Signal decoding method, device and electronic equipment based on OFDM system

Abstract

The present application discloses a signal decoding method, device and electronic device based on an OFDM system, which belongs to the field of communication technology. The signal decoding method includes: obtaining the signal-to-noise ratio and bit information of the subcarrier corresponding to the symbol in the valid signal, the valid signal includes multiple symbols, and the symbol includes multiple subcarriers; based on the bit information of the subcarrier corresponding to the symbol, determining a bit information set, the bit information in the bit information set corresponds to the same original bit; based on the comparison result between the signal-to-noise ratio corresponding to each two bit information in the bit information set, performing diversity merging on the bit information set to obtain the merged bit information; performing channel decoding based on the merged bit information. The present application determines the diversity merging strategy according to the difference between the signal-to-noise ratios of each two bit information in the bit information set, thereby reducing hardware resource consumption while ensuring high merging performance.

Description

Technical Field

[0001] The present application belongs to the field of power line carrier communication technology, and in particular relates to a signal decoding method, device and electronic equipment based on an OFDM system. Background Art

[0002] The existing power grid PLC (Power Line Communication) transmission environment is relatively harsh, and due to the complex and random narrowband interference and pulse interference in the scenario, to solve these channel problems and improve data transmission sensitivity, a diversity copy and interleaving solution is generally chosen. The same bit is sent at different time and frequency locations to reduce the probability of interference with the same bit. At the receiving end, the data and LLR (Link Level Retransmission) information corresponding to the same bit are combined and demodulated and decoded to obtain the final received bit result.

[0003] In the field of power line carrier communications, existing diversity copy merging technologies generally use a weighted merging method for different channels. Although this method can achieve the best combined signal-to-noise ratio, the calculation of weights involves division. Especially when the number of diversity copies is large, the amount of computation required for weight coefficient calculation and signal merging increases significantly, and the number of division operations also increases. This not only significantly increases computational complexity, resulting in increased hardware resource consumption and hardware costs, and extended processing delays, but also significantly increases the storage resource requirements for parameters such as noise power and weight coefficients. At the same time, a large number of division operations rely on dedicated hardware units (such as dividers). As the number of diversity paths increases, more hardware resources or complex time-division multiplexing mechanisms are required, further exacerbating computational delays, implementation costs, and power consumption. Summary of the Invention

[0004] This application aims to solve at least one of the technical problems existing in the related art. To this end, this application proposes a signal decoding method, device and electronic device based on an OFDM system, which can achieve high combining performance and reduce signal processing delay while reducing hardware resource consumption.

[0005] In a first aspect, the present application provides a signal decoding method based on an OFDM system, the method comprising:

[0006] Acquire a signal-to-noise ratio and bit information of a subcarrier corresponding to a symbol in a valid signal, wherein the valid signal includes a plurality of symbols, and the symbol includes a plurality of the subcarriers;

[0007] Determining a bit information set based on bit information of the subcarrier corresponding to the symbol, where the bit information in the bit information set corresponds to the same original bit;

[0008] performing diversity combining on the bit information set based on a comparison result between signal-to-noise ratios corresponding to every two bits of information in the bit information set to obtain combined bit information;

[0009] Channel decoding is performed based on the combined bit information.

[0010] According to the signal decoding method of the present application, performing diversity merging on the bit information set based on a comparison result between the signal-to-noise ratios corresponding to every two bits of information in the bit information set to obtain the merged bit information includes:

[0011] determining, based on a comparison result between the signal-to-noise ratios corresponding to every two bits of information in the bit information set, whether a ratio between the signal-to-noise ratio corresponding to at least one bit of information and a maximum signal-to-noise ratio does not exceed a target ratio; the maximum signal-to-noise ratio being a maximum value among the signal-to-noise ratios corresponding to each bit of information in the bit information set;

[0012] If there is at least one bit information whose signal-to-noise ratio corresponds to a ratio to the maximum signal-to-noise ratio that does not exceed the target ratio, then the at least one bit information in the bit information set is removed, and diversity merging is performed on the removed bit information set to obtain the merged bit information.

[0013] According to the signal decoding method of the present application, performing diversity combining on the eliminated bit information set to obtain the combined bit information includes:

[0014] If the bit information set after the elimination includes only one bit information, the one bit information is the merged bit information; if the bit information set after the elimination includes multiple bit information, the multiple bit information are added together to obtain the merged bit information.

[0015] According to the signal decoding method of the present application, performing diversity merging on the bit information set based on a comparison result between the signal-to-noise ratios corresponding to every two bits of information in the bit information set to obtain the merged bit information includes:

[0016] Based on a comparison result between signal-to-noise ratios corresponding to every two bits of information in the bit information set, the bit information set is divided into a plurality of bit information subsets, or at least one bit information subset and at least one single bit information; the division is aimed at ensuring that each of the bit information subsets meets a similarity condition and that the number of the plurality of bit information subsets, or the sum of the number of the at least one bit information subset and the at least one single bit information, is minimized; the similarity condition is that the ratio of the signal-to-noise ratios corresponding to every two bits of information in the bit information subset is greater than or equal to a target ratio and less than or equal to the inverse of the target ratio;

[0017] Adding the bit information in each of the bit information subsets to obtain combined bit information corresponding to each of the bit information subsets;

[0018] The combined bit information corresponding to the multiple bit information subsets is combined at a maximum ratio, or the combined bit information corresponding to the at least one bit information subset is combined at a maximum ratio with the at least one single bit information to obtain the combined bit information.

[0019] According to the signal decoding method of the present application, obtaining the signal-to-noise ratio and bit information of the subcarrier corresponding to the symbol in the valid signal includes:

[0020] Performing frame synchronization on a received signal to obtain a pilot symbol in the received signal;

[0021] Performing channel estimation based on the frequency domain data of the pilot symbol to obtain a channel estimation value of the subcarrier;

[0022] determining a signal-to-noise ratio of the subcarrier based on a channel estimation value of the subcarrier;

[0023] Based on the channel estimation value of the subcarrier, the subcarrier is demodulated to obtain bit information of the subcarrier.

