JP2010057175A - Automatic retransmission control method, communicating system, and transmitting device and receiving device thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a system throughput of an HARQ (hybrid automatic retransmission request) scheme using partial retransmission. <P>SOLUTION: An automatic retransmission control method includes, in a receiving device, a step of deciding whether each code data block is correctly received by an inspection portion of the code data block and generating yes/no information about correct reception reflecting whether the each code data block is correctly received, a step of deciding channel information of the code data block, and a step of feeding back the yes/no information about correct reception and the channel information to a transmitting device. The method includes, in the transmitting device, a step of deciding a retransmission ratio upon retransmission based on the yes/no information about correct reception and the channel information fed back from the receiving device and a step of arranging retransmission data packets based on the retransmission ratio. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an automatic retransmission control method, a communication system, a transmitter and a receiver thereof in a wireless communication system.

As demand for high-speed wireless multimedia communications increases and as radio spectrum resources become increasingly scarce, it becomes increasingly important and valuable to search for future high-efficiency mobile communication systems. In order to overcome the effects of radio mobile channel time variation and multipath fading on signal propagation, error control methods such as forward error correction coding (FEC) and automatic repeat request (ARQ) are introduced to improve system bit. Reduced error rate and secured service quality. Although the delay time in the FEC scheme is small, the redundancy of the code reduces the system throughput. In addition, ARQ can obtain an ideal throughput when the bit error rate is small, but instead, the delay time due to the ARQ becomes large and is not suitable for providing a real-time service. In order to overcome both deficiencies, a hybrid automatic repeat request (HARQ) scheme was formed by combining the two. In other words, when the ARQ system includes the FEC subsystem and the error correction function of the FEC can correct these errors, it is not necessary to use the ARQ, and only when the FEC cannot correct the error normally, the error code is transmitted through the ARQ feedback channel. Request group re-transmission. The effective combination of ARQ and FEC not only provides higher certainty compared to the FEC-only system, but also provides higher system throughput than the ARQ-only system. Hence, as demand for high data rate or high reliability communications rapidly develops, HARQ is being studied as a key technology in wireless communication systems.

HARQ technology classification HARQ is divided into synchronous HARQ technology and asynchronous HARQ technology, non-adaptive HARQ technology and adaptive HARQ technology, and different retransmission methods and retransmission mechanisms.

  Synchronous HARQ technology and asynchronous HARQ technology: HARQ can be divided into two types, synchronous and asynchronous, depending on the time at which retransmission occurs. Since synchronous HARQ knows in advance the transmission time at the receiving end, the HARQ procedure number can be obtained from the subframe number, and the asynchronous HARQ procedure transmission occurs at an arbitrary time. It is necessary to notify them as well. Asynchronous adaptive HARQ technology is more flexible in scheduling than synchronous non-adaptive HARQ technology, but requires less signaling overhead.

  Retransmission type: Depending on the content of retransmission, HARQ mainly includes three types of hybrid automatic retransmission request mechanisms and is called HARQ-I, HARQ-II, HARQ-III, or the like. All of the three types of common points perform FEC encoding and CRC check, perform FEC decoding and CRC check at the receiving end, and request retransmission if there is an error in the packet. The difference is that HARQ-I abandons the error packet, the retransmission packet and the transmitted packet are the same, and combination decoding is not performed. HARQ-II does not abandon the error packet but performs decoding in combination with the retransmission packet, and the format and content of the retransmission packet and the transmitted packet may be different. Since HARQ-III employs a CPC code (complementary punctured convolutional code), self-decoding can be performed for each transmitted packet and each retransmitted packet. Even if the redundancy (different bit puncturing) is different for each retransmission, the redundancy (the same FEC) may be the same. At this time, it is similar to the operation of HARQ-I, but at the receiving end so as to combine with the retransmission packet. It is necessary to store the error packet.

  Adaptive and non-adaptive: HARQ is further classified into two types, non-adaptive and adaptive, depending on whether or not the characteristics of data at the time of retransmission have changed. Here, characteristics of data to be transmitted include resource block allocation, modulation scheme, transmission block length, transmission duration, and the like. Adaptive transmission means that in each retransmission process, the transmitting end can change some transmission parameters based on actual channel state information. Therefore, in every transmission process, control signaling information including transmission parameters is transmitted together, but this causes extra signaling overhead. Variable transmission parameters include modulation scheme, resource unit allocation and transmission duration. In non-adaptive systems, signaling is relatively simple because these transmission parameters are known to the receiving end.

  The three criteria protocols for traditional automatic repeat request (ARQ) are stop and wait (SAW), stop-and-wait (ARQ), backward N frame (GBN, go-back-n) ARQ, and selective retransmission (SR). , selective repeat) ARQ. ARQ and HARQ are used for both FDD and TDD systems.

  In a general HARQ system, when an error data packet is detected at the receiving end, the error bit occupies only a part of the data packet, and if the entire data packet is retransmitted, a certain throughput is lost. 3GPP LTE and WiMAX system enhanced type (802.16m) are both HARQ-II and III type spare schemes. When the first attempt of decoding fails, the transmitter adds redundancy information or re-processes and retransmits, and the retransmission packet and the first packet are not exactly the same. And a data packet received in the past can be combined to obtain a better system throughput.

  FIG. 1 schematically shows the structure of the HARQ system. As shown in FIG. 1, the HARQ system includes a transmission unit 100, an ARQ control unit 101, a modulation and coding scheme (MCS) control unit 102, a radio channel 103, a channel estimation unit 104, and a reception unit 105. , A modulation scheme and coding scheme selection unit 106, an ARQ check 107, and the like. Usually, a data buffer and a reception buffer are also provided. The data buffer is for temporarily storing transmission standby data and data that has already been sent but has not yet been verified for accuracy, and the reception buffer temporarily stores received data. The data buffer, transmission unit, ARQ control unit, and MCS control unit shown in FIG. 1 constitute the transmitter part of the HARQ system. The transmitter may be, for example, a base station (Node B) in a wireless communication system, or a server in a general network (for example, the Internet or an intranet). The channel estimation unit 104, the reception unit 105, the modulation scheme and coding scheme selection unit 106, the ARQ check 107, the reception buffer, and the like shown in FIG. 1 constitute the receiver portion of the HARQ system. The receiver may be, for example, a mobile station in a wireless communication system, or a personal computer connected to a server on the Internet or an intranet. That is, the HARQ system shown in FIG. 1 is used not only for a wireless communication network but also for a wired network. The HARQ system is used for TCP / IP networks, for example.

  The general processing process of the HARQ system will be described below in conjunction with FIG.

  First, in the initial state, the transmission unit 100 modulates and codes the transmission standby data in the data buffer based on the modulation and coding information by the MCS control unit 102 at the transmitter part (transmission end), and modulates and codes the transmission standby data. A new data packet generated by performing is transmitted through an antenna or the like.

  In the receiver part (receiving end), the receiving unit 105 receives the data transmitted from the transmitting unit 100 through the channel 103 and performs a CRC check on the data received by the ARQ checking unit 107. As a result of the inspection, if it is accurate, it outputs the correctly received data bits, and returns an ACK signal to the ARQ control unit 101 at the transmitting end, otherwise returns a NACK (also referred to as NAK) signal, and Information of the current data packet (for example, bit soft information) is held in the reception buffer. At the same time, the MCS selector 106 at the receiving end calculates parameters such as an effective signal-to-noise ratio based on the channel estimation result to determine the modulation and coding scheme, and feeds back to the MCS controller 102 at the transmitting end. The feedback of MCS and ACK / NACK signals are two independent branches, and the feedback frequency may be the same or different, and is determined by the system setting or the channel environment. When the transmitter returns to the initial state, the data is encoded and modulated by the feedback MCS.

