JP5498693B2 - COMMUNICATION SYSTEM, COMMUNICATION DEVICE, AND COMMUNICATION METHOD - Google Patents

Description

  The present invention includes two communication devices, and a communication system that performs communication of a packet including a plurality of code blocks obtained by dividing a bit string between the two communication devices, a communication device in the communication system, and The present invention relates to a communication method in the communication system.

  When communication is performed between a transmission device and a reception device, hybrid automatic retransmission (HARQ) may be employed. This HARQ improves error detection capability in a receiving apparatus by combining automatic retransmission (ARQ) and error detection using a forward error detection code (FEC).

  Specifically, the transmission device transmits the same bit string a plurality of times. On the other hand, the receiving apparatus combines the same bit strings received a plurality of times, and determines the value of each bit from the combination result. Thereby, a time diversity effect is obtained and the error detection capability is improved.

  In some cases, the transmission device divides a bit string into units called code blocks having a predetermined length and transmits the data due to the convenience of arithmetic processing performed by a decoder in the reception device.

For example, in the technique described in Patent Document 1, the transmission apparatus divides a bit string of information into a plurality of blocks. Further, the transmission device adds a CRC (Cyclic Redundancy Check) bit string, which is an error detection code, to each block to generate a code block. Further, the transmission device encodes the code block and transmits it. On the other hand, the receiving apparatus performs decoding for each code block, and further detects an error in the information bit string included in the code block based on the CRC bit string included in the code block.
JP 2005-295192 A

  However, in the technique described in Patent Document 1 described above, even when an error occurs only in the information bit string in one code block, the transmission apparatus retransmits all the code blocks. For this reason, efficient retransmission control cannot be performed.

  In view of the above problems, an object of the present invention is to provide a communication system, a communication apparatus, and a communication method that enable efficient retransmission control according to the communication quality of a code block.

In order to solve the above-described problems, the present invention has the following features. A first aspect of the present invention includes a first communication device (wireless terminal 1) and a second communication device (wireless base station 2), and a bit string between the first communication device and the second communication device. There line communications including a plurality of code blocks obtained by dividing the packet, the first communication system for transmitting packet from the communication device is a fixed length to said second communication device is transmitted (the wireless communication system 10 ) comprising the first communication device, a plurality of transmission subject packet and its Re from, respectively consisting of said coding blocks and redundant bits, is the transmission packet bound by extracting packets transfer transmission unit send a first transmission packet, the second communication device, based on the redundant bits contained in each packet before Kiden feed unit of the transmitted first in a transmission packet, said code blocks each Likelihood of Determined, the first communication device comprises a ratio corresponding to the inverse of the likelihood respectively, the transmission target retransmission during transmission unit setting unit for setting a transmission unit at the time of retransmission of each packet (transmission unit setting unit 162) , from each of said plurality of transmission target packet, and a benzalkonium to send the corresponding second transmission packet that is the transmission packet bound by extracting packet transmission unit for the said retransmission gist.

  According to such a communication system, the first communication device on the transmission side extracts a plurality of packets composed of code blocks and error detection redundant bits for each transmission unit at the time of transmission, and combines them. One transmission packet is generated and transmitted. On the other hand, the second communication device on the receiving side measures and transmits the communication quality for each code block included in the received first transmission packet. Furthermore, the first communication apparatus sets a transmission unit for retransmission, which is a transmission unit for retransmission, for each code block based on the communication quality for each code block. At this time, the first communication apparatus sets a transmission unit at the time of retransmission for each code block so that the ratio is in accordance with the degree of communication quality degradation for each code block. Therefore, for each code block, the transmission unit at the time of retransmission differs according to the communication quality of the code block, and efficient retransmission control is possible.

According to a second aspect of the present invention, the second communication device is configured to determine a likelihood of each code block based on the redundant bits included in each packet of the transmission unit at the time of retransmission in the second transmission packet. The gist is to determine the degree again and to determine whether or not all the code blocks have an error based on the result of the likelihood obtained again.
A third aspect of the present invention, with the other communication devices, have rows communication for multiple code packet including blocks obtained by dividing a bit string, a fixed length in the other communication apparatus transmits a communication apparatus which use packet transmission, a plurality of transmission subject packet and its Re from, respectively consisting of said coding blocks and redundant bits, the is the transmission packet bound by extracting packets transfer transmission unit A transmission unit at the time of retransmission for each transmission target packet is set at a ratio corresponding to the reciprocal of the likelihood of each code block transmitted from the other communication device and the packet transmission unit that transmits one transmission packet. a retransmission when transmission unit setting unit, from each of said plurality of transmission target packet, the second for the transmission is the transmission packet bound by extracting packet transmission unit for the said retransmission corresponding A packet generation unit, and summarized in that and a packet retransmission unit that transmits the second transmission packet.

