Random access communication method with time slot merging mechanism and random access communication device

Abstract

The present application discloses a random access communication method and a random access communication device with a time slot merging mechanism. The random access communication method includes the following specific steps: setting random access parameters; determining the number of copies of the copy and the time slot parameters of the time slot corresponding to the copy according to the random access parameters; generating header bits and payload bits according to the random access parameters, the number of copies, and the time slot parameters; generating a transmission symbol sequence and sending the transmission symbol sequence according to the random access parameters, the header bits, and the payload bits; receiving the transmission symbol sequence to obtain access frame data; performing time slot merging and interference elimination operations on the access frame data to complete the reception of the access frame data. The present application improves the throughput performance under low signal-to-noise ratio by utilizing potential repetition gain.

Description

Technical Field

[0001] The present application relates to the technical field of random access algorithms for Internet of Things and machine type communications, and in particular to a random access communication method and a random access communication device with a time slot merging mechanism. Background Art

[0002] Compared with authorized communication, random access communication does not require complex signaling control and scheduling processes, and has advantages in scenarios with a large number of terminals and dynamic changes in terminal device groups. Since there are conflicts and competitions among terminal groups on channel resources in random access communication methods, designing high-throughput random access methods has become the focus of research in this field.

[0003] Irregular Repetition Slotted ALOHA (IRSA) is a practical and effective random access method. It is an extension of Collision Resolution Diversity Slotted ALOHA (CRDSA). It uses the progressive performance analysis based on AND-OR trees and the differential evolution algorithm to obtain the optimized probability distribution. The transmitter selects the number of replicas according to the probability density distribution, and the receiver performs the interference elimination process frame by frame. The IRSA algorithm shows good throughput performance.

[0004] In the process of implementing the prior art, the inventor discovered that:

[0005] In the IRSA algorithm, a wireless frame contains multiple copies from the same terminal, so there is potential repetition gain. However, since the IRSA algorithm can only obtain the location information of the copies after correctly demodulating and decoding the information bits, these repetition gains cannot be utilized. Under low signal-to-noise ratio, the throughput of the IRSA random access algorithm is seriously deteriorated.

[0006] Therefore, it is necessary to provide an irregularly repeated time slot ALOHA scheme with a time slot merging mechanism, and to make full use of the repetition gain to improve the throughput performance of the IRSA algorithm under low signal-to-noise ratio. Summary of the invention

[0007] The embodiment of the present application provides a technical solution for the decoding and demodulation process by proposing a new bit stream structure to be modulated, a dual modulation and coding strategy mechanism, and a time slot merging and interference elimination mechanism, so as to solve the technical problem that the throughput rate of the IRSA random access algorithm is seriously deteriorated under low signal-to-noise ratio.

[0008] The present application provides a random access communication method with a time slot merging mechanism, comprising the following specific steps:

[0009] Set random access parameters;

[0010] Determine, according to the random access parameter, the number of copies of the copy and the time slot parameter of the time slot corresponding to the copy;

[0011] Generate a header bit and a payload bit according to the random access parameter, the number of copies, and the time slot parameter;

[0012] Generate a transmission symbol sequence according to the random access parameter, the header bit, and the payload bit, and send the transmission symbol sequence;

[0013] Receiving the transmission symbol sequence to obtain access frame data;

[0014] Perform time slot merging and interference elimination operations on the access frame data to complete the reception of the access frame data.

[0015] Furthermore, the random access parameters include the maximum number of copies, the probability distribution of the number of copies, the bit length of the identity identification number, the bit length of the location information of a single copy, the header bit coding efficiency, the header bit modulation order, the payload bit coding efficiency, and the payload bit modulation order.

[0016] Further, determining the number of copies of the copy and the time slot parameter of the time slot corresponding to the copy according to the random access parameter includes the following specific steps:

[0017] Randomly select the number of copies of the copy according to the maximum number of copies and the probability distribution of the number of copies;

[0018] Randomly selecting a number of time slots corresponding to the number of replicas to obtain time slot parameters of the time slots;

[0019] The time slot parameters include the number of time slots of the time slots and the time slot number of each time slot in the time slots.

[0020] Further, generating header bits and payload bits according to the random access parameter, the number of copies, and the time slot parameter includes the following specific steps:

[0021] Randomly selecting an identity number according to the bit length of the identity number;

[0022] Arrange the time slot numbers in a random order and position according to the maximum number of copies and the bit length of the single copy location information to obtain the copy location information of all copies;

[0023] Performing a CRC check on the identity identification number and the copy location information to obtain a first CRC value;

[0024] Concatenate the identity identification number, the copy location information, and the first CRC value to obtain header bits;

[0025] According to the bit length of the single copy position information, a corresponding number of information bits are taken out from the sending bit buffer area for CRC check to obtain a second CRC value;

[0026] The information bits and the second CRC value are concatenated to obtain payload bits.

[0027] Further, generating a transmission symbol sequence according to the random access parameter, the header bit, and the payload bit and sending the transmission symbol sequence comprises the following specific steps:

[0028] According to the access-at-anytime parameter, the header bit and the payload bit are encoded and modulated to obtain a header symbol and a payload symbol;

[0029] splicing the header symbol and the payload symbol to obtain a splicing unit;

[0030] Adding a pilot and a guard interval in the splicing unit to generate a transmission symbol sequence;

[0031] The transmit symbol sequence is transmitted in the time slot.

[0032] Further, encoding and modulating the header bit and the payload bit according to the access-at-anytime parameter to obtain a header symbol and a payload symbol includes the following specific steps:

[0033] According to the header bit coding efficiency and the header bit modulation order, the header bits are encoded and modulated to obtain header symbols;

[0034] The payload bits are encoded and modulated according to the payload bit coding efficiency and the payload bit modulation order to obtain payload symbols.

