Low-power channel coding method and system designed for backscatter communication

Abstract

The present invention relates to a low-power channel coding method and system designed for a backscatter communication mode. The specific steps include: traversing bit information to be encoded, setting the original information with continuous identical symbols into a group, and calculating the number of symbols in each group, determining the odd number of symbols as an odd group, and determining the even number of symbols as an even group; expanding two identical symbols in the odd group, keeping the original odd number unchanged; filling the even group with new even items of odd length according to the remaining number of symbols and the number of even items according to preset rules; splicing the items in the filled odd group and even group into odd coding items, and flipping the last symbol of the odd coding item as a residual coding item and adding it to the end of the odd coding item to generate a final coding item; checking whether the final coding item after coding is completed has discontinuous distortion according to the symbol arrangement and length in the final coding item, and completing the coding process.

Description

Technical Field

[0001] The present invention relates to the technical field of passive communication, and in particular to a low-power channel coding method and system designed for a backscatter communication mode. Background Art

[0002] The emergence of passive communication technology provides a new solution for the energy supply of IoT terminal devices. In the passive IoT, terminal devices can obtain energy from the RF energy in the environment to support their perception and data collection, and use backscatter communication technology to modulate the collected information into the reflected RF signal by changing the impedance.

[0003] Due to the openness of wireless channels, they are extremely susceptible to interference, fading, and noise, which can cause signal distortion during transmission. Therefore, coding technology is needed to reduce the impact of interference on signals. However, the energy that passive terminal nodes can collect is limited. The calculation process of existing coding methods such as Polar codes, LDPC codes, and Turbo codes is too complicated and not suitable for use in passive terminal nodes. Other simple coding methods such as Hamming codes require the expansion of redundant bits based on the original information, which increases the number of channel symbol encodings, requiring passive terminal nodes to spend extra power to send redundant information. Therefore, it is necessary to design a low-power channel coding method based on the principle of backscatter communication.

[0004] Since backscatter communication technology modulates the collected information into the reflected RF signal by changing the impedance, the speed and number of channel symbol changes should be reduced as much as possible.

[0005] In the prior art CN117353804A, an environmental backscatter communication method and communication device disclose that after encoding and modulating the payload information bits, the backscatter communication distance can be increased and the power consumption can be reduced by spectrum spreading. The present invention reduces the power consumption by reducing the channel symbol change speed and number as much as possible during the encoding of the payload information bits. Summary of the invention

[0006] In order to solve the above problems existing in the prior art, the present invention proposes a low-power channel coding method and system designed for backscatter communication mode.

[0007] The technical solution of the present invention is as follows:

[0008] On the one hand, the present invention proposes a low-power channel coding and decoding method designed for a backscatter communication mode, and the specific steps include:

[0009] Traverse the bit information to be encoded, set the bits with consecutive identical symbols in the original information into a group, and calculate the number of symbols in each group, where the bits with an odd number of symbols are determined as an odd group, and the bits with an even number of symbols are determined as an even group;

[0010] Expand two identical symbols in the odd array, keeping the original number of odd numbers unchanged; fill the even array with new even items of odd length according to the remaining number of symbols and the number of even items according to the preset rules; concatenate the items in the filled odd array and even array into odd coding items, and flip the last symbol of the odd coding item as a residual coding item and add it to the end of the odd coding item to generate the final coding item;

[0011] Check and verify whether the final coded item after coding has been completed has discontinuous distortion according to the symbol arrangement and length in the final coded item, and complete the coding process;

[0012] When decoding unknown bit information, first separate the residual coding item at the end of the final coding item of the bit information to be decoded, and calculate the length of the residual coding item. Determine the number and length of the even items and odd items based on the length of the residual coding item, and determine the original odd items and even items based on the expansion rules during encoding. Then, concatenate all decoded items in the order before decoding to obtain the original bit information.

[0013] As a preferred implementation, the step of filling the even number array with new even number items of odd length according to the remaining number of symbols and the number of even number items according to the preset rule is specifically as follows:

[0014] The remaining symbol length that needs to be filled with even items is calculated based on the length limit of the odd-numbered coded items and the length of the odd-numbered items in the odd group after expansion;

[0015] Each even-numbered item is expanded according to the number of even-numbered items and the length of the remaining symbols that need to be filled with the even-numbered items, and the same number of symbols as the symbols in each even-numbered item are added to expand them into new even-numbered items with an odd length.