[0024] According to the signal decoding method of the present application, determining the signal-to-noise ratio of the subcarrier based on the channel estimation value of the subcarrier includes:

[0025] Performing noise estimation based on the channel estimation value of the subcarrier to obtain noise energy of the subcarrier;

[0026] A signal-to-noise ratio of the subcarrier is determined based on the noise energy of the subcarrier and the channel estimation value.

[0027] According to the signal decoding method of the present application, performing noise estimation based on the channel estimation value of the subcarrier to obtain the noise energy of the subcarrier includes:

[0028] performing filtering processing on the channel estimation value of the subcarrier to obtain a filtered channel estimation value of the subcarrier;

[0029] The noise energy of the subcarrier is determined based on a difference between the channel estimate value and the filtered channel estimate value for the subcarrier.

[0030] According to the signal decoding method of the present application, the valid signal includes a frame control signal and / or a payload signal.

[0031] In a second aspect, the present application provides a signal decoding device based on an OFDM system, the device comprising:

[0032] An information acquisition module, configured to acquire a signal-to-noise ratio and bit information of a subcarrier corresponding to a symbol in a valid signal, wherein the valid signal includes a plurality of symbols, and the symbol includes a plurality of the subcarriers;

[0033] An information processing module, configured to determine a bit information set based on bit information of a subcarrier corresponding to the symbol, wherein the bit information in the bit information set corresponds to the same original bit;

[0034] A diversity combining module is configured to perform diversity combining on the bit information set based on a comparison result between signal-to-noise ratios corresponding to every two bits of information in the bit information set to obtain combined bit information;

[0035] A channel decoding module is configured to perform channel decoding based on the combined bit information.

[0036] In a third aspect, the present application provides an electronic device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the computer program, the signal decoding method based on the OFDM system as described in the first aspect above is implemented.

[0037] In a fourth aspect, the present application provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the signal decoding method based on the OFDM system as described in the first aspect above.

[0038] In a fifth aspect, the present application provides a chip, which includes a processor and a communication interface, the communication interface and the processor are coupled, and the processor is used to run programs or instructions to implement the signal decoding method based on the OFDM system as described in the first aspect.

[0039] In a sixth aspect, the present application provides a computer program product, comprising a computer program, which, when executed by a processor, implements the signal decoding method based on the OFDM system as described in the first aspect above.

[0040] The above one or more technical solutions in the embodiments of the present application have at least one of the following technical effects:

[0041] Furthermore, by grouping bit information of the same original bit at different time-frequency positions into a bit information set, and then determining the diversity combining strategy of the bit information set based on the difference between the signal-to-noise ratios corresponding to every two bits in the bit information set, it is possible to achieve high combining performance and reduce signal processing delay while reducing hardware resource consumption and hardware costs;

[0042] Furthermore, by performing channel decoding based on the combined bit information, it is possible to obtain more accurate information sent by the transmitter, thereby improving the reliability and efficiency of communication.

[0043] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0045] Figure 1 1 is a flow chart of a signal decoding method based on an OFDM system provided in an embodiment of the present application;

[0046] Figure 2 is a schematic diagram of a frame structure provided in an embodiment of the present application;

[0047] Figure 3 1 is a schematic structural diagram of a signal decoding device based on an OFDM system provided in an embodiment of the present application;

[0048] Figure 4 It is a structural diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0049] The following will be combined with the accompanying drawings in the embodiments of the present application to clearly describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are 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 are within the scope of protection of this application.

[0050] The terms "first," "second," and the like in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of this application can be implemented in an order other than that illustrated or described herein, and that the objects distinguished by "first," "second," and the like are generally of the same type, and do not limit the number of objects; for example, the first object can be one or more. In addition, the term "and / or" in the specification and claims refers to at least one of the connected objects, and the character " / " generally indicates that the objects connected are in an "or" relationship.

[0051] The following, in conjunction with the accompanying drawings, describes in detail the signal decoding method, signal decoding device, electronic device, and readable storage medium based on an OFDM (Orthogonal Frequency Division Multiplexing) system provided by the embodiments of the present application through specific embodiments and their application scenarios.

[0052] The signal decoding method may be applied to a terminal, and may be specifically executed by hardware or software in the terminal.

[0053] The signal decoding method provided in the embodiments of the present application may be executed by an electronic device or a functional module or functional entity in the electronic device that can implement the signal decoding method. The electronic devices mentioned in the embodiments of the present application include but are not limited to mobile phones, tablet computers, computers, cameras, and wearable devices. The signal decoding method provided in the embodiments of the present application is described below using an electronic device as an example of the execution entity.

[0054] In power line carrier communications, signals are subject to various interferences (such as noise and signal fading) during transmission, which can cause data errors at the receiving end. The diversity copy combined with interleaving scheme reduces the probability of interference between identical bits by sending them at different time-frequency locations and shuffling the data order. The receiving end then combines the information of identical bits and performs demodulation and decoding.

[0055] Because interference is random, signals at different time-frequency locations may experience different levels of interference. By using diversity copying to send the same bit at different time-frequency locations, the probability of the same bit being severely interfered with is reduced. This means that even if the signal at one time-frequency location experiences severe interference, the same bit at other time-frequency locations may still be received normally.

[0056] In communications, interference sometimes occurs in patches, potentially affecting multiple consecutive bits. Interleaving disperses these consecutive bits and allows them to be transmitted at different time-frequency locations. This way, even if interference occurs at a specific time-frequency location, it doesn't affect the previously consecutive identical bits. Instead, it spreads them out to different locations, reducing the likelihood of simultaneous errors among these bits.