[0035] Further, performing time slot merging and interference elimination operations on the access frame data to complete the reception of the access frame data includes the following specific steps:

[0036] Performing a time slot merging operation on time slots with the same header in the access frame data to obtain a first merged time slot that passes the CRC check;

[0037] According to the first combined time slot, performing an interference elimination operation on the access frame data to obtain optimized frame data;

[0038] Deleting the time slot corresponding to the first combined time slot in the optimized frame data to obtain frame data to be processed;

[0039] Performing a time slot merging operation on the time slots with the same header in the frame data to be processed to obtain a second merged time slot that passes the CRC check;

[0040] According to the number of time slots in the frame data to be processed, the above-mentioned interference elimination, time slot deletion, and time slot merging operations are cyclically performed on the frame data to be processed to complete the reception of the access frame data.

[0041] Further, performing time slot merging and interference elimination operations on the access frame data to complete the reception of the access frame data includes the following specific steps:

[0042] Performing a time slot merging operation on time slots with the same header in the access frame data to obtain a first merged time slot that passes the CRC check;

[0043] According to the first combined time slot, performing an interference elimination operation on the access frame data to obtain optimized frame data;

[0044] Deleting the time slot corresponding to the first combined time slot in the optimized frame data to obtain frame data to be processed;

[0045] A time slot merging operation is performed on the time slots with the same header in the frame data to be processed, and when a second merged time slot that passes the CRC check cannot be obtained, the reception of the access frame data is completed.

[0046] Further, performing a time slot merging operation on time slots with the same header in the access frame data to obtain a first merged time slot that passes the CRC check includes the following specific steps:

[0047] Classifying time slots with the same header bits in the access frame data into the same merging group to obtain a merging group set;

[0048] Calculating the equivalent signal-to-noise ratio of each merged group in the merged group set to obtain an equivalent signal-to-noise ratio set;

[0049] According to the order of the elements in the equivalent signal-to-noise ratio set, a time slot merging operation is performed on the merging groups in the merging group set to obtain a first merging time slot that passes the CRC check.

[0050] The present application also provides a random access communication device with a time slot merging mechanism, comprising:

[0051] A setting module, used to set random access parameters;

[0052] A first processing module, configured to determine the number of copies of a copy and a time slot parameter of a time slot corresponding to the copy according to the random access parameter; and to generate a header bit and a payload bit according to the random access parameter, the number of copies, and the time slot parameter;

[0053] A sending module, configured to generate a sending symbol sequence according to the random access parameter, the header bit, and the payload bit, and send the sending symbol sequence;

[0054] A receiving module, used for receiving the transmission symbol sequence to obtain access frame data;

[0055] The second processing module is used to perform time slot merging and interference elimination operations on the access frame data to complete the reception of the access frame data.

[0056] The embodiments provided in this application have at least the following beneficial effects:

[0057] Based on the IRSA algorithm, a new bit stream structure to be modulated, a dual modulation and coding strategy mechanism, and a decoding and demodulation process with time slot merging and interference elimination mechanism are used. Compared with the traditional IRSA scheme, the present application can improve the equivalent signal-to-noise ratio through the time slot merging process and make full use of the potential repetition gain, thereby achieving a higher throughput than the traditional IRSA algorithm under low signal-to-noise ratio conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0059] Figure 1 A flowchart of a random access communication method with a time slot merging mechanism provided in an embodiment of the present application;

[0060] Figure 2 A flowchart of generating header bits and payload bits in a random access communication method with a time slot merging mechanism provided in an embodiment of the present application;

[0061] Figure 3 A flow chart of generating and sending a sending symbol sequence in a random access communication method with a time slot merging mechanism provided in an embodiment of the present application;

[0062] Figure 4 A flowchart of processing received access frame data in a random access communication method with a time slot merging mechanism provided in an embodiment of the present application;

[0063] Figure 5 A throughput performance comparison diagram of the random access communication method provided in the embodiment of the present application;

[0064] Figure 6 A schematic diagram of a random access communication device with a time slot merging mechanism provided in an embodiment of the present application.

[0065] 100 Random access communication device with time slot merging mechanism

[0066] 11 Setting Module

[0067] 12. First processing module

[0068] 13 Sending module

[0069] 14 Receiver Module

[0070] 15 Second processing module DETAILED DESCRIPTION

[0071] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in combination with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0072] Please refer to Figure 1 The present application provides a random access communication method with a time slot merging mechanism, comprising the following specific steps:

[0073] S100: Setting random access parameters.

[0074] It should be noted that when using a random access communication method with a time slot merging mechanism, various initial parameters are required for the normal operation of the method. The random access communication method here can be understood as a random access method. Preferably, the random access communication method here can be a random access method with irregular repetition time slots with a time slot merging mechanism, which can also be called an IRSA (Irregular Repetition Slotted ALOHA) random access method with a time slot merging mechanism. The receiving end and each transmitting end in the random access communication method can call the initially set random access parameters according to work needs so that the random access communication method can operate normally.

[0075] Furthermore, the random access parameters include the maximum number of copies, the probability distribution of the number of copies, the bit length of the identity identification number, the bit length of the location information of a single copy, the header bit coding efficiency, the header bit modulation order, the payload bit coding efficiency, and the payload bit modulation order.