[0016] As a preferred implementation, the length of the final coded item is 25 bits.

[0017] As a preferred implementation, the judgment rule of the step of checking whether the final coded item encoded according to the symbol arrangement and length in the final coded item has discontinuous distortion is specifically as follows:

[0018] Determine whether the length of the final coded item is 25 bits;

[0019] Determine whether there are isolated symbols in the symbol arrangement of the final coding item. If there are isolated symbols, there is discontinuous distortion;

[0020] It is determined whether there are an even number of consecutive symbols in the odd number coding item, and the distortion position is further determined according to the number of groups of the even number of consecutive symbols.

[0021] As a preferred implementation, the steps of determining the number and length of even items and odd items according to the length of the residual coding items, and determining the original odd items and even items according to the expansion rule during encoding are specifically as follows:

[0022] The number and length of even items are determined according to the length of the residual coding item:

[0023] When the length of the residual coding item is 4, the number of even items is 1 and it is the longest item, so the longest item is marked;

[0024] When the length of the residual coding item is 2 or 3, the number of even items is 2 or 3. If the length of the longest item is greater than 5, the original length of the second longest item is 2, marking the longest item as an even item;

[0025] If the length of the residual coding item is 2 or 3, the number of even items is 2 or 3, and the length of the longest item is 5, then the original length of all remaining items is 2, and the longest item is marked as an even item;

[0026] If the length of the residual coding item is 5, and all items are of equal length, then these items of equal length are all even items and the original length is 2;

[0027] Subtract 2 from the lengths of all unmarked items with unknown original lengths to obtain all odd items;

[0028] Based on the length of the decoded item, calculate the length of the last marked even item;

[0029] Finally, all decoded items are concatenated in the order before decoding to obtain the original value of one bit.

[0030] On the other hand, the present invention proposes a low-power channel coding and decoding system designed for a backscatter communication mode, comprising:

[0031] The odd-even item grouping module traverses the bit information to be encoded, sets the bits with consecutive identical symbols in the original information into a group, and calculates the number of symbols in each group. The odd-numbered bits are determined as an odd group, and the even-numbered bits are determined as an even group.

[0032] The encoding module expands two identical symbols in the odd number group, keeping the original odd number unchanged; fills the even number group with new even number items of odd length according to the remaining number of symbols and the number of even number items according to the preset rules; splices the items in the filled odd number group and the even number group into an odd number encoding item, and flips the last symbol of the odd number encoding item as a residual encoding item and adds it to the end of the odd number encoding item to generate a final encoding item;

[0033] The verification module checks whether the final coded item after verification coding has discontinuous distortion according to the symbol arrangement and length in the final coded item, thereby completing the coding process;

[0034] The decoding module, when decoding unknown bit information, first separates the residual coding item at the end of the final coding item of the bit information to be decoded, and calculates the length of the residual coding item, determines the number and length of the even items and odd items according to the length of the residual coding item, and determines the original odd items and even items according to the expansion rules during encoding, and then splices all the decoded items in the order before decoding to obtain the original bit information.

[0035] As a preferred implementation, the step of filling the even number array with new even number items of odd length according to the remaining number of symbols and the number of even number items according to the preset rule is specifically as follows:

[0036] The remaining symbol length that needs to be filled with even items is calculated based on the length limit of the odd-numbered coded items and the length of the odd-numbered items in the odd group after expansion;

[0037] Each even-numbered item is expanded according to the number of even-numbered items and the length of the remaining symbols that need to be filled with the even-numbered items, and the same number of symbols as the symbols in each even-numbered item are added to expand them into new even-numbered items with an odd length.

[0038] As a preferred implementation, the length of the final coded item is 25 bits.

[0039] As a preferred implementation, the judgment rule of the step of checking whether the final coded item encoded according to the symbol arrangement and length in the final coded item has discontinuous distortion is specifically as follows:

[0040] Determine whether the length of the final coded item is 25 bits;

[0041] Determine whether there are isolated symbols in the symbol arrangement of the final coding item. If there are isolated symbols, there is discontinuous distortion;

[0042] It is determined whether there are an even number of consecutive symbols in the odd number coding item, and the distortion position is further determined according to the number of groups of the even number of consecutive symbols.