  In the transmitter portion, after receiving the ACK feedback or NACK feedback returned from the ARQ checking unit 107, the ARQ control unit first determines whether the received feedback is ACK or NACK. If the received feedback is ACK, it returns to the initial state, encodes and modulates the data with the feedback MCS, and then transmits a new data packet. If the received feedback is NACK, 1 is added to the number of retransmissions, and when the number of retransmissions does not exceed the predetermined maximum number of retransmissions, the previously transmitted data packet is transmitted again. The format of the retransmitted data packet (eg, encoding and modulation scheme and data packet size) may be the same as in the first transmission (ie Chase Combining) or a new packet based on the latest MCS feedback. The format (that is, the HARQ-III type IR incremental redundancy method) may be selected. When the number of retransmissions reaches the upper limit, the current data packet is abandoned, returned to the initial state, and then a new data packet is transmitted.

  After receiving the retransmission data packet, the receiver combines the new information and the information held in the reception buffer, and then decodes it again (combining the retransmission data information and the holding information effectively reduces the bit error rate). And increase throughput). After the CRC check is performed on the decoded data, the check result is fed back to the transmitting end (ACK / NACK).

  As can be seen from the above, the ARQ control unit 101 transmits new data from the transmitting end when receiving the ACK signal or when the maximum number of retransmissions is reached. In this way, both the transmitting end and the receiving end require a certain buffer space for storing data that has not been transmitted correctly.

  FIG. 2 schematically shows HARQ data frames and retransmission time series. In the schematic display example shown in FIG. 2, each data frame includes a plurality of data packets (the figure shows four data packets). The receiving end (receiver portion) feeds back one CRC check result for each data packet to the transmitter portion (transmitting end). In the display example shown in FIG. 2, in the first transmitted four data packets P1, P2, P3 and P4, for example, it can be seen that P1 and P4 were correctly received by CRC check, so feedback for this P1 and P4 Is ACK. Since P2 and P3 were not received correctly, the feedback for P2 and P3 is NACK. Therefore, as shown in FIG. 2, data packets P2 and P3 will be retransmitted in the next frame, and depending on other positions in the frame, new data packets (the figure shows new data packets P5 and P6) Can be sent. In the drawing, T represents the length of a data frame, and Td represents the interval between frames.

  As can be seen from FIG. 1 and FIG. 2, in a general technique, the HARQ system performs retransmission processing on the entire data packet (PDU) of one MAC layer and occupies a large channel resource each time it is retransmitted.

  In a general HARQ retransmission mechanism, the CRC check is performed at the receiving end as a whole data packet, but if an error occurs in some bits of the data packet in the actual system, the whole (or part) packet Retransmission of occupies considerable channel resources. In order to further improve HARQ performance, a retransmission method using code blocks has been proposed. In this method, one data packet is composed of code blocks with some check codes, and retransmission data has a code block as a minimum unit.

  FIG. 3 is a schematic diagram showing a data packet structure of a technical proposal that is retransmitted by a code block. The data packet structure of FIG. 3 is merely exemplary and may include more or fewer code blocks. As shown in FIG. 3, a data packet (or also referred to as a transmission block, Transport Block, TB) in a frame includes some code blocks (four are schematically shown in the drawing). CRC check code is attached. After the source data subpacket passes through the encoder, it corresponds to a combination of one code block and a CRC check code. The entire data packet can be added with one CRC check code at the end, but it may not be added. The receiving end checks each code block, and if an error occurs, the next data packet retransmits only the code block where the error occurred, and places new data in the other code blocks. This avoids the problem of having to retransmit the entire data block in HARQ.

  In the retransmission scheme using a code block, the system throughput is increased by performing retransmission using a code block as a minimum unit instead of the entire data block. However, in 3GPP LTE systems, for example, code blocks can reach up to 6144 bits, which means that the retransmission load is still very large.

  HARQ throughput can be further increased by subdividing the granularity of the retransmitted data, and therefore a HARQ mechanism is provided by retransmitting some data, even if some data to be retransmitted is in front of the encoder, May be later.

  In HARQ by partial retransmission, for example, when an error occurs in the two data blocks CB12 and CB13 (corresponding source data subpackets are SP12 and SP13, respectively) at the time of the first transmission, it must be retransmitted. The transmitter receives three subpackets of new data (SP21, SP23, SP24) from the source data buffer unit, sends them to the encoder, adds CRC, and stores the current new code data block in the code block data buffer unit To do. Thereafter, two blocks CB12 to be retransmitted and their CRC, CB13 and CRC are taken out from the code block data buffer unit, and a part of each is taken out to constitute a new code block CB22.

  Here, CB12 and CB13 are data having the CRC check code, and when CB22 is composed of CB12 and CB13, the length of the MCS and code block does not change, but only a part of bit data of CB12 or CB13. Just leave it at a specific position on CB22. For example, CB22 = {x1, y1, x3, x4} is constituted by CB12 = {x1, x2, x3, x4} and CB13 = {y1, y2, y3, y4}. In the decomposed retransmission block, the CRC is processed in the same manner as the data bits. In this way, the four code blocks of data transmitted in the second frame are {CB21, CB22, CB23, CB24}, of which CB21, CB23 and CB24 become new code blocks, and CB22 becomes a retransmission code block. It will include a part of each of CB12 and CB13.

  By resolving and reassembling the code block to be retransmitted and the new code block by partial retransmission, the number of retransmission code blocks is made smaller than the number of code blocks that have not been received correctly determined by feedback from the receiving end. Thereby, the throughput of the system can be increased.

However, Patent Document 5 does not mention how to adaptively determine the ratio of retransmission data to the retransmission block in the partial retransmission scheme to maximize the system throughput.
It should be noted that the above description of the related art is merely a description made in order to clearly and completely explain the technical solution of the present invention and to help those skilled in the art. Therefore, if these technical solutions are described in the background art portion of the present invention, it cannot be considered that the above technical solutions are known to those skilled in the art.
The following is a reference of the present invention. By quoting these documents, it is assumed that they are the same as those described in detail in this specification.

US Pat. No. 7,152,196B2 US Patent Application Publication No. 2007 / 0061690A1 US Patent Application Publication No. 2007 / 0234186A1 US Patent Application Publication No. 2007 / 0280158A1 Chinese Patent Application Publication No. 2008 / 10127487.4

3GPP TR25.835. Report on hybrid ARQ type II / III [S] .2000; C. Bai, B. Mielczarek, W. A. Krzymie´n, and I. J. Fair, “Sub-block recovery scheme for iterative decoding of turbo codes,” in Proc. IEEE VTC’05-Fall, Dallas, USA, Sept. 2005; Tao Shi; Lei Cao, “Combining techniques and segment selective repeat on turbo coded hybrid ARQ”, in Proc. IEEE Conf. WCNC. 2004 IEEE, Vol.4, pp. 2115-2119, 21-25 March 2004.

  The present invention has been made in view of the above problems.

  An object of the present invention is to improve system throughput in HARQ by partial retransmission.

  In order to achieve the above object, the present invention improves the system throughput by adaptively determining the retransmission ratio in a communication system employing a HARQ scheme based on partial retransmission.