[0076] It should be pointed out that the maximum number of copies here is the maximum number of copies that any transmitter is allowed to send in one frame. The probability distribution of the number of copies is obtained by the progressive analysis based on the AND-OR tree and the optimization based on differential evolution described in the IRSA algorithm, and the results in the IRSA paper table can be directly used. The bit length of the identity identification number is used to indicate how many bits the identity identification number occupies. The bit length of the location information of a single copy is used to indicate how many bits a copy location information occupies. The header bit coding efficiency is used to indicate the coding efficiency used by the header bit. The header bit modulation order is used to indicate the modulation order. The payload bit coding efficiency is used to indicate the coding efficiency used by the payload bit. The payload bit modulation order is used to indicate the modulation order. Obviously, based on actual needs, in addition to the above parameters, other parameters can also be included.

[0077] S200: Determine the number of copies of a copy and a time slot parameter of a time slot corresponding to the copy according to the random access parameter.

[0078] It is obvious that the random access parameter is only the initial parameter set. Based on the initial parameter, other parameters need to be further calculated according to the preset rules. According to the set random access parameter, each sender can randomly select the number of copies according to the probability distribution of the number of copies, and then randomly select the corresponding number of time slots. It should be noted that the probability of each time slot being selected is equal.

[0079] Specifically, determining the number of copies of the copy and the time slot parameter of the time slot corresponding to the copy according to the random access parameter includes the following specific steps:

[0080] Randomly select the number of copies of the copy according to the maximum number of copies and the probability distribution of the number of copies;

[0081] Randomly selecting a number of time slots corresponding to the number of replicas to obtain time slot parameters of the time slots;

[0082] The time slot parameters include the number of time slots of the time slots and the time slot number of each time slot in the time slots.

[0083] It should be noted that the selection of the number of copies is determined by the set maximum number of copies and the probability distribution of the number of copies. At the same time, each transmitter independently selects the number of copies according to the set random access parameters. After the number of copies is determined, each transmitter selects the same number of time slots as the number of copies. When selecting time slots, the probability of each time slot being selected is equal.

[0084] S300: Generate header bits and payload bits according to the random access parameters, the number of copies, and the time slot parameters.

[0085] It can be understood that after each transmitting end determines the number of copies and time slot parameters according to the random access parameters, it can prepare the data information to be sent. The data information here mainly includes header bits and payload bits. The header bits are mainly used for identity identification, and the payload bits are mainly used for information carrying. One copy corresponds to one time slot, and the header bits and payload bits of all copies of each transmitting end are the same.

[0086] For further information, please refer to Figure 2 , generating header bits and payload bits according to the random access parameter, the number of copies, and the time slot parameter, comprising the following specific steps:

[0087] S301: randomly selecting an identity identification number according to the bit length of the identity identification number;

[0088] S302: Arrange the time slot numbers in a random order and position according to the maximum number of replicas and the bit length of the single replica location information to obtain the replica location information of all replicas;

[0089] S303: Perform CRC check on the identity identification number and the copy location information to obtain a first CRC value;

[0090] S304: Concatenate the identity identification number, the copy location information, and the first CRC value to obtain header bits;

[0091] S305: taking out a corresponding number of information bits from the sending bit buffer area according to the bit length of the single copy position information, performing CRC check, and obtaining a second CRC value;

[0092] S306: Concatenate the information bits and the second CRC value to obtain payload bits.

[0093] It is obvious that each transmitting end needs to follow certain rules when generating header bits and payload bits. In order to avoid duplication of identity identification numbers between each transmitting end, the identity identification number can be randomly selected according to the bit length of the identity identification number. The bit length of the identity identification number of each transmitting end is the same, and the content of the identity identification number is randomly selected when transmitting. According to the set maximum number of copies and the bit length of the single copy position information, the selected time slot number can be placed in a random order and position, so as to determine the copy position information of all copies according to the time slot position. It should be noted that the first CRC value for the header bit and the second CRC value for the payload bit are two different CRC values, and the CRC bit lengths of the first CRC value and the second CRC value can be set in advance in the random access parameters as needed. The information bit here can be understood as a data bit containing data information. The length of the data bit here can be understood as the number of bits occupied by the data information, and the length of the data bit also needs to be set in advance in the random access parameters. Preferably, different modulation and coding strategies can be used for the header bit and the payload bit. When splicing the header bits, splicing is performed in the order of the identity identification number, the copy position information, and the first CRC value. When splicing the payload bits, they are spliced ​​in the order of the information bits and the second CRC value. In a specific implementation, the bit length of the identity identification number here can be 16 bits, the maximum number of copies here can be 8, the bit length of the single copy location information here can be 8 bits, the CRC bit length of the first CRC value and the second CRC value here can both be 16 bits, the bit length of the single copy location information here can be 8 bits, and the length of the information bit here can be 8192 bits. 1 bit here is equal to 1 data bit, that is, 1 bit. It should be noted that the description of the header bits and payload bits here is only for a certain sending end, and the generation method of the header bits and payload bits of other sending ends is the same.

[0094] S400: Generate a transmission symbol sequence according to the random access parameter, the header bit, and the payload bit, and send the transmission symbol sequence.

[0095] It can be understood that after the header bits and the payload bits are generated, the data sending operation can be further performed according to the corresponding specific parameters in the random access parameters.

[0096] For details, please refer to Figure 3 , generating a transmission symbol sequence according to the random access parameter, the header bit, and the payload bit and sending the transmission symbol sequence, comprising the following specific steps:

[0097] S401: Encode and modulate the header bit and the payload bit according to the access-at-anytime parameter to obtain a header symbol and a payload symbol;

[0098] S402: concatenate the header symbol and the payload symbol to obtain a concatenated unit;

[0099] S403: Adding a pilot and a guard interval to the splicing unit to generate a transmission symbol sequence;

[0100] S404: Send the transmit symbol sequence in the time slot.