[0043] As a preferred implementation, the steps of determining the number and length of even items and odd items according to the length of the residual coding items, and determining the original odd items and even items according to the expansion rule during encoding are specifically as follows:

[0044] The number and length of even items are determined according to the length of the residual coding item:

[0045] When the length of the residual coding item is 4, the number of even items is 1 and it is the longest item, so the longest item is marked;

[0046] When the length of the residual coding item is 2 or 3, the number of even items is 2 or 3. If the length of the longest item is greater than 5, the original length of the second longest item is 2, marking the longest item as an even item;

[0047] If the length of the residual coding item is 2 or 3, the number of even items is 2 or 3, and the length of the longest item is 5, then the original length of all remaining items is 2, and the longest item is marked as an even item;

[0048] If the length of the residual coding item is 5, and all items are of equal length, then these items of equal length are all even items and the original length is 2;

[0049] Subtract 2 from the lengths of all unmarked items with unknown original lengths to obtain all odd items;

[0050] Based on the length of the decoded item, calculate the length of the last marked even item;

[0051] Finally, all decoded items are concatenated in the order before decoding to obtain the original value of one bit.

[0052] The present invention has the following beneficial effects:

[0053] 1. The present invention optimizes the backscatter communication principle, and the encoded symbol information is flipped only once more than the original symbol information, thereby reducing the additional power consumption caused by bit flipping.

[0054] 2. The information encoded by the present invention presents a sparse symbol structure, which reduces the symbol flipping frequency, thereby further reducing the transmission power consumption.

[0055] 3. The encoding and decoding process of the present invention involves a small amount of calculation, which reduces the consumption of computing resources;

[0056] 4. The present invention supports the use of redundant information to verify discontinuous signal distortion and can correct isolated distortion. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 is a flow chart of the steps of the present invention;

[0058] Figure 2 It is a schematic diagram of the coding structure;

[0059] Figure 3 A flowchart of the specific steps for coding;

[0060] Figure 4 is a schematic diagram of a coding example;

[0061] Figure 5 The following is a flowchart of the specific steps for decoding. DETAILED DESCRIPTION

[0062] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0063] It should be understood that the step numbers used in this document are only for convenience of description and are not intended to limit the order in which the steps are executed.

[0064] It should be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0065] The terms “include” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0066] The term "and / or" means and includes any and all possible combinations of one or more of the associated listed items.

[0067] Embodiment 1:

[0068] See also Figure 1 , a low-power channel coding method designed for backscatter communication, the specific steps include:

[0069] Traverse the bit information to be encoded, set the bits with consecutive identical symbols in the original information into a group, and calculate the number of symbols in each group, where the bits with an odd number of symbols are determined as an odd group, and the bits with an even number of symbols are determined as an even group;

[0070] In this embodiment, the channel coding method proposed in this solution will expand the original information into a sparse symbol structure by byte, as shown in the following example: Figure 2 As shown, ① is the odd coding item; ② is the residual coding item; ③ is the total number of bits 25; and the channel symbols used are 0 and 1. The sparse symbol structure consists of the odd coding item and the residual coding item, and each byte of information is expanded to 25 bits. The odd coding item requires that the number of connected identical symbols can only be an odd number, and isolated symbols with a length of 1 cannot appear; the residual coding item records additional redundant information for information verification, and they are all the same symbols. The expanded sparse symbol structure is flipped only once more at the junction of the residual coding item and the odd coding item relative to the original single byte of information.

[0071] Expand two identical symbols in the odd array, keeping the original number of odd numbers unchanged; fill the even array with new even items of odd length according to the remaining number of symbols and the number of even items according to the preset rules; concatenate the items in the filled odd array and even array into odd coding items, and flip the last symbol of the odd coding item as a residual coding item and add it to the end of the odd coding item to generate the final coding item;

[0072] In this embodiment, the encoding process of the channel coding method proposed in this scheme is mainly as follows: Figure 3 As shown. First, traverse the bit information to be encoded, group the original information according to symbols, group consecutive identical symbols into a group, and calculate the number of symbols in each group. The odd number is the odd group, and the even number is the even group. For the odd group, directly expand two identical symbols and keep the original odd number unchanged. For the even group, fill it according to the remaining number of symbols and the number of even items. The rule is to fill all items in the even group with odd numbers. If there are multiple even items, the filled number is evenly divided, and the remaining items are used as residual coding items. The specific coding example is as follows Figure 4 As shown, ① is the odd-numbered item filled with two identical symbols; ② is the even-numbered item filled with the odd-numbered item; ③ is the residual coding item.