Here, the retransmission ratio refers to the ratio of data to be retransmitted in the first data block because the retransmission data block was not correctly received in the previous transmission.

  The following technical solutions are provided based on the present invention.

  The communication system according to the first embodiment includes a transmitter and a receiver, and transmits a frame including one or more data packets including one or more code data blocks from the transmitter to the receiver. In a communication system having a check part for each code data block itself, the receiver determines whether each code data block is correctly received by the check part, and each code data block is A test unit that generates reception accuracy information that reflects whether or not the signal has been correctly received, a channel information determination unit that determines channel information of the code data block, and the transmission accuracy information and the channel information that are transmitted from the transmitter. A feedback unit for feeding back to the transmitter, the transmitter from the receiver A feedback receiving unit that receives the feedback accuracy information and the channel information that are fed back; a retransmission ratio determination unit that determines a retransmission ratio in retransmission based on the reception accuracy information and the channel information received by the feedback reception unit; And a data packet placement unit that places retransmission data packets based on the retransmission ratio determined by the retransmission ratio determination unit.

  A communication system according to the second embodiment includes a transmitter and a receiver, and transmits a frame including one or more data packets including one or more code data blocks from the transmitter to the receiver, and the code In a communication system including a check part for each code data block itself for each data block, the receiver determines whether each code data block is correctly received by the check part, and each code data Based on the inspection unit that generates reception accuracy information reflecting whether or not the block has been received correctly, the channel information determination unit that determines the channel information of the code data block, the reception accuracy information and the channel information A retransmission ratio determination unit for determining a retransmission ratio in retransmission, and the reception accuracy information And a feedback unit that feeds back the retransmission ratio to the transmitter, and the transmitter receives the accurate reception information fed back from the receiver and the feedback reception unit that receives the retransmission ratio, and the retransmission ratio. And a data packet placement unit for placing retransmission data packets based on the data packet.

  The transmitter according to the third embodiment is a transmitter in a communication system having a transmitter and a receiver, and includes a frame having one or more data packets including one or more code data blocks from the transmitter to the receiver. And a check part for the code data block itself for each code data block, and the receiver determines whether each code data block is correctly received based on the check part, and Feedback correctness information reflecting whether or not the code data block is correctly received and channel information of the code data block are fed back, and the transmitter feedbacks the reception accuracy information fed back from the receiver and the information A feedback receiving unit for receiving channel information, and the feedback receiving unit Therefore, based on the received correctness information and the channel information received, a retransmission ratio determination unit that determines a retransmission ratio in retransmission, and a data packet arrangement unit that arranges retransmission data packets based on the retransmission ratio determined by the retransmission ratio determination unit Is provided.

  A receiver according to a fourth embodiment is a receiver in a communication system having a transmitter and a receiver, and includes a frame having one or more data packets including one or more code data blocks from the transmitter to the receiver. And for each code data block, a check part for the code data block itself is provided, and the receiver determines whether each code data block is correctly received by the check part, An inspection unit that generates reception accuracy information reflecting whether or not the code data block is correctly received, a channel information determination unit that determines channel information of the code data block, the reception accuracy information and the channel A retransmission ratio determination unit for determining a retransmission ratio in retransmission based on the information; Come and a feedback unit for feeding back information and the retransmission ratio to the transmitter.

  An automatic retransmission control method according to a fifth embodiment includes a transmitter and a receiver, and transmits a frame including one or more data packets including one or more code data blocks from the transmitter to the receiver. In the automatic retransmission control method in a communication system including a check part for each code data block for each code data block, the receiver determines whether each code data block is correctly received by the check part. Generating correct reception information reflecting whether or not each code data block was correctly received; determining channel information of the code data block; receiving correct information and channel information; Feedback to the transmitter, wherein in the transmitter, the reception Receiving the correct reception information and the channel information fed back from, receiving the correct reception information and the channel information, determining a retransmission ratio in retransmission, and retransmitting the data packet based on the retransmission ratio Arranging.

  The automatic retransmission control method according to the sixth embodiment includes a transmitter and a receiver, and transmits a frame including one or more data packets including one or more code data blocks from the transmitter to the receiver. In the automatic retransmission control method in a communication system including a check portion for the code data block itself for each code data block, whether or not each code data block is correctly received by the check portion at the receiver. And generating reception accuracy information reflecting whether or not each code data block has been received correctly, determining channel information of the code data block, the reception accuracy information and the A step of determining a retransmission ratio in retransmission based on channel information; And a step of feeding back the retransmission ratio to the transmitter, wherein the transmitter receives the correct reception information and the retransmission ratio fed back from the receiver, and retransmits based on the retransmission ratio. Placing a data packet.

  According to the present invention, in HARQ by partial retransmission, the throughput of the system can be improved by adaptively determining the retransmission ratio in data retransmission.

The drawings illustrate examples and form part of the specification, and the embodiments are described in more detail in conjunction with the text description.
A schematic diagram of a general HARQ system is shown. It is a schematic diagram which shows the time series of the data frame and resending of a general HARQ system. The schematic diagram of the data packet structure resent by a code block is shown. FIG. 1 shows a schematic structural diagram of a communication system according to a first embodiment. FIG. 5 shows a schematic structural diagram of a transmitter according to a second embodiment. The typical flowchart of the process which a transmitter performs is shown. FIG. 5 shows a schematic diagram of data packet arrangement processing when there is no retransmission data. FIG. 4 is a schematic diagram of data packet arrangement processing when there is retransmission data according to the first embodiment. FIG. 10 shows a schematic diagram of a data packet arrangement process of the second embodiment. The graph shows the packet error rate performance corresponding to different retransmission ratios. The flowchart of the retransmission ratio calculation process is shown. FIG. 6 shows a schematic block diagram of a communication system according to a third embodiment. FIG. 10 shows a schematic block diagram of a transmitter according to a fourth embodiment. It is one illustration of the retransmission data block structure combined before encoding. It is one example of the retransmission data block configuration combined after encoding. It is another illustration of the retransmission data block configuration combined after encoding. It is another illustration of the retransmission data block configuration combined after encoding. FIG. 6 shows a schematic diagram of the effect of different MCS selections on the retransmission ratio.

  The features of the above and other aspects of the present invention will become more apparent with reference to the following description and drawings. In the following description and drawings, specific embodiments are disclosed in detail. Of course, the scope of the present invention is not limited to this, and various changes, corrections, and replacements can be made within the scope of the present invention.

  Features described and / or illustrated in one embodiment may be used in one or more other embodiments in the same or similar manner, combined with features in other embodiments, or other implementations Features in the form can be replaced.

  As used herein, the term “comprising / comprising” refers to the presence of a feature, element, step or combination, but does not exclude the presence of or addition of one or more other features, elements, steps or combinations.

  Various aspects of the invention can be better understood with reference to the following drawings. The components in the drawings are not drawn to scale but merely illustrate embodiments. For convenience of displaying and describing a certain part of the embodiment, the corresponding part in the drawing can be enlarged. That is, it can be larger than other members in the exemplary device actually manufactured by the embodiment. Elements and features described in one drawing or embodiment may be combined with elements and features shown in one or more other drawings or embodiments. In the drawings, like numerals indicate corresponding members in the several views, and may indicate corresponding members used in one or more embodiments.

  Hereinafter, a method and apparatus according to embodiments will be described with reference to the drawings, taking a general single antenna system as an example. However, the embodiment is not limited to a single antenna system, but can be similarly applied to a MINO-OFDM multi-antenna system or a CDMA system. The embodiment is also applied to retransmission of general Internet network data.