[0101] It should be pointed out that the header bits and payload bits need to be further processed before they can be sent. Each transmitting end can encode and modulate the header bits and payload bits according to the specific parameters set in the random access parameters, thereby obtaining the header symbol and the payload symbol. The splicing unit is obtained by combining the header symbol and the payload symbol in sequence. The splicing unit here can also be understood as a modulation symbol sequence or a modulation symbol. After each transmitting end splices the header symbol and payload symbol that have been modulated, and adds the pilot and protection interval, it can obtain the transmission symbol sequence. Each transmitting end sends the transmission symbol sequence in each time slot selected by it.

[0102] Further, encoding and modulating the header bit and the payload bit according to the access-at-anytime parameter to obtain a header symbol and a payload symbol includes the following specific steps:

[0103] According to the header bit coding efficiency and the header bit modulation order, the header bits are encoded and modulated to obtain header symbols;

[0104] The payload bits are encoded and modulated according to the payload bit coding efficiency and the payload bit modulation order to obtain payload symbols.

[0105] It is understandable that both the header symbol and the payload symbol are obtained through coding and modulation according to specific rules, and they respectively adopt different modulation and coding strategy mechanisms. Preferably, the header bit coding efficiency can be 1 / 3, the header bit modulation order can be 2, the payload bit coding efficiency can be 1 / 2, and the payload bit modulation order can be 4.

[0106] S500: Receive the transmission symbol sequence to obtain access frame data.

[0107] It should be noted that when the receiving end receives the transmission symbol sequence, it receives the transmission symbol sequence sent by each transmitting end. The access frame data here contains different transmission symbol sequences from each transmitting end. The transmission symbol sequence here can be understood as the copy information corresponding to the time slot, and one transmission symbol sequence corresponds to one copy information carried by one time slot.

[0108] S600: Perform time slot merging and interference elimination operations on the access frame data to complete the reception of the access frame data.

[0109] It should be noted that the access frame data is an access frame composed of multiple continuous time slots, and one time slot is a radio frame. The access frame data is composed of radio frames sent by each transmitter. Obviously, the radio frames sent by the same transmitter in the access frame data, that is, the time slots, can be merged with the corresponding time slots. At the same time, after obtaining the accurate data information of a certain transmitter, the original access frame data can be further interfered with according to the accurate data information obtained, and the remaining access frame data can be processed cyclically to finally complete the reception of the access frame data.

[0110] For details, please refer to Figure 4 , performing time slot merging and interference elimination operations on the access frame data to complete the reception of the access frame data, including the following specific steps:

[0111] S601: Perform a timeslot merging operation on the timeslots with the same header in the access frame data to obtain a first merged timeslot that passes the CRC check;

[0112] S602: Perform an interference elimination operation on the access frame data according to the first combined time slot to obtain optimized frame data;

[0113] S603: Delete the time slot corresponding to the first combined time slot in the optimized frame data to obtain frame data to be processed;

[0114] S604: Perform a time slot merging operation on the time slots with the same header in the frame data to be processed to obtain a second merged time slot that passes the CRC check;

[0115] S605: According to the number of time slots in the frame data to be processed, the above-mentioned interference elimination, time slot deletion, and time slot merging operations are cyclically performed on the frame data to be processed to complete the reception of the access frame data.

[0116] It can be understood that when processing access frame data, the receiving end can merge time slots with the same header. The same header here means that the header bits in the time slot are the same, and the same header bits indicate that they come from the same transmitting end. The first merged time slot that passes the CRC check refers to the payload symbol that passes the CRC check after demodulation and decoding, which means that the first merged time slot has been correctly parsed and the data information carried by the time slot has been successfully received. By re-encoding and re-modulating the bit stream composed of the header bits and payload bits in the first merged time slot, the code element waveform corresponding to the first merged time slot can be restored, and the access frame data can be used to perform interference elimination operations to obtain optimized frame data that is less affected by interference. Since the first merged time slot is a time slot that has passed the CRC check, the time slot corresponding to the first merged time slot in the optimized frame data can be deleted at this time to obtain the frame data to be processed. When screening the second merged time slot in the frame data to be processed, the same method as screening the first merged time slot is adopted. After the second merged time slot that passes the CRC check is screened out, the process of screening the second merged time slot needs to be repeated until no more merged time slots can be screened out from the access frame data or all time slots in the access frame data are processed. The first merged time slot, the second merged time slot and other merged time slots here need to include at least one time slot. It should be noted that, if the first merged time slot that passes the CRC check cannot be obtained, the processing of the access frame data will end directly and the next access frame data will be processed instead.

[0117] Further, performing time slot merging and interference elimination operations on the access frame data to complete the reception of the access frame data includes the following specific steps:

[0118] Performing a time slot merging operation on time slots with the same header in the access frame data to obtain a first merged time slot that passes the CRC check;

[0119] According to the first combined time slot, performing an interference elimination operation on the access frame data to obtain optimized frame data;

[0120] Deleting the time slot corresponding to the first combined time slot in the optimized frame data to obtain frame data to be processed;

[0121] A time slot merging operation is performed on the time slots with the same header in the frame data to be processed, and when a second merged time slot that passes the CRC check cannot be obtained, the reception of the access frame data is completed.