  Such a communication apparatus generates and transmits a first transmission packet by extracting and combining a plurality of packets composed of code blocks and error detection redundant bits for each transmission unit at the time of transmission. Furthermore, the communication apparatus sets a transmission unit at the time of retransmission, which is a transmission unit at the time of retransmission, for each code block based on the communication quality for each code block measured by another communication apparatus. At this time, the first communication apparatus sets a transmission unit at the time of retransmission for each code block so that the ratio is in accordance with the degree of communication quality degradation for each code block. Therefore, for each code block, the transmission unit at the time of retransmission differs according to the communication quality of the code block, and efficient retransmission control is possible.

According to a fourth aspect of the present invention, there is an abnormality notification indicating that the reception of the code block from the other communication device has not ended normally, or the reception of the code block from the other communication device is normal. A notification receiving unit (wireless communication unit 106) that receives one of the normal notifications indicating that the process has ended, and the packet retransmission unit receives the abnormality notification or from the transmission by the packet transmission unit The gist is to transmit the second transmission packet when the normal notification is not received within a predetermined time.

  Such a communication apparatus measures and transmits the communication quality for each code block included in the transmission packet received from another communication apparatus. Thereby, the other communication apparatus can set the transmission unit at the time of retransmission for each code block based on the communication quality for each code block. At this time, the other communication apparatus sets the transmission unit at the time of retransmission for each code block so that the ratio is in accordance with the degree of deterioration of communication quality for each code block. Depending on the communication quality of the code block, the transmission unit at the time of retransmission differs, and efficient retransmission control becomes possible.

A sixth aspect of the present invention includes a first communication device and a second communication device, and a plurality of code blocks obtained by dividing a bit string between the first communication device and the second communication device. there line communications packet including the first a communication method in a communication system for transmitting packet of a fixed length from the communication device to the second communication device is transmitted, the first communication device, said code since, respectively Re plurality of transmission subject packet and its comprising a block and a redundancy bit, and transmitting the first transmission packet which is the transmission packet bound by extracting packets transfer transmission unit, before Symbol first 2 communication device, based on the redundant bits contained in each packet of heat transmission unit of the transmitted first in a transmission packet, determining a likelihood of each of the code blocks, before Symbol first copies Device, at a ratio corresponding to the inverse of the likelihood, respectively, and setting a transmission unit at the time of retransmission of each of the transmission target packet, the first communication device, from each of said plurality of transmission target packet, the corresponding And a step of transmitting a second transmission packet, which is the transmission packet obtained by extracting and combining the transmission unit packets at the time of retransmission.

  According to the present invention, it is possible to perform efficient retransmission control in accordance with the communication quality of code blocks.

  Next, an embodiment of the present invention will be described with reference to the drawings. Specifically, (1) the configuration of the communication system, (2) the operation of the communication system, (3) the operation and effect, and (4) other embodiments will be described. In the description of the drawings in the following embodiments, the same or similar parts are denoted by the same or similar reference numerals.

(1) Configuration of Communication System First, the configuration of a communication system according to an embodiment of the present invention will be described in the order of (1.1) overall schematic configuration of communication system and (1.2) configuration of communication apparatus.

(1.1) Overall Schematic Configuration of Communication System FIG. 1 is an overall schematic diagram of a radio communication system 10 according to an embodiment of the present invention.

  As shown in FIG. 1, the wireless communication system 10 includes a wireless terminal 1 and a wireless base station 2. In FIG. 1, a radio terminal 1 and a radio base station 2 transmit and receive signals to each other.

(1.2) Configuration of Radio Terminal (1.2.1) Schematic Configuration Diagram of Radio Terminal FIG. 2 is a schematic configuration diagram of the radio terminal 1. As illustrated in FIG. 2, the wireless terminal 1 includes a control unit 102, a storage unit 103, a wireless communication unit 106, an antenna 108, a monitor 110, a microphone 112, a speaker 114, and an operation unit 116. The wireless terminal 1B has the same configuration as the wireless terminal 1.

  The control unit 102 is configured by a CPU, for example, and controls various functions provided in the wireless terminal 1. The storage unit 103 is configured by a memory, for example, and stores various types of information used for control in the wireless terminal 1.

  The wireless communication unit 106 transmits and receives wireless signals via the antenna 108.

  The monitor 110 displays an image received via the control unit 102 and displays operation details (input telephone number, address, etc.). The microphone 112 collects sound and outputs sound data based on the collected sound to the control unit 102. The speaker 114 outputs sound based on the sound data acquired from the control unit 102.

  The operation unit 116 is configured by a numeric keypad, function keys, and the like, and is an interface used for inputting user operation details.

