Detailed Description
In the embodiment of the application, the term "and/or" describes the association relation of the association objects, which means that three relations can exist, for example, A and/or B, and can mean that A exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the context-dependent object is an "or" relationship. The term "plurality" in embodiments of the present application means two or more, and other adjectives are similar.
The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments, but not all embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.
In 5G communication systems, data traffic channels are encoded using low density parity check codes (LDPC). In this coding scheme, the primary transmission data corresponds to the core coding matrix, and the retransmission data corresponds to the extension matrix. Meanwhile, to ensure the reliability of transmission, the system adopts a retransmission scheduling policy of hybrid automatic repeat request (HARQ). For example, when the transmitting end transmits data, the data is encoded according to the LDPC encoding scheme, where primary transmission data is encoded by using a core encoding matrix, and if an error occurs in the transmission process, retransmission is performed, and data during retransmission is encoded by using an extension matrix.
When decoding error occurs in the received data transmission by the terminal, the HARQ combining process is started. The terminal will save a portion of the data in the current data transmission to the buffer. For example, in one data reception, the terminal finds a decoding error, it does not discard all data directly, but stores a part of useful data. And the terminal reads the part of data from the buffer area and performs HARQ merging operation when transmitting the data next time. In the process, after the terminal performs rate de-matching and HARQ combining, the information to be processed not only contains the corresponding part of the core matrix in initial transmission, but also contains the information of the expansion matrix added in retransmission. This results in that the amount of data that the terminal needs to process at retransmission tends to be larger than at initial transmission. In the case of multiple retransmissions, the amount of data processed is up to 2-3 times the amount of data originally transmitted.
In the existing 3GPP protocol, retransmission is performed in units of Transport Blocks (TBs) or Coded Block Groups (CBGs), the number of coded blocks CBs being optionally 2, 4, 6, 8. The receiving device also processes the data according to the corresponding TB or CBG. However, the processor capabilities of the receiving device are fixed. Since the amount of data to be processed during retransmission is much larger than that during initial transmission (especially when the TB is used as a unit for retransmission, the data amount increases more significantly), there is a case that the processing capability of the receiving apparatus cannot meet the requirement. For example, the processor of the receiving device can process a certain amount of data every second, and if the amount of retransmitted data is too large, exceeding this processing capability, the data processing may be not timely, an error occurs, or the data cannot be processed.
Therefore, the application provides a method and a device for processing retransmission data, aiming at the problem that the processing data volume is increased rapidly during retransmission caused by LDPC coding characteristics and HARQ mechanisms and exceeds the processing capacity of a receiving device, so as to improve the retransmission efficiency, ensure the transmission reliability and optimize the processing performance.
Referring to fig. 1, fig. 1 is a flowchart of a processing method of retransmission data. A method of processing retransmission data, the method comprising:
S110, receiving the data of the code block of the primary transmission, recording the position information of the code block of the primary transmission code error and storing the decoding result of the code block of the primary transmission code correct.
Specifically, in receiving the encoded block data of the initial transmission, the receiving apparatus needs to identify which encoded blocks (CBs) were decoded in error at the time of the initial transmission. It is critical to record the location information of these decoding errors in the Transport Block (TB) or Coded Block Group (CBG). This facilitates targeted processing of CBs for these particular locations later, such as computing their corresponding resources. Meanwhile, for a CB that is decoded correctly in the initial transmission, the receiving device will save the decoding result. This is because it is a waste of resources if these CBs that have been decoded correctly are processed again during the retransmission process. After these results are stored, the decoding operations of these CBs can be skipped at the time of retransmission, thereby reducing the processing amount of the receiving apparatus. For example, if there are 10 CBs in the initial transmission, 6 of them are decoded correctly, and after the decoding result of these 6 CBs is saved, there is no need to re-decode these 6 CBs at the time of retransmission.
And S120, when retransmission corresponding to the primary transmission occurs, calculating time domain frequency domain resources and pilot frequency resources corresponding to the coding blocks with the primary decoding errors according to the position information of the coding blocks with the primary decoding errors and the configuration information of the retransmission, so that only the time domain frequency domain resources data and the pilot frequency data corresponding to the primary decoding errors are transmitted when data is transmitted.
Specifically, when retransmission occurs, the configuration information of the retransmission includes information such as a mode of retransmission (e.g., incremental redundancy retransmission or chase retransmission, etc.), a resource allocation strategy of retransmission (e.g., specific positions, numbers, etc. of allocated time-domain and frequency-domain resource blocks), and a relevant configuration of pilot resources (e.g., sequence, interval, etc. of pilot). By combining the position information of the coding block with the initial decoding error and the configuration information of the retransmission, after time domain frequency domain resource data and pilot frequency resources (such as DMRS) corresponding to the CB with the initial decoding error are obtained, only the resource data corresponding to the CB with the initial decoding error can be transmitted when the data is forwarded.