[0057] The merging technology for correlated diversity copies typically uses maximum ratio combining. Maximum ratio combining generally weights different channels according to signal-to-noise ratio information to achieve the optimal combined signal-to-noise ratio. However, the weight calculation involves division, which is more complex than addition or multiplication in hardware implementation. Especially when the number of diversity copies is large, it will greatly increase the complexity of the operation.

[0058] In response to the above problems, an embodiment of the present application provides a signal decoding method based on an OFDM system.

[0059] Figure 1 FIG. 1 is a flow chart of a signal decoding method based on an OFDM system provided in an embodiment of the present application. Figure 1 As shown, the signal decoding method includes: step 110, step 120, step 130 and step 140.

[0060] Step 110: Acquire a signal-to-noise ratio and bit information of a subcarrier corresponding to a symbol in a valid signal, where the valid signal includes multiple symbols, and the symbol includes multiple subcarriers;

[0061] Step 120: Determine a bit information set based on the bit information of the subcarrier corresponding to the symbol, where the bit information in the bit information set corresponds to the same original bit.

[0062] In actual implementation, for a valid signal in the received signal, a preset number of continuous sampling points can be taken as a symbol in the time domain, and each symbol can be divided into multiple subcarriers in the frequency domain. By demodulating each subcarrier of each symbol, the bit information of each subcarrier of each symbol can be obtained. According to the mapping relationship between the same original bit and the time-frequency position, the bit information corresponding to the same original bit can be obtained, and these bit information are combined into a bit information set. Here, the number of bit information corresponding to the same original bit can be two or more, and the distribution position can be on different subcarriers of the same symbol, on different symbols of the same subcarrier, or on different subcarriers of different symbols. The embodiment of the present application does not make specific limitations on this.

[0063] Step 130: Based on the comparison result between the signal-to-noise ratios corresponding to every two bits of information in the bit information set, perform diversity combination on the bit information set to obtain combined bit information;

[0064] Step 140: Perform channel decoding based on the combined bit information.

[0065] It is understandable that the receiving end may receive the same bit sent at different time-frequency locations. Because these bits may be subject to varying degrees of interference, the received signal quality may also vary. The receiving end will combine the data corresponding to these identical bits (or LLR information, which is a measure of received signal reliability). Specifically, the receiving end will combine the bit information corresponding to the same original bit referred to in step 120 to obtain combined bit information. Channel decoding will then be performed based on the combined bit information to restore the combined bit information to the original bit originally transmitted.

[0066] It should be noted that, considering the high computational complexity of maximum ratio combining, the embodiment of the present application adopts an equal-gain combining method that directly adds the two-way bit information, without the need to calculate weights. At the same time, considering that when the difference in the signal-to-noise ratio of the two-way bit information is small, the equal-gain combining method can ensure a higher signal-to-noise ratio, and its performance is close to that of maximum ratio combining. Therefore, the embodiment of the present application calculates the ratio between the signal-to-noise ratios corresponding to each two bits of information in the bit information set, compares the difference between the signal-to-noise ratios corresponding to each two bits of information, obtains a comparison result between the signal-to-noise ratios corresponding to each two bits of information, and then determines whether the bit information needs to be combined with equal gain based on the difference in the comparison results, thereby completing the diversity combining of the bit information set and obtaining the combined bit information. Here, the signal-to-noise ratio is the ratio of signal power to noise power, that is, the ratio of signal energy to noise energy.

[0067] In actual implementation, a specific diversity combining strategy may be that if it is determined that the ratio between the signal-to-noise ratios corresponding to two bits of information is within the range of a target ratio and the inverse of the target ratio, it indicates that the difference in the signal-to-noise ratios of the two bits is small and they can be directly added together. If it is determined that the ratio between the signal-to-noise ratios of the two bits is lower than the target ratio or higher than the inverse of the target ratio, it indicates that the difference in the signal-to-noise ratios of the two bits is large, then the bits may not be combined and the bit information with the higher signal-to-noise ratio may be directly selected. The diversity combining strategy may also be that it is first determined that the ratio between the signal-to-noise ratios corresponding to two or more bits of information is within the range of a target ratio and the inverse of the target ratio, indicating that the difference in the signal-to-noise ratios of these bits of information is small, then these bits of information may be directly added together, and then the added bits of information may be subsequently combined with other bits of information. This embodiment of the present application does not specifically limit this.

[0068] Here, the target ratio is less than 1. The target ratio can be a pre-set fixed ratio. The specific value can be set according to the actual application scenario, or calculated according to the signal-to-noise ratio of different diversity combining methods in the simulation operation. The target ratio can also be an updateable ratio, for example, updated and adjusted according to the accuracy of signal decoding. The embodiments of the present application do not make specific limitations on this.

[0069] Similarly, if the signal-to-noise ratio is expressed in decibels, the embodiment of the present application can calculate the difference between the signal-to-noise ratios corresponding to every two bits of information in the bit information set, thereby comparing the difference between the signal-to-noise ratios corresponding to every two bits of information and obtaining a comparison result.

[0070] According to the signal decoding method provided in the embodiment of the present application, bit information of the same original bit distributed at different time-frequency positions is formed into a bit information set, and then the diversity merging strategy of the bit information set is determined based on the difference between the signal-to-noise ratios corresponding to each two bit information in the bit information set. This achieves the goal of reducing hardware resource consumption and hardware costs while ensuring high merging performance and reducing the signal processing delay. Channel decoding is performed on this basis, which can obtain more accurate information sent by the transmitter, thereby improving the reliability and efficiency of communication.

[0071] In some embodiments, step 130 may include:

[0072] determining, based on a comparison result between the signal-to-noise ratios corresponding to every two bits of information in the bit information set, whether a ratio between the signal-to-noise ratio corresponding to at least one bit of information and a maximum signal-to-noise ratio does not exceed a target ratio; the maximum signal-to-noise ratio being a maximum value among the signal-to-noise ratios corresponding to each bit of information in the bit information set;

[0073] If the ratio between the signal-to-noise ratio corresponding to at least one bit information and the maximum signal-to-noise ratio does not exceed the target ratio, at least one bit information in the bit information set is removed, and the removed bit information set is diversity combined to obtain the combined bit information.

