the two pieces of data. The calculated value is added to the downlink data and transferred to modulation and coding section 103.

  Then, the modulation and encoding unit 103 modulates the two different downlink data transferred from the CRC adding unit 104 according to the transmission method included in the control information (see FIG. 8) notified from the transmission method determining unit 106, respectively. Encoding is performed and transferred to the transmission / reception unit 102. Also, the modulation and encoding unit 103 modulates and encodes the control information (see FIG. 8) notified from the transmission method determination unit 106 according to a predetermined transmission method, and transfers the control information to the transmission and reception unit 102. In this case, modulation and coding section 103 performs modulation and coding so that the amount of transmission downlink data after modulation and coding becomes a size included in 1 TTI (ST306).

  Finally, the transmission / reception unit 102 performs spreading processing of downlink data received from the modulation and coding unit 103 and control information (see FIG. 8) associated therewith, and wirelessly transmits from the predetermined transmission / reception antennas 101-1 and 101-2. Transmit to receiving apparatus 200 (ST307).

  Next, with reference to FIG. 4, the reception processing operation of the uplink data transmitted from the wireless reception device 200 by the wireless transmission device 100 will be described. Uplink data transmitted from the wireless reception device 200 is input to the transmission / reception unit 102 via the transmission / reception antennas 101-1 and 101-2. The transmission / reception unit 102 performs combining processing (reception diversity), despreading processing, and the like on the input uplink data, and transfers the data to the demodulation / decoding unit 107 (ST401).

  Demodulation / decoding section 107 demodulates / decodes the uplink data transferred from transmission / reception section 102 according to a predetermined transmission method, and transfers it to signal analysis section 108 (ST402). Subsequently, the signal analysis unit 108 determines the type of the uplink data transferred from the demodulation / decoding unit 107. In the uplink data type determination, it is determined whether it is NACK (ST403), whether it is ACK (ST413), whether it is a radio quality signal (ST415), and uplink data. Is determined (ST417).

  First, when the type of the uplink data is NACK (ST403: Yes), the signal analysis unit 108 notifies the retransmission management unit 110 of the NACK notification signal and the accompanying user identification number and data identification number of the NACK. . Retransmission management section 110 stores, in buffer 105, downlink data to be retransmitted in response to the NACK notification signal, and the user identification number and data identification number of the NACK associated therewith (ST404).

  Then, when the radio scheme (transmission antenna, power, spreading code) for retransmission downlink data is allocated in the transmission method determination unit 106 (ST405: Yes), the radio quality table (FIG. 6), it is determined whether there is a transmission method capable of transmitting all the downlink data to be retransmitted in one transmission interval TTI according to the wireless quality information that can be acquired from (ST406).

  When there is a transmission method (modulation / coding rate / antenna format) that can transmit all downlink data to be retransmitted in one transmission interval TTI in accordance with radio quality information, data type, and number of retransmissions information. (ST406: Yes), selects the transmission method and proceeds to ST409 (ST407). If it does not exist (ST406: No), the transmission method with the highest possibility of reception capable of transmitting all the downlink data to be retransmitted using all the transmission antennas is selected and the process proceeds to ST409 (ST408). In this case, the allocated transmission power amount is improved as much as possible. Here, when a transmission method (antenna format) in which data transmitted by using one transmission / reception antenna 101 at the time of initial transmission is divided into two data and transmitted from the two transmission / reception antennas 101 is selected, an antenna to notify The format information is set to “1”. If it is not divided into two data, it is set to “0”.

  In ST409, retransmission management section 110 increments the retransmission count information of the entry in the retransmission management table (see FIG. 7) corresponding to the downlink data to be retransmitted by one. In ST410, the transmission scheme determination unit 106 generates the control information shown in FIG. 8 for notifying the transmission scheme (modulation / coding rate / antenna format) / retransmission control information (data identification number, retransmission count information), The downlink data to be retransmitted and the antenna format information are transferred to CRC adding section 104, and the generated control information is transferred to modulation and coding section 103.