[0122] It is understandable that the receiving end can choose different processing methods according to various situations when processing access frame data. In a specific embodiment, after obtaining the first merged time slot that passes the CRC check, the receiving end can restore the code element waveform corresponding to the first merged time slot by re-encoding and re-modulating the bit stream composed of the header bits and payload bits in the first merged time slot, and thereby perform interference elimination operations on the access frame data to obtain optimized frame data that is less affected by interference. Since the first merged time slot is a time slot that has passed the CRC check, the time slot corresponding to the first merged time slot in the optimized frame data can be deleted at this time to obtain the frame data to be processed. The time slots with the same header in the frame data to be processed are merged. If the second merged time slot that passes the CRC check cannot be obtained, the processing of the access frame data is terminated and the next access frame data is processed instead.

[0123] Preferably, the specific formula for performing the interference elimination operation is as follows:

[0124]

[0125] Among them, z(t) represents the codeword waveform after the interference cancellation is performed, x(t) represents the codeword waveform before the interference cancellation is performed, and y(t) represents the codeword waveform obtained by re-encoding and modulating the decoded and demodulated bit stream. represents the estimated value of the channel gain, represents the estimated value of the timing error, represents the estimated value of frequency deviation, Represents an estimate of the phase bias.

[0126] Specifically, performing a time slot merging operation on time slots with the same header in the access frame data to obtain a first merged time slot that passes the CRC check includes the following specific steps:

[0127] Classifying time slots with the same header bits in the access frame data into the same merging group to obtain a merging group set;

[0128] Calculating the equivalent signal-to-noise ratio of each merged group in the merged group set to obtain an equivalent signal-to-noise ratio set;

[0129] According to the order of the elements in the equivalent signal-to-noise ratio set, a time slot merging operation is performed on the merging groups in the merging group set to obtain a first merging time slot that passes the CRC check.

[0130] It should be pointed out that when performing the time slot merging operation on the access frame data, frame synchronization is first performed on each time slot. Here, frame synchronization refers to the synchronization of the wireless frame. One time slot is a wireless frame, and multiple continuous time slots constitute an access frame data. When the frame synchronization is successful, the pilot of the time slot is used to perform timing synchronization, signal power, noise power, frequency deviation, and phase deviation estimation on the time slot, and then the header symbol is demodulated and decoded to obtain the header bit. When the header bit passes the CRC check, the header bit and each estimated value are stored. Among them, the time slots containing the same header bit are recorded as the same merging group. The content that needs to be stored in a merging group includes the estimated values ​​of the signal power, frequency deviation, etc. of multiple time slots, and finally the multiple time slots are averaged to obtain the estimated values ​​of the merging group. Since different merging groups come from signals of different terminals, the estimated values ​​stored in different merging groups are independent of each other. After completing the above operations on all time slots in the access frame data, if there is no merging group in the storage area, the demodulation of the access frame data is terminated and the next access frame data is processed. The storage area here can be understood as a merge group set, that is, when there are no elements in the merge group set, the demodulation of the access frame data is terminated and the next access frame data is processed. When there is a merge group in the merge group set, the receiving end performs a time slot merging operation on the merge group with the largest equivalent signal-to-noise ratio, and then demodulates and decodes the payload part. At this time, if the payload bit passes the CRC check, the merge group with the largest equivalent signal-to-noise ratio is the first merged time slot. When the payload bit corresponding to the merge group with the largest equivalent signal-to-noise ratio cannot pass the CRC check, the merge group with the largest equivalent signal-to-noise ratio in the remaining merge groups in the merge group set is subjected to a time slot merging operation, and then demodulates and decodes its payload part. At this time, if the payload bit passes the CRC check, the merge group is the first merged time slot. If the first merged time slot still cannot be obtained, the above steps are repeated in the remaining other merge groups until the first merged time slot that meets the conditions is found. When all merge groups cannot pass the CRC check, the demodulation of the access frame data is terminated, and the next access frame data is processed. In a specific implementation, it is assumed that the number of merge groups is 5. Let n = 1, after time slot merging, demodulation and decoding of the merged group with the largest equivalent signal-to-noise ratio, the CRC check fails, indicating that the merged group has failed to receive. Let n = 2, and time slot merging, demodulation and decoding of the merged group with the second largest equivalent signal-to-noise ratio are performed. If the CRC check still fails, n is allowed to increase. If the merged group with the fifth largest equivalent signal-to-noise ratio still fails to pass the CRC check after n increases to 5, it means that all merged groups cannot be successfully demodulated and decoded, and the processing of the access frame data ends.If n increases to a certain value, such as 4, and the CRC check passes after time slot merging, demodulation and decoding of the merging group with the fourth largest equivalent signal-to-noise ratio, then the merging group is deleted, interference elimination is performed, and the access frame data is reprocessed to confirm whether more merging groups can be found after interference elimination. The above process is repeated until the number of merging groups is 0 or the CRC check after time slot merging, demodulation and decoding of all merging groups fails.

[0131] Preferably, the formula for calculating the equivalent signal-to-noise ratio of the combined group is as follows:

[0132]

[0133] Among them, Group i represents the i-th merge group, represents the estimated value of the equivalent signal-to-noise ratio of the i-th merge group, represents the set of time slot numbers included in the i-th merge group, represents the number of time slots contained in the i-th merge group, represents the estimated value of the signal power in the lth time slot, Represents an estimate of the noise power.

