A dynamic caching method and system for hybrid automatic repeat request in a communication system

Abstract

This invention provides a dynamic caching method and system for hybrid automatic repeat request (HARQ) in a communication system, belonging to the field of caching technology. The method includes: decoding the currently transmitted coded block data; determining whether the currently transmitted coded block data is initial transmission data when a decoding error occurs; and outputting a first cache request information when the coded block data is initial transmission data and a decoding error occurs. The first cache request information includes the cache capacity after rate matching of the decoded erroneous coded block data. Beneficial effects: By adopting a dynamic HARQ buffer size allocation strategy, the problems of memory waste and excessive power consumption that may occur under traditional fixed HARQ buffer sizes are effectively solved. By dynamically allocating HARQ buffer size for decoded erroneous code blocks, not only can more efficient memory usage be achieved, but also the read and write operations of the HARQ buffer can be reduced, further saving power consumption and improving the overall system performance.

Description

Technical Field

[0001] This invention relates to the field of caching technology, and in particular to a dynamic caching method and system for hybrid automatic retransmission requests in a communication system. Background Technology

[0002] Hybrid Automatic Repeat Request (HARQ) is a crucial retransmission merging technique in communication systems, particularly prevalent in 5G wireless communication. For instance, 5G networks can configure up to 16 HARQ processes using PDSCH, and in Release 17, this number was expanded to 32. Each HARQ process needs to support retransmission merging with a maximum redundancy version (RV) of 4. For 5G systems supporting ultra-high-order modulation schemes like 1024QAM and up to 100MHz bandwidth, this requires a significant amount of storage space for each soft bit (Log-Likelihood Ratio, LLR) output from each CB decoder in each HARQ process. This presents a substantial challenge in terms of chip area, cost, and power consumption.

[0003] In the 5G New Radio (NR) protocol, the Physical Downlink Shared Channel (PDSCH) can support up to 32 HARQ processes, each of which needs to support retransmission merging. Each HARQ process contains a large number of Code Blocks (CBs). The circular buffer size (or buffer capacity) for retransmission merging of each CB is Ncb (according to protocol 38.212). Therefore, the static HARQ buffer size required for a single HARQ process is Max CB number * MaxNcb * LLR bit width; where Max Ncb is the maximum value among all possible configuration scenarios, and Max CB number is the maximum bandwidth, i.e., the number of CBs when scheduling the maximum Modulation and Coding Scheme (MCS). These are static parameters. Each decoding operation outputs a soft bit to the corresponding soft bit position of the corresponding CB in the HARQ buffer.

[0004] Existing technologies optimize the Max CB number by storing only the soft bits of CB blocks that have been decoded incorrectly, and not storing them when the decoding is successful. However, this method still has its limitations. This static allocation of cache capacity means that a fixed amount of storage space will be allocated to each CB regardless of whether the decoding is successful or not. This leads to a certain degree of waste of storage space, especially when the decoding is successful.

[0005] Existing technologies do not offer optimization solutions for the characteristics of HARQ buffers and the features of data retransmitted each time after rate matching. Summary of the Invention

[0006] To address the above technical problems, this invention provides a dynamic caching method and system for hybrid automatic retransmission requests in a communication system.

[0007] The technical problem solved by this invention can be achieved by the following technical solutions:

[0008] A first aspect of the present invention is to provide a dynamic caching method for hybrid automatic repeat request in a communication system, comprising:

[0009] Decode the currently transmitted coded block data;

[0010] In the event of a decoding error, determine whether the currently transmitted coded block data is the initial transmission data;

[0011] When the encoded block data is initial transmission data and decoding error occurs, a first cache request information is output. The first cache request information includes the cache capacity after rate matching of the decoded encoded block data.

[0012] Preferably, it further includes:

[0013] When the encoded block data is the initial transmission data and the decoding is correct, the cache request process exits and enters the decoding process for the next transmitted encoded block data.

