Data retransmission method and device

Abstract

The invention provides a data retransmission method and device, in the method, for the Yth data retransmission, the sum value of the length of initial data transmission and the length of previous (Y-1) th data retransmission can be the accumulated transmission length of data, and the switching point of IR-HARQ and CC-HARQ is determined according to the length of the Yth data retransmission and the accumulated transmission length, so that the switching point of the IR-HARQ and the CC-HARQ is determined according to the length of the Yth data retransmission and the accumulated transmission length. The coding gain can be obtained, and the low implementation complexity can be kept at the same time.

Description

Technical Field

[0001] This application relates to the field of communication technologies, and in particular, to a method and apparatus for data retransmission. Background Art

[0002] In a new radio (NR) system, retransmission is an effective method to improve the spectral efficiency of a channel. Currently, hybrid automatic repeat request (HARQ) technology is usually adopted. HARQ is divided into chase combine (CC)-HARQ and incremental redundancy (IR)-HARQ. Among them, CC-HARQ repeats part or all of the initial transmission codeword, which improves the transmission energy of the codeword bits and has a simple structure. However, since the receiving end always decodes short codes, there is no coding gain. IR-HARQ incrementally transmits the codeword bits that were not transmitted during the initial transmission and has coding gain, but the implementation is relatively complex.

[0003] Therefore, how to have coding gain and maintain a low implementation complexity during data retransmission is a hot issue in current research. Summary of the Invention

[0004] Embodiments of this application provide a method and apparatus for data retransmission, which can have coding gain and maintain a low implementation complexity during data retransmission.

[0005] To achieve the above object, this application adopts the following technical solutions:

[0006] In a first aspect, a method for data retransmission is provided. This method can be executed by a first communication device, or by a module (such as a processor, a chip, or a chip system, etc.) applied to the first communication device, or by a logical node, a logical module, or software that can implement all or part of the functions of the first communication device. For the convenience of description, the following takes the example that this method is executed by the first communication device. The method includes: for the Yth data retransmission, obtaining a first length, where the first length is the sum of the length of the initial data transmission and the lengths of the previous Y - 1 data retransmissions. Determining the Yth data retransmission manner according to the length of the Yth data retransmission and the first length.

[0007] Based on the method described in the first aspect, it can be known that for the Yth data retransmission, the sum of the length of the initial data transmission and the lengths of the previous Y - 1 data retransmissions can be the cumulative transmission length of the data. By determining the switching point between IR-HARQ and CC-HARQ according to the length of the Yth data retransmission and the cumulative transmission length, not only can coding gain be obtained, but also a low implementation complexity can be maintained.

[0008] In a possible design, when the sum of the length of the Y-th data retransmission and the first length is less than or equal to the length N of the first sequence 2 , data retransmission is performed according to the second sequence with a length of (N 2 - N 1 ); or when the sum of the length of the Y-th data retransmission and the first length is greater than N 2 , data retransmission is performed according to the bits corresponding to the second sequence and the first length; or, when the first length is greater than or equal to N 2 , data retransmission is performed according to the bits corresponding to the first length, where N 1 and N 2 are positive integers, and N 2 is greater than N 1 .

[0009] It can be understood that if the sum of the length of the Y-th data retransmission and the cumulative transmission length is less than or equal to the length of the first sequence, data retransmission is performed using the bits in the first sequence except for the initial transmission. If the sum of the length of the Y-th data retransmission and the cumulative transmission length is greater than the length of the first sequence, data retransmission is performed using the bits in the first sequence except for the initial transmission and the bits corresponding to the cumulative transmission length, which is equivalent to using IR-HARQ. If the cumulative transmission length is greater than or equal to the length of the first sequence, data retransmission is performed using the bits corresponding to the cumulative transmission length, which is equivalent to using CC-HARQ. In this way, not only can coding gain be obtained, but also a relatively low implementation complexity can be maintained.

[0010] In a possible design, data retransmission is performed according to the second sequence with a length of (N 2 - N 1 ), including: corresponding to the first data retransmission, starting data retransmission from the end position of the initial data transmission in the first sequence; or, corresponding to the Y-th data retransmission, starting data retransmission from the end position of the (Y - 1)-th data retransmission in the second sequence. That is, when performing data retransmission, bits can be selected starting from the end position of the previous transmission, which can enable decoding a longer code during decoding, having coding gain, and improving decoding accuracy.

[0011] Optionally, the length N 2 of the first sequence is the same as N times the length of the mother code corresponding to the initial data transmission, where N is a positive integer. It can be understood that if there is a puncturing operation during the initial data transmission, the length N 2 of the first sequence is the same as N times the length of the mother code corresponding to the initial data transmission. If there is no puncturing operation during the initial data transmission, the length N 2 of the first sequence is the same as N times the length of the initial data transmission. The length of the first sequence can be simply determined based only on the length of the mother code corresponding to the initial data transmission, reducing the implementation complexity.

[0012] Optionally, the length N of the first sequence 2 is determined according to the length of the mother code corresponding to the initial data transmission and the initial transmission code rate. Among them, when the initial transmission code rate is greater than the code rate threshold, the length N of the first sequence 2 is the same as M times the length of the mother code corresponding to the initial data transmission. When the initial transmission code rate is less than or equal to the code rate threshold, the length N of the first sequence 2 is the same as N times the length of the mother code corresponding to the initial data transmission, where M is a positive integer and M is greater than or equal to N. It can be understood that the length N of the first sequence 2 is related to the initial transmission code rate. The higher the initial transmission code rate, the larger N 2 is, which can avoid the reduction of communication efficiency and ensure the stability of communication.

[0013] In a possible design solution, the method described in the first aspect may further include: before retransmitting data according to the second sequence with a length of (N 2 -N 1 ), obtaining K to-be-encoded information bits. Determining K first bit positions according to the reliability sequence with a length of N 1 and determining K second bit positions according to the reliability sequence with a length of N 2 , where K is less than or equal to N 1 . According to the K to-be-encoded information bits, determining the information bits corresponding to A first bit positions among the K first bit positions. The information bits corresponding to the A second bit positions in the second sequence have a corresponding relationship with the information bits corresponding to the A first bit positions; where the A second bit positions are A bit positions among the K second bit positions.

[0014] It can be understood that this possible design solution is a way to obtain the second sequence. A part of the information bits (such as A information bits) of the to-be-encoded information bits with a length of K are simultaneously mapped to A first bit positions and A second bit positions to obtain the second sequence. Since there is a corresponding check relationship between the A first bit positions and the A second bit positions, when decoding the A second bit positions, the result has been obtained through the decoding result of the A first bit positions, which can improve the decoding performance.

[0015] In a possible design solution, the A first bit positions are determined according to the K first bit positions and the K second bit positions.

[0016] In a possible design solution, the numbers of the K first bit positions are i, and the numbers of the K third bit positions corresponding to the K first bit positions are i + N 2 -N 1 , where i is greater than or equal to 0 and i is less than or equal to N 1-1. The number of the A third - bit positions is j, and the number of the A first - bit positions is j-(N 2 -N 1 ), where j is greater than or equal to N 2 -N 1 , and j is less than or equal to N 2 -1. The A third - bit positions are the bit positions among the K third - bit positions whose numbers are different from those of the K second - bit positions.

[0017] In a possible design, the A first - bit positions are the A bit positions with relatively low reliability among the K first - bit positions.

[0018] It can be seen that the above provides three implementation schemes for determining the A first - bit positions, so that in practice, flexible selection can be made according to the actual situation.

[0019] In a possible design, the A second - bit positions are determined according to the K first - bit positions and the K second - bit positions.

[0020] In a possible design, the numbers of the K first - bit positions are i, and the numbers of the K third - bit positions corresponding to the K first - bit positions are i + N 2 -N 1 , where i is greater than or equal to 0 and i is less than or equal to N 1 -1. The A second - bit positions are the bit positions among the K second - bit positions whose numbers are different from those of the K third - bit positions.

[0021] In a possible design, the A second - bit positions are the A bit positions among the K second - bit positions whose numbers are less than N 2 -N 1 of.

[0022] It can be seen that the above provides three implementation schemes for determining the A second - bit positions, so that in practice, flexible selection can be made according to the actual situation.