[0134] Please refer to Figure 5 , which is a throughput performance comparison diagram of the random access communication method provided in the embodiment of the present application. The throughput performance comparison diagram is obtained through simulation comparison, by setting the channel to an additive white Gaussian noise channel, and setting the parameters: the bit length of the identity identification number is 16 bits, the maximum number of copies is 8, the bit length of the single copy location information is 8 bits, the CRC bit length of the first CRC value and the second CRC value are both 16 bits, the bit length of the single copy location information is 8 bits, the length of the information bit is 8192 bits, the header bit coding efficiency is 1 / 3, the header bit modulation order is 2, the payload bit coding efficiency is 1 / 2, and the payload bit modulation order is 4. There are 20 terminals sending signals in the wireless frame (because the number of time slots in a frame is 50, the traffic is 20 / 50=40%). Use the existing IRSA algorithm and the method proposed in the present invention respectively. By Figure 5 It can be seen that the method proposed in the present invention, i.e., the random access communication method, has the same throughput performance as IRSA when the signal-to-noise ratio is high enough, but has a higher throughput when the signal-to-noise ratio is low. Therefore, it can be shown that the random access method or random access communication method of the present invention is superior to the existing IRSA algorithm.

[0135] Please refer to Figure 6 The present application also provides a random access communication device 100 with a time slot merging mechanism, comprising:

[0136] A setting module 11, used to set random access parameters;

[0137] The first processing module 12 is used to determine the number of copies of the copy and the time slot parameter of the time slot corresponding to the copy according to the random access parameter; and is also used to generate a header bit and a payload bit according to the random access parameter, the number of copies, and the time slot parameter;

[0138] A sending module 13, configured to generate a sending symbol sequence according to the random access parameter, the header bit, and the payload bit, and send the sending symbol sequence;

[0139] The receiving module 14 is used to receive the transmission symbol sequence and obtain access frame data;

[0140] The second processing module 15 is used to perform time slot merging and interference elimination operations on the access frame data to complete the reception of the access frame data.

[0141] It should be noted that the setting module 11 is an important part of the normal operation of the random access communication device 100 with a time slot merging mechanism. The random access communication device 100 here can be understood as allowing the random access communication method to run on a carrier. Preferably, the random access communication method here can be a random access method with irregular repetition time slots with a time slot merging mechanism, which can also be called an IRSA (Irregular Repetition Slotted ALOHA) random access method with a time slot merging mechanism. The receiving end and each transmitting end in the random access communication method can call the initial set random access parameters according to work needs so that the random access communication method can operate normally.

[0142] Furthermore, the random access parameters include the maximum number of copies, the probability distribution of the number of copies, the bit length of the identity identification number, the bit length of the location information of a single copy, the header bit coding efficiency, the header bit modulation order, the payload bit coding efficiency, and the payload bit modulation order.

[0143] It should be pointed out that the maximum number of copies here is the maximum number of copies that any transmitter is allowed to send in one frame. The probability distribution of the number of copies is obtained by the progressive analysis based on the AND-OR tree and the optimization based on differential evolution described in the IRSA algorithm, and the results in the IRSA paper table can be directly used. The bit length of the identity identification number is used to indicate how many bits the identity identification number occupies. The bit length of the location information of a single copy is used to indicate how many bits a copy location information occupies. The header bit coding efficiency is used to indicate the coding efficiency used by the header bit. The header bit modulation order is used to indicate the modulation order. The payload bit coding efficiency is used to indicate the coding efficiency used by the payload bit. The payload bit modulation order is used to indicate the modulation order. Obviously, based on actual needs, in addition to the above parameters, other parameters can also be included.

[0144] It is obvious that the random access parameter is only the initial parameter set. Based on the initial parameter, other parameters need to be further calculated according to the preset rules. According to the set random access parameter, each sender can randomly select the number of copies according to the probability distribution of the number of copies, and then randomly select the corresponding number of time slots. It should be noted that the probability of each time slot being selected is equal.

[0145] Specifically, the first processing module 12 is specifically used for:

[0146] Randomly select the number of copies of the copy according to the maximum number of copies and the probability distribution of the number of copies;

[0147] Randomly selecting a number of time slots corresponding to the number of replicas to obtain time slot parameters of the time slots;

[0148] The time slot parameters include the number of time slots of the time slots and the time slot number of each time slot in the time slots.

[0149] It should be noted that the selection of the number of copies is determined by the set maximum number of copies and the probability distribution of the number of copies. At the same time, each transmitter independently selects the number of copies according to the set random access parameters. After the number of copies is determined, each transmitter selects the same number of time slots as the number of copies. When selecting time slots, the probability of each time slot being selected is equal.

[0150] Furthermore, the first processing module 12 is also specifically used for:

[0151] Randomly selecting an identity number according to the bit length of the identity number;

[0152] Arrange the time slot numbers in a random order and position according to the maximum number of copies and the bit length of the single copy location information to obtain the copy location information of all copies;

[0153] Performing a CRC check on the identity identification number and the copy location information to obtain a first CRC value;

[0154] Concatenate the identity identification number, the copy location information, and the first CRC value to obtain header bits;

[0155] According to the bit length of the single copy position information, a corresponding number of information bits are taken out from the sending bit buffer area for CRC check to obtain a second CRC value;

[0156] The information bits and the second CRC value are concatenated to obtain payload bits.

[0157] It can be understood that after the header bits and the payload bits are generated, the data sending operation can be further performed according to the corresponding specific parameters in the random access parameters.

[0158] Specifically, the sending module 13 is specifically used for:

[0159] According to the access-at-anytime parameter, the header bit and the payload bit are encoded and modulated to obtain a header symbol and a payload symbol;

[0160] splicing the header symbol and the payload symbol to obtain a splicing unit;

[0161] Adding a pilot and a guard interval in the splicing unit to generate a transmission symbol sequence;

[0162] The transmit symbol sequence is transmitted in the time slot.