[0014] Preferably, it further includes:

[0015] When the encoded block data is retransmitted data and the decoding is incorrect, a second buffer request information is output according to the current retransmission count. The second buffer request information includes the buffer capacity of the intersection of the initial data and the retransmitted data corresponding to each retransmission count after rate matching.

[0016] Preferably, it further includes:

[0017] When the current number of retransmissions reaches the set retransmission threshold and a decoding error occurs, exit the cache request process and release the cache of the currently transmitted encoded block data.

[0018] Preferably, it further includes:

[0019] When the encoded block data is retransmitted data and the decoding is correct, exit the cache request process and release the cache of the currently transmitted encoded block data.

[0020] A second aspect of the present invention is to provide a dynamic caching system for hybrid automatic repeat request in a communication system, comprising:

[0021] The decoding module is used to decode the currently transmitted coded block data.

[0022] The judgment module, connected to the decoding module, is used to determine whether the currently transmitted coded block data is the initial transmission data when a decoding error occurs.

[0023] The first cache request module, connected to the judgment module, is used to output a first cache request information when the encoded block data is initial transmission data and the decoding is incorrect. The first cache request information includes the cache capacity after rate matching of the encoded block data with decoding errors.

[0024] Preferably, the decoding module is further configured to: exit the cache request process and proceed to the decoding process of the next transmitted code block data when the encoded block data is the initial transmission data and the decoding is correct.

[0025] Preferably, it further includes:

[0026] The retransmission count determination module, connected to the judgment module, is used to determine the current retransmission count when the encoded block data is retransmitted data and the decoding is incorrect;

[0027] The second cache request module, connected to the retransmission count determination module, is used to output a second cache request information based on the current retransmission count. The second cache request information includes the cache capacity of the intersection of the initial transmission data and the retransmission data corresponding to each retransmission count after rate matching.

[0028] Preferably, it further includes:

[0029] The first release module, connected to the retransmission count determination module, is used to exit the cache request process and release the cache of the currently transmitted encoded block data when the current retransmission count reaches a set retransmission count threshold and a decoding error occurs.

[0030] Preferably, it further includes:

[0031] The second release module is used to exit the cache request process and release the cache of the currently transmitted encoded block data when the encoded block data is retransmitted data and the decoding is correct.

[0032] The advantages or beneficial effects of the technical solution of this invention are as follows:

[0033] This invention effectively solves the problems of memory waste and excessive power consumption that may occur under the traditional fixed HARQ buffer size by adopting a dynamic HARQ buffer size allocation strategy. By dynamically allocating the HARQ buffer size for code blocks with decoding errors, not only can more efficient memory use be achieved, but also the read and write operations of the HARQ buffer can be reduced, further saving power consumption and improving the overall performance of the system. Attached Figure Description

[0034] Figure 1 This is a flowchart illustrating the dynamic caching method in a preferred embodiment of the present invention.

[0035] Figure 2 This is a schematic diagram of the overall process of implementing the dynamic caching method in a preferred embodiment of the present invention;

[0036] Figure 3 This is a schematic diagram of a dynamically cached HARQ buffer in a preferred embodiment of the present invention;

[0037] Figure 4 This is a block diagram of the dynamic caching system in a preferred embodiment of the present invention. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0040] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the scope of the invention.

[0041] See Figure 1 In a preferred embodiment of the present invention, based on the above-mentioned problems existing in the prior art, a dynamic caching method for hybrid automatic repeat request in a communication system is provided, comprising:

[0042] S1, decode the currently transmitted coded block data;

[0043] S2, when a decoding error occurs, determines whether the currently transmitted coded block data is the initial transmission data;

[0044] S3, when the encoded block data is the initial transmission data and the decoding is incorrect, output a first cache request information, which includes the cache capacity after rate matching of the encoded block data with decoding errors.

[0045] Specifically, the static allocation of cache capacity in existing technologies means that a fixed amount of storage space will be allocated to each CB regardless of whether the decoding is successful or not. Especially when the decoding is successful, this cache request method leads to a certain degree of waste of storage space.