[First embodiment]
FIG. 4 is a schematic block diagram of the communication system according to the first embodiment. For the sake of convenience, FIG. 4 shows only one transmitter 200-1 and one receiver 300-1 communicating with each other. However, it goes without saying that there may be multiple transmitters and multiple receivers in the communication system.

As shown in FIG. 4, the transmitter 200-1 includes a source data buffer unit 201, an encoding unit 202, a CRC addition unit 203, a modulation unit 204, a transmission antenna (Tx) 207, and an MCS (modulation and modulation). (Encoding system) A control unit 206, an ARQ control unit 205, and a feedback reception unit 208 are provided. Among them, the ARQ control unit 205 includes a retransmission determination unit 2051 and a data packet arrangement unit 2052. Data packet placement unit 2052 places data packets according to a partial retransmission scheme.
In transmitter 200-1, ARQ control is performed before data is encoded.

  Receiver 300-1 includes a receiving antenna (Rx) 301, a demodulation unit 302, a decoding unit 303, a CRC checking unit 304, a data output unit 305, a retransmission ratio calculation unit 306, an ARQ control unit 307, A channel estimation unit 308, an MCS selection unit 309, and a feedback unit 310 are provided.

  The ARQ control unit 307 includes an ARQ control unit 3070, a retransmission determination unit 3071, a reception buffer 3072, and a data synthesis unit 3073.

  First, data is received by the receiving antenna 301, and after the data of the receiving antenna 301 is decoded via the demodulation unit 302, it is first determined by the retransmission determination unit 3071 whether or not it is retransmission data. Decoding by the decoding unit 303 and CRC checking by the CRC checking unit 304, otherwise, the retransmitted data enters the data combining unit 3073 and is combined. At this time, the retransmitted data and the first data in the reception buffer 3072 are combined. Synthesized. Decoding is performed by the decoding unit 303, and CRC inspection is performed by the CRC inspection unit 304. If the result is correct, the data is output via the data output unit 305, and the ARQ control unit 3070 feeds back the ACK information to the transmitting end via the feedback unit 310. Otherwise, the next synthesis is performed. In addition, the current data is left in the reception buffer 3072, and the ARQ control unit 3070 feeds back a NACK signal to the transmission end.

  The MCS selection unit 309 in the receiver 300-1 calculates a signal-to-noise ratio, that is, a signal-to-noise ratio (SNR) value based on the channel estimation result of the channel estimation unit 308, and then calculates an appropriate value depending on a predetermined packet error rate. A modulation and coding scheme (MCS) is selected and fed back to the transmitter 200-1 via the feedback unit 310.

  The receiver 300-1 has a retransmission ratio calculation unit 306. The retransmission ratio calculation unit 306 determines the retransmission ratio (hereinafter referred to as α) and feeds it back to the transmitter 200-1 via the feedback unit 310. The transmitter 200-1 arranges retransmission data packets based on the fed back retransmission ratio.

  The following will first define the retransmission ratio (α).

FIG. 14 shows the definition of the retransmission ratio α of the partial retransmission HARQ in the transmitter 200-1 shown in FIG. 4 (that is, when combined before encoding). The encoder is a systematic code encoder, and one data block is N ₀₀ + N ₁₀ bits before encoding, and the length of check bits is N _p bits after encoding. Then

ここで、N₀₀は再送データのビット数を表し、N₁₀は新しいデータのビット数を表す。

Here, N ₀₀ represents the number of bits of retransmission data, and N ₁₀ represents the number of bits of new data.

  In a HARQ system based on Chase combining, there is a 3 dB combined gain at the receiving end at one retransmission, and the gain due to partial retransmission is between 0 and 3 dB. In the present embodiment, the retransmission ratio is taken into account, and the numerical value of the retransmission ratio is determined based on the current signal-to-noise ratio and the modulation and coding scheme. Thereby, an increase in throughput can be realized with a minimum retransmission ratio. When α represents the retransmission ratio, αε [0, 1], α = 0 represents a new data packet, and α = 1 represents HARQ for Chase combining, that is, retransmission of the entire code block. If α is between 0 and 1, it indicates partial data retransmission.

  FIG. 6 shows a schematic flowchart of a retransmission processing method of the transmitter 200-1 according to one example of the present embodiment.

  First, in step 601, feedback receiving unit 208 of transmitter 200-1 receives feedback information such as ACK / NACK and retransmission ratio from receiver 300-1.

  The format of the ACK / NACK feedback information is determined by both reception / transmission. For example, for a situation where one frame shown in FIGS. 2 and 3 has four data packets and each frame packet has four subpackets, according to one embodiment, an ACK and a 16-bit word are used. NACK signal can be fed back. The four most recent bits represent the four subpackets of the first data packet, the four following bits represent the four subpackets of the second data packet, and the four following bits are the third. The last four bits represent the fourth data packet. For the first four bits, if the first bit is 1, it means that an error has occurred in the first subpacket in the first data packet, and the first bit is 0 And the first subpacket in the first data packet is correctly received. If the second bit is 1, it means that an error has occurred in the second subpacket in the first data packet, and if the second bit is 0, the first data packet Means that the second sub-packet at is correctly received. The same applies hereinafter.

  According to other embodiments, various states are predefined and numbered. The receiver 300-1 transmits the number, and the transmitter 200-1 determines an erroneous packet and a subpacket based on the number received from the receiver 300-1.

  In step 601, after receiving the ACK / NACK feedback information by the feedback receiving unit 208, in step 602, the retransmission determining unit 2051 determines whether there is a code block to be retransmitted and the number of code blocks to be retransmitted. .

  If there is no code block to be retransmitted, a normal data acquisition process is performed by the data packet placement unit 2052 in step 603. If there is a code block to be retransmitted, in step 605, the data packet allocation unit 2052 generates a retransmission code block by performing data acquisition and combination based on the retransmission ratio fed back from the receiver 300-1. . The code block data enters modulation and subsequent processing at step 606.

  Hereinafter, a specific flow in which data is generated in steps 603 and 605 will be described. FIG. 7 shows the situation when there is no retransmission data, and FIGS. 8 and 9 show the situation when there is retransmission data.

  FIG. 7 shows a schematic diagram of data acquisition and encoding processing when there is no data code block to be retransmitted. Among them, the upper part of the functional block diagram shows the data structure corresponding to the block diagram, and as an example, every time it is transmitted Assume that the resource block occupied by the data packet is fixed and includes a total of four code blocks. When there is no code block to be retransmitted, new data is obtained from the resource data buffer 201 by the data packet placement unit 2052. Further, the obtained data is divided into some subpackets (SubPacket, for example, SP11-SP14 in FIG. 7, of which SPij represents the jth subpacket transmitted for the i-th time, and so on). The encoder 202 encodes these subpackets based on the encoding method determined by the MCS control unit 206, and the code block (CodeBlock, CB11-CB14, CB11 is the bit number after SP11 encoding). CBij represents the j-th code block transmitted for the i-th time). Subsequently, a CRC check code (CRC1-CRC4) is added to each code block by the CRC adding unit 203, and then sent to the subsequent transmission processing unit via the modulator 204. In the following description of this specification, P represents source bit data before encoding, code block CB represents bit data after encoding, and one subpacket passes through an encoder into one code block. Correspondingly, depending on the upper and lower sentences, a code block may refer to a combination of a code block and its CRC. At the receiving end, the data is decoded in units of code blocks.