[0163] It should be pointed out that the header bits and payload bits need to be further processed before they can be sent. Each transmitting end can encode and modulate the header bits and payload bits according to the specific parameters set in the random access parameters, thereby obtaining the header symbol and the payload symbol. The splicing unit is obtained by combining the header symbol and the payload symbol in sequence. The splicing unit here can also be understood as a modulation symbol sequence or a modulation symbol. After each transmitting end splices the header symbol and payload symbol that have been modulated, and adds the pilot and protection interval, it can obtain the transmission symbol sequence. Each transmitting end sends the transmission symbol sequence in each time slot selected by it.

[0164] Further, encoding and modulating the header bit and the payload bit according to the access-at-anytime parameter to obtain a header symbol and a payload symbol includes the following specific steps:

[0165] According to the header bit coding efficiency and the header bit modulation order, the header bits are encoded and modulated to obtain header symbols;

[0166] The payload bits are encoded and modulated according to the payload bit coding efficiency and the payload bit modulation order to obtain payload symbols.

[0167] It is understandable that both the header symbol and the payload symbol are obtained through coding and modulation according to specific rules, and they respectively adopt different modulation and coding strategy mechanisms. Preferably, the header bit coding efficiency can be 1 / 3, the header bit modulation order can be 2, the payload bit coding efficiency can be 1 / 2, and the payload bit modulation order can be 4.

[0168] It should be noted that when receiving the transmission symbol sequence, the receiving module 14 receives the transmission symbol sequence sent by each transmitting end. The access frame data here includes different transmission symbol sequences from each transmitting end. The transmission symbol sequence here can be understood as the copy information corresponding to the time slot, and one transmission symbol sequence corresponds to one copy information carried by one time slot.

[0169] It should be noted that the access frame data is an access frame composed of multiple continuous time slots, and one time slot is a radio frame. The access frame data is composed of radio frames sent by each transmitter. Obviously, the radio frames sent by the same transmitter in the access frame data, that is, the time slots, can be merged with the corresponding time slots. At the same time, after obtaining the accurate data information of a certain transmitter, the original access frame data can be further interfered with according to the accurate data information obtained, and the remaining access frame data can be processed cyclically to finally complete the reception of the access frame data.

[0170] Specifically, the second processing module 15 is specifically used for:

[0171] Performing a time slot merging operation on time slots with the same header in the access frame data to obtain a first merged time slot that passes the CRC check;

[0172] According to the first combined time slot, performing an interference elimination operation on the access frame data to obtain optimized frame data;

[0173] Deleting the time slot corresponding to the first combined time slot in the optimized frame data to obtain frame data to be processed;

[0174] Performing a time slot merging operation on the time slots with the same header in the frame data to be processed to obtain a second merged time slot that passes the CRC check;

[0175] According to the number of time slots in the frame data to be processed, the above-mentioned interference elimination, time slot deletion, and time slot merging operations are cyclically performed on the frame data to be processed to complete the reception of the access frame data.

[0176] Further, performing time slot merging and interference elimination operations on the access frame data to complete the reception of the access frame data includes the following specific steps:

[0177] Performing a time slot merging operation on time slots with the same header in the access frame data to obtain a first merged time slot that passes the CRC check;

[0178] According to the first combined time slot, performing an interference elimination operation on the access frame data to obtain optimized frame data;

[0179] Deleting the time slot corresponding to the first combined time slot in the optimized frame data to obtain frame data to be processed;

[0180] A time slot merging operation is performed on the time slots with the same header in the frame data to be processed, and when a second merged time slot that passes the CRC check cannot be obtained, the reception of the access frame data is completed.

[0181] It is understandable that the receiving end can choose different processing methods according to various situations when processing access frame data. In a specific embodiment, after obtaining the first merged time slot that passes the CRC check, the receiving end can restore the code element waveform corresponding to the first merged time slot by re-encoding and re-modulating the bit stream composed of the header bits and payload bits in the first merged time slot, and thereby perform interference elimination operations on the access frame data to obtain optimized frame data that is less affected by interference. Since the first merged time slot is a time slot that has passed the CRC check, the time slot corresponding to the first merged time slot in the optimized frame data can be deleted at this time to obtain the frame data to be processed. The time slots with the same header in the frame data to be processed are merged. If the second merged time slot that passes the CRC check cannot be obtained, the processing of the access frame data is terminated and the next access frame data is processed instead.

[0182] Preferably, the specific formula for performing the interference elimination operation is as follows:

[0183]

[0184] Among them, z(t) represents the codeword waveform after the interference cancellation is performed, x(t) represents the codeword waveform before the interference cancellation is performed, and y(t) represents the codeword waveform obtained by re-encoding and modulating the decoded and demodulated bit stream. represents the estimated value of the channel gain, represents the estimated value of the timing error, represents the estimated value of frequency deviation, Represents an estimate of the phase bias.

[0185] Specifically, performing a time slot merging operation on time slots with the same header in the access frame data to obtain a first merged time slot that passes the CRC check includes the following specific steps:

[0186] Classifying time slots with the same header bits in the access frame data into the same merging group to obtain a merging group set;

[0187] Calculating the equivalent signal-to-noise ratio of each merged group in the merged group set to obtain an equivalent signal-to-noise ratio set;

[0188] According to the order of the elements in the equivalent signal-to-noise ratio set, a time slot merging operation is performed on the merging groups in the merging group set to obtain a first merging time slot that passes the CRC check.

[0189] Preferably, the formula for calculating the equivalent signal-to-noise ratio of the combined group is as follows:

[0190]

[0191] Among them, Group i represents the i-th merge group, represents the estimated value of the equivalent signal-to-noise ratio of the i-th merge group, represents the set of time slot numbers included in the i-th merge group, represents the number of time slots contained in the i-th merge group, represents the estimated value of the signal power in the lth time slot, Represents an estimate of the noise power.