  In next ST411, CRC adding section 104 performs CRC calculation according to the antenna format information. When dividing into two data and transmitting from two antennas, CRC is calculated for the combination of the two data. The calculated value is added to the downlink data to be retransmitted and given to modulation and coding section 103. The modulation and coding section 103 modulates and encodes downlink data to be retransmitted according to the transmission method included in the control information (see FIG. 8), and controls and codes the control information (see FIG. 8) according to a predetermined transmission method. Do.

  In the next ST412, the transmission / reception section 102 performs spreading processing of the downlink data to be retransmitted and control information (see FIG. 8), and the like, and transmits the data from the predetermined transmission / reception antennas 101-1 and 101-2 to the radio reception apparatus 200. Then, the process ends.

  Next, when the type of the uplink data is ACK (ST413: Yes), the signal analysis unit 108 notifies the retransmission management unit 110 of the ACK notification signal and the user identification number and data identification number of the ACK accompanying therewith. To do. Upon receiving the ACK notification signal, retransmission management section 110 deletes the entry in the retransmission management table (see FIG. 7) corresponding to the user identification number and data identification number associated with the ACK, and ends the process (ST414).

  Next, when the type of the uplink data is a radio quality signal (ST415: Yes), the signal analysis unit 108 obtains the radio quality signal notification signal and the user identification number of the radio quality signal and the radio quality information associated therewith. The wireless quality management unit 109 is notified. Radio quality management section 109 receives the radio quality signal notification signal, writes the user identification number and radio quality information associated with the radio quality signal in the radio quality table (see FIG. 6), and ends the process (ST416). Here, if an entry with the same user identification number has already been written, only the wireless quality information is rewritten.

  Next, when the type of uplink data is uplink data generated by radio receiving apparatus 200 (ST417: Yes), signal analysis section 108 transfers the uplink data to the host apparatus and ends the process (ST418). ). On the other hand, when the type of the uplink data is not the uplink data generated by the wireless reception device 200 (ST417: No), the signal analysis unit 108 ends the process without transferring the uplink data to the higher-level device.

  Next, with reference to FIG. 5, a processing operation when the wireless reception device 200 receives downlink data from the wireless transmission device 100 will be described. The downlink data here includes the control information shown in FIG. 8 and the radio quality measurement signal generated by the radio quality measurement signal generator 111.

  In the wireless reception device 200, when each of the transmission / reception antennas 201-1 and 201-2 receives downlink data, the data transmitted by the transmission / reception antennas 101-1 and 101-2 of the wireless transmission device 100 are overlapped. Therefore, the transmission / reception unit 202 separates and converts the downlink data received by the transmission / reception antennas 201-1 and 201-2 into the data format transmitted by the transmission / reception antennas 101-1 and 101-2 of the wireless transmission device 100. Then, each despreading process is performed (ST501), and downlink data type determination is performed (ST502).

  As a result, when the received downlink data is a radio quality measurement signal (ST502: Yes), the transmission / reception unit 202 transfers the received radio quality measurement signal to the radio quality measurement unit 206. The radio quality measurement unit 206 measures the radio quality between the radio transmission device 100 and the radio reception device 200 (downlink) based on the radio quality measurement signal transferred from the transmission / reception unit 202, and generates a radio quality signal from the result. Then, the data is transferred to the modulation and coding section 209 (ST503).

  If the received downlink data is not a radio quality measurement signal as a result of the downlink data type determination in ST502 (ST502: No), the transmission / reception section 202 also includes the received downlink data (including control information shown in FIG. 8). ) Is transferred to the demodulation and decoding unit 203. The demodulation and decoding unit 203 demodulates and decodes the control information (see FIG. 8) for notifying the downlink data transmission scheme / retransmission control information according to a predetermined transmission scheme, and receives the received downlink data as control information (see FIG. 8). ) Is demodulated by the modulation method included in ().

  Subsequently, in the demodulation and decoding unit 203, two different downlink data (data respectively transmitted by the transmission / reception antennas 101-1 and 101-2 of the wireless transmission device 100) according to the antenna format information included in the control information (see FIG. 8). Is originally one data, the two data are combined (ST505, 506).