[0046] In the decoding process, this invention determines the size of the requested HARQ buffer based on the current decoding error data. By dynamically allocating the HARQ buffer size for the decoded code blocks, not only can more efficient memory usage be achieved, but also the read and write operations of the HARQ buffer can be reduced, further saving power consumption and improving the overall system performance. By adopting a dynamic HARQ buffer size allocation strategy, the problems of memory waste and excessive power consumption that may occur under the traditional fixed HARQ buffer size are effectively solved.

[0047] In a preferred embodiment, such as Figure 2 As shown, it also includes:

[0048] If the encoded block data is the initial transmission data and the decoding is correct, exit the cache request process and proceed to the decoding process of the next transmitted encoded block data.

[0049] Specifically, in existing technologies, a HARQ buffer is allocated to each CB regardless of whether the decoding is successful or not, resulting in a waste of storage space. In this embodiment, for each CB, if the decoding is correct on the first transmission, the processing flow of the next CB can be directly entered without applying for a HARQ buffer or saving the decoding soft bits, thereby reducing the resource occupation of the correctly decoded CB and saving network resources.

[0050] In a preferred embodiment, such as Figure 2 As shown, it also includes:

[0051] When the encoded block data is retransmitted data and the decoding is incorrect, a second buffer request information is output according to the current retransmission count. The second buffer request information includes the buffer capacity of the intersection of the initial data and the retransmitted data corresponding to each retransmission count after rate matching.

[0052] Specifically, in this embodiment, if the initial data decoding fails, the HARQ process is entered to retransmit the current CB. If the retransmitted data still fails to decode, a specific operation is performed: the soft bit size obtained after rate matching of the initial data is obtained; the soft bit size obtained after rate matching of the retransmitted data for each retransmission number is obtained; the two are merged, and the buffer capacity of the intersection of the merged data is used as the size of the HARQ buffer for this request.

[0053] It should be noted that, see Figure 3 Intersection refers to merging the overlapping parts of the buffer, which avoids repeated calculations and prevents duplicate requests for cache from consuming buffer resources that would otherwise be useless, thus saving resources.

[0054] In a preferred embodiment, such as Figure 2 As shown, it also includes:

[0055] When the current number of retransmissions reaches the set retransmission threshold and a decoding error occurs, exit the cache request process and release the cache of the currently transmitted encoded block data.

[0056] It should be noted that the retransmission threshold can be set according to actual needs. Generally, a retransmission threshold of 4 times is sufficient to support a maximum redundancy version RV=4.

[0057] In a preferred embodiment, such as Figure 2 As shown, it also includes:

[0058] If the encoded block data is retransmitted data and the decoding is correct, exit the cache request process and release the cache of the currently transmitted encoded block data.

[0059] Specifically, in this embodiment, if the retransmitted data is decoded correctly, the current CB processing flow ends, there is no need to save the soft bits of this retransmission and merging, and the current CB's HARQ buffer is released.

[0060] Furthermore, according to the cyclic buffer Ncb after PDSCH channel rate matching in the downlink (DL) of the NR system, it is divided into 4 blocks according to the RV version, such as... Figure 3 The transmission is performed in four steps: RV0, RV1, RV2, and RV3.

[0061] Unlike existing technologies that directly request the size of the HARQ buffer based on the size of Ncb, and then store the soft bits transmitted each time according to their corresponding positions in Ncb, the length of the data transmitted to LDPC for decoding is fixed at Ncb.

[0062] The overall process of the dynamic caching method in this embodiment of the invention is as follows: Figure 2 As shown, by optimizing the static Ncb HARQbuffer size to dynamically allocate the HARQ buffer, and with the data length transmitted to the LDPC decoder also being dynamic, the LDPC decoder automatically pads the missing data portion, thus solving the problem of excessively large HARQ buffer memory size caused by the original static HARQbuffer size. The specific steps for each CB in each HARQ process are as follows:

[0063] Step A1: Initial data decoding:

[0064] If the initial data is decoded correctly, the buffer request process exits and the decoding process of the next transmitted coded block data begins. At this point, there is no need to request a HARQ buffer or save the decoded soft bits, and the process directly enters the next CB processing flow.