[0073] Check and verify whether the final coded item after coding has been completed has discontinuous distortion according to the symbol arrangement and length in the final coded item, and complete the coding process;

[0074] In this embodiment, the operation of checking and verifying the final coding item is specifically as follows:

[0075] The received symbol information is divided into 25 bits as an independent structure, and each structure is checked separately;

[0076] Check whether there are isolated symbols, such as 00100 or 11011. If there are, it means that the isolated symbols are distorted;

[0077] Separate the residual coding items at the tail. Only an odd number of consecutive symbols can appear in the odd coding items. If two even numbers of consecutive symbols appear, it means that the symbol between the two even items is distorted. If there is only one even number of consecutive symbols, it means that the symbol between the even item and the residual coding item is distorted. If 001111 appears, it means that the original signal is 000111.

[0078] When decoding unknown bit information, first separate the residual coding item at the end of the final coding item of the bit information to be decoded, and calculate the length of the residual coding item. Determine the number and length of the even items and odd items based on the length of the residual coding item, and determine the original odd items and even items based on the expansion rules during encoding. Then, concatenate all decoded items in the order before decoding to obtain the original bit information.

[0079] In this embodiment, after ensuring that there are only an odd number of consecutive symbols in the odd-numbered coding items and no isolated symbols appear, it means that the received signal does not have discontinuous distortion. After encoding by the encoding method of this scheme, the minimum value of the length of the odd-numbered items obtained by padding the even-numbered items will always be greater than the maximum value of the length of the odd-numbered items after padding; since the residual coding items are at the tail and there is no sign jump, the residual coding items can be separated first, and the residual coding items record the number of even-numbered items, so the even-numbered items can be separated from the odd-numbered coding items. The decoding process is to use the residual coding items to restore the even-numbered items in the odd-numbered coding items, and then restore the odd-numbered items. The specific process is as follows. Figure 5 shown.

[0080] As a preferred implementation of this embodiment, the step of filling the even number array with new even number items of odd length according to the remaining number of symbols and the number of even number items according to the preset rule is specifically as follows:

[0081] The remaining symbol length that needs to be filled with even items is calculated based on the length limit of the odd-numbered coded items and the length of the odd-numbered items in the odd group after expansion;

[0082] Each even-numbered item is expanded according to the number of even-numbered items and the length of the remaining symbols that need to be filled with the even-numbered items, and the same number of symbols as the symbols in each even-numbered item are added to expand them into new even-numbered items with an odd length.

[0083] In this embodiment, the entire encoding process is specifically as follows:

[0084] (1) Group the original symbols of a byte into odd and even groups according to the number of consecutive symbols;

[0085] (2) The odd-numbered terms expand to two identical symbols;

[0086] (3) Calculate the current number of symbols as n;

[0087] (4) Fill the even-numbered items with odd-numbered items of odd length according to the value of n and the number of even-numbered items;

[0088] (5) Concatenate the above filled items together as odd-numbered coded items;

[0089] (6) According to the last sign of the odd-numbered coding item, flip it as the sign of the residual coding item;

[0090] (7) Add a residual coding term after the odd-numbered coding term and make the total length 25.

[0091] As a preferred implementation of this embodiment, the length of the final encoding item is 25 bits.

[0092] As a preferred implementation of this embodiment, the judgment rule of the step of checking whether the final coded item encoded according to the symbol arrangement and length in the final coded item has discontinuous distortion is specifically as follows:

[0093] Determine whether the length of the final coded item is 25 bits;

[0094] Determine whether there are isolated symbols in the symbol arrangement of the final coding item. If there are isolated symbols, there is discontinuous distortion;

[0095] It is determined whether there are an even number of consecutive symbols in the odd number coding item, and the distortion position is further determined according to the number of groups of the even number of consecutive symbols.