  Then, when the downlink data is retransmitted by the retransmission number information included in the control information (see FIG. 8), demodulation / decoding section 203 combines retransmission data with retransmission management section 207. A signal and a data identification number included in the control information (see FIG. 8) are notified. Upon receiving the notification, the retransmission management unit 207 acquires storage data (downlink data transmitted so far) corresponding to the data identification number included in the control information (see FIG. 8) from the buffer 208, The transmitted downlink data is combined and transferred to demodulation / decoding section 203 (ST508).

  Demodulation / decoding section 203 decodes the downlink data (combined data in the case of retransmission) in accordance with the encoding method included in the control information (see FIG. 8) (ST510), and notifies CRC determination section 204.

  On the other hand, in the demodulating / decoding unit 203, when the downlink data is not the retransmission but the first transmission (ST507: No, ST509: Yes), based on the retransmission number information included in the control information (see FIG. 8), the synthesis is performed. The process proceeds directly to ST510 without performing the process, but if the retransmission and the initial transmission cannot be recognized (ST509: No), the process is terminated without performing the subsequent processes.

  The CRC determination unit 204 performs CRC determination of the downlink data (ST511). If no error is detected as a result of the CRC determination (ST511: Yes), the ACK generation request signal and the accompanying data identification number are notified to the retransmission management unit 207, and the downlink data is transferred to the application processing unit 205. . The application processing unit 205 performs higher layer processing of the downlink data. (ST512). Retransmission management section 207 receives the notification, generates ACK corresponding to the downlink data, and outputs the ACK to modulation and coding section 209 (ST513).

  In addition, if an error is detected as a result of the CRC determination (ST511: No), the CRC determination unit 204 notifies the retransmission management unit 207 of the NACK generation request signal and the accompanying data identification number and downlink data. . Upon receiving the notification, retransmission management section 207 stores the downlink data in buffer 208 in accordance with the data identification number (ST514), generates a NACK (retransmission request signal) corresponding to the downlink data, and provides a modulation and coding section. The data is output to 209 (ST515).

  Then, modulation and coding section 209 modulates and codes each generated signal (radio quality signal, ACK, NACK, and uplink data) according to a predetermined transmission scheme, and transfers the modulated signal to transmission / reception section 202 (ST516).

  The transmission / reception unit 202 performs spreading processing of uplink data (including radio quality signals, ACKs, and NACKs) transferred from the modulation and coding unit 1109, and wirelessly passes through predetermined transmission / reception antennas 201-1 and 201-2. Transmit to transmitting apparatus 100 (ST517).

  As described above, the wireless transmission device 100 transmits the wireless data including the wireless quality measurement signal in the downlink data, and receives the wireless quality signal from the wireless reception device 200 by including the wireless quality measurement signal. , And the transmission method (modulation method, coding method, antenna format) from a plurality of transmission / reception antennas is determined based on the wireless quality. Therefore, for example, as shown in FIG. When the data is transmitted using the modulation scheme / coding scheme, the modulation scheme / code corresponding to the current radio quality is obtained when the reception probability at the radio reception apparatus 200 is equal to or less than a predetermined threshold at the current radio quality. Change the system to one with a higher reception probability. Instead, the same amount of data as in the initial transmission can be transmitted by transmitting data from a plurality of transmission antennas using a modulation scheme / coding scheme different from that in the initial transmission. In this case, radio receiving apparatus 200 can combine retransmission data in the same format as initial transmission data in accordance with the transmitted antenna format information.

  9 shows each transmission / reception antenna when transmitting from the first wireless transmission / reception device (wireless transmission device) shown in FIG. 1 to the second wireless transmission / reception device (wireless reception device) shown in FIG. 2 at the time of initial transmission and retransmission. It is a figure explaining the modulation system of the data transmitted from.

  9, the wireless transmission device 100 is described with reference to FIG. 3 at the time of initial transmission in accordance with the wireless quality with the wireless reception device 200 indicated by the wireless quality signal periodically notified from the wireless reception device 200. In this procedure, the transmission antenna 101-1 transmits data 900 and the transmission antenna 101-2 transmits data 901 to the radio reception apparatus 200 within one transmission interval TTI, respectively, using the 16QAM modulation scheme. Data 900 and data 901 are different from each other. For convenience, the data 900 is displayed by being divided into data 900a transmitted in the first half and data 900b transmitted in the second half within one transmission interval TTI. This is a MIMO multiplexing scheme.