  When there is a code block to be retransmitted, the data packet placement unit 2052 performs data acquisition and combination in step 605 to generate a data code block for retransmission. FIG. 8 shows a schematic diagram in which source data is combined and retransmitted before encoding according to the first embodiment.

  In FIG. 8, it is assumed that an error occurs in the second code block CB12 transmitted in the previous frame and the retransmission ratio α fed back from the receiver 300-1 is 0.5. The ARQ control unit 205 (data packet placement unit 2052) obtains new data from the source data buffer unit 201 and configures the first, third and fourth subpackets SP21, SP23, SP24, and the second subpacket SP22. In this case, 1/2 (0.5) of the source data SP12 that could not be accurately transmitted in the previous frame is retransmitted data, and the other half of the second subpacket SP22 is composed of new data. In addition, the encoder 202 encodes the subpackets SP21-SP24 acquired according to the encoding method determined by the MCS control unit 206 to obtain code blocks CB21-CB24. The CRC adding unit 203 adds a CRC to the code block, the modulation unit 204 modulates the code block after adding the CRC according to the modulation scheme determined by the MCS control unit 206, and the receiver 300-1 by the transmitting antenna 207. Send to.

  FIG. 8 illustrates the processing of the data packet placement unit 2052 taking the case where α is 0.5 as an example, but the processing process is the same when the retransmission ratio α is another value. For example, when the retransmission ratio α is 0.25, the retransmission block includes 3/4 new data and 1/4 retransmission data. When the retransmission ratio α is 0.33 (1/3), the retransmission block includes 2/3 new data and 1/3 retransmission data.

  The HARQ mechanism for partial data retransmission can subdivide the granularity of HARQ retransmission data, and can effectively use channel resources to increase system throughput. Hereinafter, a process in which receiver 300-1 determines the retransmission ratio will be described.

  For a given modulation code scheme, performance curves (relationship between packet error rate and signal-to-noise ratio) corresponding to different retransmission ratios α under a Gaussian channel are different. A performance curve with different retransmission ratios is determined in advance through simulation, and a performance curve at a different α value in the modulation and coding scheme is acquired, and a look-up table can be obtained as shown in FIG. . Through the above method, a plurality of lookup tables corresponding to different modulation code methods can be obtained. In addition, these lookup tables are stored in a storage unit (not shown) of the receiver 300-1.

  Hereinafter, the process of determining the retransmission ratio by the retransmission ratio calculation unit 306 will be described with reference to FIG. First, in step 1101, a lookup table corresponding to a modulation code scheme selected from a plurality of lookup tables is selected based on the modulation code scheme selected by the MCS selection unit. In step 1102, the channel estimation unit 308 performs channel estimation on the current data block, and calculates a signal-to-noise ratio value of the data block based on the channel estimation result. In step 1103, an appropriate α value is selected based on the packet error rate (block error rate) set by the system and the calculated signal-to-noise ratio value. Specifically, the performance curve closest to the point determined by the packet error rate (block error rate) and the signal-to-noise ratio value is determined, and the α value corresponding to the performance curve is set as the selected retransmission ratio. In step 1104, the selected retransmission ratio α is fed back to the transmitter 200-1 by the feedback unit 310 via uplink signaling.

  Hereinafter, an operation of feeding back the retransmission ratio from the feedback unit 310 will be described in detail.

類似のフォーマットはTDDとFDDシステムにいずれも応用可能であり、TDDシステムにおいてダウンリンク時間ピリオドの異なる時間でシグナリングとデータを発送することができる。FDDシステムにおいて、シグナリングは専用周波数帯を通して、データと共に発送される。 In this embodiment, it is possible to improve the throughput with the smallest number of retransmissions. The retransmission ratio α provides an accurate data decomposition and combination indication for partial data retransmission HARQ. This embodiment has the price to increase the feedback of the retransmission ratio α as compared with the traditional HARQ based on Chase synthesis. Α is represented by a small number of bits, and is fed back to the transmitting end by the feedback unit 310 or notified to the receiving end by the transmitting end in the control signaling part. For example, Tables 1 to 4 show α values that can be 2 bits and 3 bits. The more complex the scheme, or the more options included in the scheme, the more complex the corresponding fields. One skilled in the art can adjust the format of the notification according to actual demand.

Similar formats can be applied to both TDD and FDD systems, where signaling and data can be sent at different times in the downlink time period in the TDD system. In the FDD system, signaling is routed with data through a dedicated frequency band.

  Also, for the determined retransmission ratio α value, when retransmission data and new data are at different positions in the data block, the packet error rate performance of the system may be different. Therefore, in one example of the present embodiment, the arrangement method of retransmission data and new data in the retransmission packet is also variable. Moreover, the arrangement of retransmission data and new data may differ depending on the number of retransmissions.

を表す。もし、指示シーケンスb_k（n）＝0が第nのビット位置に一つの再送ビットを放置することを表すと、b_k（n）＝1は第nのビット位置に一つの新しいデータを放置することを表す。再送データブロックと新しいデータブロックを順に放置した場合、指示シーケンスを以下のように表示できる。

図14と図15に示すように、上記式は再送ビットを放置した後に新しいデータビットを放置したフォーマットに対応する。他の実施例において、再送データビットと新しいデータビットを交替にして放置し、異なる再送信回数の場合に放置位置も異なってもよい。この時、指示シーケンスを以下のように表示できる。

ここで、1/αは必ず整数でなければならない。 For example, in one embodiment, the number of bits of the N ₁₀ is retransmitted data, N ₁₁ represents the number of bits of new data, and N _{1 =} N ₁₀ + N ₁₁ denote the total length of the information bits. In addition, the bit sequence instruction after arranging the information bit combination is represented by b _k (n), where k is the number of retransmissions and n is the bit position.

Represents. If the indication sequence b _k (n) = 0 indicates that one retransmission bit is left at the nth bit position, b _k (n) = 1 leaves one new data at the nth bit position. Represents what to do. When the retransmission data block and the new data block are left in order, the instruction sequence can be displayed as follows.

As shown in FIGS. 14 and 15, the above equation corresponds to a format in which a new data bit is left after a retransmission bit is left. In another embodiment, the retransmission data bits and the new data bits may be left alternately, and the left positions may be different for different retransmission times. At this time, the instruction sequence can be displayed as follows.

Here, 1 / α must be an integer.

  Correspondingly, as indicated by a broken line 2053 in FIG. 4, the ARQ control unit 205 of the transmitter 200-1 has a format notification unit 2053. The format notification unit 2053 notifies the above instruction sequence to the receiver 300-1, so that the receiver 300-1 can acquire the position of the data bit, and thereby correctly synthesize the retransmission data.

  If data cannot be received correctly after retransmission, multiple retransmissions can be performed. For example, if the first retransmission fails, the receiver 300-1 feeds back the NACK signal and the retransmission ratio, the transmitter 200-1 performs the second retransmission, and if the second retransmission fails, the third retransmission I do. If the number of retransmissions is set to a maximum of 3 times and the packet cannot be received correctly after the third retransmission, the data packet is discarded. In the next frame, a new data packet is transmitted. When retransmitting a plurality of times, the numerical value of α may be recalculated in consideration of the signal-to-noise ratio synthesis gain of the previous retransmission data.

[Second Embodiment]
The communication system according to the second embodiment will be described below. FIG. 5 shows a schematic structural diagram of a transmitter 200-2 according to the second embodiment. The structure of the receiver in the second embodiment is the same as that shown in FIG. Therefore, the second embodiment will be described below with reference to FIGS. 5 and 4.