[0023] In a second aspect, a data decoding method is provided. This method can be executed by a second communication device, or by a module (such as a processor, a chip, or a chip system, etc.) applied to the second communication device, or by a logical node, a logical module, or software that can implement all or part of the functions of the second communication device. For the sake of convenient description, the following takes the example that this method is executed by the first communication device. The method includes: corresponding to the Y - th data re - transmission, obtaining the information to be decoded. When the sum of the length of the Y - th data re - transmission and the first length is less than or equal to the length N of the first sequence 2 , according to the length of the received information to be decoded, obtaining the corresponding HARQ re - transmission mode. Decoding the information to be decoded according to the HARQ re - transmission mode.

[0024] It should be noted that the first length may be the cumulative transmission length, that is, the length of the information to be decoded that the second communication device has cumulatively received. When the first length is less than or equal to the length N2 of the first sequence, the information to be decoded is decoded according to the IR-HARQ retransmission method. When the first length is greater than N2, the information to be decoded is decoded according to the CC-HARQ retransmission method.

[0025] It can be understood that the related technical effects of the method in the second aspect above can also refer to the related introduction in the first aspect above, and will not be elaborated here.

[0026] In a third aspect, a communication device is provided. The communication device includes: a module for executing the method described in any one of the first aspect to the second aspect, such as a transceiver module and a processing module. For example, the transceiver module is used to indicate the transceiver function of the communication device, and the processing module is used to execute the functions of the communication device other than the transceiver function.

[0027] Optionally, the transceiver module may include a sending module and a receiving module. Among them, the sending module is used to implement the sending function of the communication device described in the third aspect, and the receiving module is used to implement the receiving function of the communication device described in the third aspect.

[0028] Optionally, the communication device described in the third aspect may further include a storage module, and the storage module stores programs or instructions. When the processing module executes the programs or instructions, the communication device can execute the method described in any one of the first aspect to the second aspect.

[0029] It can be understood that the communication device described in the third aspect may be a terminal or a network device, or may be a chip (system) or other components or assemblies that can be set in a terminal or a network device, or may also be a device including a terminal or a network device. This application does not make any limitations in this regard.

[0030] In addition, the technical effects of the communication device described in the third aspect can refer to the technical effects of the first aspect above, and will not be elaborated here.

[0031] In a fourth aspect, a communication device is provided. The communication device includes: a processor, and the processor is used to execute the method described in any one of the first aspect to the second aspect.

[0032] In a possible design, the communication device described in the fourth aspect may further include a transceiver. The transceiver may be a transceiver circuit or an interface circuit. The transceiver may be used for the communication device described in the fourth aspect to communicate with other communication devices.

[0033] In a possible design, the communication device described in the fourth aspect may further include a memory. The memory may be integrated with the processor or may be provided separately. The memory may be used to store the computer programs and / or data involved in the method described in any one of the first aspect to the second aspect.

[0034] In the embodiments of the present application, the communication device described in the fourth aspect may be the terminal or network device described in any one of the first aspect to the second aspect, or a chip (system) or other component or assembly that can be disposed in the terminal or network device, or a device including the terminal or network device.

[0035] In addition, the technical effects of the communication device described in the fourth aspect may refer to the technical effects of the method described in any one of the first aspect to the fifth aspect, which will not be elaborated here.

[0036] Fifth aspect, a communication device is provided. The communication device includes: a processor, the processor is coupled to a memory, and the processor is configured to execute a computer program stored in the memory, so that the communication device executes the method described in any one of the first aspect to the fifth aspect.

[0037] In a possible design, the communication device described in the fifth aspect may further include a transceiver. The transceiver may be a transceiver circuit or an interface circuit. The transceiver may be used for the communication device described in the fifth aspect to communicate with other communication devices.

[0038] In the embodiments of the present application, the communication device described in the fifth aspect may be the terminal or network device described in any one of the first aspect to the fifth aspect, or a chip (system) or other component or assembly that can be disposed in the terminal or network device, or a device including the terminal or network device.

[0039] In addition, the technical effects of the communication device described in the fifth aspect may refer to the technical effects of the method described in the first aspect, which will not be elaborated here.

[0040] Sixth aspect, a communication device is provided, including: a processor and a memory; the memory is used to store a computer program, and when the processor executes the computer program, the communication device is enabled to execute the method described in any one of the first aspect to the second aspect.

[0041] In a possible design, the communication device described in the sixth aspect may further include a transceiver. The transceiver may be a transceiver circuit or an interface circuit. The transceiver may be used for the communication device described in the sixth aspect to communicate with other communication devices.

[0042] In the embodiments of the present application, the communication device described in the sixth aspect may be the terminal or network device described in any one of the first aspect to the second aspect, or a chip (system), other component or assembly that can be disposed in the terminal or network device, or a device including the terminal or network device.

[0043] In addition, for the technical effects of the communication device described in the sixth aspect, reference may be made to the technical effects of the method described in any one of the first aspect to the second aspect, which will not be elaborated here.

[0044] In a seventh aspect, a communication system is provided. The communication system includes: a first communication device for executing the method described in the first aspect, and a second communication device for executing the method described in the second aspect.

[0045] In an eighth aspect, a computer-readable storage medium is provided, including: a computer program or instruction; when the computer program or instruction runs on a computer, the computer is caused to execute the method described in any one of the first aspect to the second aspect.

[0046] In a ninth aspect, a computer program product is provided, including a computer program or instruction, when the computer program or instruction runs on a computer, the computer is caused to execute the method described in any one of the first aspect to the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a schematic diagram of 8*8 polar code encoding;

[0048] Figure 2 It is a schematic diagram of the framework of the polar code provided by the embodiment of the present application Figure 1 ;

[0049] Figure 3 It is a schematic diagram of the framework of the polar code provided by the embodiment of the present application Figure 2 ;

[0050] Figure 4 It is a schematic diagram of the architecture of the communication system provided by the embodiment of the present application Figure 1 ;

[0051] Figure 5 It is a schematic diagram of the architecture of the communication system provided by the embodiment of the present application Figure 2 ;

[0052] Figure 6 It is a schematic diagram of the architecture of the communication system provided by the embodiment of the present application Figure 3 ;

[0053] Figure 7 It is a schematic diagram of the architecture of the communication system provided by the embodiment of the present application Figure 4 ;

[0054] Figure 8 Schematic diagram of the data retransmission process provided by an embodiment of the present application;

[0055] Figure 9 Schematic diagram of the circular buffer provided by an embodiment of the present application;

[0056] Figure 10 Structural schematic diagram of the communication device provided by an embodiment of the present application Figure 1 ;

[0057] Figure 11 Structural schematic diagram of the communication device provided by an embodiment of the present application Figure 2 。 Detailed implementation manners

[0058] For easy understanding, the technical terms involved in the embodiments of the present application will be introduced first below.

[0059] 1. Polar code

[0060] The polar code is the first channel coding scheme that can be strictly proven to "achieve" the Shannon channel capacity. It has characteristics such as good error correction performance and low decoding complexity. Currently, it has been determined by the 3rd Generation Partnership Project (3GPP) to be the uplink / downlink control channel coding scheme in the 5th generation (5G) enhanced mobile broadband (eMBB) scenario.

[0061] Figure 1 Schematic diagram of 8*8 polar code encoding. As Figure 1 shown, "+" represents the exclusive OR operation. The bits to be encoded are sorted according to the reliability of the corresponding bit sub-channels. Generally, the bits with higher reliability are set as information bit positions, which carry information bits in actual transmission, such as u 7 , u 6 , u 5 , u 3 are the 4 bits with higher reliability and are set as information bits. The bits with lower reliability are set as frozen bits, such as u 4 , u 2 , u 1 , u 0 are the 4 bits with lower reliability and are set as frozen bits. The values of the frozen bits are usually set to 0 and are known to both the sender and the receiver in actual transmission.