  On the other hand, as described with reference to FIG. 5, when the wireless reception device 200 cannot correctly receive the data 900 transmitted from the transmission antenna 101-1 of the wireless transmission device 100, the wireless reception device 100 A retransmission request signal (NACK) is transmitted.

  The wireless transmission device 100 that has received the retransmission request signal confirms the wireless quality with the wireless reception device 200 at this time according to the procedure described in FIG. 4, and transmits to the wireless reception device 200 using the same modulation scheme (16QAM). When data is transmitted, if it is determined that the possibility that the radio reception apparatus 200 can be correctly received is equal to or less than a certain value, a modulation scheme (QPSK) in which the possibility that it can be correctly received is equal to or greater than a certain value is selected, and The retransmission of the downlink data 900 transmitted from -1 is executed as shown in FIG.

  That is, as shown in FIG. 9, the same data 902 as the data 900a, which is the first half of the data 900 at the time of initial transmission, is transmitted from the transmission antenna 101-1 to the wireless reception device 200 by the QPSK modulation method. The same data 903 as the certain data 900b is transmitted from the transmission antenna 101-2 by the QPSK modulation method. This is also a MIMO multiplexing scheme.

  In this case, the radio transmission apparatus 100 transmits the data 902 and data 903, which are downlink data, accompanied by antenna format information indicating that they are originally one data in the procedure described with reference to FIG.

  Therefore, as described with reference to FIG. 5, radio receiving apparatus 200 combines data 902 and data 903 according to the notified antenna format information into one data. Furthermore, the data 900 at the time of initial transmission and the data at the time of retransmission (data obtained by combining the data 902 and 903) are combined and received by the wireless transmission device 100 if it is confirmed that the data has been correctly received. An acknowledgment signal (ACK) is transmitted. Thereby, the data transmission sequence from the wireless transmission device 100 to the wireless reception device 200 is completed.

  As described above, according to the present embodiment, the same data capacity can be transmitted at the same time as at the time of first transmission even at the time of retransmission, so that processing such as HARQ for combining the first transmission data and the retransmission data can be simplified. . In addition, since a modulation / coding scheme according to the current radio quality can be selected, data can be transmitted at an optimum data transmission rate, and data transmission efficiency can be improved.

  The present invention is not limited to the embodiment described above. That is, in the embodiment described above, the number of antennas of the wireless transmission device and the number of antennas of the wireless reception device are the same, but the number of antennas of the wireless reception device may be larger than the number of antennas of the wireless transmission device.

  Although the number of transmission / reception antennas is not limited to two, in the embodiment described above, for example, when two transmission / reception antennas are used to originally transmit one piece of data divided into two different data, Although the data is divided and transmitted in the first half, it may be transmitted using different division methods.

  In the embodiment described above, spreading / despreading processing is performed using a spreading code. However, the present invention is not limited to a mobile communication system using CDMA.

  The present invention is suitable for use in a MIMO transmission system radio transmission apparatus and radio reception apparatus.

The block diagram which shows the structure of the 1st radio | wireless transmitter / receiver which concerns on one embodiment of this invention The block diagram which shows the structure of the 2nd radio | wireless transmitter / receiver which concerns on one embodiment of this invention The flowchart explaining the operation | movement operation | movement of the downlink data which the 1st wireless transmission / reception apparatus shown in FIG. 1 received from the high-order apparatus. The flowchart explaining the processing operation when the first wireless transmission / reception apparatus shown in FIG. 1 receives uplink data from the second wireless transmission / reception apparatus shown in FIG. FIG. 2 is a flowchart for explaining a processing operation when the second wireless transmission / reception device shown in FIG. 2 receives downlink data from the first wireless transmission / reception device shown in FIG. The figure which shows the structural example of the wireless quality table with which the wireless quality management part shown in FIG. 1 is provided. The figure which shows the structural example of the retransmission management table with which the retransmission management part shown in FIG. 1 is provided. The figure explaining the control information attached to the downlink data transmitted from the 1st radio | wireless transmission / reception apparatus shown in FIG. 1 to the 2nd radio | wireless transmission / reception apparatus shown in FIG. The figure explaining the modulation system of the data transmitted from each transmission / reception antenna at the time of transmitting to the 2nd radio | wireless transmission / reception apparatus shown in FIG. 2 from the 1st radio | wireless transmission / reception apparatus shown in FIG. The figure explaining the modulation system of the data transmitted from each transmission-and-reception antenna at the time of the first transmission and retransmission at the time between the conventional multi-input multi-output radio | wireless transmitter / receivers