[0096] As a preferred implementation of this embodiment, the steps of determining the number and length of even items and odd items according to the length of the residual coding items, and determining the original odd items and even items according to the expansion rule during encoding are specifically as follows:

[0097] The number and length of even items are determined according to the length of the residual coding item:

[0098] When the length of the residual coding item is 4, the number of even items is 1 and it is the longest item, so the longest item is marked;

[0099] When the length of the residual coding item is 2 or 3, the number of even items is 2 or 3. If the length of the longest item is greater than 5, the original length of the second longest item is 2, marking the longest item as an even item;

[0100] If the length of the residual coding item is 2 or 3, the number of even items is 2 or 3, and the length of the longest item is 5, then the original length of all remaining items is 2, and the longest item is marked as an even item;

[0101] If the length of the residual coding item is 5, and all items are of equal length, then these items of equal length are all even items and the original length is 2;

[0102] Subtract 2 from the lengths of all unmarked items with unknown original lengths to obtain all odd items;

[0103] Based on the length of the decoded item, calculate the length of the last marked even item;

[0104] Finally, all decoded items are concatenated in the order before decoding to obtain the original value of one bit.

[0105] In this embodiment, the operation of decoding the bit information to be decoded is specifically as follows:

[0106] (1) Separate the residual coding item at the end of the final coding item, that is, the last continuous symbol item;

[0107] (2) Calculate the residual coding item length as m;

[0108] (3) If the value of m is 4, it means there is only one even-numbered item, so jump to step (7);

[0109] (4) If the value of m is 2 or 3, it means that the number of even items is 2 or 3, and the length of the longest item is greater than 5, then the original length of the second longest item is 2, mark the longest item as an even item, and jump to step (7);

[0110] (5) If the value of m is 2 or 3, it means that the number of even items is 2 or 3, and the length of the longest item is 5. Then the original length of these items is 2. Mark the longest item as an even item and jump to step (7);

[0111] (6) If the value of m is 5 and all items are of equal length, then the original length of these items of equal length is 2, and jump to step (7);

[0112] (7) Subtract 2 from the length of each unmarked item to obtain all odd items;

[0113] (8) Based on the length of the decoded item, calculate the original length of the last even item;

[0114] (9) Concatenate all decoded items in the order before decoding to obtain the original value of a byte;

[0115] Embodiment 2:

[0116] A low-power channel coding system designed for backscatter communication, including:

[0117] The odd-even item grouping module traverses the bit information to be encoded, sets the bits with consecutive identical symbols in the original information into a group, and calculates the number of symbols in each group. The odd-numbered bits are determined as an odd group, and the even-numbered bits are determined as an even group.

[0118] The encoding module expands two identical symbols in the odd number group, keeping the original odd number unchanged; fills the even number group with new even number items of odd length according to the remaining number of symbols and the number of even number items according to the preset rules; splices the items in the filled odd number group and the even number group into an odd number encoding item, and flips the last symbol of the odd number encoding item as a residual encoding item and adds it to the end of the odd number encoding item to generate a final encoding item;

[0119] The verification module checks whether the final coded item after verification coding has discontinuous distortion according to the symbol arrangement and length in the final coded item, thereby completing the coding process;

[0120] The decoding module, when decoding unknown bit information, first separates the residual coding item at the end of the final coding item of the bit information to be decoded, and calculates the length of the residual coding item, determines the number and length of the even items and odd items according to the length of the residual coding item, and determines the original odd items and even items according to the expansion rules during encoding, and then splices all the decoded items in the order before decoding to obtain the original bit information.

[0121] As a preferred implementation of this embodiment, the step of filling the even number array with new even number items of odd length according to the remaining number of symbols and the number of even number items according to the preset rule is specifically as follows:

[0122] The remaining symbol length that needs to be filled with even items is calculated based on the length limit of the odd-numbered coded items and the length of the odd-numbered items in the odd group after expansion;

[0123] Each even-numbered item is expanded according to the number of even-numbered items and the length of the remaining symbols that need to be filled with the even-numbered items, and the same number of symbols as the symbols in each even-numbered item are added to expand them into new even-numbered items with an odd length.

[0124] As a preferred implementation of this embodiment, the length of the final encoding item is 25 bits.