[0062] In recent years, with polar codes being included in the 5G standard, the research on polar code decoding has become a hot issue in the field of communication. Currently, the mainstream polar code decoding methods can be classified into two categories according to their decoding timing, namely sequential decoding and non-sequential decoding. Sequential decoding means that the decoder decodes according to the natural timing designed for polar codes. Non-sequential decoding means that the decoder outputs the decoding results in parallel according to other structures of polar codes (such as Tanner graph, Trellis graph, etc.). Currently, the main polar code sequential decoding algorithms include successive cancellation (SC) decoding, successive cancellation list (SCL) decoding, successive cancellation stack (SCS) decoding, and cyclic redundancy check-aided successive cancellation list (CA-SCL) decoding, etc. The non-sequential decoding methods mainly include belief propagation (BP) decoding, etc. In terms of decoding performance, SCL decoding has a great improvement compared with SC decoding. After adding CRC check, CA-SCL can make the performance of polar codes better than that of low density parity check (LDPC) codes and Turbo codes. Therefore, SCL decoding and CA-SCL decoding are mainly adopted in actual systems currently.

[0063] The following sections introduce two scenarios of hybrid automatic repeat request transmission of polar codes and polar codes supporting self-decoding respectively.

[0064] 2. Hybrid Automatic Repeat Request

[0065] Hybrid automatic repeat request (HARQ) transmission is a general technology in wireless communication. HARQ is divided into chase combine (CC)-HARQ and incremental redundancy (IR)-HARQ. In HARQ, the forward error correction (FEC) and automatic repeat request (ARQ) methods are jointly used, which can significantly improve the spectrum efficiency.

[0066] The basic working process of HARQ is as follows: First, the transmitting end sends an encoded packet as the initial transmission. The receiving end receives the symbol sequence and attempts to decode it. If the decoding is successful, the receiving end sends feedback information: the characters have been successfully received (Acknowledgement, ACK). That is, based on the feedback information, the transmitting end stops sending. If the decoding fails, the receiving end caches the received symbol sequence (or the corresponding demodulated soft information) and sends feedback information: the characters have not been successfully received (Negative Acknowledgement, NACK), or does not send a signal. When the transmitting end receives the feedback information NACK (or does not receive the ACK signal), it continues to send the re-encoded bit sequence (as incremental redundancy). The receiving end performs joint decoding using the sequences received twice.

[0067] Compared with transmitting the data in HARQ transmission in one go in multiple transmissions, HARQ allows stopping the transmission when the decoding is successfully completed in the middle, thus improving the system throughput. If the initial transmission is successful, there is no need to retransmit, which is equivalent to saving spectrum resources, that is, improving the spectrum efficiency. If the initial transmission fails, the receiving end performs joint decoding on the data received twice, and still can achieve the error correction performance of long codes.

[0068] 3. CC-HARQ

[0069] Figure 2 Figure shows a schematic diagram of CC-HARQ based on Polar codes. It can include an initial transmission sequence of length 8 (or also called U code) and a retransmission sequence of length 8 (or also called V code). The initial transmission sequence and the retransmission sequence can jointly form an encoded bit sequence of length 16. When the receiving end fails to decode, the transmitting end obtains the retransmission codeword bits by repeated transmission. The receiving end performs soft combination on the received symbols of the same encoded bit and then decodes. When decoding CC-HARQ, it is only equivalent to decoding a short code, and no additional copy bit operation is required, so the implementation is simpler. However, since the receiving end always decodes a short code, CC-HARQ only has an energy gain and does not have a coding gain, and the performance gap is relatively large from the optimal at high code rates.

[0070] 4. IR-HARQ

[0071] Figure 3The figure shows a schematic diagram of IR-HARQ based on Polar codes. It can include a first transmission sequence of length 8 (or also referred to as U code) and a retransmission sequence of length 8 (or also referred to as V code). The first transmission sequence and the retransmission sequence can be jointly combined into a coded bit sequence of length 16. In the first transmission sequence, the bit positions filled with Pattern 1 and Pattern 2 are information bit positions. In the retransmission sequence, the bit positions filled with Pattern 3 are information bit positions. There is a corresponding check between the bit positions filled with Pattern 3 and the bit positions filled with Pattern 1, that is, the same information bits are placed in the bit positions filled with Pattern 3 and their mapped bit positions filled with Pattern 1.

[0072] Based on the above Figure 3 For the Polar code described above, the receiving device can decode the first transmission sequence alone. Among them, the bit positions filled with Pattern 1 and Pattern 2 are information bit positions. If the decoding is successful, the transmitting device does not need to continue transmitting the coded bit sequence. If the decoding fails, the receiving device can jointly decode the first transmission sequence and the retransmission sequence, that is, it can decode the Polar code of length 16 jointly formed by the first transmission sequence and the retransmission sequence. Among them, the bit positions filled with Pattern 2 and Pattern 3 are information bit positions. When decoding the bit positions filled with Pattern 1, the result has been obtained through decoding the same bit positions filled with Pattern 3, and the bit positions filled with Pattern 1 become known values, which can be understood as dynamic frozen bit positions.

[0073] Through this framework, whether decoding the U code alone or jointly decoding the U code and the V code, the information bit positions are always carried on high-reliability positions, ensuring the optimal decoding performance.

[0074] It can be seen that compared with CC-HARQ, IR-HARQ is equivalent to decoding a longer code, which not only has power gain but also coding gain, but the implementation of IR-HARQ is relatively complex.

[0075] In the prior art, a method of using IR-HARQ for the first retransmission and CC-HARQ for subsequent retransmissions is adopted to combine the two. However, for the case where the resources for the first retransmission are relatively small, such a retransmission method can only obtain very little IR-HARQ gain.

[0076] In view of the above technical problems, the embodiments of the present application propose the following technical solutions.

[0077] Next, the technical solutions in the present application will be described in conjunction with the accompanying drawings.

[0078] The technical solutions of the embodiments of the present application can be applied to various communication systems, such as wireless network (Wi-Fi) systems, vehicle-to-everything (V2X) communication systems, device-to-device (D2D) communication systems, vehicle networking communication systems, fourth-generation (4G) mobile communication systems, such as long-term evolution (LTE) systems, worldwide interoperability for microwave access (WiMAX) communication systems, fifth-generation (5G), such as new radio (NR) systems, and future communication systems, etc.

[0079] In the embodiments of the present application, "indication" may include direct indication and indirect indication, and may also include explicit indication and implicit indication. If the information indicated by a certain piece of information (such as the first indication information, the second indication information, or the third indication information, etc. below) is called the information to be indicated, then in the specific implementation process, there are many ways to indicate the information to be indicated. For example, but not limited to, the information to be indicated can be directly indicated, such as the information to be indicated itself or the index of the information to be indicated, etc. The information to be indicated can also be indirectly indicated by indicating other information, where there is an association relationship between the other information and the information to be indicated. It is also possible to only indicate a part of the information to be indicated, while the other parts of the information to be indicated are known or pre-agreed. For example, the indication of specific information can also be achieved by means of the arrangement order of each piece of information pre-agreed (such as stipulated by the protocol), so as to reduce the indication overhead to a certain extent. At the same time, the common parts of each piece of information can be identified and indicated uniformly to reduce the indication overhead caused by separately indicating the same information.

[0080] In addition, the specific indication method can also be various existing indication methods. For example, but not limited to, the above indication methods and their various combinations, etc. The specific details of various indication methods can refer to the prior art and will not be elaborated herein. As can be seen from the above, for example, when it is necessary to indicate multiple pieces of information of the same type, there may be a situation where the indication methods of different information are different. In the specific implementation process, the required indication method can be selected according to specific needs. The embodiments of the present application do not limit the selected indication method. In this way, the indication methods involved in the embodiments of the present application should be understood to cover various methods that can enable the party to be indicated to obtain the information to be indicated.

[0081] It should be understood that the information to be indicated can be sent as a whole or divided into multiple sub-information and sent separately, and the sending periods and / or sending timings of these sub-information can be the same or different. The specific sending method is not limited in the embodiments of the present application. Among them, the sending periods and / or sending timings of these sub-information can be predefined, for example, predefined according to a protocol, or can be configured by the sending device by sending configuration information to the receiving device.