(1.2.2) Detailed Configuration of Wireless Terminal Next, a detailed configuration of the wireless terminal 1, specifically, a functional block configuration of the control unit 102 will be described. FIG. 3 is a functional block configuration diagram of the control unit 102 of the wireless terminal 1.

  As shown in FIG. 3, the control unit 102 includes a CRC adding unit 152, a code block generating unit 154, FEC encoders 156-1, 156-2, and 156-3, and rate matching units 158-1, 158-2, and 158-. 3, a code block combining unit 160, and a transmission unit setting unit 162.

  The CRC adding unit 152 inputs a bit string of information. Next, the CRC adding unit 152 adds a CRC bit string to the information bit string to generate a transmission target bit string. Further, the CRC adding unit 152 outputs the transmission target bit string to the code block generating unit 154.

  The code block generation unit 154 inputs a transmission target bit string. Next, the code block generation unit 154 divides the transmission target bit string into blocks (code blocks) having a predetermined length. Here, the code block generation unit 154 divides the transmission target bit string into three code blocks (code blocks # 1 to # 3) having a predetermined length.

  Further, the code block generation unit 154 outputs the code block # 1 to the FEC encoder 156-1. The code block generation unit 154 outputs the code block # 2 to the FEC encoder 156-2 and outputs the code block # 3 to the FEC encoder 156-3.

  The FEC encoder 156-1 receives the code block # 1 and performs encoding. Furthermore, the FEC encoder 156-1 outputs the encoded code block # 1 to the subsequent rate matching unit 158-1. Similarly, the FEC encoder 156-2 performs encoding of the input code block # 2, and outputs the encoded code block # 2 to the subsequent rate matching unit 158-2. Similarly, the FEC encoder 156-3 encodes the input code block # 3 and outputs the encoded code block # 3 to the subsequent rate matching unit 158-3. The coded code blocks # 1 to # 3 include their own identification information.

  The rate matching unit 158-1 receives the encoded code block # 1. Next, rate matching section 158-1 adds redundant bit # 1 for error detection, which is a CRC bit string, to encoded code block # 1, and generates transmission target packet # 1. Furthermore, the rate matching unit 158-1 extracts the first transmission unit, which is the transmission unit set by the transmission unit setting unit 162, from the transmission target packet # 1, and outputs the first transmission unit to the code block combining unit 160.

  Similarly, the rate matching unit 158-2 inputs the encoded code block # 2, and adds an error detection redundant bit # 2 that is a CRC bit string to the encoded code block # 2. The transmission target packet # 2 is generated. Further, rate matching section 158-2 extracts transmission target packet # 2 for each second transmission unit, which is the transmission unit set by transmission unit setting section 162, and outputs it to code block combining section 160. Similarly, rate matching section 158-3 inputs encoded code block # 3 and adds error detection redundancy bit # 3, which is a CRC bit string, to encoded code block # 3. Thus, transmission target packet # 3 is generated. Further, rate matching section 158-3 extracts transmission target packet # 3 for each third transmission unit, which is the transmission unit set by transmission unit setting section 162, and outputs the extracted packet to code block combining section 160. Note that the redundant bit includes identification information of the encoded code block to which the redundant bit is added.

  The transmission unit setting unit 162 sets the first to third transmission units described above. Specifically, the transmission unit setting unit 162 has the same length of the first transmission unit to the third transmission unit and the first transmission unit to the third transmission unit at the first transmission to the radio base station 1. The first transmission unit to the third transmission unit are set so that the total length becomes the packet length of the HARQ packet having a fixed length.

  Also, the transmission unit setting unit 162 receives the communication quality (described later) of the code blocks # 1 to # 3 from the radio base station 2 via the antenna 108 and the radio communication unit 106 during retransmission to the radio base station 2. In this case, the ratio of the first transmission unit to the third transmission unit is a ratio corresponding to the degree of deterioration of the communication quality of the code blocks # 1 to # 3, and the total of the first transmission unit to the third transmission unit. The first transmission unit to the third transmission unit are set so that the length becomes the packet length of the HARQ packet having a fixed length.

  The code block combining unit 160 extracts the first transmission unit packet extracted from the transmission target packet # 1, the second transmission unit packet extracted from the transmission target packet # 2, and the transmission target packet # 3. The issued third transmission unit packets are input and combined to generate a HARQ packet. Further, the code block combining unit 160 outputs the generated HARQ packet to the wireless communication unit 106. The HARQ packet is transmitted to the radio base station 2 via the radio communication unit 106 and the antenna 108.

(1.3) Configuration of Radio Base Station (1.3.1) Schematic Configuration Diagram of Radio Base Station FIG. 4 is a schematic configuration diagram of the radio base station 2. As illustrated in FIG. 4, the wireless base station 2 includes a control unit 202, a storage unit 203, a wired communication unit 204, a wireless communication unit 206, and an antenna 208.