[0192] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0193] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0194] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A random access communication method with a time slot merging mechanism, characterized in that: The specific steps include: Set random access parameters; Determine, according to the random access parameter, the number of copies of the copy and the time slot parameter of the time slot corresponding to the copy; Generate a header bit and a payload bit according to the random access parameter, the number of copies, and the time slot parameter; Generate a transmission symbol sequence according to the random access parameter, the header bit, and the payload bit, and send the transmission symbol sequence; Receiving the transmission symbol sequence to obtain access frame data; Perform time slot merging and interference elimination operations on the access frame data to complete the reception of the access frame data.

2. The random access communication method according to claim 1, characterized in that: The random access parameters include the maximum number of copies, the probability distribution of the number of copies, the bit length of the identity identification number, the bit length of the single copy location information, the header bit coding efficiency, the header bit modulation order, the payload bit coding efficiency, and the payload bit modulation order.

3. The random access communication method according to claim 2, characterized in that: Determining the number of copies of the copy and the time slot parameter of the time slot corresponding to the copy according to the random access parameter includes the following specific steps: Randomly select the number of copies of the copy according to the maximum number of copies and the probability distribution of the number of copies; Randomly selecting a number of time slots corresponding to the number of replicas to obtain time slot parameters of the time slots; The time slot parameters include the number of time slots of the time slots and the time slot number of each time slot in the time slots.

4. The random access communication method according to claim 3, characterized in that: Generating header bits and payload bits according to the random access parameter, the number of copies, and the time slot parameter includes the following specific steps: Randomly selecting an identity number according to the bit length of the identity number; Arrange the time slot numbers in a random order and position according to the maximum number of copies and the bit length of the single copy location information to obtain the copy location information of all copies; Performing a CRC check on the identity identification number and the copy location information to obtain a first CRC value; Concatenate the identity identification number, the copy location information, and the first CRC value to obtain header bits; According to the bit length of the single copy position information, a corresponding number of information bits are taken out from the sending bit buffer area for CRC check to obtain a second CRC value; The information bits and the second CRC value are concatenated to obtain payload bits.

5. The random access communication method according to claim 1, characterized in that: Generating a transmission symbol sequence according to the random access parameter, the header bit, and the payload bit and sending the transmission symbol sequence comprises the following specific steps: According to the random access parameter, the header bit and the payload bit are encoded and modulated to obtain a header symbol and a payload symbol; splicing the header symbol and the payload symbol to obtain a splicing unit; Adding a pilot and a guard interval in the splicing unit to generate a transmission symbol sequence; The transmit symbol sequence is transmitted in the time slot.

6. The random access communication method according to claim 5, characterized in that: According to the random access parameter, encoding and modulating the header bit and the payload bit to obtain a header symbol and a payload symbol includes the following specific steps: According to the header bit coding efficiency and the header bit modulation order, the header bits are encoded and modulated to obtain header symbols; The payload bits are encoded and modulated according to the payload bit coding efficiency and the payload bit modulation order to obtain payload symbols.

7. The random access communication method according to claim 1, characterized in that: Performing time slot merging and interference elimination operations on the access frame data to complete the reception of the access frame data includes the following specific steps: Performing a time slot merging operation on time slots with the same header in the access frame data to obtain a first merged time slot that passes the CRC check; According to the first combined time slot, performing an interference elimination operation on the access frame data to obtain optimized frame data; Deleting the time slot corresponding to the first combined time slot in the optimized frame data to obtain frame data to be processed; Performing a time slot merging operation on the time slots with the same header in the frame data to be processed to obtain a second merged time slot that passes the CRC check; According to the number of time slots in the frame data to be processed, the above-mentioned interference elimination, time slot deletion, and time slot merging operations are cyclically performed on the frame data to be processed to complete the reception of the access frame data.

8. The random access communication method according to claim 1, characterized in that: Performing time slot merging and interference elimination operations on the access frame data to complete the reception of the access frame data includes the following specific steps: Performing a time slot merging operation on time slots with the same header in the access frame data to obtain a first merged time slot that passes the CRC check; According to the first combined time slot, performing an interference elimination operation on the access frame data to obtain optimized frame data; Deleting the time slot corresponding to the first combined time slot in the optimized frame data to obtain frame data to be processed; A time slot merging operation is performed on the time slots with the same header in the frame data to be processed, and when a second merged time slot that passes the CRC check cannot be obtained, the reception of the access frame data is completed.

9. The random access communication method according to any one of claims 7 or 8, characterized in that: Performing a timeslot merging operation on timeslots with the same header in the access frame data to obtain a first merged timeslot that passes a CRC check comprises the following specific steps: Classifying time slots with the same header bits in the access frame data into the same merging group to obtain a merging group set; Calculating the equivalent signal-to-noise ratio of each merged group in the merged group set to obtain an equivalent signal-to-noise ratio set; According to the order of the elements in the equivalent signal-to-noise ratio set, a time slot merging operation is performed on the merging groups in the merging group set to obtain a first merging time slot that passes the CRC check.

10. A random access communication device with a time slot merging mechanism, characterized in that: include: A setting module, used to set random access parameters; A first processing module, configured to determine the number of copies of the copy and the time slot parameter of the time slot corresponding to the copy according to the random access parameter; Also used to generate header bits and payload bits according to the random access parameter, the number of copies, and the time slot parameter; A sending module, configured to generate a sending symbol sequence according to the random access parameter, the header bit, and the payload bit, and send the sending symbol sequence; A receiving module, used for receiving the transmission symbol sequence to obtain access frame data; The second processing module is used to perform time slot merging and interference elimination operations on the access frame data to complete the reception of the access frame data.

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