[0074] In actual implementation, the maximum value of the signal-to-noise ratio corresponding to each bit information in the bit information set, namely the maximum signal-to-noise ratio, can be first determined, and the bit information corresponding to the maximum signal-to-noise ratio is the maximum bit information. Then, the ratio of the signal-to-noise ratio corresponding to each bit information other than the maximum bit information to the maximum bit information is determined. If there is at least one bit information whose ratio between the signal-to-noise ratio and the maximum signal-to-noise ratio is less than or equal to the target ratio, it means that the signal-to-noise ratio of at least one bit information is significantly different from the maximum signal-to-noise ratio. At least one bit information in the bit information set can be eliminated, and then diversity combination is performed on the eliminated bit information set to obtain combined bit information. If there is no bit information whose ratio between the signal-to-noise ratio and the maximum signal-to-noise ratio is less than or equal to the target ratio, it means that the signal-to-noise ratio of each bit information is slightly different from the maximum signal-to-noise ratio. Then, each bit information in the bit information set can be directly added to obtain the combined bit information.

[0075] It should be noted that the target ratio is less than 1. In order to ensure the maximum performance after equal-gain merging, the target ratio can be determined in advance based on the difference in signal-to-noise ratios before and after the equal-gain merging of the two bit information samples. When the ratio between the signal-to-noise ratios corresponding to two bits of information exceeds the target ratio, that is, when the difference in the signal-to-noise ratios of the two bits of information is small, the two bits of information are combined in an equal-gain manner. This not only ensures better performance than selective merging, but also ensures that the difference between the signal-to-noise ratio of equal-gain merging and the signal-to-noise ratio of maximum ratio merging is not too large. Compared with the maximum ratio merging method, the amount of calculation is greatly reduced, and the engineering implementation is simpler. On the contrary, when the difference in the signal-to-noise ratios of the two bits of information is large, the equal-gain merging method cannot obtain better performance. At this time, the selective merging method can be used to eliminate the bit information with a low signal-to-noise ratio. Based on this, in order to further reduce the computational complexity of diversity merging, we can first directly determine the bit information corresponding to the maximum signal-to-noise ratio, and then compare the ratio between the signal-to-noise ratio corresponding to each other bit information in the bit information set and the maximum signal-to-noise ratio with the target ratio, thereby determining the bit information that can be eliminated, and then perform equal-gain merging on the bit information set after elimination.

[0076] The target ratio is For example, if the signal-to-noise ratio set composed of the signal-to-noise ratios corresponding to the bit information in the bit information set is [3, 4, 7, 8], then there is no signal-to-noise ratio corresponding to a bit information and the signal-to-noise ratio corresponding to the maximum signal-to-noise ratio whose ratio is less than or equal to , directly add up each bit information in the bit information set; if the signal-to-noise ratio set is [1,2,3,9], the bit information corresponding to the signal-to-noise ratio of 1, 2, and 3 can be eliminated, and the bit information corresponding to the signal-to-noise ratio of 9 can be directly used as the combined bit information; if the signal-to-noise ratio set is [2,6,8,9,10], the bit information corresponding to the signal-to-noise ratio of 2 can be eliminated, and then the remaining bit information is added up.

[0077] It is understood that in order to better illustrate the difference between the signal-to-noise ratios, the above-mentioned signal-to-noise ratios all refer to unitless values, that is, the ratio of signal energy to noise energy. For example, the signal-to-noise ratio of A-bit information is 10, and the signal-to-noise ratio of B-bit information is 30. The ratio between the two is , and if the signal-to-noise ratio is expressed in decibels, the difference between the two is about -4.7dB.

[0078] According to the signal decoding method provided in the embodiment of the present application, by combining equal gain combining with selective combining, the algorithm is completely avoided while ensuring performance similar to maximum ratio combining, thereby greatly reducing the computational complexity.

[0079] In some embodiments, performing diversity combining on the eliminated bit information set to obtain combined bit information may include:

[0080] If the bit information set after elimination includes only one bit information, the one bit information is the merged bit information; if the bit information set after elimination includes multiple bit information, the multiple bit information are added together to obtain the merged bit information.

[0081] In actual implementation, if the bit information set after elimination includes only one bit information, that is, the bit information corresponding to the maximum signal-to-noise ratio, then this bit information is the merged bit information; if the bit information set after elimination includes multiple bit information, these bit information can be directly added together to obtain the merged bit information.

[0082] It can be understood that compared with the maximum ratio combining method for the bit information set after elimination, the embodiment of the present application can achieve a combining performance close to the maximum ratio combining performance through equal gain combining, while reducing the computational complexity and reducing hardware resource consumption.

[0083] In some embodiments, step 130 may include:

[0084] Based on a comparison result between signal-to-noise ratios corresponding to every two bits of information in the bit information set, the bit information set is divided into a plurality of bit information subsets, or at least one bit information subset and at least one single bit information; the division is targeted at ensuring that each bit information subset meets a similarity condition and that the number of the plurality of bit information subsets, or the sum of the number of the at least one bit information subset and the at least one single bit information, is minimized; the similarity condition is that the ratio of the signal-to-noise ratios corresponding to every two bits of information in the bit information subset is greater than or equal to a target ratio and less than or equal to the inverse of the target ratio;

[0085] Adding the bit information in each bit information subset to obtain combined bit information corresponding to each bit information subset;

[0086] The combined bit information corresponding to the plurality of bit information subsets is combined at a maximum ratio, or the combined bit information corresponding to at least one bit information subset is combined at a maximum ratio with at least one single bit information to obtain combined bit information.