This reduces the amount of transmitted data in the forward direction, and thus reduces the amount of data received by the receiving device. For example, if such optimization is not performed, the entire TB or CBG data is transmitted at the time of the forward transmission, and only the data related to the erroneous CB is transmitted now, greatly reducing the processing load of the receiving device data receiving module. At the same time, this also helps to reduce the throughput of other modules of the receiving device (e.g. channel estimation module, equalization module, bit (bit) level processing module, etc.), since they only need to handle the resources associated with the primary decoding error CB, and not the resources corresponding to the entire TB or CBG.
Therefore, the steps S110 and S120 implement transmission of only the resource data corresponding to the primary decoding error during data forwarding by recording the position information of the coding block with the primary decoding error and storing the decoding result of the coding block with the correct primary decoding error, and calculating the time domain frequency domain resource and the pilot frequency resource corresponding to the coding block with the primary decoding error, thereby reducing the data receiving amount and the processing amount of the receiving device, avoiding the performance bottleneck encountered by the receiving device during retransmission, and improving the retransmission efficiency and the overall system performance.
In some embodiments, in step S120, when the retransmission corresponding to the primary transmission occurs, calculating the time domain frequency domain resource corresponding to the coding block with the primary decoding error according to the position information of the coding block with the primary decoding error and the configuration information of the retransmission includes the case that UCI is not multiplexed with data in step S121 and the case that data is multiplexed with UCI in step S122.
Specifically, in the communication system, there are two different information transmission cases of step S121 and step S122. When there is no multiplexing of UCI and data, user Control Information (UCI) and data are independently transmitted, respectively, and they occupy dedicated resources, respectively. The data allocates resources according to the data quantity, transmission requirement and the like of the UCI, for example, the UCI allocates resources according to a specific coding block resource allocation mode, and the UCI allocates resources according to a strategy based on factors such as control information type, importance and the like of the UCI. The receiving end can independently receive, process and decode the two signals, and interference or complex separation operation generated by multiplexing does not exist. When there is multiplexing of data with UCI, UCI and data are mixed and transmitted on the same physical resource in order to improve the utilization of limited radio resources. When the resources are allocated, the reasonable proportion of the two resources is considered, and the reasonable proportion is determined according to the priority, transmission requirements and other complex factors, and corresponding mapping rules are required to be formulated. The transmitting end performs multiplexing operation to transmit the two combinations, and the receiving end performs demultiplexing by using complex algorithm and technology to accurately recover the data and UCI.
S121, when the uplink control information is not multiplexed with the data, calculating the amount of resources which can be occupied by a single coding block, determining the amounts of resources occupied by different coding blocks, and determining the positions of the coding blocks in the total data resources according to the positions of the coding blocks in the transmission blocks.
Specifically, in the data retransmission process, in the configuration stage, the PHY (physical layer) calculates and records the time domain and frequency domain positions of coding blocks with decoding errors in data resources based on the mapping relationship of pre-stored Coding Blocks (CBs) in a Transport Block (TB) or a Coding Block Group (CBG) without multiplexing User Control Information (UCI) with data. The purpose of this operation is to more efficiently utilize data resources during retransmission, reducing unnecessary processing and transmission, thereby improving retransmission efficiency and system performance.
Referring to fig. 2, in the CB result of the initial transmission or retransmission NG, the CBs 1 to CB 14 are in a normal state in terms of data resources except for the decoding errors of the CBs 11, 12 and 13. And determining CB related information according to the position mapping relation of the CB 1 to the CB 14, and analyzing a time domain (related to symbol 0 to symbol 13) and a frequency domain (related to RE 0 to RE n) in the data resource. For each CB, its corresponding portion in the data resource is examined, and its specific locations in the time and frequency domains are determined.
Illustratively, said calculating the amount of resources that can be occupied by a single coded block includes:
S1211, determining the total number of data resources occupied by the user equipment D and the number of coding blocks in transmission C, and passing through the formulaCalculating the amount of resources E that can be occupied by a single code block, whereinRepresenting a rounding down operation.
In particular, in a communication system, a User Equipment (UE) occupies a certain amount of data resources when transmitting data. The total number of this data resource is denoted here by D and the units are Resource Elements (REs). The resource element is the smallest physical resource unit in wireless communication, and is specifically defined in both the time domain and the frequency domain. For example, within a particular frequency band and time interval, these resource elements are allocated to different user equipments for data transmission. During data transmission, data is divided into a plurality of Coded Blocks (CBs) for transmission. C indicates the number of encoded blocks in this transmission. For example, if a larger file is to be transmitted, divided into 10 encoded blocks, then c=10 at this time.