[0065] If the initial data decoding is incorrect, then apply for a HARQ buffer based on the size (denoted as E1) after matching the initial CB rate.

[0066] Step A2: Decode the first retransmitted data. This involves combining the soft bits E2 from the first retransmitted data with the initial soft bits E1 stored in the HARQ buffer and then sending the combined data to the LDPC decoder for decoding. Any missing data portions are automatically padded by the LDPC decoder.

[0067] If the first retransmitted data is decoded correctly, the buffer request process is exited and the buffer of the currently transmitted coded block data is released. At this point, the current CB processing flow ends, and there is no need to request a HARQ buffer or save the decoded soft bits of this merge. The process then proceeds directly to the next CB processing flow.

[0068] If the first retransmission data is decoded incorrectly, the intersection of the soft bit size after the initial CB rate matching (denoted as E1) and the soft bit size after the first retransmission CB rate matching (denoted as E2) is used as the size of the second HARQbuffer request (the union of E1 and E2), and the merged soft bits are saved.

[0069] Furthermore, by increasing the size of the HARQ buffer based on the first request, and merging the overlapping parts of soft bits during the merging process, the duplicate calculations are avoided, thus preventing the buffer resources occupied by useless data due to repeated cache requests and saving resources.

[0070] Furthermore, from Figure 3As can be seen, the size of E1 is much smaller than Ncb. Moreover, according to the protocol's requirements for the bit error rate of the UE terminal, in most scenarios, only one retransmission and merging is generally sufficient for correct decoding. In this embodiment of the invention, the method of requesting a HARQ buffer based on the decoding result eliminates the need for a second HARQ buffer request and a second storage and read / write of soft bits if decoding fails once and is successfully retransmitted, thus greatly reducing the consumption of buffer resources.

[0071] Step A3: Decoding the second retransmitted data. The soft bit E3 from the second retransmission is combined again with the soft bits (the union of E1 and E2) stored in the HARQ buffer and sent to the LDPC decoder for decoding. For any missing data portions, the LDPC decoder automatically pads them.

[0072] If the second retransmitted data is decoded correctly, the buffer request process is exited and the buffer of the currently transmitted coded block data is released. At this point, the current CB processing flow ends, and there is no need to request a HARQ buffer or save the decoded soft bits of this merge. The process then proceeds directly to the next CB processing flow.

[0073] If the second retransmission data is decoded incorrectly, the size of the third HARQ buffer (the union of E1, E2, and E3) is determined by merging the soft bit size after matching the initial CB rate (denoted as E1), the soft bit size after matching the first CB rate (denoted as E2), and the soft bit size after matching the second CB rate (denoted as E3), and the merged soft bits are saved.

[0074] Furthermore, by increasing the size of the HARQ buffer based on the second application, and merging the overlapping parts of soft bits during the merging process, the duplicate calculations are avoided, thus preventing the buffer resources occupied by useless data due to repeated cache requests and saving resources.

[0075] Step A3: The third retransmission data is decoded. The soft bit E4 from the third retransmission is combined again with the soft bits (the union of E1, E2, and E3) stored in the HARQ buffer and sent to the LDPC decoder for decoding. Any missing data portions are automatically padded by the LDPC decoder.

[0076] If the third retransmitted data is decoded correctly, the buffer request process is exited and the buffer of the currently transmitted coded block data is released. At this point, the current CB processing flow ends, and there is no need to request a HARQ buffer or save the decoded soft bits of this merge. The process then proceeds directly to the next CB processing flow.

[0077] If the third retransmission data is decoded incorrectly, the current CB retransmission decoding is the last retransmission, and there is no need to request a HARQ buffer or save the decoded soft bits of this merge.