  In the first embodiment, ARQ control is performed before data is encoded. In the second embodiment, ARQ control is performed after data is encoded. In the following description, differences between the first embodiment and the second embodiment will be mainly described, and overlapping descriptions for the same parts will be omitted.

  As shown in FIG. 5, the transmitter 200-2 includes a modulation unit 204, a transmission antenna 207, an MCS control unit 206, an ARQ control unit 205, and feedback reception similar to the transmitter 200-1 shown in FIG. Unit 208 etc. are provided. Further, the transmitter 200-2 has a code block data buffer 209, and stores a data block series before modulation in which it is not confirmed whether or not the data has been correctly received. Therefore, if there is data to be retransmitted, the corresponding data code block may be extracted from the code block data buffer unit 208, and there is no need to encode it again. If the ACK signal is returned from all the previously transmitted data, the code block data buffer unit 208 deletes the corresponding stored data.

FIG. 15 shows the definition of the retransmission ratio α of the partial retransmission HARQ in the transmitter 200-2 shown in FIG. 5 (that is, when combined after encoding). HARQ that retransmits a part of data after encoding does not distinguish between information bits and CRC check bits, and retransmission code blocks are retransmission data of all different blocks, and no new data exists. Assuming that the length of the retransmission data of the first code block is N ₀₀ and the length of the retransmission data of the second code block is N ₁₀ , the retransmission ratio is as follows.

  Each partial retransmission HARQ supports retransmission of a plurality of code blocks, and the retransmission ratio for each code block may be different. FIG. 16 shows another example of partial retransmission HARQ combined after encoding. The retransmission code block includes three subpackets, and the retransmission ratio of the previous two code blocks is 0.25. One retransmission ratio is 0.5. The different ratio is determined by the signal-to-noise ratio of the code block. In a general communication system, data channel changes of a plurality of consecutive frames are not all large, and the retransmission ratio is uniform. As shown in FIG. 17, each of the three sub-blocks is 0.33, and the overhead of the signaling part is also small at this time. When the retransmission ratios of different combination parts are different, the transmitting end needs to inform the receiving end of the retransmission ratio and position of each part, and signaling overhead is large.

  The HARQ process in the second embodiment will be described below.

  If the number of data code blocks to be retransmitted is one, the entire erroneous data block can be retransmitted, which is equal to general HARQ. Alternatively, it is possible to wait until the number of erroneous data packets becomes one or more before disassembling and combining and retransmitting.

  In the second embodiment, the determination for the retransmission ratio is the same as in the first embodiment. When the calculated retransmission ratio is 0.5 and there are exactly two erroneous code blocks, one retransmission block is combined by taking half (0.5) from each of the two code blocks. For the same reason, when the retransmission ratio is α and there is an erroneous code block of exactly 1 / α, it is possible to combine the retransmission blocks by taking a portion of the α ratio from the 1 / α code block. In an actual system, the combination can be flexibly performed by the current erroneous block. For example, when the retransmission ratio is 0.5, two erroneous blocks can be combined into one retransmission block, and when there are four erroneous blocks, they can be combined into two retransmission blocks. In a general communication system, the change in the data signal-to-noise ratio in one frame is small and the retransmission ratio is the same. In this embodiment, when the retransmission blocks are combined in each code block, the ratio occupied by the retransmission blocks is equal. That is, 1/2, 1/3 or 1/4.

  FIG. 9 shows processing in transmitter 200-2 when the number of data code blocks to be retransmitted is two. As shown in FIG. 9, two data blocks CB12 and CB13 (corresponding source data subpackets are SP12 and SP13, respectively) have to be retransmitted during the first transmission and need to be retransmitted. Block retransmission ratios are fixed at 0.5 and 0.5, respectively.

  The data packet placement unit 2052 acquires new data (SP21, SP23, SP24) of three subpackets from the source data buffer unit 201, sends them to the encoder 203, adds CRC, and adds the current new encoded data block Is stored in the code block data buffer unit 209. Also, the two blocks CB12 to be retransmitted and their CRC and CB13 and their CRC are extracted from the code block data buffer unit 209, and half (1/2, 0.5) are taken out of them to combine a new code block (CB22). Here, CB12 and CB13 are data including the CRC check code.When combining CB22 with these, the length of the MCS and code block does not change, and only a part of bit data of CB12 or CB13 is disassembled and combined. Just leave it at a specific position on CB22. For example, when CB12 = {x1, x2, x3, x4} and CB13 = {y1, y2, y3, y4}, CB22 = {x1, y1, x3, x4} is configured.

  The method of disassembly and combination is the same as that described in the first embodiment. The CRC is processed in the same way as the data bits for disassembling the retransmission block. In this way, the four code blocks of the data transmitted in the second frame are {CB21, CB22, CB23, CB24}, of which CB21, CB23 and CB24 are new code blocks, and CB22 is a retransmitted code block. Each part of blocks CB12 and CB13.

  Similar to the first embodiment, the data block decomposition method is determined by both transmission and reception. In one embodiment, after making a decision by the transmitting end, the receiving end can be notified. In this case, the transmitter 200-2 has the same format notification unit 2053 as in the first embodiment, and notifies the receiver of the parts acquired from the code block and the combination method for these parts.

スキームが複雑であるほど、又はスキームに含まれたオプションが多いほど、相応のフィールドも複雑になる。当業者は実際の需要に応じて通知のフォーマットを調整できる。 For example, if one frame shown in FIGS. 2 and 3 has four data packets, and each data packet has four code blocks, the retransmission ratio is 0.5 (half of the data from each erroneous code block is taken). For example, the following fields can be used for the notification.

The more complex the scheme, or the more options included in the scheme, the more complex the corresponding fields. One skilled in the art can adjust the format of the notification according to actual demand.

  Also, different decomposition and combining schemes are predetermined for both reception and transmission, and corresponding retransmission packet positions and code schemes to be retransmitted in a data packet can be represented by a group of fixed codes. For example, when the four code blocks in FIG. 8 are decomposed and retransmitted, in addition to representing the ACK / NAK signal of the corresponding data block with four bits, four feedback bits are added to obtain the desired decomposition format at the receiving end. For example, {1110} indicates that the transmission end leaves the retransmission data in the second block, and retransmits the first half of two erroneous code blocks at the time of the odd number of retransmissions and two at the time of the even number of retransmissions. Retransmission of the second half of the erroneous block, {1101} indicates that the retransmission data is left in the first block, and other operations are the same as the previous one. In this way, the receiving end can complete the disassembly and combining without signaling information when receiving retransmission data. The method can save resources for downlink control signaling, but instead, the overhead of uplink feedback information is large, and more feedback bits need to represent the desired resolution and location information at the receiving end.

[Third embodiment]
The communication system according to the third embodiment will be described below. FIG. 12 is a schematic configuration diagram of a communication system according to the third embodiment.

  In the first embodiment, the retransmission ratio is calculated on the reception side and fed back to the transmission side. However, in the third embodiment, the retransmission ratio is calculated on the transmission side. Other parts are the same as those of the first embodiment.

  As shown in FIG. 12, the receiver 300-3 does not include a retransmission ratio calculation unit. The transmitter 300-3 calculates the signal-to-noise ratio at the receiving end based on the channel information of the channel estimation unit 308, determines the encoding and modulation scheme, and then feeds back to the transmitter 200-3 via the feedback unit 311. To do.