By the formulaThe amount of data resources that each coded block can occupy can be calculated. This facilitates accurate planning in terms of resource allocation and management. For example, if the UE occupies resources of 100 REs in total (d=100) and there are 5 CBs (c=5) in transmission, the resources that each CB can occupy are known to be 100/5=20 REs by calculation. The calculation result can be used for evaluating the rationality of each coding block on resource allocation and adjusting the number of the coding blocks or the resource allocation strategy under different transmission scenes (such as different UE demands, different network loads and the like) so as to achieve more efficient resource utilization and data transmission.
Illustratively, determining the amount of resources occupied by the different encoded blocks includes:
S1212, calculating j=mod (D, C), wherein mod represents a modulo operation, and determining the amount of resources occupied by different code blocks based on the value of j, i.e., the amount of resources occupied by the code blocks arranged in the first j is E+1, arranged in the backThe amount of resources occupied by the coded blocks of a number is E.
Specifically, on the basis of the single Coded Block (CB) resource calculation of step S1211 described above, CB resource allocation is further refined. For a total of C CBs, they are split into two parts here. The first j CBs (j is an integer less than C), each of which occupies a resource amount of e+1. This means that the first j CBs occupy 1 unit more resource than the latter CBs. And the latter C-j CBs, each occupying the amount of resources E.
The formula j=mod (D, C), i.e., the remainder of dividing D by C. For example, if d=17, c=5, then 17\div5, where remainder 2 is the result of the modulo operation, i.e., j=2.
For example, let d=17 (the total number of data resources occupied by the UE is 17 REs), and c=5 (the number of CBs in transmission is 5). First j=mod (D, C), i.e. 17\div5, is calculated so j=2. According to the above resource allocation rule, the resources occupied by the first j=2 CBs are e+1, followed byThe resource occupied by a CB is E. According toTo calculate the average occupied resources of a single CB. Then the amount of resources occupied by each of the first 2 CBs is 3+1=4 and the total amount of resources occupied by these 2 CBs is 2×4=8. The amount of resources occupied by each of the last 3 CBs is 3, and the total amount of resources occupied by these 3 CBs is 3×3=9. The total amount of resources occupied is 8+9=17, which is exactly equal to the value of D.
Illustratively, determining the position of the encoded block in the total data resource based on its position in the transport block comprises:
s1213, calculating its position in the total data resource (the total data resource is not including pilot resources) according to the position index i of the code block in the transport block:
if i is less than or equal to j, the resource position occupied by the coding block is;
If i is greater than or equal to j, the resource position occupied by the coding block is。
Specifically, the amount of resources occupied by different Coded Blocks (CBs) has been determined in step S1212 (i.e., the first j CBs occupy e+1 resources, laterE resources are occupied by CB), the specific position of CB in the total data resources is further calculated here from its position index i in the Transport Block (TB).
When i is less than or equal to j, CB whose occupied resource is expressed as the position of the total data resource is satisfied for the position index i. The calculation is based on the previously determined resource occupancy of each CB.
For example, assuming i=1, e=3, j=3, then,. This means that the location of the resources occupied by CB satisfying i.ltoreq.j for the 1 st (i=1) in the total data resource is from the 3 rd resource to the 7 th resource (here it is assumed that the resources are numbered sequentially).
When i is greater than or equal to j, when the position index i meets i is greater than or equal to j, the position of the resources occupied by CB in the total data resources is。
For example, assuming i=4, e=3, j=3, then,. This means that the location of the resources occupied by the 4 th (i=4) CB satisfying i+.j in the total data resources is from the 14 th resource to the 17 th resource.
After calculating the position of the CB in the total data resources, further calculating the data symbol index and the Resource Element (RE) index of the CB according to the resource number of each data symbol, namely determining and recording the position of the CB in the time domain and the frequency domain. For example, if each data symbol is known to contain 5 REs, and it has been determined that the position of a certain CB in the total data resources is from the 10 th resource to the 14 th resource, then the position of this CB in the time and frequency domain can be determined by calculating the index of this CB in the data symbol (such as the 2 nd to the 3 rd data symbol) and the specific index (10-14) in the RE. Such calculations and records help to accurately locate and operate each CB during data transmission, processing, and retransmission operations.
S122, when the uplink control information is multiplexed with the data, calculating the resource quantity of the uplink control information, adjusting the data resource of the user equipment, determining the resource position of the coding block, if the resource quantity of the uplink control information has the maximum value, calculating the resource positions of a plurality of groups of coding blocks to be recombined, and calculating the related resource again according to the resource quantity of the decoded control information.
Specifically, when Uplink Control Information (UCI) is multiplexed with data, the resource amount of UCI is first calculated. Due to UCI multiplexing with data, data resources of the user equipment need to be adjusted, and then a resource location of a Coding Block (CB) is determined accordingly. If the UCI resource quantity has the limit of the maximum value, a plurality of groups of CB resource positions when UCI resource quantity is measured to the maximum value are needed to be calculated respectively, and finally, the results are combined. After the receiving end decodes the UCI, the obtained UCI resource amount may be different from that of the transmitting end, and related resources are re-calculated according to the decoded UCI resource amount, for example, the data resources are re-adjusted and the resource position of the CB is re-determined, so as to improve the accuracy and reliability of the communication system.