[0078] The advantage of this embodiment is that it dynamically allocates the buffer size for merging data based on the number of merging operations, effectively solving the problem of excessively large HARQ buffer memory size caused by the previously static and unchanging HARQ buffer size. Furthermore, considering that in real-world networks, a large number of retransmissions only require merging once, meaning that in most scenarios only a small amount of buffer is needed to meet the merging requirements, this embodiment provides a more economical and efficient solution.

[0079] Example 2

[0080] See Figure 4 This invention provides a dynamic caching system for hybrid automatic retransmission requests in a communication system, comprising:

[0081] Decoding module 1 is used to decode the currently transmitted coded block data;

[0082] Judgment module 2, connected to decoding module 1, is used to determine whether the currently transmitted coded block data is the initial transmission data when a decoding error occurs;

[0083] The first cache request module 3 and the connection judgment module 2 are used to output a first cache request information when the encoded block data is the initial transmission data and the decoding is incorrect. The first cache request information includes the cache capacity after rate matching of the encoded block data with decoding errors.

[0084] Specifically, the static allocation of cache capacity in existing technologies means that a fixed amount of storage space will be allocated to each CB regardless of whether the decoding is successful or not. Especially when the decoding is successful, this cache request method leads to a certain degree of waste of storage space.

[0085] In the decoding process, this invention determines the size of the requested HARQ buffer based on the current decoding error data. By dynamically allocating the HARQ buffer size for the decoded code blocks, not only can more efficient memory usage be achieved, but also the read and write operations of the HARQ buffer can be reduced, further saving power consumption and improving the overall system performance. By adopting a dynamic HARQ buffer size allocation strategy, the problems of memory waste and excessive power consumption that may occur under the traditional fixed HARQ buffer size are effectively solved.

[0086] In a preferred embodiment, the decoding module 1 is further configured to: exit the cache request process and proceed to the decoding process of the next transmitted code block data when the encoded block data is the initial transmitted data and the decoding is correct.

[0087] Specifically, in existing technologies, a HARQ buffer is allocated to each CB regardless of whether the decoding is successful or not, resulting in a waste of storage space. In this embodiment, for each CB, if the decoding is correct on the first transmission, the processing flow of the next CB can be directly entered without applying for a HARQ buffer or saving the decoding soft bits, thereby reducing the resource occupation of the correctly decoded CB and saving network resources.

[0088] In a preferred embodiment, it further includes:

[0089] The retransmission count determination module 4 is connected to the judgment module 2 and is used to determine the current retransmission count when the encoded block data is retransmitted data and the decoding is incorrect.

[0090] The second cache request module 5 is connected to the retransmission count determination module 4. It is used to output a second cache request information based on the current retransmission count. The second cache request information includes the cache capacity of the intersection of the initial transmission data and the retransmission data corresponding to each retransmission count after rate matching.

[0091] Specifically, in this embodiment, if the initial data decoding fails, the HARQ process is entered to retransmit the current CB. If the retransmitted data still fails to decode, a specific operation is performed: the soft bit size obtained after rate matching of the initial data is obtained; the soft bit size obtained after rate matching of the retransmitted data for each retransmission number is obtained; the two are merged, and the buffer capacity of the intersection of the merged data is used as the size of the HARQ buffer for this request.

[0092] In a preferred embodiment, it further includes:

[0093] The first release module 6 is connected to the retransmission count determination module 4. It is used to exit the cache request process and release the cache of the currently transmitted encoded block data when the current retransmission count reaches the set retransmission count threshold and a decoding error occurs.

[0094] Specifically, in this embodiment, if the number of retransmissions of the current CB reaches the set retransmission threshold, then the retransmission decoding of the current CB is the last retransmission. If the last retransmission still results in a decoding error, then there is no need to increase the HARQ buffer allocation size, nor is it necessary to save the decoded soft bits of this merge. The buffer of the currently transmitted coded block data is directly released, and the processing flow of the current CB ends.

[0095] In a preferred embodiment, it further includes:

[0096] The second release module 7 is used to exit the cache request process and release the cache of the currently transmitted encoded block data when the encoded block data is retransmitted data and the decoding is correct.