  The control unit 202 is configured by a CPU, for example, and controls various functions provided in the radio base station 2. The storage unit 203 is configured by a memory, for example, and stores various information used for control in the radio base station 2 and the like.

  The wired communication unit 204 communicates with a gateway server or the like in an upper network (not shown). The wireless communication unit 206 transmits and receives wireless signals via the antenna 208.

(1.3.2) Detailed Configuration of Radio Base Station Next, a detailed configuration of the radio base station 2, specifically, a functional block configuration of the control unit 202 will be described. FIG. 5 is a functional block configuration diagram of the control unit 202 of the radio base station 2.

  As shown in FIG. 5, the control unit 202 includes a code block dividing unit 252, rate dematching units 254-1, 254-2, and 254-3, FEC decoders 256-1, 256-2, and 256-3, communication quality. A measurement unit 258, a code block combination unit 260, and a CRC check unit 262 are included.

  The code block division unit 252 receives the HARQ packet from the wireless terminal 1 via the antenna 208 and the wireless communication unit 206. Next, the code block dividing unit 252 adds the identification information of the encoded code block included in the encoded code block in the HARQ packet and the redundant bit included in the redundant bit in the HARQ packet. The identification information of the coded code block is detected.

  Next, the code block dividing unit 252 extracts the packet of the first transmission unit including the encoded code block # 1 including the identification information of the encoded code block # 1 and the redundant bit # 1 from the HARQ packet, Output to the rate dematching unit 254-1.

  Similarly, the code block dividing unit 252 extracts a packet of the second transmission unit including the encoded code block # 2 including the identification information of the encoded code block # 2 and the redundant bit # 2 from the HARQ packet, The data is output to the rate dematching unit 254-2. Further, similarly, the code block dividing unit 252 extracts a packet of the third transmission unit including the encoded code block # 3 including the identification information of the encoded code block # 3 and the redundant bit # 3 from the HARQ packet. And output to the rate dematching unit 254-3.

  The rate dematching unit 254-1 receives the first transmission unit packet and extracts the code block # 1 and the redundant bit # 1 from the first transmission unit packet. Further, the rate dematching unit 254-1 outputs the code block # 1 to the FEC decoder 256-1 and the communication quality measurement unit 258, and outputs the redundant bit # 1 to the communication quality measurement unit 258.

  Similarly, the rate dematching unit 254-2 receives the second transmission unit packet, and extracts the code block # 2 and the redundant bit # 2 from the second transmission unit packet. Further, the rate dematching unit 254-2 outputs the code block # 2 to the FEC decoder 256-2 and the communication quality measurement unit 258, and outputs redundant bit # 2 to the communication quality measurement unit 258. Similarly, the rate dematching unit 254-3 inputs the third transmission unit packet, and extracts the code block # 3 and the redundant bit # 3 from the third transmission unit packet. Further, the rate dematching unit 254-3 outputs the code block # 3 to the FEC decoder 256-3 and the communication quality measurement unit 258, and outputs redundant bit # 3 to the communication quality measurement unit 258.

  The communication quality measuring unit 258 receives the code block # 1 and the redundant bit # 1 from the rate dematching unit 254-1. Similarly, the communication quality measurement unit 258 receives the code block # 2 and redundant bit # 2 from the rate dematching unit 254-2, and receives the code block # 3 and redundant bit # 3 from the rate dematching unit 254-3. Enter.

  Next, the communication quality measurement unit 258 detects an error (CRC check) of the code block # 1 based on the redundant bit # 1 that is a CRC bit string and detects an error of the code block # 2 based on the redundant bit # 2 that is a CRC bit string And error detection of code block # 3 based on redundant bit # 3, which is a CRC bit string. Further, the communication quality measuring unit 258 outputs the error detection results of the code blocks # 1 to # 3 to the wireless communication unit 206 as the communication quality of the code blocks # 1 to # 3. The communication qualities of the code blocks # 1 to # 3 are transmitted to the wireless terminal 1 via the wireless communication unit 206 and the antenna 208.

  Also, the communication quality measurement unit 258 outputs an ACK to the radio communication unit 206 when the error detection results of the code blocks # 1 to # 3 all indicate that there are no errors. Also, the communication quality measurement unit 258 outputs a NACK to the radio communication unit 206 when any of the error detection results of the code blocks # 1 to # 3 indicates that there is an error. The ACK or NACK is transmitted to the wireless terminal 1 via the wireless communication unit 206 and the antenna 208.