[0082] "Predefined" or "preconfigured" can be implemented by pre-saving corresponding codes, tables or other ways that can be used to indicate relevant information in the device. The embodiments of the present application do not limit its specific implementation method. Among them, "saving" can mean saving in one or more memories. The one or more memories can be separately provided, or can be integrated in an encoder, decoder, processor, or communication device. The one or more memories can also be partly separately provided and partly integrated in a decoder, processor, or communication device. The type of memory can be any form of storage medium, which is not limited in the embodiments of the present application.

[0083] The "protocol" involved in the embodiments of the present application can refer to a protocol family in the communication field, a standard protocol similar to the frame structure of a protocol family, or a related protocol applied to a future communication system. The embodiments of the present application do not make specific limitations on this.

[0084] In the embodiments of the present application, descriptions such as "when...", "in the case of...", "if", and "if" all mean that the device will perform corresponding processing under a certain objective situation, which does not limit time, and does not require the device to have a judgment action when implemented, nor does it mean that there are other limitations.

[0085] In the description of the embodiments of the present application, unless otherwise specified, " / " indicates that the objects associated before and after are in an "or" relationship. For example, A / B may represent A or B. The "and / or" in the embodiments of the present application is merely a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Here, A and B can be singular or plural. Also, in the description of the embodiments of the present application, unless otherwise specified, "a plurality of" means two or more than two. "At least one (item)" or its similar expression refers to any combination of these items, including any combination of a single item or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, a - b, a - c, b - c, or a - b - c, where a, b, and c can be single or multiple. Additionally, for the convenience of clearly describing the technical solutions of the embodiments of the present application, in the embodiments of the present application, terms such as "first" and "second" are used to distinguish the same items or similar items with basically the same functions and roles. Those skilled in the art can understand that terms such as "first" and "second" do not limit the quantity and execution order, and "first", "second", etc. do not necessarily mean different. At the same time, in the embodiments of the present application, words such as "exemplary" or "for example" are used to represent examples, illustrations, or explanations. Any embodiment or design solution described as "exemplary" or "for example" in the embodiments of the present application should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Exactly, using words such as "exemplary" or "for example" aims to present relevant concepts in a specific way for easy understanding.

[0086] The network architecture and service scenarios described in the embodiments of the present application are for more clearly explaining the technical solutions of the embodiments of the present application, and do not constitute a limitation to the technical solutions provided by the embodiments of the present application. Those of ordinary skill in the art know that with the evolution of the network architecture and the emergence of new service scenarios, the technical solutions provided by the embodiments of the present application are equally applicable to similar technical problems.

[0087] To facilitate the understanding of the embodiments of the present application, first, a communication system shown in Figure 4 is taken as an example to detail the communication system applicable to the embodiments of the present application. Exemplarily, Figure 4 is a schematic diagram of the architecture of a communication system applicable to the method provided by the embodiments of the present application.

[0088] The communication system may include: a first communication device and a second communication device.

[0089] The communication device can be a terminal or a network device. For example, if the first communication device is a terminal and the second communication device is a network device, or the first communication device is a network device and the second communication device is a terminal. Of course, it can also be communication between terminals or communication between network devices.

[0090] In a specific example, such as Figure 4 As shown, the communication system mainly includes at least one of the following: a terminal, and a network device, such as an access network device.

[0091] For example, a possible, non-limiting architecture of the communication system can be as Figure 5 shown. As Figure 5 shown, the communication system 10 includes a radio access network (RAN) 100, a core network (CN) 200, and the Internet 300. The RAN 100 includes at least one RAN node (such as Figure 5 110a and 110b in Figure 5 , collectively referred to as 110) and at least one terminal (such as Figure 5 120a - 120j in

[0092] collectively referred to as 120). The RAN 100 may also include other RAN nodes, for example, wireless relay devices and / or wireless backhaul devices (

[0093] Figure 5 not shown in

[0092] ). The terminal 120 is connected to the RAN node 110 wirelessly. The RAN node 110 is connected to the core network 200 wirelessly or wired. The core network devices in the core network 200 and the RAN nodes 110 in the RAN 100 may be different physical devices respectively, or may be the same physical device integrating the core network logic function and the radio access network logic function.

[0093] The RAN 100 can be a 3GPP-related cellular system, for example, a 4G or 5G mobile communication system, or an evolved system for the future (such as a 6G mobile communication system). The RAN 100 can also be an open RAN (O-RAN or ORAN), a cloud radio access network (CRAN), or a wireless fidelity (WiFi) system. The RAN 100 can also be a communication system integrating two or more of the above systems.

[0093] RAN node 110, sometimes also referred to as an access network device, RAN entity, access node, etc., forms part of a communication system and is used to assist a terminal in achieving wireless access. Multiple RAN nodes 110 in communication system 10 can be of the same type or different types. In some scenarios, the roles of RAN node 110 and terminal 120 are relative. For example, Figure 5 network element 120i can be a helicopter or a drone, which can be configured as a mobile base station. For terminals 120j accessing RAN 100 through network element 120i, network element 120i is a base station; but for base station 110a, network element 120i is a terminal. RAN node 110 and terminal 120 are sometimes both referred to as communication devices. For example, Figure 5 network elements 110a and 110b in the figure can be understood as communication devices with base station functions, and network elements 120a - 120j can be understood as communication devices with terminal functions.

[0094] In one possible scenario, the RAN node can be a base station, evolved NodeB (eNodeB), access point (AP), transmission reception point (TRP), next generation NodeB (gNB), next generation base station in a 6th generation (6G) mobile communication system, base station in a future mobile communication system, or an access node in a WiFi system, etc. The RAN node can be a macro base station (such as Figure 5 110a in the figure), a micro base station or an indoor station (such as Figure 5 110b in the figure), a relay node or a donor node, or a radio controller in a CRAN scenario. Optionally, the RAN node can also be a server, a wearable device, a vehicle or an in-vehicle device, etc. For example, the access network device in vehicle to everything (V2X) technology can be a road side unit (RSU). All or part of the functions of the RAN node in this application can also be implemented by software functions running on hardware, or by virtualized functions instantiated on a platform (such as a cloud platform). The RAN node in this application can also be a logical node, logical module or software that can implement all or part of the RAN node functions.

[0095] In another possible scenario, multiple RAN nodes cooperate to assist a terminal in achieving wireless access, and different RAN nodes respectively implement partial functions of a base station. For example, the RAN node can be a central unit (CU), a distributed unit (DU), a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU), etc. The CU and the DU can be separately provided, or can also be included in the same network element, such as a baseband unit (BBU). The RU can be included in a radio frequency device or a radio frequency unit, such as included in a remote radio unit (RRU), an active antenna unit (AAU), or a remote radio head (RRH).

[0096] In different systems, the CU (or CU-CP and CU-UP), DU, or RU can also have different names, but those skilled in the art can understand their meanings. For example, in the ORAN system, the CU can also be called an O-CU (open CU), the DU can also be called an O-DU, the CU-CP can also be called an O-CU-CP, the CU-UP can also be called an O-CU-UP, and the RU can also be called an O-RU. For the convenience of description, in this application, the CU, CU-CP, CU-UP, DU, and RU are used as examples for description. Any one of the CU (or CU-CP, CU-UP), DU, and RU in this application can be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0097] It can be understood that the above-mentioned RAN node can be a newly defined name, and the RAN node can also have different expressions, such as an access node, a network device, a wireless access node, etc., which are not limited. In this application, if there is no special description later, the network device is used for expression.

[0098] A terminal can also be referred to as a terminal device, user equipment (UE), mobile station, mobile terminal, etc. Terminals can be widely applied in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, remote healthcare, smart grid, smart furniture, smart office, smart wearables, smart transportation, smart city, etc. A terminal can be a mobile phone, tablet computer, computer with wireless transceiver function, wearable device, vehicle, drone, helicopter, airplane, ship, robot, robotic arm, smart home device, etc. The embodiments of this application do not limit the device form of the terminal.

[0099] The communication system of the embodiments of this application is applicable to coding scenarios and can be implemented through an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or software (program code in a memory). As Figure 6 shown, coding mainly involves source coding and channel coding, as well as channel decoding and source recovery parts. The specific principle can refer to the relevant technologies of 3GPP. Figure 7 is the coding process of Polar codes, which involves parts such as coding construction, outer code concatenation, bit copy, interleaving, bit mapping, coding, bit interleaving, and bit selection. Among them, the core innovation points of the embodiments of this application mainly involve coding construction and bit selection.