Explanation of symbols

100 First wireless transceiver (wireless transmitter)
101-1, 101-2 Transmission / reception antenna 102 Transmission / reception unit 103 Modulation encoding unit 104 CRC addition unit 105 Buffer 106 Transmission method determination unit 107 Demodulation decoding unit 108 Signal analysis unit 109 Radio quality management unit 110 Retransmission management unit 111 Radio quality measurement signal Generation unit 200 Second wireless transmission / reception device (wireless reception device)
201-1 and 201-2 Transmission / reception antenna 202 Transmission / reception unit 203 Demodulation decoding unit 204 CRC determination unit 205 Application processing unit 206 Radio quality measurement unit 207 Retransmission management unit 208 Buffer 209 Modulation coding unit

Claims (4)

A wireless transmission device including a plurality of transmission antennas and performing MIMO (Multi-Input Multi-Output) transmission,
Wireless quality management means for managing the wireless quality of the communication partner device;
A transmission method determination means for determining a transmission method in consideration of the current wireless quality of the communication counterpart device at the time of data transmission, and generating control information including the determined transmission method;
Modulation and encoding means for encoding and modulating the transmission data accompanied by the control information based on the transmission method determined by the transmission method determining means;
Transmitting means for transmitting the data output from the modulation and encoding means to each of the communication counterpart devices from each of the plurality of transmission antennas,
The transmission method determining means divides the data transmitted from one antenna at the time of initial transmission when the transmission probability determined at the time of initial transmission is equal to or less than a predetermined threshold when transmitting retransmission data. A radio transmission apparatus that changes a transmission method to transmit from a plurality of antennas and includes antenna format information indicating a method of combining data transmitted from each transmission antenna in the control information. A wireless receiving device that includes a plurality of receiving antennas and performs MIMO (Multi-Input Multi-Output) reception,
Receiving means for receiving transmission data from the wireless transmission device according to claim 1 from each of the plurality of receiving antennas;
A radio receiving apparatus comprising: demodulation and decoding means for demodulating and decoding data based on the control information and combining the data based on a combining method indicated by antenna format information included in the control information. A transmission method of a wireless transmission device including a plurality of transmission antennas and performing MIMO (Multi-Input Multi-Output) transmission,
A wireless quality control process for managing the wireless quality of the communication partner device;
A transmission method determination step of determining a transmission method in consideration of the current wireless quality of the communication counterpart device during data transmission, and generating control information including the determined transmission method;
A modulation and encoding step for encoding and modulating the transmission data accompanied by the control information based on the transmission scheme determined in the transmission scheme determination step;
Transmitting the data encoded and modulated in the modulation encoding step from each of the plurality of transmission antennas to the communication counterpart device, and
The transmission method determining step divides the data transmitted from one antenna at the time of initial transmission when the transmission probability determined at the time of initial transmission is equal to or less than a predetermined threshold when transmitting retransmission data. A transmission method in which the transmission method is changed so as to transmit from a plurality of antennas, and antenna format information indicating a method of combining data transmitted from each transmission antenna is included in the control information. A reception method of a wireless reception device that includes a plurality of reception antennas and performs MIMO (Multi-Input Multi-Output) reception,
A receiving step of receiving data transmitted from a communication partner device from each of the plurality of receiving antennas by the transmission method according to claim 3;
A demodulation decoding step of demodulating and decoding data based on the control information and combining the data based on a combining method indicated by antenna format information included in the control information.

Images