Referring to fig. 3, in case that there is multiplexing of data with UCI (uplink control information), time and frequency domain resources of UCI need to be taken into consideration as well. In the CB result of the initial transmission or retransmission NG, other CBs except CB 11, CB 12 and CB 13 decoding errors in CB 1-CB 14 are in a normal state in terms of data resources. Two columns of symbol 0 to symbol 1 represent CSI (channel state information), two columns of symbol 2 and symbol 11 represent pilot frequencies (DMRS), symbol 3 represents ACK (acknowledgement information), and symbol 4 to symbol 9 represent that these time domain positions are not occupied by specific UCI information.
Illustratively, calculating the resource amount of the uplink control information, and determining the resource location of the coding block after adjusting the data resource of the user equipment includes:
S1221, calculating time domain and frequency domain resources of uplink control information, subtracting the resource amount U occupied by the uplink control information from the total data resources D in the process of calculating the total data resources D occupied by the user equipment to obtain the total data resources D ', and calculating the time domain and frequency domain positions of the coding blocks by using the total data resources D' to obtain the resource positions of the coding blocks.
In particular, time domain resources are typically associated with time-dependent elements, such as symbols (symbols) or the like. Calculating the time domain resources of UCI implies determining how many such units the UCI occupies in the time dimension. For example, in a wireless communication system based on Orthogonal Frequency Division Multiplexing (OFDM), a transmission period is divided into a plurality of symbols, and UCI occupies several symbols therein for transmission. The frequency domain resources are typically associated with frequency dependent elements such as sub-carriers (sub-carriers). Calculating the frequency domain resource of UCI is to determine how many subcarriers the UCI occupies in the frequency dimension.
UCI occupies a part of resources due to multiplexing of UCI and data. To obtain the amount of resources actually used for data transmission, the total number of data resources D needs to be subtracted by the amount of resources U occupied by UCI. The total number of data resources D' =d-U thus obtained represents the net amount of resources available for data transmission after the UCI occupation resources are removed.
In the time domain, the starting and ending positions of each CB in the time domain are determined according to D' and a preset rule that each CB occupies resources in the time domain (such as that each CB occupies a plurality of symbols, etc.). For example, if D' represents that the number of symbols available for data transmission is 20, each CB occupies 2 symbols in the time domain, the location of each CB in the time domain may be determined according to a certain order (e.g., sequential allocation or according to a certain priority allocation).
In the frequency domain, the starting and ending positions of each CB in the frequency domain are determined according to D' and a frequency domain resource allocation rule (such as that each CB occupies a few subcarriers, etc.). For example, if D' represents that the number of subcarriers available for data transmission is 30 and each CB occupies 3 subcarriers in the frequency domain, the location of each CB in the frequency domain may be determined in a certain order as well. By such calculation, the resource position of the encoded block is finally obtained, which is very important for the correct transmission, reception and subsequent processing (such as decoding and the like) of the data.
Further, when UCI exists CSI-part2 (in the case where CSI-part2 is a part of channel state Information (CHANNEL STATE Information)), UCI resources obtained by calculation may exist as a minimum value Umin and a maximum value Umax. This means that the amount of UCI resources occupied is not a fixed value but varies within a certain range in this particular case. For example, UCI resource requirements have different lower limits (Umin) and upper limits (Umax) depending on different channel states or system configurations due to CSI-part2 related factors.
For example, if the resource amount of the uplink control information has the maximum value, calculating the resource positions of the plurality of groups of coding blocks for recombination, and recalculating the related resources according to the resource amount of the decoded control information comprises:
S1222, if there are minimum Umin and maximum Umax in the resource amount of the uplink control information, the maximum Umax is used when calculating the time domain and frequency domain resources of the uplink control information, the minimum Umin and maximum Umax are used when calculating the total number D 'of data resources, two groups of time domain and frequency domain positions of the coding block are generated, and the two groups are combined into one group, and after the decoding of the uplink control information is completed, the resource amount U occupied by the uplink control information is obtained, and the total number D' of data resources and the time domain and frequency domain positions of the coding block are recalculated.
Specifically, the maximum value Umax is used in calculating time and frequency domain resources of UCI. This is a conservative way of computation, ensuring that the maximum resource requirement is taken into account when computing UCI resource occupancy. In the time domain, it means that the symbols or slots are calculated with the most occupied UCI, and in the frequency domain, the subcarriers are calculated with the most occupied UCI. This can avoid problems due to insufficient UCI resources in subsequent resource allocation and data transmission processes.