[0125] As a preferred implementation of this embodiment, the judgment rule of the step of checking whether the final coded item encoded according to the symbol arrangement and length in the final coded item has discontinuous distortion is specifically as follows:

[0126] Determine whether the length of the final coded item is 25 bits;

[0127] Determine whether there are isolated symbols in the symbol arrangement of the final coding item. If there are isolated symbols, there is discontinuous distortion;

[0128] It is determined whether there are an even number of consecutive symbols in the odd number coding item, and the distortion position is further determined according to the number of groups of the even number of consecutive symbols.

[0129] As a preferred implementation of this embodiment, the steps of determining the number and length of even items and odd items according to the length of the residual coding items, and determining the original odd items and even items according to the expansion rule during encoding are specifically as follows:

[0130] The number and length of even items are determined according to the length of the residual coding item:

[0131] When the length of the residual coding item is 4, the number of even items is 1 and it is the longest item, so the longest item is marked;

[0132] When the length of the residual coding item is 2 or 3, the number of even items is 2 or 3. If the length of the longest item is greater than 5, the original length of the second longest item is 2, marking the longest item as an even item;

[0133] If the value of n is 2 or 3, the number of even items is 2 or 3, and the length of the longest item is 5, then the original length of all remaining items is 2, and the longest item is marked as an even item;

[0134] If the value of n is 5, and all items are of equal length, then these items of equal length are all even items and the original length is 2;

[0135] Subtract 2 from the lengths of all unmarked items with unknown original lengths to obtain all odd items;

[0136] Based on the length of the decoded item, calculate the length of the last marked even item;

[0137] Finally, all decoded items are concatenated in the order before decoding to obtain the original value of one bit.

[0138] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A low-power channel coding method designed for backscatter communication, characterized in that: The specific steps include: Traverse the bit information to be encoded, set the bits with consecutive identical symbols in the original information into a group, and calculate the number of symbols in each group, where the bits with an odd number of symbols are determined as an odd group, and the bits with an even number of symbols are determined as an even group; Expand two identical symbols in the odd array, keeping the original number of odd numbers unchanged; fill the even array with new even items of odd length according to the remaining number of symbols and the number of even items according to the preset rules; concatenate the items in the filled odd array and even array into odd coding items, and flip the last symbol of the odd coding item as a residual coding item and add it to the end of the odd coding item to generate the final coding item; Check and verify whether the final coded item after coding has been completed has discontinuous distortion according to the symbol arrangement and length in the final coded item, and complete the coding process; When decoding unknown bit information, first separate the residual coding item at the end of the final coding item of the bit information to be decoded, and calculate the length of the residual coding item. Determine the number and length of the even items and odd items based on the length of the residual coding item, and determine the original odd items and even items based on the expansion rules during encoding. Then, concatenate all decoded items in the order before decoding to obtain the original bit information.

2. The low-power channel coding method designed for backscatter communication according to claim 1, characterized in that: The step of filling the even number array with new even number items of odd length according to the remaining number of symbols and the number of even number items according to the preset rule is specifically as follows: The remaining symbol length that needs to be filled with even items is calculated based on the length limit of the odd-numbered coded items and the length of the odd-numbered items in the odd group after expansion; Each even-numbered item is expanded according to the number of even-numbered items and the length of the remaining symbols that need to be filled with the even-numbered items, and the same number of symbols as the symbols in each even-numbered item are added to expand them into new even-numbered items with an odd length.

3. The low-power channel coding method designed for backscatter communication according to claim 1, characterized in that: The length of the final coded item is 25 bits.

4. The low-power channel coding method designed for backscatter communication according to claim 3, characterized in that: The specific judgment rule of the step of checking and verifying whether the final coded item encoded according to the symbol arrangement and length in the final coded item has discontinuous distortion is: Determine whether the length of the final coded item is 25 bits; Determine whether there are isolated symbols in the symbol arrangement of the final coding item. If there are isolated symbols, there is discontinuous distortion; It is determined whether there are an even number of consecutive symbols in the odd number coding item, and the distortion position is further determined according to the number of groups of the even number of consecutive symbols.