  The FEC decoder 256-1 receives the code block # 1 and performs decoding. Further, the FEC decoder 256-1 outputs the decoded code block # 1 to the code block combining unit 260. Similarly, the FEC decoder 256-2 decodes the input code block # 2, and outputs the decoded code block # 2 to the code block combining unit 260. Further, similarly, the FEC decoder 256-3 decodes the input code block # 3 and outputs the decoded code block # 3 to the code block combining unit 260.

  The code block combining unit 260 inputs the code blocks # 1 to # 3 after decoding. Next, the code block combining unit 260 combines the decoded code blocks # 1 to # 3 to generate a transmission target bit string. Further, the code block combining unit 260 outputs the generated transmission target bit string to the CRC check unit 262.

  The CRC check unit 262 inputs a transmission target bit string. Next, the CRC check unit 262 extracts an information bit string and a CRC bit string from the transmission target bit string, and performs error detection of the information bit string based on the CRC bit string. Further, the CRC check unit 262 outputs an information bit string when no error is detected.

(2) Operation of Radio Communication System FIG. 6 is a sequence diagram showing operations of the radio terminal 1 and the radio base station 2 that constitute the radio communication system 10.

  In step S101, the wireless terminal 1 generates a HARQ packet.

  FIG. 7 is a diagram illustrating a HARQ packet generation process. In the following, it is assumed that the block which is the minimum transmission unit has a length L. In the first step shown in FIG. 7A, the wireless terminal 1 divides the transmission target bit string into code blocks # 1 to # 3 having a length of 2L.

  In the second step shown in FIGS. 7B1 to 7B3, the wireless terminal 1 adds five redundant bits # 1, which are CRC bit strings of length L, to the code block # 1, and transmits 7L in length. Target packet # 1 is generated. Similarly, the wireless terminal 1 adds five redundant bits # 2, which are CRC bit strings of length L, to the code block # 2, generates a transmission target packet # 2 having a length of 7L, and adds a long length to the code block # 3. Five redundant bits # 3, which is a CRC bit string of length L, are added to generate a transmission target packet # 3 having a length of 7L.

  In the third step shown in FIG. 7C, the transmission unit setting unit 162 in the wireless terminal sets the first to third transmission units to 4L which is 1/3 of the packet length of the HARQ packet. Further, the wireless terminal 1 extracts and combines the packets of the first transmission unit to the third transmission unit, which are blocks of 4L from the beginning of the transmission target packets # 1 to # 3, respectively. A 12L HARQ packet # 1 is generated.

  Again, referring back to FIG. In step S102, the wireless terminal 1 transmits a HARQ packet. The radio base station 2 receives the HARQ packet.

  In step S103, the communication quality measurement unit 258 in the radio base station 2 measures the communication quality (CRC check) of each code block included in the HARQ packet.

  FIG. 8 is a diagram illustrating an example of a CRC check in step S103. The communication quality measuring unit 258, from the HARQ packet shown in FIG. 7 (c), as shown in FIGS. 8 (a) to 8 (c), the first transmission unit packet consisting of the code block # 1 and the redundant bit # 1 Then, the second transmission unit packet composed of code block # 2 and redundant bit # 2 and the third transmission unit packet composed of code block # 3 and redundant bit # 3 are extracted.

  Further, the communication quality measuring unit 258 performs a CRC check on the code block # 1 based on the redundant bit # 1. Similarly, the communication quality measuring unit 258 performs a CRC check on the code block # 2 based on the redundant bit # 2, and performs a CRC check on the code block # 3 based on the redundant bit # 3. In FIG. 8, the CRC check results for code blocks # 1 and # 2 are NG, that is, an error is detected in code blocks # 1 and # 2, and the CRC check result for code block # 3 is OK. That is, no error is detected in the code block # 3.

  Again, referring back to FIG. In step S104, the communication quality measurement unit 258 in the radio base station 2 determines whether or not all code blocks have errors based on the CRC check result in step S103, in other words, all code blocks are normal. It is determined whether or not it has been received. When all the code blocks are normally received, in step S105, the radio base station 2 transmits ACK to the radio terminal 1, and ends a series of operations.

  On the other hand, when there is a code block that has not been normally received (in the case of negative determination in step S104), in step S106, the radio base station 2 sends NACK and code block communication quality to the radio terminal 1. Send. For example, in the example of FIG. 7, the radio base station 2 has a code block indicating that the CRC check result for code blocks # 1 and # 2 is NG, and the CRC check result for code block # 3 is OK. Send communication quality. The wireless terminal 1 receives the code block communication quality.

  In step S107, the radio terminal 1 determines whether or not a NACK from the radio base station has been received, or whether or not an ACK has not been received within a predetermined time. When NACK is not received and ACK is received within a predetermined time, the radio terminal 1 ends a series of operations.