Referring to fig. 4, if UCI has CSI part2 (refer to fig. 4), in the CB result of the initial transmission or retransmission NG shown in fig. 4, other CBs except for the decoding errors of CB 11, CB 12, and CB 13 in CB 1-CB 14 are in a normal state in terms of data resources. Two columns of symbol 0 to symbol 1 represent CSI (channel state information), two columns of symbol 2 and symbol 11 represent pilots (DMRS), symbol 3 represents ACK (acknowledgement information), symbol 5 has a minimum value Umin, and symbol 6 has a maximum value Umax.
In calculating the total number of data resources D', Umin and Umax are required. Since the UCI resource amount varies between Umin and Umax, the influence of such variation on the data resources needs to be taken into consideration when calculating the total number of data resources D '(D' =d-U, where D is the total number of raw data resources and U is the UCI resource amount). For example, the corresponding D 'value needs to be calculated according to different values of UCI resource amount between Umin and Umax, or a weighted average manner is adopted to comprehensively consider the influence of Umin and Umax on D'.
Because Umin and Umax are involved in the calculation, there are two sets of time and frequency domain positions of the Coded Block (CB). This is because different values of UCI resource amounts (Umin and Umax) may result in different total amounts of data resources D', which in turn affects the resource location calculation of CB. For example, when calculated using Umin, the time and frequency domain positions of one set of CBs are obtained, and when calculated using Umax, the time and frequency domain positions of another set of CBs are obtained. The time and frequency domain positions of the two groups then need to be combined into one group. For example, the two sets of location information may be combined according to a certain priority or in accordance with a principle that is more advantageous for data transmission and reception, to obtain one integrated CB resource location information.
After UCI decoding is completed, an accurate value of the resource U occupied by UCI can be obtained. Since the previous estimation based on Umin and Umax in the calculation process now yields accurate U values, the time and frequency domain positions of D' and CB need to be recalculated. This step may improve the accuracy of the calculation, ensuring that subsequent calculations (e.g., data transmission, reception, processing, etc.) are based on more accurate resource allocation information. The recalculation of D ' is performed by subtracting the exact U value (D ' =d-U) from the total number of original data resources D, and then recalculating the time and frequency domain positions of CB according to the new D ', and the result of the recalculation is used for subsequent calculations.
In some embodiments, in step S120, when the retransmission corresponding to the primary transmission occurs, calculating the pilot resource corresponding to the coding block with the primary decoding error according to the position information of the coding block with the primary decoding error and the configuration information of the retransmission includes:
s123, when corresponding pilot frequency resources are calculated according to the coding block position information of the primary decoding error, the pilot frequency resources are grouped according to the number of pilot frequencies and the number of occupied symbols, and whether the pilot frequency is subjected to channel estimation and the resource position is recorded is determined according to whether the coding blocks to be processed, the recorded number of groups needing channel estimation and whether the last time and the current scheduling interval are within a preset threshold value.
Specifically, when an initial decoding error is detected, a corresponding pilot resource is calculated from the erroneous code block position information. Firstly, pilot frequency resources are grouped according to the number of pilot frequencies and the number of occupied symbols, and then whether the pilot frequency is subjected to channel estimation is determined according to whether the pilot frequency has a coding block to be processed, the number of recorded groups needing channel estimation and whether the last scheduling interval and the current scheduling interval are within a preset threshold value, and the resource positions of the pilot frequency are recorded so as to optimize the efficiency of channel estimation and data transmission.
Illustratively, step S123 includes:
s1231, performing grouping operation according to the number of pilots and the number of symbols occupied by the pilots, where the number of groupings is equal to the number of symbols divided by the number of pilots:
if the pilot frequency group has the coding block to be processed, determining the frequency domain position of the pilot frequency according to the frequency domain position of the coding block in the group, and carrying out channel estimation on the pilot frequency group and recording;
if the pilot frequency group has no data to be processed and two groups of situations needing channel estimation exist, the pilot frequency group is skipped, and corresponding pilot frequency resources do not need to be recorded;
If the pilot frequency group has no data to be processed and only one group of recorded conditions exists currently, when the interval between the last scheduling and the current scheduling is within the preset threshold range, the pilot frequency group is skipped and the corresponding pilot frequency resource is not recorded, otherwise, the resource position of the pilot frequency group is recorded.
Specifically, the pilot is a reference signal for channel estimation and demodulation. First, the number of pilots and the number of occupied symbols are grouped. The grouping number calculation formula is grouping number=symbol number/guide number. This means that the pilot resources are grouped according to their distribution in the time domain (number of symbols) and the frequency domain (number of pilots) for subsequent channel estimation and resource management.