[0097] Specifically, in this embodiment, if the retransmitted data is decoded correctly, the current CB processing flow ends, there is no need to save the soft bits of this retransmission and merging, and the current CB's HARQ buffer is released.

[0098] The advantages or beneficial effects of adopting the above technical solution are as follows: By adopting a dynamic HARQ buffer size allocation strategy, the present invention effectively solves the problems of memory waste and excessive power consumption that may occur under the traditional fixed HARQ buffer size; by dynamically allocating the HARQ buffer size for code blocks with decoding errors, not only can more efficient memory use be achieved, but also the read and write operations of the HARQ buffer can be reduced, further saving power consumption and improving the overall performance of the system.

[0099] The above are merely preferred embodiments of the present invention and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should recognize that any equivalent substitutions and obvious changes made using the content of this specification and illustrations should be included within the protection scope of the present invention.

Claims

1. A dynamic caching method for hybrid automatic repeat request in a communication system, characterized in that, include: Decode the currently transmitted coded block data; In the event of a decoding error, determine whether the currently transmitted coded block data is the initial transmission data; When the encoded block data is initial transmission data and the decoding is incorrect, a first cache request information is output. The first cache request information includes the cache capacity after rate matching of the decoded encoded block data. When the encoded block data is retransmitted data and the decoding is incorrect, a second buffer request information is output according to the current retransmission count. The second buffer request information includes the buffer capacity of the intersection of the initial data and the retransmitted data corresponding to each retransmission count after rate matching.

2. The dynamic caching method for hybrid automatic repeat request in a communication system according to claim 1, characterized in that, Also includes: When the encoded block data is the initial transmission data and the decoding is correct, the cache request process exits and enters the decoding process for the next transmitted encoded block data.

3. The dynamic caching method for hybrid automatic repeat request in a communication system according to claim 1, characterized in that, Also includes: When the current number of retransmissions reaches the set retransmission threshold and a decoding error occurs, exit the cache request process and release the cache of the currently transmitted encoded block data.

4. The dynamic caching method for hybrid automatic repeat request in a communication system according to claim 1, characterized in that, Also includes: When the encoded block data is retransmitted data and the decoding is correct, exit the cache request process and release the cache of the currently transmitted encoded block data.

5. A dynamic caching system for hybrid automatic repeat request in a communication system, characterized in that, include: The decoding module is used to decode the currently transmitted coded block data. The judgment module, connected to the decoding module, is used to determine whether the currently transmitted coded block data is the initial transmission data when a decoding error occurs. The first cache request module, connected to the judgment module, is used to output a first cache request information when the encoded block data is initial transmission data and the decoding is incorrect. The first cache request information includes the cache capacity after rate matching of the decoded encoded block data. The retransmission count determination module, connected to the judgment module, is used to determine the current retransmission count when the encoded block data is retransmitted data and the decoding is incorrect; The second cache request module, connected to the retransmission count determination module, is used to output a second cache request information based on the current retransmission count. The second cache request information includes the cache capacity of the intersection of the initial transmission data and the retransmission data corresponding to each retransmission count after rate matching.

6. The dynamic caching system for hybrid automatic repeat request in a communication system according to claim 5, characterized in that, The decoding module is also used to: when the encoded block data is the initial transmission data and the decoding is correct, exit the cache request process and enter the decoding process for the next transmission of encoded block data.

7. The dynamic caching system for hybrid automatic repeat request in a communication system according to claim 5, characterized in that, Also includes: The first release module, connected to the retransmission count determination module, is used to exit the cache request process and release the cache of the currently transmitted encoded block data when the current retransmission count reaches a set retransmission count threshold and a decoding error occurs.

8. The dynamic caching system for hybrid automatic repeat request in a communication system according to claim 5, characterized in that, Also includes: The second release module is used to exit the cache request process and release the cache of the currently transmitted encoded block data when the encoded block data is retransmitted data and the decoding is correct.

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