  On the other hand, when NACK is received from the radio base station 2 or when ACK is not received within a predetermined time, the radio terminal 1 generates a HARQ packet for retransmission in step S108.

  FIG. 9 is a diagram illustrating a configuration of a HARQ packet for retransmission. FIG. 9 shows an example in the wireless base station 2 where the CRC check result for code blocks # 1 and # 2 is NG and the CRC check result for code block # 3 is OK.

  In this case, considering that the retransmission of the code blocks # 1 and # 2 is necessary and the retransmission of the code block # 3 is unnecessary, the transmission unit setting unit 162 in the wireless terminal 1 has the first transmission unit and the second transmission unit. The transmission unit is set to 6L, which is 1/2 of the packet length of the HARQ packet. Next, the transmission unit setting unit 162 in the wireless terminal 1 extracts 6L from the block next to the last block among the blocks that have been transmitted immediately before the transmission target packet # 1. Similarly, the transmission unit setting unit 162 in the wireless terminal 1 extracts 6L from the block next to the last block among the blocks that have been transmitted immediately before the transmission target packet # 2. Further, the wireless terminal 1 combines the packet of the first transmission unit and the packet of the second transmission unit, which are 6L blocks extracted from the transmission target packets # 1 and # 2, thereby retransmitting HARQ for retransmission having a length of 12L. Packet # 2 is generated.

  Again, referring back to FIG. In step S109, the wireless terminal 1 transmits a retransmission HARQ packet. The radio base station 2 receives the retransmission HARQ packet.

  In step S110, the communication quality measurement unit 258 in the radio base station 2 measures the communication quality of each code block (CRC retransmission) included in the HARQ packet received in step S102 and the retransmission HARQ packet received in step S109. Check).

  FIG. 10 is a diagram illustrating an example of CRC recheck in step S110. As shown in FIG. 10 (a1), the communication quality measurement unit 258 in the radio base station 2 receives the code block # 1 and redundant bit # 1 received in step S102, and the code block # 1 received in step S109. Combine with redundant bit # 1. Here, code block # 1 and one of redundant bits # 1 have been received twice. In this case, the communication quality measurement unit 258 in the radio base station 2 combines the Euclidean distances of the bits at the same position for the two code blocks # 1 and the two redundant bits # 1, and based on the combined value of the Euclidean distances. Thus, each bit of code block # 1 and redundant bit # 1 received twice is determined. Further, the communication quality measurement unit 258 in the radio base station 2 performs a CRC check of the code block # 1 based on the redundant bit # 1.

  Similarly, the communication quality measurement unit 258 in the radio base station 2 combines the code block # 2 and the redundant bit # 2 received in step S102 and step S109 as shown in FIG. 10 (a2). Next, the communication quality measuring unit 258 in the radio base station 2 determines each bit of the code block # 2 and redundant bit # 2 received twice. Further, the communication quality measuring unit 258 in the radio base station 2 performs a CRC check on the code block # 2 based on the redundant bit # 2.

  Again, referring back to FIG. In step S111, the radio base station 2 determines whether or not all code blocks have errors based on the CRC recheck result in step S110, in other words, whether or not all code blocks have been normally received. Determine. When all the code blocks are normally received, in step S112, the radio base station 2 transmits an ACK, and the radio terminal 1 receives the ACK. This completes a series of operations.

  On the other hand, when there is a code block that has not been normally received (in the case of negative determination in step S111), in step S106, the radio base station 2 again sends NACK and code block communication quality to the radio terminal 1. The operation after transmitting is repeated.

(3) Operation / Effect According to the radio communication system 10 according to the embodiment of the present invention, the radio terminal 1 on the transmission side generates a plurality of transmission target packets composed of a code block and redundant bits for error detection. Further, the wireless terminal 1 generates and transmits a HARQ packet by combining each transmission target packet by a predetermined transmission unit.

  On the other hand, the radio base station 2 on the receiving side extracts a predetermined transmission unit of each transmission target packet included in the received HARQ packet, and is included in the transmission target packet based on the redundant bit included in the transmission target packet. A CRC check is performed on the code block, and the result is transmitted as communication quality for each code block included in the transmission target packet.

  Furthermore, the wireless terminal 1 sets a transmission unit at the time of retransmission for each code block based on the CRC check result that is the communication quality for each received code block. At this time, the wireless terminal 1 uses the same transmission unit of the transmission target packet including each code block whose CRC check result is NG, and the HARQ packet packet in which the total length of each transmission unit is a fixed length. The HARQ packet is generated and transmitted by combining the packets of the transmission units extracted from the transmission target packets. On the other hand, the transmission unit of a transmission target packet including a code block whose CRC check result is OK is set to zero. That is, the wireless terminal 1 does not retransmit a transmission target packet including a code block whose CRC check result is OK. Therefore, for each code block, the transmission unit at the time of retransmission differs according to the communication quality of the code block, and efficient retransmission control is possible.