If there is a CB (i.e., a coded block with an initial decoding error) in the pilot set that needs to be processed, then channel estimation of the set of pilots must be performed. This is because accurate channel state information needs to be acquired through channel estimation for subsequent data demodulation and retransmission operations. And determining the frequency domain position of the pilot frequency according to the frequency domain position of the CB in the group, and recording. The purpose of this is to ensure that the pilot resources are aligned with CBs that need to be processed in the frequency domain, thereby improving the accuracy of channel estimation and the success rate of data demodulation.
If there is no data to be processed in the pilot set and there are already two sets of channel estimates that must be done, the set of pilots can be skipped and the corresponding pilot resources are not recorded. This is because the system has already obtained enough channel state information through channel estimation of the other two groups, the pilot resources of the current group can be saved for other more urgent channel estimation needs.
If there is no data TO be processed in the pilot set and there is only one set of recorded channel estimation at present, but the last scheduling interval, the historical Frequency Offset (FO) and the Time Offset (TO) are all within the preset threshold range, the set of pilots can be skipped, and the corresponding pilot resources are not recorded. This is based on the stability of the historical information that no additional estimation is needed to determine the current channel state.
If the above conditions are not met (i.e., the scheduling interval, histories FO and TO are outside of the threshold range), the resource locations of the set of pilots are recorded. This is because the channel state changes and additional channel estimation is required to ensure the reliability of data transmission.
In some embodiments, the method further comprises:
When the user equipment operates the transmission of the data stream through the control stream, only the calculated time domain frequency domain resources are written in the control stream, and all the time domain frequency domain resources of the user equipment are not required to be transmitted.
Specifically, in a communication system, a receiving device has the capability to stream data through a control flow, here exemplified by C-Plane of ORAN (Open Radio Access Network, open wireless access network). The control plane is responsible for managing and controlling communication connections in the communication system, including resource allocation, connection establishment, and maintenance functions. Normally, all time domain frequency domain resource related information of a certain User Equipment (UE) needs to be transmitted. However, if the receiving apparatus has the above control flow operation capability, it is not necessary to transmit all time domain frequency domain resources of the UE. But only certain time-domain frequency-domain resources obtained through calculation, including resources of a Coding Block (CB), uplink Control Information (UCI) and pilot, need to be written in the control flow. In the forward transmission, data is transmitted between the base station and a Remote Radio Unit (RRU) or a Distributed Unit (DU). The forward packet contains various communication related information such as resource allocation information, user data, etc. The size of the forward data packet can be reduced by writing only the calculated specific time domain frequency domain resources in the control flow, instead of transmitting all the time domain frequency domain resources of the UE. This helps to improve the transmission efficiency of the forward link, reduce transmission delay, and save bandwidth resources of the forward link, thereby optimizing the performance of the overall communication system.
In some embodiments, the method further comprises:
And after the channel estimation is completed, the multi-input multi-output equalization processing and the bit level processing after the equalization is completed are operated only for the time domain and frequency domain resources corresponding to the coding block and the uplink control information.
In particular, during the data reception completion phase, channel estimation is an important operation for acquiring state information of a channel for subsequent correct processing of received data. The pilot data is a reference signal dedicated to channel estimation. Here, only the recorded pilot data is channel estimated, meaning that at this stage, not all pilot data is channel estimated, but only pilot data that has been recorded before. This has the advantage of reducing the throughput of the physical layer. The physical layer is responsible for processing transmission, reception, processing, etc. of physical signals in the communication system. If channel estimation is performed on all pilot data, a great deal of computing resources and time are consumed. By limiting the channel estimation to only the recorded pilot data, unnecessary computation can be avoided, thereby improving the processing efficiency of the physical layer.
After the channel estimation is completed, MIMO (multiple input multiple output) equalization operation starts. MIMO technology improves performance of a communication system by using multiple antennas at a transmitting end and a receiving end. The purpose of MIMO equalization is to eliminate the channel effects such as multipath fading and recover the original transmitted signal. Here, MIMO equalization processes only time and frequency domain resources corresponding to CB (code block) and UCI (uplink control information). This means that in MIMO equalization operation, not all time and frequency domain resources are processed, but resources related to CB and UCI are focused. The method is also used for reducing the processing amount of a physical layer, avoiding complex balancing operation on unnecessary resources and improving the processing efficiency.
After equalization is completed, bit (Bit) level processing is performed. Bit level processing includes operations such as demodulation, descrambling, demultiplexing of the received data to recover the original Bit information.
In some embodiments, the method further comprises:
For the coded block with correct primary decoding, the decoding operation is directly skipped during retransmission. And for the coding block with the primary decoding error, performing bit-level processing, hybrid automatic repeat request combining and decoding operation, wherein the bit-level processing comprises demodulation, descrambling, de-multiplexing and low-density parity check code decoding operation.