[0100] In this communication system, for the Yth data retransmission, the sum of the length of the initial data transmission and the lengths of the previous Y - 1 data retransmissions can be the cumulative transmission length of the data. The switching point between incremental redundancy hybrid automatic repeat request (IR-HARQ) and chase combining hybrid automatic repeat request (CC-HARQ) is determined according to the length of the Yth data retransmission and the cumulative transmission length. In this way, not only can coding gain be obtained, but also a relatively low implementation complexity can be maintained.

[0101] The embodiments of this application do not limit the device form of the network device. The device for implementing the functions of the network device can be the network device itself; it can also be a device that can support the network device to implement this function, such as a chip system. This device can be installed in the network device or used in combination with the network device. In the embodiments of this application, the chip system can be composed of chips or can also include chips and other discrete devices.

[0102] Next, it will be combined with Figures 8 - 9, the interaction process between each network element / device in the above communication system is introduced in detail through method embodiments. The data retransmission method provided in the embodiments of the present application can be applied to the above communication system and specifically applied to various scenarios / processes mentioned in the above communication system. The following is a specific introduction.

[0103] Figure 8 It is a schematic flowchart of the data retransmission method provided in the embodiments of the present application. This data retransmission method is applicable to the above communication system and mainly involves the interaction between a first communication device and a second communication device.

[0104] As Figure 8 shown, the process of this data retransmission method is as follows:

[0105] S801. For the Yth data retransmission, the first communication device obtains a first length.

[0106] Among them, the first length may be the sum of the length of the initial data transmission and the lengths of the previous Y - 1 data retransmissions, that is, the cumulative transmission length or the cumulative number of bits transmitted of the data before the Yth data retransmission. The length of the initial data transmission is less than or equal to N 1 , N 1 is a positive integer. It can be understood that N 1 may be the length of the mother code corresponding to the initial data transmission. If there is a puncturing operation on the initial transmission sequence during the initial data transmission, the length of the initial data transmission is less than N1. If there is no puncturing operation on the initial transmission sequence during the initial data transmission, the length of the initial data transmission is equal to N 1 .

[0107] S802. The first communication device determines the method of the Yth data retransmission according to the length of the Yth data retransmission and the first length.

[0108] Here, the method of the Yth data retransmission may be IR - HARQ or CC - HARQ.

[0109] In a possible design solution, S802 may include: when the sum of the length of the Yth data retransmission and the first length is less than or equal to the length N 2 of the first sequence, the first communication device performs data retransmission according to a second sequence with a length of (N 2 - N 1 ); or, when the sum of the length of the Yth data retransmission and the first length is greater than N 2 , the first communication device performs data retransmission according to the second sequence and the bits corresponding to the first length; or, when the first length is greater than or equal to N 2 , the first communication device performs data retransmission according to the bits corresponding to the first length.

[0110] Among them, N 1 and N2 is a positive integer, N 2 greater than N 1 .

[0111] It can be understood that the first sequence can be an encoded bit sequence obtained by polar code encoding according to the mother code corresponding to data retransmission, and the second sequence can be the encoded bit sequence in the first sequence except for the initial transmission sequence. Here, the first communication device determines the method of the Y-th data retransmission according to the cumulative transmission length (the first length). If the sum of the cumulative transmission length and the length of the Y-th data retransmission is less than or equal to N 2 , then the first communication device performs data retransmission according to the second sequence. If the sum of the cumulative transmission length and the length of the Y-th data retransmission is greater than N 2 , then data retransmission is performed according to the second sequence and the bits corresponding to the cumulative transmission length, which is equivalent to performing data retransmission using IR-HARQ. If the cumulative transmission length is greater than N 2 , then the first communication device performs data retransmission according to the bits corresponding to the cumulative transmission length, that is, repeats and sends the bits that have been transmitted, which is equivalent to performing data retransmission using CC-HARQ. This step is equivalent to determining the switching point between IR-HARQ and CC-HARQ according to the cumulative transmission length.

[0112] In a possible design scheme, corresponding to the first data retransmission, the first communication device starts data retransmission from the end position of the initial data transmission in the first sequence; or, corresponding to the Y-th data retransmission, the first communication device starts data retransmission from the end position of the (Y - 1)-th data retransmission in the second sequence.

[0113] It can be understood that when performing data retransmission, the first communication device can select bits starting from the end position of the previous transmission. Here, a corresponding number of bit sequences can be selected from the first sequence in reverse order for transmission.

[0114] For example, the first sequence is {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}, and the length N 2 is 16. When performing the initial data transmission, the first communication device selects the bit sequence {12, 13, 14, 15} corresponding to the initial transmission from the first sequence in reverse order and starts sending from {15} to {12}. Corresponding to the first data retransmission, the first communication device starts from the end position {12} of the initial data transmission in the first sequence and selects the bit sequence {8, 9, 10, 11} corresponding to the first retransmission from the end in reverse order for data retransmission, and so on. Corresponding to the Y-th data retransmission, the first communication device starts data retransmission from the end position of the (Y - 1)-th data retransmission in the first sequence in reverse order.

[0115] Optionally, the first communication device places the first sequence in a circular buffer, and selects a corresponding number of bit sequences from the back to the front according to the transmission resources in the circular buffer for transmission. When the bit sequences in the circular buffer are all transmitted, continue to transmit from the back to the front.

[0116] Exemplarily, as Figure 9 shown, the first communication device places the first sequence with a length of 32 in the circular buffer in a counterclockwise order. Then, according to the transmission resources in the circular buffer, select a corresponding number of bit sequences in a clockwise direction from the starting point for transmission. If 8 bits are transmitted in the initial transmission, start the first data retransmission from the 9th bit, and always start from the end position of the previous retransmission to select a corresponding number of bit sequences in a clockwise direction for transmission. For example, select the 9th to 16th bits in a clockwise direction for the first data retransmission, the 17th to 24th bits for the second data retransmission, and the 25th to 32nd bits for the third data retransmission.

[0117] In addition, if the length of the Yth data retransmission is such that the bit sequences in the circular buffer have been all transmitted, continue to select a corresponding number of bit sequences from the starting point for transmission. For example, continuing the above example, as Figure 9 shown by the dashed line in, the end position of the second data retransmission is the 24th bit in a clockwise direction. If the length corresponding to the third data retransmission exceeds 8, select the 25th to 32nd bits in a clockwise direction, and continue to select a corresponding number of bits from the starting point in a clockwise direction for the third data retransmission. Corresponding to the fourth data retransmission, at this time the cumulative transmission length is greater than the length of the first sequence, which is 32. Based on the bits of the cumulative transmission length for retransmission, continue to select a corresponding number of bit sequences from the end position of the third data retransmission for transmission, that is, the bits of the fourth data retransmission are to repeatedly transmit the bits that have been transmitted.

[0118] In a specific embodiment, when the rate matching method for the initial data transmission is shorten, then remove the bit positions corresponding to the shortened initial transmission sequence in the first sequence, and then place the first sequence after removing the bit positions in the circular buffer; otherwise, place the first sequence with a length of N 2 in the circular buffer.

[0119] It can be understood that when the rate matching method for the initial data transmission is puncture, place the first sequence with a length of N 2 in the circular buffer. At this time, the bit positions corresponding to the punctured initial transmission sequence in the first sequence are frozen.

[0120] In another specific embodiment, perform interleaving on the first sequence, and place the interleaved first sequence in the circular buffer, where the interleaving can be bit interleaving, sub-block interleaving, etc.

[0121] It can be understood that this possible design scheme provides a scheme for bit selection during data retransmission, that is, when retransmitting data, bits can be selected starting from the end position of the previous transmission, which can enable a longer code to be decoded during decoding, have coding gain, and improve decoding accuracy.

[0122] Optionally, the length N of the first sequence 2 is the same as N times the length of the mother code corresponding to the initial data transmission, where N is a positive integer.