(4) Other Embodiments As described above, the present invention has been described according to the embodiment. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  In the above-described embodiment, the communication quality measurement unit 258 in the radio base station 2 performs the CRC check of the code blocks # 1 to # 3 based on the redundant bits # 1 to # 3 that are CRC bit strings. If 1 to # 3 are not CRC bit strings, the likelihood of code blocks # 1 to # 3 based on these redundant bit strings # 1 to # 3 is detected, and the likelihood is also used as the communication quality of code blocks # 1 to # 3. Good. FIG. 11 is a diagram illustrating an example of likelihood detection of code blocks # 1 to # 3.

  Further, the transmission unit setting unit 162 in the wireless terminal 1 uses the likelihood of the code blocks # 1 to # 3 based on the likelihood of the code blocks # 1 to # 3 based on the likelihood of the code blocks # 1 to # 3. The first transmission unit to the third transmission unit are set so as to be a ratio corresponding to the reciprocal of the degree and the packet length of the HARQ packet having a fixed total length of the first transmission unit to the third transmission unit. You may do it.

  For example, as shown in FIG. 11, when the likelihood of the code block # 1 is 0.2 and the likelihood of the code blocks # 2 and # 3 is 0.4, the first transmission unit to the third transmission unit The ratio is 1 / 0.2: 1 / 0.4: 1 / 0.4, that is, 2: 1: 1. When the length of the HARQ packet is 12L, the first transmission unit is 6L, and the second transmission unit and the third transmission unit are 3L.

  Thereafter, the wireless terminal 1 generates a HARQ packet for retransmission by combining the first transmission unit of the transmission target packet # 1, the second transmission unit of the transmission target packet # 2, and the third transmission unit of the transmission target packet # 3. And transmitted to the radio base station 2. FIG. 12 is a diagram illustrating a configuration of a HARQ packet for retransmission when the first transmission unit is 6L, and the second transmission unit and the third transmission unit are 3L.

  The communication quality measurement unit 258 in the radio base station 2 that has received the retransmission HARQ packet measures the communication quality of each code block included in the already received HARQ packet and the newly received retransmission HARQ packet (likelihood). Re-detection).

  FIG. 13 is a diagram illustrating an example of likelihood redetection. As shown in FIG. 13 (a1), the communication quality measurement unit 258 in the radio base station 2 receives the already received code block # 1 and redundant bit # 1, and the newly received code block # 1 and redundant bit # 1. Combine with 1. Here, code block # 1 and one of redundant bits # 1 have been received twice. In this case, the communication quality measurement unit 258 in the radio base station 2 combines the Euclidean distances of the bits at the same position for the two code blocks # 1 and the two redundant bits # 1, and based on the combined value of the Euclidean distances. Thus, each bit of code block # 1 and redundant bit # 1 received twice is determined. Further, the communication quality measurement unit 258 in the radio base station 2 detects the likelihood of the code block # 1 based on the redundant bit # 1.

  Further, the communication quality measuring unit 258 in the radio base station 2 uses the already received code block # 2 and redundant bit # 2 and the newly received redundant bit # 2 as shown in FIG. 13 (a2). Based on the combination and redundant bit # 2, the likelihood of code block # 2 is detected. Similarly, as shown in FIG. 13 (a3), the communication quality measurement unit 258 in the radio base station 2 receives the already received code block # 3 and redundant bit # 3, and the newly received redundant bit # 3. And the likelihood of the code block # 3 is detected based on the redundant bit # 3.

  After that, the radio base station 2 determines whether or not all code blocks have an error based on the result of likelihood redetection, in other words, whether or not all code blocks have been normally received. For example, when it is determined that the reception is normal when the likelihood is 0.8 or more, in the example of FIG. 13, the code blocks # 1 to # 3 are determined to be normal reception.

  When all the code blocks are normally received, the radio base station 2 transmits an ACK, and the radio terminal 1 receives the ACK. On the other hand, when there is a code block that has not been normally received, the radio base station 2 transmits NACK and code block communication quality to the radio terminal 1.

  Thus, it should be understood that the present invention includes various embodiments and the like not described herein. Therefore, the present invention is limited only by the invention specifying matters in the scope of claims reasonable from this disclosure.