In particular, in a communication system, when a coded block is decoded correctly at the time of initial transmission, this means that the receiving end has successfully decoded correctly the information carried by the coded block from the received signal. In this case, if this coded block needs to be retransmitted (e.g. due to the retransmission mechanism of the system, e.g. to ensure higher reliability or to cope with interference, etc.), its decoding operation is skipped directly. This is because it is known that the initial decoding is correct and the decoding process does not need to be performed again, thereby saving computational resources and time.
When the encoded block decodes an error at the time of initial transmission, a series of operations are required to correct the error and decode it correctly. First is bit (bit) level processing, which involves a number of sub-operations:
Demodulation operation-recovering the original modulation symbols from the received signal. For example, if Quadrature Phase Shift Keying (QPSK) modulation is used, the demodulation operation is to convert the received signal into corresponding QPSK symbols.
Descrambling operation, namely removing the scrambling code added at the transmitting end for increasing the randomness of the signal. Scrambling codes are added during transmission to improve confidentiality and anti-interference capability of signals, and descrambling is needed at a receiving end to restore original data.
Demultiplexing operation-if multiple data streams are multiplexed (e.g., time division multiplexed, frequency division multiplexed, etc.) at the transmitting end, a demultiplexing operation is required at the receiving end to separate the mixed data streams into the original single data streams.
Low density parity check code (LDPC) decoding operation an LDPC code is an error correcting code by which bit errors generated during transmission are corrected.
After completing the bit level processing, hybrid automatic repeat request combining is performed. HARQ is a technique combining Forward Error Correction (FEC) and automatic repeat request (ARQ). In the retransmission process, the receiving end combines (e.g. by maximum ratio combining) the signals of the primary transmission and retransmission, so as to improve the quality of the signals and the probability of correct decoding. After the bit-level processing and HARQ combining, the decoding operation is performed again, so that it is expected that the information carried by the encoded block can be correctly decoded.
In some embodiments, the bit (bit) level processing after equalization is performed, and the operation only for the time domain and the frequency domain resources corresponding to the coding block and the uplink control information includes:
if the cyclic redundancy check result of all the coding blocks is correct, merging the primary transmission result to confirm the cyclic redundancy check result of the transmission block;
and step two, if the cyclic redundancy check error of the coding block exists in the retransmission process, combining the error results with the result stored in the previous time, and then executing the operation of the step one again to process the next retransmission.
Specifically, in a communication system, CB (coded block) is a basic unit of data transmission, and CRC (cyclic redundancy check) is a method for detecting whether an error occurs in the data transmission process. If all CBs have the result of CRC OK (i.e. cyclic redundancy check pass), this means that each coded block is not error detected during transmission. In this case, the results of the initial transmission are combined, and then a TB (transport block) CRC result confirmation is performed. TB is a larger data unit consisting of a plurality of CBs. The combining primary transmission result involves integrating the relevant information (such as relevant parameters of coding, modulation, etc.) of each CB in the primary transmission, and then performing CRC check on the whole TB to ensure the data integrity of the whole transport block. If the TB CRC also gets an OK result, a reporting operation is performed, informing the relevant network entity (e.g. base station, etc.) of the successful result. At the same time, previously saved results associated with this transmission are cleared, as the transmission has completed successfully, and there is no need to preserve these temporary results.
If there is still a CRC NG of CB during this retransmission (i.e. the cyclic redundancy check fails), this indicates that part of the encoded block is still in error during transmission. At this time, CB results that do not pass the CRC check in these retransmissions are combined with the results that were previously saved. The result of the previous save contains information about the CB in the previous transmission (the initial transmission or the previous retransmission), such as the coding scheme, the modulation scheme, and the previous CRC check result. After the result is combined, repeating the first step, i.e. performing operations such as TB CRC result confirmation based on the combined result again, so as to process the next retransmission. Thus, the transmission error can be continuously attempted to be corrected, and the probability of successful transmission of the whole transmission block is improved.
Therefore, the present application reduces the processing load, i.e., the computation and operation burden of the physical layer (e.g., baseband processing, channel estimation, equalization, etc.) and the data link layer (e.g., data reassembly, decoding, etc.) in the communication system when the CB CRC NG (i.e., the coded block cyclic redundancy check is not passed) is small.
But if all CBs are NG status, i.e. all coded blocks do not pass the CRC check during transmission. In this case, the initial transmission can be performed again by cooperating with a MAC (medium access control) layer to avoid this. The MAC layer is responsible for controlling and managing the transmission of data over the physical link, with retransmission meaning retransmission of the entire transport block in hopes of successfully passing the CRC check during the new transmission. Alternatively, the method may be performed after the total number of CBs and the number of NG CBs reach a predetermined value (i.e., a predetermined threshold value). When the total number of CBs and the number of NG CBs exceed the preset threshold value, the method for processing the retransmission data is started. This can avoid the problem that the throughput effect cannot be reduced when all CBs are NG.
The processing apparatus for retransmission data provided by the present application will be described below, and the processing apparatus for retransmission data described below and the processing method for retransmission data described above may be referred to correspondingly to each other.