[0123] It can be understood that the first communication device can determine the length N according to N 1 to determine the length N 2 , and this N times can be a multiple arbitrarily set according to experience or actual situation. For example, it can be 2 times, that is, N 2 = 2N 1 . In addition, if there is a puncturing operation during the initial data transmission, the length N of the first sequence 2 is the same as N times the length of the mother code corresponding to the initial data transmission. If there is no puncturing operation during the initial data transmission, the length N of the first sequence 2 is the same as N times the length of the initial data transmission, which can simply determine the length of the first sequence and reduce the implementation complexity.

[0124] Optionally, the length N of the first sequence 2 is determined according to the length of the mother code corresponding to the initial data transmission and the initial transmission code rate. Among them, when the initial transmission code rate is greater than the code rate threshold, the length N of the first sequence 2 is the same as M times the length of the mother code corresponding to the initial data transmission. When the initial transmission code rate is less than or equal to the code rate threshold, the length N of the first sequence 2 is the same as N times the length of the mother code corresponding to the initial data transmission, where M is a positive integer and M is greater than or equal to N.

[0125] Optionally, the length N of the first sequence 2 is determined according to the length of the mother code corresponding to the initial data transmission and the initial transmission code rate. Among them, when the initial transmission code rate is greater than or equal to the code rate threshold, the length N of the first sequence 2 is the same as M times the length of the mother code corresponding to the initial data transmission. When the initial transmission code rate is less than the code rate threshold, the length N of the first sequence 2 is the same as N times the length of the mother code corresponding to the initial data transmission, where M is a positive integer and M is greater than or equal to N.

[0126] It can be understood that the first communication device can determine N according to N 1 and the initial transmission code rate to determine N 2 , and the initial transmission code rate can be determined according to the length K of the information bits to be encoded and the length E1 of the initial transmission encoded bits, that is, the initial transmission code rate is If the initial transmission code rate is greater than the code rate threshold R1 , then N 2 is the same as M times of N, where M times can be any multiple set according to experience or actual situation. For example, it can be 4 times, that is, if then N 2 = 4N 1 . The value of the code rate threshold R1 can be set arbitrarily according to experience or actual situation.

[0127] Optionally, the length N of the mother code corresponding to the initial data transmission 1 can be determined according to the length K of the information bits to be encoded and the length E1 of the initial transmission encoded bits. A specific method is to reuse the current NR standard: that is, let If and then Otherwise, then

[0128] In this way, the length N of the first sequence 2 is related to the initial transmission code rate. The higher the initial transmission code rate, the larger N 2 , which can avoid the reduction of communication efficiency and ensure the stability of communication.

[0129] In a possible design solution, the method for obtaining the data retransmission may further include: before retransmitting the data according to the second sequence with a length of (N 2 - N 1 ), the first communication device acquires K information bits to be encoded. The first communication device determines K first bit positions according to the reliability sequence with a length of N 1 , and determines K second bit positions according to the reliability sequence with a length of N 2 , where K is less than or equal to N 1 . The first communication device determines the information bits corresponding to A first bit positions among the K first bit positions according to the K information bits to be encoded. The information bits corresponding to the A second bit positions in the second sequence have a corresponding relationship with the information bits corresponding to the A first bit positions; where the A second bit positions are A bit positions among the K second bit positions, A ≤ K, and A is a positive integer.

[0130] Among them, the reliability sequence can be used to indicate the reliability corresponding to each bit position of the sequence. The larger the value of the reliability, the more reliable the bit position corresponding to the reliability. The reliability sequence can be predefined by the protocol, and the first communication device can select the reliability sequence with a length of N 1 from one or more reliability sequences predefined by the protocol and the reliability sequence with a length of N 2 . If the reliability sequence is arranged in descending order of reliability, the first communication device can select the reliability sequence with a length of N 1 2 1The first K bits of the reliability sequence are taken as the K first bits, and the length is N 2 The first K bits of the reliability sequence of the first communication device are used as the K second bits. If the reliability sequence is arranged from low to high according to the reliability, the first communication device can select a length of N 1 The last K bits of the reliability sequence are taken as the K first bits, and the length is N. 2 The last K bits of the reliability sequence are used as the K second bits.

[0131] Here, the K first bits can be recorded as Indicates length N 1 The first bit set I in the sequence 1 , the I 1 The K first bits may be included. The K second bits may be recorded as Indicates length N 2 The second bit set I in the sequence 2 , the I 2 K second bits may be included. For example, K is 7, N 1 is 8, N 2 Take 16 as an example, the length is N 1 The reliability sequence {0,1,2,4,3,5,6,7} is arranged from low to high reliability. is {1,2,4,3,5,6,7}, and its length is N 2 The reliability sequence {0,1,2,4,8,3,5,9,6,10,12,7,11,13,14,15} is arranged from low to high reliability. is {10,12,7,11,13,14,15}.

[0132] The first communication device determines information bits corresponding to A first bits among the K first bits according to the K information bits to be encoded, wherein the A first bits can be determined in two specific ways, as follows:

[0133] In a first possible design, A first bits are determined based on K first bits and K second bits.

[0134] The K first bits are numbered i, and the K third bits corresponding to the K first bits are numbered i+N. 2 -N 1 , i is greater than or equal to 0, i is less than or equal to N 1 -1. The third bits of A are numbered j, and the first bits of A are numbered j-(N 2 -N 1 ), j is greater than or equal to N 2-N 1 where j is less than or equal to N 2 -1, the A third bit positions are the bit positions among the K third bit positions that have different numbers from the K second bit positions.

[0135] That is to say, the first communication device can determine the K third bit positions according to the K first bit positions, and determine the A first bit positions according to the A third bit positions among the K third bit positions.

[0136] Optionally, the K first bit positions can be denoted as the K second bit positions are denoted as It can be Add (N 2 -N 1 ) to the number i of each first bit position in to obtain the K third bit positions indicating the bit positions among the K third bit positions that have different numbers from the K second bit positions. Furthermore, it can be Subtract (N 2 -N 1 ) from the number j of each third bit position in

[0137] For example, taking K as 7, N 1 as 8, N 2 as 16 as an example, assuming the K first bit positions are {1, 2, 4, 3, 5, 6, 7}, and the K second bit positions are {10, 12, 7, 11, 13, 14, 15}. It can be Add 8 (i.e., N 2 -N 1 ) to the number i of each first bit position in to obtain the K third bit positions Furthermore, the bit position {9} among the K third bit positions that has a different number from the K second bit positions can be determined as the A third bit positions Furthermore, it can be Subtract 8 (i.e., N 2 -N 1 ) from the number j of each third bit position in

[0138] It should be noted that the above first possible design illustrates the determination method of A first bit positions by taking the definition starting from bit 0 as an example. It can be understood that when starting from bit 1, the number of the third bit position corresponding to the first bit position numbered i is i + N 2 -N 1 , 1 ≤ i ≤ N 1 . The number of the first bit position corresponding to the third bit position numbered j is j - (N 2 -N 1 ), N 2 -N 1 +1 ≤ j ≤ N 2 .

[0139] In the second possible design, the A first bit positions are the A bit positions with relatively low reliability among the K first bit positions.

[0140] Among them, the number of bit positions with numbers less than N 2 -N 1 among the K second bit positions can be determined as the specific value of A.

[0141] Exemplarily, taking K as 7, N 1 as 8, N 2 as 16 as an example, assuming that the 7 (i.e., K) second bit positions are {10, 12, 7, 11, 13, 14, 15}, then the number of bit positions with numbers less than 8 (i.e., N 2 -N 1 ) among the 7 second bit positions can be determined as 1, that is, A is equal to 1.

[0142] Exemplarily, taking K as 7, A as 1, and the determined 7 first bit positions as {1, 2, 4, 3, 5, 6, 7} as an example, assuming that the 7 first bit positions are sorted from high to low in terms of reliability as 7, 6, 5, 3, 4, 2, 1, then the A first bit positions can be determined as {1}.

[0143] It should be noted that in this second possible design, the specific value of A is illustrated by taking the definition starting from bit 0 as an example. It can be understood that when starting from bit 1, the number of bit positions with numbers less than or equal to N 2 -N 1 among the K second bit positions can be determined as the specific value of A.