[0087] In actual implementation, the bit information set can be arranged in ascending order of signal-to-noise ratio, and traversal can be started from the first bit information. If the signal-to-noise ratio ratio of the i-th bit information to the first bit information is greater than the inverse of the target ratio, the process stops, and the first subset is generated from the 1st bit information to the i-1th bit information. Then, traversal can be started from the i-th bit information. If the signal-to-noise ratio ratio of the j-th bit information to the i-th bit information is greater than the inverse of the target ratio, the process stops, and the second subset is generated from the i-th bit information to the j-1th bit information, and so on, until all the bit information has been traversed. In this way, the bit information set can be divided into multiple bit information subsets, or at least one bit information subset and at least one single bit information, and each bit information subset is guaranteed to meet the similarity condition, and the number of multiple bit information subsets, or the sum of the number of at least one bit information subset and at least one single bit information is as small as possible. If at least one bit information subset and at least one single bit information are divided out, the single bit information refers to the bit information that cannot be divided into the bit information subset, because each bit information subset will not meet the similarity condition after adding any single bit information.

[0088] Similarly, the embodiment of the present application can also arrange the bit information set in order of signal-to-noise ratio from large to small, and then traverse it in the above manner. The final division result may be different from the result of the division in the above manner, but as long as the number of subsequent maximum ratio merging is the same, that is, the amount of computational complexity of the diversity merging is the same, both division methods are acceptable, and the embodiment of the present application does not make specific limitations on this.

[0089] The target ratio is , taking the inverse of the target ratio as 3 as an example, if the signal-to-noise ratio set is [1,2,3,9], then the bit information corresponding to the signal-to-noise ratios of 1, 2, and 3 can be used as a bit information subset, and the bit information corresponding to the signal-to-noise ratio of 9 can be used as a single bit information; or the bit information corresponding to the signal-to-noise ratios of 1 and 2 can be used as a bit information subset, and the bit information corresponding to the signal-to-noise ratios of 3 and 9 can be used as another bit information subset. In both division methods, only the maximum ratio merging of the two information channels is required.

[0090] If the signal-to-noise ratio set is [1, 2, 3, 8, 18, 27], the bit information corresponding to the signal-to-noise ratios of 1, 2, and 3 can be used as a bit information subset, the bit information corresponding to the signal-to-noise ratios of 8 and 18 can be used as another bit information subset, and the bit information corresponding to the signal-to-noise ratio of 27 can be used as a single bit information. Alternatively, the bit information corresponding to the signal-to-noise ratios of 1 and 2 can be used as a bit information subset, the bit information corresponding to the signal-to-noise ratios of 3 and 8 can be used as another bit information subset, and the bit information corresponding to the signal-to-noise ratios of 18 and 27 can be used as a third bit information subset. Both division methods only require the maximum ratio merging of the three information channels.

[0091] When performing maximum ratio combining on each channel of information, the signal-to-noise ratio of each channel of information (for example, the inverse of the noise power when the signal power is 1) can be directly used as a weighting coefficient, or the normalized value of the signal-to-noise ratio of each channel of information can be used as the weighting coefficient, and then the information of each channel is calculated and combined based on the weighting coefficient of each channel of information. This embodiment of the present application does not specifically limit this.

[0092] It should be noted that the target ratio is less than 1. In order to ensure the maximization of the performance after equal-gain merging, the target ratio can be determined in advance based on the difference in signal-to-noise ratios before and after the equal-gain merging of the two bit information samples. The similarity condition is that the ratio between the signal-to-noise ratios corresponding to each two bit information in the bit information subset is greater than or equal to the target ratio, and less than or equal to the inverse of the target ratio. The similarity condition can ensure that the bit information subset using equal-gain merging has higher merging performance, and on this basis, maximum ratio merging is performed, that is, through the combination of equal-gain merging and maximum ratio merging, the performance is close to that of a single maximum ratio merging, while also reducing division operations and significantly reducing computational complexity. Compared to directly using maximum ratio merging, the embodiment of the present application can reduce the amount of computational complexity of diversity merging. For example, if diversity copies are performed 16 times in an OFDM system, then for the same bit information at 16 different positions, if maximum ratio combining is performed directly, the number of complex divisions, complex multiplications, and complex additions are 16, 16, and 15 respectively; if equal-gain combining is performed first and then maximum ratio combining is performed on every two, the number of complex divisions, complex multiplications, and complex additions are 8, 8, and 15 respectively. It can be seen that equal-gain combining combined with maximum ratio combining can significantly reduce the complexity of the operation.

[0093] In addition to the similarity condition, the goal of bit information set partitioning also includes minimizing the number of multiple bit information subsets, or the sum of at least one bit information subset and at least one single bit information, so as to ensure that the number of subsequent maximum ratio combining is minimized as much as possible, thereby minimizing the computational complexity of diversity combining. For example, taking the target ratio as 1 / 3 as an example, if the signal-to-noise ratio set is [1, 3, 7, 9, 15, 18, 21], although it can be partitioned into 1, [3, 7, 9], [15, 18, 21], or [1, 3], [7, 9, 15, 18, 21], or 1, [3, 7], [9, 15, 18, 21], considering the number of combinations, the final partitioning result should be the bit information subsets corresponding to the signal-to-noise ratios [1, 3] and [7, 9, 15, 18, 21] respectively.

[0094] It can be understood that when the signal energy of two bit information is the same, the similarity condition is equivalent to the ratio between the noise energies corresponding to every two bit information in the bit information subset being greater than or equal to the target ratio and less than or equal to the inverse of the target ratio.

[0095] Specially, there may be a situation where there is only one bit information subset. Simply add up each bit information in the bit information set. For example, if the signal-to-noise ratio set corresponding to the bit information set is [1, 2, 3], then the bit information set is the bit information subset that meets the conditions. Simply add up the three bits of information in the bit information set to obtain the merged bit information. There may also be a situation where all the information is single bit information. Simply add up these single bits of information. For example, if the signal-to-noise ratio set corresponding to the bit information set is [1, 4, 16], then the bit information set is divided into three single bits of information. Simply add up these three bits of information to obtain the merged bit information.