5. The low-power channel coding method designed for backscatter communication according to claim 1, characterized in that: The steps of determining the number and length of even items and odd items according to the length of the residual coding items, and determining the original odd items and even items according to the expansion rule during encoding are specifically as follows: The number and length of even items are determined according to the length of the residual coding item: When the length of the residual coding item is 4, the number of even items is 1 and it is the longest item, so the longest item is marked; When the length of the residual coding item is 2 or 3, the number of even items is 2 or 3. If the length of the longest item is greater than 5, the original length of the second longest item is 2, marking the longest item as an even item; If the length of the residual coding item is 2 or 3, the number of even items is 2 or 3, and the length of the longest item is 5, then the original length of all remaining items is 2, and the longest item is marked as an even item; If the length of the residual coding item is 5, and all items are of equal length, then these items of equal length are all even items and the original length is 2; Subtract 2 from the lengths of all unmarked items with unknown original lengths to obtain all odd items; Based on the length of the decoded item, calculate the length of the last marked even item; Finally, all decoded items are concatenated in the order before decoding to obtain the original value of one bit.

6. A low-power channel coding system designed for backscatter communication, characterized in that: include: The odd-even item grouping module traverses the bit information to be encoded, sets the bits with consecutive identical symbols in the original information into a group, and calculates the number of symbols in each group. The odd-numbered bits are determined as an odd group, and the even-numbered bits are determined as an even group. The encoding module expands two identical symbols in the odd number group, keeping the original odd number unchanged; fills the even number group with new even number items of odd length according to the remaining number of symbols and the number of even number items according to the preset rules; splices the items in the filled odd number group and the even number group into an odd number encoding item, and flips the last symbol of the odd number encoding item as a residual encoding item and adds it to the end of the odd number encoding item to generate a final encoding item; The verification module checks whether the final coded item after verification coding has discontinuous distortion according to the symbol arrangement and length in the final coded item, thereby completing the coding process; The decoding module, when decoding unknown bit information, first separates the residual coding item at the end of the final coding item of the bit information to be decoded, and calculates the length of the residual coding item, determines the number and length of the even items and odd items according to the length of the residual coding item, and determines the original odd items and even items according to the expansion rules during encoding, and then splices all the decoded items in the order before decoding to obtain the original bit information.

7. The low-power channel coding system designed for backscatter communication according to claim 6, characterized in that: The step of filling the even number array with new even number items of odd length according to the remaining number of symbols and the number of even number items according to the preset rule is specifically as follows: The remaining symbol length that needs to be filled with even items is calculated based on the length limit of the odd-numbered coded items and the length of the odd-numbered items in the odd group after expansion; Each even-numbered item is expanded according to the number of even-numbered items and the length of the remaining symbols that need to be filled with the even-numbered items, and the same number of symbols as the symbols in each even-numbered item are added to expand them into new even-numbered items with an odd length.

8. The low-power channel coding system designed for backscatter communication according to claim 6, characterized in that: The length of the final coded item is 25 bits.

9. The low-power channel coding system designed for backscatter communication according to claim 8, characterized in that: The specific judgment rule of the step of checking and verifying whether the final coded item encoded according to the symbol arrangement and length in the final coded item has discontinuous distortion is: Determine whether the length of the final coded item is 25 bits; Determine whether there are isolated symbols in the symbol arrangement of the final coding item. If there are isolated symbols, there is discontinuous distortion; It is determined whether there are an even number of consecutive symbols in the odd number coding item, and the distortion position is further determined according to the number of groups of the even number of consecutive symbols.

10. The low-power channel coding system designed for backscatter communication according to claim 6, characterized in that: The steps of determining the number and length of even items and odd items according to the length of the residual coding items, and determining the original odd items and even items according to the expansion rule during encoding are specifically as follows: The number and length of even items are determined according to the length of the residual coding item: When the length of the residual coding item is 4, the number of even items is 1 and it is the longest item, so the longest item is marked; When the length of the residual coding item is 2 or 3, the number of even items is 2 or 3. If the length of the longest item is greater than 5, the original length of the second longest item is 2, marking the longest item as an even item; If the length of the residual coding item is 2 or 3, the number of even items is 2 or 3, and the length of the longest item is 5, then the original length of all remaining items is 2, and the longest item is marked as an even item; If the length of the residual coding item is 5, and all items are of equal length, then these items of equal length are all even items and the original length is 2; Subtract 2 from the lengths of all unmarked items with unknown original lengths to obtain all odd items; Based on the length of the decoded item, calculate the length of the last marked even item; Finally, all decoded items are concatenated in the order before decoding to obtain the original value of one bit.

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