[0144] The first communication device maps the information bits corresponding to the A first bit positions to A second bit positions of a third sequence with a length of (N 2 -N 1 ) to obtain a second sequence. Among them, the A second bit positions can be determined in two specific ways as follows:

[0145] In the first possible design, A second bit positions are determined based on K first bit positions and K second bit positions.

[0146] Among them, the numbers of K first bit positions are i, and the numbers of K third bit positions corresponding to the K first bit positions are i + N 2 -N 1 , where i is greater than or equal to 0 and i is less than or equal to N 1 -1. The A second bit positions are the bit positions among the K second bit positions with different numbers from the K third bit positions.

[0147] That is to say, the first communication device can determine K third bit positions according to K first bit positions, and determine A second bit positions according to the K third bit positions.

[0148] Optionally, the K first bit positions can be denoted as The K second bit positions are denoted as It can be Add (N 2 -N 1 ) to the number i of each first bit position in to obtain K third bit positions which represents the bit positions among the K second bit positions with different numbers from the K third bit positions.

[0149] For example, taking K as 7, N 1 as 8, N 2 as 16 as an example, assuming the K first bit positions are {1, 2, 4, 3, 5, 6, 7}, and the K second bit positions are {10, 12, 7, 11, 13, 14, 15}. Add 8 (i.e., N -N 2 -N 1 ) to the number i of each first bit position in to obtain K third bit positions

[0150] It should be noted that the above first possible design illustrates the determination method of A second bit positions by taking the definition starting from bit 0 as an example. It can be understood that when starting from bit 1, the number of the third bit position corresponding to the first bit position with number i is i + N 2 -N 1 , 1 ≤ i ≤ N 1 .

[0151] In the second possible design, the A second bit positions are those among the K second bit positions with numbers less than N2 -N 1 A bits of

[0152] Exemplarily, with K being 7, N 1 being 8, N 2 being 16 as an example, assuming that 7 (i.e., K) second bits are {10, 12, 7, 11, 13, 14, 15}, then it can be determined that the bits with numbers less than 8 (i.e., N 2 -N 1 ) in the 7 second bits are {7}, that is, A second bits are {7}.

[0153] It should be noted that the determination method of A second bits in this second possible design is described by taking the definition starting from bit 0 as an example. It can be understood that when the definition starts from bit 1, A second bits are A bits in the K second bits with numbers less than or equal to N 2 -N 1 .

[0154] Based on the above description of A second bits, the first communication device can map the information bits corresponding to A first bits to A second bits of a third sequence with a length of (N 2 -N 1 ) to obtain a second sequence. Among them, the first communication device can use A second bits in the third sequence with a length of (N 2 -N 1 ) as A information bit positions, and map the information bits corresponding to A first bits to A information bit positions of the third sequence. The first communication device can also set the values of N 2 -N 1 -A bit positions other than A second bits in the third sequence to 0 to obtain a second sequence.

[0155] It can be understood that this possible design scheme is a way to obtain a second sequence. A part of the information bits (such as A information bits) of the information bits to be encoded with a length of K are simultaneously mapped to A first bits and A second bits to obtain a second sequence. Since there is a corresponding check relationship between A first bits and A second bits, the decoding complexity can be reduced and the decoding performance can be improved.

[0156] S803. The second communication device receives the retransmitted data sent by the first communication device.

[0157] The retransmitted data received by the second communication device corresponds to the Y-th data retransmission, and can be information to be decoded. The information to be decoded corresponds to the sequence of the data initial transmission or data retransmission mentioned in S802.

[0158] The second communication device obtains the corresponding HARQ retransmission mode according to the length of the information to be decoded received. The information to be decoded is decoded according to the HARQ retransmission mode. It should be noted that the first length may be the cumulative transmission length, that is, the length of the information to be decoded cumulatively received by the second communication device. When the first length is less than or equal to the length N2 of the first sequence, the information to be decoded is decoded according to the IR-HARQ retransmission mode. When the first length is greater than N2, the information to be decoded is decoded according to the CC-HARQ retransmission mode.

[0159] When the sum of the length of the information to be decoded and the first length is less than or equal to the length N of the first sequence 2 the HARQ retransmission mode is IR-HARQ, and the second communication device decodes the information to be decoded according to the IR-HARQ retransmission mode; or, when the sum of the length of the information to be decoded and the first length is greater than N 2 the HARQ retransmission mode is a combination of IR-HARQ and CC-HARQ, and the second communication device decodes the information to be decoded according to IR-HARQ and CC-HARQ, that is, the bits that have been repeatedly transmitted in the length of the information to be decoded are decoded according to the CC-HARQ mode for the information to be decoded, and the bits that have not been transmitted in the length of the information to be decoded are decoded according to the IR-HARQ mode for the information to be decoded; or, when the first length is greater than or equal to N 2 the HARQ retransmission mode is CC-HARQ, and the second communication device decodes the information to be decoded according to the CC-HARQ retransmission mode, where the first length is the sum of the length of the initial data transmission and the lengths of the first Y-1 data retransmissions, N 1 and N 2 are positive integers, N 2 is greater than N 1 .

[0160] The specific implementation principle of S803 is similar to that of S801-S802 above and can be understood by reference. It will not be elaborated here.

[0161] In summary, for the Yth data retransmission, the sum of the length of the initial data transmission and the lengths of the first Y-1 data retransmissions can be the cumulative transmission length of the data. The switching point between IR-HARQ and CC-HARQ is determined according to the length of the Yth data retransmission and the cumulative transmission length. In this way, not only can coding gain be obtained, but also a relatively low implementation complexity can be maintained.

[0162] The above combines Figures 8 - 9 and details the method provided in the embodiments of the present application. The following combines Figures 10 - 11 and details the communication device for executing the method for data retransmission provided in the embodiments of the present application.

[0163] Figure 10 This is a schematic diagram of the structure of a communication device provided by an embodiment of the present application. Figure 1 Exemplarily, as Figure 10 shown, the communication device 1000 includes a transceiver module 1001 and a processing module 1002. For ease of description, Figure 10 only the main components of the communication device are shown.

[0164] Among them, the transceiver module 1001 is used to perform the transceiver function of the method shown above Figure 8 , and the processing module 1002 is used to perform other functions of the method shown above Figure 10 except for the transceiver function.

[0165] Optionally, the transceiver module 1001 may include a sending module ( Figure 10 not shown in Figure 10 ) and a receiving module (

[0166] not shown in Figure 10 ). Among them, the sending module is used to implement the sending function of the communication device 1000, and the receiving module is used to implement the receiving function of the communication device 1000. Figure 10 Optionally, the communication device 1000 may further include a storage module (

[0167] not shown in

[0168] ), and the storage module stores programs or instructions. When the processing module 1002 executes the programs or instructions, the communication device 1000 can perform the functions of the terminal or network device in the method shown above Figures 8 - 9 .

[0169] Figure 11 This is a schematic diagram of the structure of a communication device provided by an embodiment of the present application. Figure 2 Exemplarily, the communication device may be a terminal, or a chip (system) or other component or assembly that can be set in the terminal. As Figure 11As shown, the communication device 1100 may include a processor 1101. Optionally, the communication device 1100 may further include a memory 1102 and / or a transceiver 1103. Among them, the processor 1101 is coupled to the memory 1102 and / or the transceiver 1103, such as being connected through a communication bus, being connected through an on-chip interface, or being connected through other communication lines. Optionally, the memory 1102 may be integrated with the processor 1101.

[0170] The following will specifically introduce each component of the communication device 1100 in conjunction with Figure 11 :

[0171] Among them, the processor 1101 is the control center of the communication device 1100, which may be a single processor or a collective term for multiple processing elements. For example, the processor 1101 is one or more central processing units (CPUs), or may be an application specific integrated circuit (ASIC), or may be one or more integrated circuits configured to implement the embodiments of the present application, such as: one or more digital signal processors (DSPs), or one or more field programmable gate arrays (FPGAs).

[0172] Optionally, the processor 1101 may execute various functions of the communication device 1100 by running or executing software programs stored in the memory 1102 and by calling data stored in the memory 1102. For example, it may execute the Figure 8 data retransmission method shown above.