  The ARQ control unit 205 of the transmitter 200-3 includes a retransmission ratio calculation unit 2054. The feedback receiving unit 208 receives the feedback of the signal-to-noise ratio from the receiver 300-3 and transmits it to the retransmission ratio calculating unit 2054. The retransmission ratio calculation unit 2054 calculates the retransmission ratio based on the ACK / NACK information and the signal-to-noise ratio information fed back from the receiver 300-3.

  The process in which the retransmission ratio calculation unit 2054 calculates the retransmission ratio is the same as the process in which the retransmission ratio calculation unit 306 in the first embodiment calculates the retransmission ratio, and the data packet placement unit 2052 places the data packet. Is the same as described in the first embodiment. Therefore, the overlapping description is omitted here.

[Fourth embodiment]
The communication system according to the fourth embodiment will be described below. FIG. 13 is a schematic configuration diagram of a communication system according to the third embodiment.

  In the second embodiment, the retransmission ratio is calculated on the reception side and fed back to the transmission side. However, in the fourth embodiment, the retransmission ratio is calculated on the transmission side. Other parts are the same as those of the second embodiment.

  As shown in FIG. 13, the receiver does not include a retransmission ratio calculation unit. The transmitter feeds back the signal-to-noise ratio acquired by the channel estimation unit 308 and the signal-to-clutter ratio calculation unit 310 via the feedback unit 310 to the transmitter 200-4.

  The ARQ control unit 205 of the transmitter 200-4 includes a retransmission ratio calculation unit 2054. The feedback receiving unit 208 receives the feedback of the signal-to-noise ratio from the receiver 300-3 and transmits it to the retransmission ratio calculating unit 2054. A retransmission ratio calculation unit 2054 calculates a retransmission ratio based on ACK / NACK information and signal-to-noise ratio information fed back from the receiver.

  The process in which the retransmission ratio calculation unit 2054 calculates the retransmission ratio is the same as the process in which the retransmission ratio calculation unit 306 in the second embodiment calculates the retransmission ratio, and the data packet placement unit 2052 places the data packet. Is the same as described in the second embodiment. Therefore, the overlapping description is omitted here.

  According to the present disclosure, in the partial retransmission HARQ scheme, the retransmission ratio in retransmission is automatically determined according to the channel state on the reception side or transmission side, and the ratio of new data and retransmission data in retransmission is optimized. The system throughput can be improved.

  The first to fourth embodiments have been described above. Of course, the scope of the present invention is not limited to the specific embodiments described above, and various improvements and modifications can be made to the present invention without departing from the spirit or scope of the present invention. Thus, if these improvements and modifications are within the scope of the appended claims and the same, they should also belong to the present invention.

The following additional notes are described regarding the first to fourth embodiments.
(Supplementary Note 1) A frame having a transmitter and a receiver, the frame having one or more data packets each including one or more code data blocks is transmitted from the transmitter to the receiver, and the code data block for each code data block In a communication system comprising an inspection part for itself,
The receiver determines whether or not each code data block is correctly received by the check part, and generates a reception correct information reflecting whether or not each code data block is correctly received. Unit,
A channel information determination unit for determining channel information of the code data block;
A feedback unit that feeds back the reception accuracy information and the channel information to the transmitter;
With
The transmitter has a feedback receiving unit for receiving the reception accuracy information and the channel information fed back from the receiver;
Based on the reception accuracy information received by the feedback reception unit and the channel information, a retransmission ratio determination unit for determining a retransmission ratio in retransmission,
A data packet placement unit for placing retransmission data packets based on the retransmission ratio determined by the retransmission ratio determination unit;
Is provided.
(Supplementary note 2) The communication system according to supplementary note 1, wherein the data packet placement unit retransmits a part of data of a data packet that could not be correctly transmitted based on the retransmission ratio.
(Supplementary note 3) The communication system according to supplementary note 1, wherein the retransmission ratio determination unit determines the retransmission ratio based on a lookup table reflecting transmission performance with different retransmission ratios taken in advance.
(Supplementary note 4) The communication system according to any one of Supplementary notes 1 to 3, wherein the transmitter further includes a format notification unit that informs the receiver of a combination format of retransmission data packets.
(Additional remark 5) It has a transmitter and a receiver, transmits a frame having one or more data packets including one or more code data blocks from the transmitter to the receiver, and the code for each code data block. In a communication system comprising an inspection part for the data block itself,
The receiver determines whether or not each code data block is correctly received by the check part, and generates a reception correct information reflecting whether or not each code data block is correctly received. Unit,
A channel information determination unit for determining channel information of the code data block;
A retransmission ratio determination unit for determining a retransmission ratio in retransmission based on the reception accuracy information and the channel information;
A feedback unit that feeds back the reception accuracy information and the retransmission ratio to the transmitter;
With
The transmitter is configured to receive the reception accuracy information fed back from the receiver and a feedback reception unit that receives the retransmission ratio;
And a data packet placement unit that places retransmission data packets based on the retransmission ratio.
(Supplementary note 6) The communication system according to supplementary note 5, wherein the data packet placement unit retransmits a part of the data packet that could not be transmitted accurately based on the retransmission ratio.
(Supplementary note 7) The communication system according to supplementary note 5, wherein the retransmission ratio determination unit determines the retransmission ratio based on a lookup table reflecting transmission performance with different retransmission ratios taken in advance.
(Supplementary Note 8) The communication system according to any one of Supplementary Notes 5 to 7, wherein the transmitter further includes a format notification unit that notifies the receiver of a combination format of retransmission data.
(Supplementary note 9) In a transmitter in a communication system having a transmitter and a receiver, the transmitter transmits a frame having one or more data packets including one or more code data blocks to the receiver, and Each code data block has a check part for the code data block itself, and the receiver determines whether each code data block is correctly received based on the check part, and each code data block is received correctly. Feedback correct reception information reflecting whether or not it has been done, and channel information of the code data block,
The transmitter is configured to receive the reception accuracy information and the channel information fed back from the receiver, a feedback receiving unit,
Based on the reception accuracy information received by the feedback receiving unit and the channel information, a retransmission ratio determination unit for determining a retransmission ratio in retransmission,
A data packet placement unit for placing retransmission data packets based on the retransmission ratio determined by the retransmission ratio determination unit;
A transmitter comprising:
(Supplementary note 10) The transmitter according to supplementary note 9, wherein the data packet arrangement unit retransmits a part of data of a data packet that could not be accurately transmitted based on the retransmission ratio.
(Supplementary note 11) The transmitter according to supplementary note 9, wherein the retransmission ratio determination unit determines the retransmission ratio based on a lookup table reflecting transmission performance with different retransmission ratios taken in advance.
(Supplementary note 12) The transmitter according to Supplementary notes 9 to 11, further comprising a format notification unit that informs the receiver of a combination format of retransmission data.
(Supplementary note 13) In a receiver in a communication system having a transmitter and a receiver, the transmitter transmits a frame having one or more data packets including one or more code data blocks to the receiver, and Each code data block has a check portion for the code data block itself,
The receiver determines whether or not each code data block is correctly received by the check part, and generates a reception correct information reflecting whether or not each code data block is correctly received. Unit,
A channel information determination unit for determining channel information of the code data block;
A retransmission ratio determination unit for determining a retransmission ratio in retransmission based on the reception accuracy information and the channel information;
A feedback unit that feeds back the reception accuracy information and the retransmission ratio to the transmitter;
A receiver comprising:
(Supplementary note 14) The transmitter according to supplementary note 13, wherein the retransmission ratio determination unit determines the retransmission ratio based on a lookup table reflecting transmission performance with different retransmission ratios taken in advance.
(Supplementary Note 15) A frame having a transmitter and a receiver, the frame having one or more data packets each including one or more code data blocks is transmitted from the transmitter to the receiver, and the code for each code data block is transmitted. In an automatic retransmission control method in a communication system including an inspection part for a data block itself,
In the receiver, the step of determining whether each code data block is correctly received by the checking portion and generating reception accuracy information reflecting whether each code data block is correctly received When,
Determining channel information of the code data block;
Feeding back the correct reception information and the channel information to the transmitter, and
In the transmitter, receiving the reception accuracy information and the channel information fed back from the receiver;
Based on the received correct reception information and the channel information, determining a retransmission ratio in retransmission,
An automatic retransmission control method comprising: arranging retransmission data packets based on the retransmission ratio.
(Supplementary note 16) The step of arranging the retransmission data packet further includes a step of retransmitting a part of the data packet that could not be correctly transmitted based on the retransmission ratio. Automatic retransmission control method.
(Supplementary note 17) In the supplementary note 15, the step of determining the retransmission ratio further includes a step of determining the retransmission ratio based on a lookup table reflecting transmission performance with different retransmission ratios taken in advance. The automatic retransmission control method described.
(Supplementary Note 18) A frame having a transmitter and a receiver, the frame having one or more data packets each including one or more code data blocks is transmitted from the transmitter to the receiver, and for each code data block In an automatic retransmission control method in a communication system including a check portion for the code data block itself,
In the receiver, the step of determining whether each code data block is correctly received by the checking portion and generating reception accuracy information reflecting whether each code data block is correctly received When,
Determining channel information of the code data block;
Determining a retransmission ratio in retransmission based on the reception accuracy information and the channel information;
Feeding back the reception accuracy information and the retransmission ratio to the transmitter, and
In the transmitter, receiving the reception accuracy information fed back from the receiver and the retransmission ratio;
Allocating retransmission data packets based on the retransmission ratio, and an automatic retransmission control method.
(Supplementary note 19) The step of arranging the retransmission data packet further includes a step of retransmitting a part of the data packet that could not be correctly transmitted based on the retransmission ratio. Automatic retransmission control method.
(Supplementary note 20) The supplementary note 18, wherein the step of determining the retransmission ratio further comprises a step of determining the retransmission ratio based on a lookup table reflecting transmission performance with different retransmission ratios taken in advance. The automatic retransmission control method described.