Referring to fig. 5, fig. 5 is a block diagram of a processing apparatus for retransmitting data. A retransmission data processing apparatus 500 includes a primary transmission processing module 510 and a retransmission processing module 520.
Illustratively, the primary processing module 510 is configured to receive primary encoded block data, record location information of an encoded block with a primary decoding error, and store decoding results of an encoded block with a primary decoding error.
The retransmission processing module 520 is configured to calculate, when retransmission corresponding to the primary transmission occurs, time domain frequency domain resources and pilot resources corresponding to the coding block with the primary decoding error according to the position information of the coding block with the primary decoding error and the configuration information of the retransmission, so as to transmit only the time domain frequency domain resource data and the pilot data corresponding to the primary decoding error when data is transmitted.
Specifically, the processing device 500 for retransmitting data solves the problem that the LDPC coding characteristic and the HARQ mechanism cause a rapid increase in the amount of processing data at the time of retransmission and thus exceed the processing capability of the receiving device by the initial transmission processing module 510 and the retransmission processing module 520. The primary processing module 510 receives primary code block data and records code block position information of primary code errors and stores decoding results of code blocks with correct primary codes, which helps to distinguish code blocks in different states. Based on this, when the retransmission corresponding to the primary transmission occurs, the retransmission processing module 520 calculates the corresponding time domain frequency domain resource and pilot frequency resource according to the position information of the primary decoding error coding block and the configuration information of the retransmission, so that only the resource data and pilot frequency data corresponding to the primary decoding error are transmitted when the data is transmitted. The method has the advantages that by accurately positioning the related resources of the coding block with the error of the primary decoding and transmitting only the resources, unnecessary processing and transmission of the coding block with the correct primary decoding are avoided, the data quantity during retransmission is greatly reduced, the receiving device cannot exceed the processing capacity of the receiving device due to excessive data processing, the efficiency of the whole system in the retransmission process is improved, and meanwhile, the utilization of the resources is optimized.
In some embodiments, the present application further provides a receiving apparatus for retransmitting data, where the receiving apparatus includes:
the data receiving module is used for receiving the primary transmission data and the retransmission data and transmitting the received data to the data processing module;
The data processing module is used for carrying out decoding processing on the received data, judging the decoding result of the coding block, identifying the coding block with the primary decoding error, and carrying out re-decoding on the error coding block according to the retransmission data;
The storage module is used for storing the decoding result of the coding block with correct primary decoding and the position information of the coding block with incorrect primary decoding;
The resource calculation module is used for calculating time domain frequency domain resources and pilot frequency resources corresponding to the coding blocks with the initial decoding errors according to the position information of the coding blocks with the initial decoding errors and the configuration information of retransmission when retransmission occurs
It can be understood that the receiving device can execute the steps of the retransmission data processing method according to the application through the cooperative work of the data receiving module, the data processing module, the storage module and the resource calculating module, so as to realize the effective receiving and processing of the retransmission data.
For example, in a wireless communication system, the receiving device may be a base station, and receive, through an antenna, primary transmission data and retransmission data sent from a terminal device, and complete a processing flow of the retransmission data through processing of an internal module.
The receiving means of the retransmission data may also be a device or module dedicated to handling the retransmission data, designed to perform the steps of a specific retransmission data handling method. In solving the problem of the rapid increase of the retransmission data quantity caused by the LDPC coding characteristic and the HARQ mechanism, the receiving device firstly analyzes the primary transmission data according to the rule in the processing method. For example, it can identify the code blocks whose primary codes are correct and process them according to the corresponding rules, avoiding unnecessary repetition of these already correct code blocks upon retransmission. For the code block with the primary decoding error, operations such as bit level processing, resource calculation and the like can be performed according to the specified steps, and the data part needing to be retransmitted is accurately positioned and processed, rather than all data is comprehensively processed. This avoids a large number of duplicate data processing scenarios that may occur due to LDPC coding and HARQ mechanisms.
The method has the advantages that through accurate operation and effective screening of data, the data volume required to be processed during retransmission is greatly reduced, and the situation that the processing capacity of a receiving device is exceeded due to overlarge data volume is ensured. The method improves the working efficiency of the receiving device, reduces the processing time and the resource consumption, simultaneously enhances the stability and the reliability of the whole communication system in the data retransmission process, and optimizes the overall performance of the system.
It should be noted that, the processing device for retransmission data and the receiving device for retransmission data provided in the embodiments of the present application can implement all the method steps implemented in the method embodiments and achieve the same technical effects, and detailed descriptions of the same parts and beneficial effects as those of the method embodiments in the embodiments are omitted herein.
It will be apparent to those skilled in the art that various modifications and variations can be made to the present application without departing from the spirit or scope of the application. Thus, it is intended that the present application also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.