[0096] It should be noted that compared with the direct use of maximum ratio combining method, the embodiment of the present application adopts a two-stage combining method of equal gain combining and then maximum ratio combining, which reduces the requirements for channel estimation and sensitivity to noise, and significantly reduces the complexity of hardware implementation and hardware resource requirements, and is more suitable for low-cost, low-power or poor channel conditions.

[0097] In some embodiments, step 110 may include:

[0098] Performing frame synchronization on the received signal to obtain pilot symbols in the received signal;

[0099] Perform channel estimation based on the frequency domain data of the pilot symbol to obtain a channel estimation value of the subcarrier;

[0100] determining a signal-to-noise ratio of the subcarrier based on a channel estimate value of the subcarrier;

[0101] Based on the channel estimation value of the subcarrier, the subcarrier is demodulated to obtain the bit information of the subcarrier.

[0102] In practice, the receiver performs frame synchronization detection on the incoming received signal, extracts pilot symbols from the synchronized signal frame based on the pilot position, and converts the pilot symbols to the frequency domain using a Fast Fourier Transform (FFT) to obtain the frequency domain data of the received pilot symbols. Based on the locally stored frequency domain data of the pilot symbols, a least squares (LS) estimation is performed on each subcarrier in the received frequency domain data to obtain a channel estimate for each subcarrier. The signal-to-noise ratio (SNR) of each subcarrier is then calculated based on the channel estimate. The channel estimate is then used to demodulate each subcarrier to obtain its bit information. This bit information is then input into a channel decoder to output the final bit stream.

[0103] Here, the pilot symbol may be a SYNCP (Synchronization Preamble) in a preamble symbol, or other pilot symbols such as Scattered Pilots (SP) and Demodulation Reference Signals (DM-RS), which is not specifically limited in the embodiment of the present application.

[0104] It should be noted that the embodiment of the present application estimates the signal-to-noise ratio of the data symbol by using the channel estimation value of the pilot symbol based on the correlation between the channel response and noise power of the pilot symbol and the data symbol, demodulating the subcarrier, and calculating the signal-to-noise ratio of the pilot symbol using the channel estimation value of the pilot symbol to estimate the signal-to-noise ratio of the data symbol. In addition, during the demodulation process of the subcarrier, phase correction is also performed based on the channel estimation value to ensure that the phase of the obtained bit information is aligned, which facilitates subsequent diversity combining.

[0105] In some embodiments, determining a signal-to-noise ratio of a subcarrier based on a channel estimate value of the subcarrier may include:

[0106] Perform noise estimation based on the channel estimation value of the subcarrier to obtain the noise energy of the subcarrier;

[0107] A signal-to-noise ratio (SNR) of the subcarrier is determined based on the noise energy of the subcarrier and the channel estimate.

[0108] In actual implementation, noise energy estimation can be performed on each subcarrier based on the channel estimation value of each subcarrier to obtain the noise energy of each subcarrier, and then the signal energy of each subcarrier is calculated based on the channel estimation value of each subcarrier after filtering. Therefore, the signal-to-noise ratio of each subcarrier can be obtained based on the ratio of signal energy to noise energy.

[0109] Here, the specific method of noise estimation can be to estimate the residual signal calculated based on the frequency domain data of the received pilot symbol, the frequency domain data of the locally stored pilot symbol and the channel estimation value of the subcarrier, or it can be estimated based on the difference between the channel estimation values ​​before and after filtering of the subcarrier. The embodiments of the present application do not make specific limitations on this.

[0110] In some embodiments, performing noise estimation based on the channel estimation value of the subcarrier to obtain the noise energy of the subcarrier may include:

[0111] Filtering the channel estimation value of the subcarrier to obtain a filtered channel estimation value of the subcarrier;

[0112] The noise energy of the subcarrier is determined based on a difference between the channel estimate and the filtered channel estimate for the subcarrier.

[0113] In actual implementation, in order to achieve accurate noise estimation, the embodiment of the present application can filter the channel estimation value of each subcarrier to obtain the channel estimation value after filtering of each subcarrier, that is, the filtered channel estimation value. It can be considered that the channel estimation value before filtering is the result of the superposition of signal energy and noise energy. The channel estimation value after filtering can determine the signal energy. On this basis, the noise estimation can be performed according to the difference between the channel estimation value of each subcarrier before filtering and after filtering to obtain the noise energy of each subcarrier.

[0114] In some embodiments, the valid signal may include a frame control signal and / or a payload signal.

[0115] In practice, valid signals can be frame control signals, payload signals, or even both. In this case, the frame control signals and payload signals can be processed in parallel. Here, the frame control signals are used to transmit control instructions related to data transmission, while the payload signals are signals that carry user data.

[0116] In some embodiments, the following are the main techniques for merging the subset copies:

[0117] Solution 1: Selective merging: Based on the channel information of different bits, such as signal-to-noise ratio (SNR) and signal energy, the bit with the higher SNR and signal energy is selected as the channel information of the current bit.

[0118] Solution 2: Equal-gain combining: Equal-gain combining, also known as phase equalization, corrects only the phase offset of the channel, not the amplitude. Equal-gain combining is not the optimal combining method in any sense. It is only optimal when the signal-to-noise ratio of each signal is the same, maximizing it.

[0119] Solution 3, Maximum Ratio Combining: Compared with equal-gain combining, Maximum Ratio Combining generally weights different channels according to the signal-to-noise ratio information to obtain the best combined signal-to-noise ratio;

[0120] Of the three solutions mentioned above, Solution 1 cannot achieve diversity signal-to-noise ratio gain, Solution 2 cannot achieve the best combined signal-to-noise ratio, and although Solution 3 achieves the best combined signal-to-noise ratio, it involves division, which increases computational complexity.