Claims (9)

A transmitter having a transmitter and a receiver, transmitting a frame having one or more data packets including one or more code data blocks from the transmitter to the receiver, and a check portion for the code data block itself for each code data block In a communication system comprising:
The receiver determines whether or not each code data block is correctly received by the check part, and generates a reception correct information reflecting whether or not each code data block is correctly received. Unit,
A channel information determination unit for determining channel information of the code data block;
A feedback unit that feeds back the reception accuracy information and the channel information to the transmitter;
With
The transmitter has a feedback receiving unit for receiving the reception accuracy information and the channel information fed back from the receiver;
Based on the reception accuracy information received by the feedback reception unit and the channel information, a retransmission ratio determination unit for determining a retransmission ratio in retransmission,
A data packet placement unit for placing retransmission data packets based on the retransmission ratio determined by the retransmission ratio determination unit;
Is provided.   The communication system according to claim 1, wherein the data packet placement unit retransmits a part of the data packet that could not be transmitted correctly based on the retransmission ratio.   The communication system according to claim 1 or 2, wherein the retransmission ratio determination unit determines the retransmission ratio based on a look-up table reflecting transmission performance based on different retransmission ratios taken in advance.   4. The communication system according to claim 1, wherein the transmitter further includes a format notification unit that informs the receiver of a combination format of retransmission data packets. Transmitting a frame having one or more data packets including one or more code data blocks from the transmitter to the receiver, and for each code data block, the code data block itself In a communication system comprising an inspection part,
The receiver determines whether or not each code data block is correctly received by the check part, and generates a reception correct information reflecting whether or not each code data block is correctly received. Unit,
A channel information determination unit for determining channel information of the code data block;
A retransmission ratio determination unit for determining a retransmission ratio in retransmission based on the reception accuracy information and the channel information;
A feedback unit that feeds back the reception accuracy information and the retransmission ratio to the transmitter;
With
The transmitter is configured to receive the reception accuracy information fed back from the receiver and a feedback reception unit that receives the retransmission ratio;
And a data packet placement unit that places retransmission data packets based on the retransmission ratio. In a transmitter in a communication system having a transmitter and a receiver, a frame including one or more data packets including one or more code data blocks is transmitted from the transmitter to the receiver, and for each code data block A check portion for the code data block itself, and the receiver determines whether each code data block is correctly received based on the check portion, and whether each code data block is correctly received or not. Feedback the correct and correct received information and the channel information of the code data block,
The transmitter is configured to receive the reception accuracy information and the channel information fed back from the receiver, a feedback receiving unit,
Based on the reception accuracy information received by the feedback receiving unit and the channel information, a retransmission ratio determination unit for determining a retransmission ratio in retransmission,
A data packet placement unit for placing retransmission data packets based on the retransmission ratio determined by the retransmission ratio determination unit;
A transmitter comprising: In a receiver in a communication system having a transmitter and a receiver, a frame having one or more data packets including one or more code data blocks is transmitted from the transmitter to the receiver, and for each code data block And a check portion for the code data block itself,
The receiver determines whether or not each code data block is correctly received by the check part, and generates a reception correct information reflecting whether or not each code data block is correctly received. Unit,
A channel information determination unit for determining channel information of the code data block;
A retransmission ratio determination unit for determining a retransmission ratio in retransmission based on the reception accuracy information and the channel information;
A feedback unit that feeds back the reception accuracy information and the retransmission ratio to the transmitter;
A receiver comprising: A transmitter and a receiver, wherein the transmitter transmits a frame including one or more data packets including one or more code data blocks to the receiver, and each code data block is associated with the code data block itself. In an automatic retransmission control method in a communication system having an inspection part,
In the receiver, the step of determining whether each code data block is correctly received by the checking portion and generating reception accuracy information reflecting whether each code data block is correctly received When,
Determining channel information of the code data block;
Feeding back the reception accuracy information and the channel information to the transmitter;
With
In the transmitter, receiving the reception accuracy information and the channel information fed back from the receiver;
Based on the received correct reception information and the channel information, determining a retransmission ratio in retransmission,
An automatic retransmission control method comprising: arranging retransmission data packets based on the retransmission ratio. A transmitter and a receiver, wherein the transmitter transmits a frame including one or more data packets including one or more code data blocks to the receiver, and the code data block is provided for each code data block. In an automatic retransmission control method in a communication system having an inspection part for itself,
In the receiver, the step of determining whether each code data block is correctly received by the checking portion and generating reception accuracy information reflecting whether each code data block is correctly received When,
Determining channel information of the code data block;
Determining a retransmission ratio in retransmission based on the reception accuracy information and the channel information;
Feeding back the reception accuracy information and the retransmission ratio to the transmitter, and
In the transmitter, receiving the reception accuracy information fed back from the receiver and the retransmission ratio;
Allocating retransmission data packets based on the retransmission ratio, and an automatic retransmission control method.

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