1 is an overall schematic configuration diagram of a communication system according to an embodiment of the present invention. It is a schematic block diagram of the radio | wireless terminal which concerns on embodiment of this invention. It is a functional block block diagram of the control part in the radio | wireless terminal which concerns on embodiment of this invention. 1 is an overall schematic configuration diagram of a radio base station according to an embodiment of the present invention. It is a functional block diagram of the control part in the wireless base station which concerns on embodiment of this invention. It is a sequence diagram which shows operation | movement of the radio | wireless communications system which concerns on embodiment of this invention. It is a figure which shows the production | generation process of the HARQ packet which concerns on embodiment of this invention. It is a figure which shows an example of the CRC check which concerns on embodiment of this invention. It is a figure which shows the structure of the HARQ packet for resending which concerns on embodiment of this invention. It is a figure which shows an example of the CRC recheck which concerns on embodiment of this invention. It is a figure which shows an example of the likelihood detection which concerns on embodiment of this invention. It is a figure which shows the other structure of the HARQ packet for resending which concerns on embodiment of this invention. It is a figure which shows an example of likelihood redetection which concerns on embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Wireless terminal, 2 ... Wireless base station, 10 ... Wireless communication system, 102 ... Control part, 103 ... Memory | storage part, 106 ... Wireless communication part, 108 ... Antenna, 110 ... Monitor, 112 ... Microphone, 114 ... Speaker, 116 ... Operation unit 152 ... CRC addition unit 154 ... Code block generation unit 156-1, 156-2, 156-3 ... FEC encoder 158-1, 158-2, 158-3 ... Rate matching unit 160 ... Code block combining unit 162 ... transmission unit setting unit 202 202 control unit 203 storage unit 204 wired communication unit 206 wireless communication unit 208 antenna 252 code block division units 254-1 and 254 -2, 254-3 ... rate dematching units 256-1, 256-2, 256-3 ... FEC decoder, 258 ... communication quality measuring unit, 260 ... Doburokku coupling portion, 262 ... CRC check unit

Claims (5)

Having a first communication device and a second communication device, performing communication of a packet including a plurality of code blocks obtained by dividing a bit string between the first communication device and the second communication device; A communication system in which a fixed-length transmission packet is transmitted from a first communication device to the second communication device,
The first communication device is
From each of a plurality of transmission target packets composed of the code block and redundant bits, a first transmission packet that is the transmission packet obtained by extracting and combining the packets in a transmission unit is transmitted;
The second communication device is
Based on the redundant bits included in each packet of the transmission unit in the transmitted first transmission packet, the likelihood for each code block is obtained,
The first communication device is
A retransmission-time transmission unit setting unit for setting a transmission unit at the time of retransmission for each transmission target packet at a ratio according to the reciprocal of each likelihood;
A communication system for transmitting, from each of the plurality of transmission target packets, a second transmission packet that is the transmission packet obtained by extracting and combining the corresponding transmission unit packets at the time of retransmission. The second communication device is
Based on the redundant bits included in each packet of the transmission unit at the time of retransmission in the second transmission packet, the likelihood for each code block is obtained again,
The communication system according to claim 1, wherein it is determined whether or not all the code blocks have an error based on the result of the likelihood obtained again. A communication device that communicates a packet including a plurality of code blocks obtained by dividing a bit string with another communication device, and transmits a transmission packet having a fixed length to the other communication device. ,
A packet transmission unit that transmits a first transmission packet that is a transmission packet obtained by extracting and combining packets of transmission units from a plurality of transmission target packets each including the code block and redundant bits;
A transmission unit setting unit for retransmission, which sets a transmission unit for retransmission for each transmission target packet at a ratio according to the inverse of each likelihood for each code block transmitted from the other communication device;
A packet retransmission unit that transmits a second transmission packet that is the transmission packet obtained by extracting and combining the corresponding transmission unit packets at the time of retransmission from each of the plurality of transmission target packets. An abnormality notification indicating that reception of the code block from the other communication device is not normally completed, or a normal notification indicating that reception of the code block from the other communication device is normally completed. A notification receiving unit for receiving either
The packet retransmission unit transmits the second transmission packet when the abnormality notification is received or when the normal notification is not received within a predetermined time from transmission by the packet transmission unit. 3. The communication device according to 3. Having a first communication device and a second communication device, performing communication of a packet including a plurality of code blocks obtained by dividing a bit string between the first communication device and the second communication device; A communication method in a communication system in which a fixed-length transmission packet is transmitted from a first communication device to the second communication device,
The first communication device extracts a transmission unit packet from each of a plurality of transmission target packets composed of the code block and redundant bits, and transmits the first transmission packet that is the transmission packet, and
The second communication device determines a likelihood for each code block based on the redundant bits included in each of the transmission unit packets in the transmitted first transmission packet;
The first communication device sets a transmission unit at the time of retransmission for each transmission target packet at a ratio according to the reciprocal of each likelihood; and
The first communication device includes a step of transmitting a second transmission packet that is the transmission packet obtained by extracting and combining the corresponding transmission unit packets at the time of retransmission from each of the plurality of transmission target packets. Communication method.

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