[0121] Therefore, the embodiment of the present application provides a diversity combining optimization solution based on subcarrier signal-to-noise ratio. The embodiment of the present application is applied to the field of power line carrier communication, and the specific steps are as follows:

[0122] 1. Calculate the subcarrier channel estimation, noise estimation, and signal-to-noise ratio corresponding to the current bit based on the received data.

[0123] Receive the signal and synchronize it to obtain the synchronization position, perform FFT transformation and demodulate the synchronization symbols in the received signal based on the synchronization position, and obtain the channel estimation results, noise estimation results and signal-to-noise ratio results of each subcarrier;

[0124] Figure 2 This is a schematic diagram of the frame structure provided by the embodiment of the present application. Figure 2 As shown, the frame structure includes a preamble symbol, which includes multiple SYNCP synchronization symbols. Channel or noise estimation can be performed using a single SYNCP synchronization symbol, or by averaging multiple SYNCP synchronization symbols. The preamble symbol is followed by frame control signals, data payload signals, etc.

[0125] Channel estimation process: Frame synchronization is performed on the received signal. The synchronization symbol (i.e., the SYNCP symbol sent by the transmitter) can be determined based on the synchronization peak during the frame synchronization process. Then, LS channel estimation can be performed on each subcarrier based on the synchronization symbol. Let N be the number of subcarriers, then

[0126]

[0127] For LS channel estimation of HPLC (High-speed Power Line Communications), is the received SYNCP symbol (it can also be the average result of FFT of several received SYNCP symbols), To transmit the frequency domain data of the SYNCP symbol (i.e., the frequency domain data of the local SYNCP symbol), unused subcarrier positions are filled with 0, N is the number of subcarriers; k is the subcarrier number, and the larger the number, the larger the corresponding subcarrier frequency; H[k] is the channel estimation result. Y[k] is a complex number, and the corresponding H[k] is also a complex number. It should be noted that in the embodiment of the present application, channel estimation is performed using the SYNCP symbol in the pilot signal. By utilizing the received pilot symbol and the local pilot symbol, the LS channel estimation result can be obtained.

[0128] The embodiments of the present application do not specifically limit the noise estimation and signal-to-noise ratio calculation methods for each subcarrier. For example, in power line carrier communication, since it is easily affected by various noise interferences, the channel estimation results of each subcarrier can be filtered. By subtracting the channel estimation after filtering from the channel estimation before filtering, the noise of each subcarrier can be calculated, thereby obtaining the noise energy (i.e., the noise estimation result) and the signal-to-noise ratio result.

[0129] 2. Demodulate the subcarrier and calculate the bit information.

[0130] This refers to demodulating the signals following the preamble (including frame control signals and data payload signals) to obtain the demodulated information of the subsequent symbols (a symbol can be 1024 points. 1024 points are taken in the time domain and transformed into a frequency domain signal after FFT transformation. Each symbol contains the same number of subcarriers). The demodulation result is the bit information of each subcarrier of each symbol.

[0131]

[0132] In the above formula is the received subcarrier, is the subcarrier after compensation based on the channel estimation result, is the channel estimation result in step 1.

[0133] 3. Compare the signal-to-noise ratios of the received data corresponding to the same bit.

[0134] Here, the same bit may be on different subcarriers in the same symbol, or on different subcarriers in different symbols. The specific location can be determined according to the actual communication protocol. The protocol will specify the location of the same bit at the receiver and the transmitter. That is, the location of the same bit is known to the receiver and can be compared after demodulation.

[0135] 4. If the signal-to-noise ratios of the two are close (the difference does not exceed 4.7dB) or the noise does not exceed 3 times, equal gain merging is performed.

[0136] If this condition is met, equal-gain combining is performed on identical bits. Under normal circumstances, combining performance is guaranteed to be consistently better than selective combining in scenarios with similar signal-to-noise ratios, and its performance is close to that of maximum ratio combining. However, compared to maximum ratio combining, it saves division operations and simplifies engineering implementation.

[0137] 5. If the signal-to-noise ratio or noise difference between the two is large, the bit information with higher signal-to-noise ratio or smaller noise is selected.

[0138] If the condition in step 4 is not met, the bit information with a high signal-to-noise ratio or low noise is selected, that is, selective merging is used at this time.

[0139] In some embodiments, the bit diversity combining concept of the embodiments of the present application can be a combination of selective combining and equal gain combining based on signal-to-noise ratio information, aiming to select which combining scheme to use based on the signal-to-noise ratio differences of different channels, and to obtain performance close to maximum ratio combining while reducing hardware resources.

[0140] Taking the case of two-way bit merging and two-way noise being independent as an example, after demodulation, the demodulation result of the same bit can be written as

[0141]

[0142]

[0143] The channel estimation of the demodulated bit result is For example,

[0144] Therefore, the current bit demodulation result based on the maximum ratio combining of channel energy degenerates into equal gain combining:

[0145]

[0146] At this time, the signal-to-noise ratio of the combined signal is

[0147]

[0148] Here Indicates the combined signal (including two bit signals and noise signal 、 ), then the signal energy is 4 (assuming The power is 1); the noise energy is and . =Signal energy / noise energy.

[0149] The maximum ratio combining result based on the signal-to-noise ratio is:

[0150]

[0151] At this time, the signal-to-noise ratio of the combined signal is

[0152]

[0153] Similarly, the signal energy here is , the noise energy is , =Signal energy / noise energy.

[0154] Therefore, it can be seen that the maximum ratio combining method based on the signal-to-noise ratio (SNR) performs better. When the bit noise energies of the two channels are close (the signal energies are the same in this example), the performance of the two schemes is similar. The greater the difference in the bit noise between the two channels, the performance of the first combining scheme deteriorates.

[0155] However, the second merging scheme requires dividing by the noise energy, which increases the amount of computation and delay, and is also difficult to implement. Furthermore, due to the uncertainty of the noise, more fixed-point bit widths need to be reserved, which comes at a high cost in hardware resources.