[0173] In a specific implementation, as an embodiment, the processor 1101 may include one or more CPUs, such as Figure 11 CPU0 and CPU1 shown in

[0174] In a specific implementation, as an embodiment, the communication device 1100 may also include multiple processors, such as Figure 11 the processor 1101 and the processor 1104 shown in

[0175] Among them, the memory 1102 is used to store the software program for executing the solution of this application, and is controlled by the processor 1101 for execution. The specific implementation method can refer to the above method embodiments and will not be elaborated here.

[0176] Optionally, the memory 1102 can be a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, a random access memory (RAM) or other types of dynamic storage devices that can store information and instructions, or can also be an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM), or other optical disc storage, optical disc storage (including compact discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), magnetic disk storage media, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory 1102 can be integrated with the processor 1101 or exist independently, and is coupled to the processor 1101 through the interface circuit of the communication device 1100 ( Figure 11 not shown in the figure), and the embodiments of this application do not make specific limitations on this.

[0177] The transceiver 1103 is used for communication with other communication devices. For example, when the communication device 1100 is a terminal, the transceiver 1103 can be used for communication with a network device or with another terminal device. Another example is that when the communication device 1100 is a network device, the transceiver 1103 can be used for communication with a terminal or with another network device.

[0178] Optionally, the transceiver 1103 can include a receiver and a transmitter ( Figure 11 not shown separately). Among them, the receiver is used to implement the receiving function, and the transmitter is used to implement the transmitting function.

[0179] Optionally, the transceiver 1103 can be integrated with the processor 1101 or exist independently, and is coupled to the processor 1101 through the interface circuit of the communication device 1100 ( Figure 11 not shown in the figure), and the embodiments of this application do not make specific limitations on this.

[0180] It can be understood that Figure 11The structure of the communication device 1100 shown does not limit the communication device. An actual communication device may include more or fewer components than shown, or combine certain components, or have a different component arrangement.

[0181] In addition, for the technical effects of the communication device 1100, reference may be made to the technical effects of the method described in the foregoing method embodiments, which will not be elaborated herein.

[0182] It should be understood that the processor in the embodiments of the present application may be a central processing unit (CPU), and the processor may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0183] It should also be understood that the memory in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of random access memory (RAM) are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchlink DRAM (SLDRAM), and direct rambus RAM (DR RAM).

[0184] The above embodiments can be implemented in whole or in part by software, hardware (such as circuits), firmware, or any combination thereof. When implemented using software, the above embodiments can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, the processes or functions described in the embodiments of the present application are generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (such as infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or a data center that contains one or more collections of available media. The available media can be magnetic media (such as floppy disks, hard disks, magnetic tapes), optical media (such as DVDs), or semiconductor media. The semiconductor media can be a solid-state drive.

[0185] It should be understood that the term "and / or" in this document is merely a description of the association relationship between associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Here, A and B can be singular or plural. Additionally, the character " / " in this document generally represents an "or" relationship between the associated objects before and after, but it may also represent an "and / or" relationship, which can be specifically understood by referring to the context before and after.

[0186] In the present application, "at least one" means one or more, and "a plurality" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can represent: a, b, c, a - b, a - c, b - c, or a - b - c, where a, b, and c can be single or multiple.

[0187] It should be understood that in various embodiments of the present application, the magnitudes of the sequence numbers of the above processes do not imply the order of execution. The order of execution of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0188] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of this application.

[0189] Those skilled in the art can clearly understand that for the convenience and conciseness of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments, and will not be elaborated herein.

[0190] In several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces. The indirect couplings or communication connections of devices or units can be electrical, mechanical, or other forms.

[0191] The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they can be located in one place, or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0192] In addition, the functional units in each embodiment of this application can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit.

[0193] When the above-mentioned functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of this application. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical discs that can store program codes.

Claims

1. A method for data retransmission, characterized in that, comprising: For the Y-th data retransmission, obtain a first length, where the first length is the sum of the length of the initial data transmission and the lengths of the previous Y - 1 data retransmissions; Determine the method of the Y-th data retransmission according to the length of the Y-th data retransmission and the first length.

2. The method according to claim 1, characterized in that, The step of determining the method of the Y-th data retransmission according to the length of the Y-th data retransmission and the first length includes: when the sum of the length of the Y-th data retransmission and the first length is less than or equal to the length N of the first sequence 2 perform data retransmission according to a second sequence with a length of (N 2 - N 1 ); or, When the sum of the length of the Y-th data retransmission and the first length is greater than N 2 , data retransmission is performed according to the bits corresponding to the second sequence and the first length; or, When the first length is greater than or equal to N 2 , data retransmission is performed according to the bits corresponding to the first length, where N 1 and N 2 are positive integers, and N 2 is greater than N 1 .

3. The method according to claim 2, characterized in that, The data retransmission according to the second sequence of length (N 2 -N 1 ) includes: Corresponding to the first data retransmission, start the data retransmission from the end position of the initial data transmission in the first sequence; or, Corresponding to the Y-th data retransmission, start the data retransmission from the end position of the (Y - 1)-th data retransmission in the second sequence.

4. The method according to claim 2 or 3, characterized in that, The length N of the first sequence 2 is the same as N times the length of the mother code corresponding to the initial data transmission, where N is a positive integer.

5. The method according to claim 2 or 3, characterized in that, The length N of the first sequence 2 It is determined according to the length of the mother code corresponding to the initial data transmission and the initial transmission code rate.

6. The method according to claim 5, characterized in that, When the initial transmission code rate is greater than the code rate threshold, the length N 2 of the first sequence is the same as M times the length of the mother code corresponding to the initial data transmission; When the initial transmission code rate is less than or equal to the code rate threshold, the length N of the first sequence 2 is the same as N times the length of the mother code corresponding to the initial data transmission, where M is a positive integer and M is greater than or equal to N.

7. The method according to claim 2, characterized in that, Before performing data retransmission on the second sequence with a length of (N 2 -N 1 ), the method further includes: Obtain K information bits to be encoded; Determine K first bit positions according to a reliability sequence of length N 1 and determine K second bit positions according to a reliability sequence of length N 2 , where K is less than or equal to N 1 ; According to the K information bits to be encoded, determine the information bits corresponding to A first bit positions among the K first bit positions; The information bits corresponding to A second bit positions in the second sequence have a corresponding relationship with the information bits corresponding to the A first bit positions; where the A second bit positions are A bit positions among the K second bit positions.

8. The method according to claim 7, characterized in that, The A first bit positions are determined according to the K first bit positions and the K second bit positions.

9. The method according to claim 8, characterized in that, The numbers of the K first bit positions are i, and the numbers of the K third bit positions corresponding to the K first bit positions are i + N 2 -N 1 , where i is greater than or equal to 0 and i is less than or equal to N 1 -1; the numbers of the A third bit positions are j, and the numbers of the A first bit positions are j - (N 2 -N 1 ), where j is greater than or equal to N 2 -N 1 , where j is less than or equal to N 2 -1, and the A third bit positions are the bit positions among the K third bit positions that have different numbers from the K second bit positions.

10. The method according to any one of claims 7 to 9, characterized in that, The A first bit positions are the A first bit positions with relatively low reliability among the K first bit positions.

11. The method according to any one of claims 7 to 10, characterized in that, The A second bit positions are determined according to the K first bit positions and the K second bit positions.

12. The method according to claim 11, characterized in that, The numbers of the K first bit positions are i, and the numbers of the K third bit positions corresponding to the K first bit positions are i + N 2 -N 1 , where i is greater than or equal to 0 and i is less than or equal to N 1 -1; The A second bit positions are the bit positions among the K second bit positions with different numbers from the K third bit positions.

13. The method according to any one of claims 7 to 12, characterized in that, The A second bit positions are the A bit positions among the K second bit positions whose numbers are less than N 2 -N 1 of the A bit positions.

14. A communication device, characterized in that, The device includes: a module for executing the method according to any one of claims 1 - 13.

15. A communication device, characterized in that, The communication device includes: a processor and a memory; the memory is used to store computer instructions, and when the processor executes the instructions, the method according to any one of claims 1 - 13 is executed.

16. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a computer program or instructions, and when the computer program or instructions run on a computer, the computer is made to execute the method according to any one of claims 1 - 13.

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