[0156] Therefore, the embodiment of the present application aims to be based on the first merging scheme and reduce the performance degradation caused by large noise differences. When the noise difference is large, instead of merging, the bit information of the channel with a larger signal-to-noise ratio is selected. When the noise difference is large, equal gain merging is performed.

[0157] In the example of the embodiment of the present application where the energy of the two bit signals is the same, in order to ensure that the signal-to-noise ratio after equal gain merging is greater than that before merging, it is necessary to ensure that and Moreover, if this condition is met, the difference between the signal-to-noise ratio of equal-gain combining and the signal-to-noise ratio of maximum ratio combining will not be too great;

[0158] Therefore, when the embodiment of the present application finds that the noise difference between the two bits exceeds 3 times, or the difference in the signal-to-noise ratio expressed in decibels exceeds 4.7dB, it is not appropriate to directly merge them. Instead, the result with the larger signal-to-noise ratio should be selected. At this time, compared with maximum ratio merging, selective merging can maintain better signal performance while avoiding operations; when the embodiment of the present application finds that the noise difference between the two bits does not exceed 3 times, or the difference in the signal-to-noise ratio expressed in decibels does not exceed 4.7dB, equal gain merging can be performed. At this time, equal gain merging can also maintain better signal performance while avoiding operations. It should be noted that the example here uses the merging of two bits as an example. In actual communication, there may be more than two channels.

[0159] The signal decoding method provided in the embodiment of the present application can be executed by a signal decoding device. In the embodiment of the present application, the signal decoding device provided in the embodiment of the present application is described by taking the signal decoding method performed by the signal decoding device as an example.

[0160] An embodiment of the present application also provides a signal decoding device based on an OFDM system.

[0161] Figure 3 FIG. 1 is a schematic diagram of the structure of a signal decoding device based on an OFDM system provided in an embodiment of the present application. Figure 3 As shown, the signal decoding device includes: an information acquisition module 310 , an information processing module 320 , a diversity combining module 330 and a channel decoding module 340 .

[0162] An information acquisition module 310 is configured to acquire a signal-to-noise ratio and bit information of a subcarrier corresponding to a symbol in a valid signal, wherein the valid signal includes a plurality of symbols, and the symbol includes a plurality of the subcarriers;

[0163] An information processing module 320 is configured to determine a bit information set based on the bit information of the subcarrier corresponding to the symbol, where the bit information in the bit information set corresponds to the same original bit;

[0164] A diversity combining module 330 is configured to perform diversity combining on the bit information set based on a comparison result between signal-to-noise ratios corresponding to every two bits of information in the bit information set to obtain combined bit information;

[0165] The channel decoding module 340 is configured to perform channel decoding based on the combined bit information.

[0166] According to the signal decoding device provided in the embodiment of the present application, by forming a bit information set with bit information distributed at different time-frequency positions of the same original bit, and then determining the diversity merging strategy of the bit information set based on the difference between the signal-to-noise ratios corresponding to every two bits of information in the bit information set, it is achieved that while reducing hardware resource consumption and hardware costs, high merging performance is ensured and the signal processing delay is reduced. Channel decoding is performed on this basis, and relatively accurate information sent by the transmitter can be obtained, thereby improving the reliability and efficiency of communication.

[0167] The signal decoding device in the embodiments of the present application can be an electronic device or a component of an electronic device, such as an integrated circuit or chip. The electronic device can be a terminal or other device other than a terminal. For example, the electronic device can be a mobile phone, a tablet computer, a laptop computer, a PDA, an in-vehicle electronic device, a mobile internet device (MID), an augmented reality (AR) / virtual reality (VR) device, a robot, a wearable device, an ultra-mobile personal computer (UMPC), a netbook, or a personal digital assistant (PDA). It can also be a server, a network attached storage (NAS), a personal computer (PC), a television (TV), a teller machine, or a self-service machine, etc., and the embodiments of the present application are not specifically limited thereto.

[0168] The signal decoding device in the embodiments of the present application may be a device having an operating system. The operating system may be a Microsoft (Windows) operating system, an Android operating system, an iOS operating system, or other possible operating systems, which are not specifically limited in the embodiments of the present application.

[0169] The signal decoding device provided in the embodiment of the present application can achieve Figures 1 to 2 To avoid repetition, the various processes implemented in the method embodiment are not described here.

[0170] In some embodiments, as Figure 4 As shown, an embodiment of the present application also provides an electronic device 400, including a processor 401, a memory 402, and a computer program stored in the memory 402 and executable on the processor 401. When the program is executed by the processor 401, the various processes of the above-mentioned signal decoding method embodiment based on the OFDM system are implemented, and the same technical effect can be achieved. To avoid repetition, it will not be repeated here.

[0171] It should be noted that the electronic devices in the embodiments of the present application include the mobile electronic devices and non-mobile electronic devices mentioned above.

[0172] An embodiment of the present application also provides a non-transitory computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the various processes of the above-mentioned signal decoding method embodiment based on the OFDM system and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0173] The processor is the processor in the electronic device described in the above embodiment. The readable storage medium includes a computer readable storage medium, such as a computer read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0174] An embodiment of the present application further provides a computer program product, including a computer program, which implements the above-mentioned signal decoding method based on the OFDM system when executed by a processor.

[0175] The processor is the processor in the electronic device described in the above embodiment. The readable storage medium includes a computer readable storage medium, such as a computer read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0176] An embodiment of the present application further provides a chip, which includes a processor and a communication interface, wherein the communication interface is coupled to the processor, and the processor is used to run programs or instructions to implement the various processes of the above-mentioned signal decoding method embodiment based on the OFDM system, and can achieve the same technical effect. To avoid repetition, it will not be repeated here.

[0177] It should be understood that the chip mentioned in the embodiments of the present application can also be called a system-level chip, a system chip, a chip system or a system-on-chip chip, etc.

[0178] It should be noted that, in this article, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising 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, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element. In addition, it should be noted that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in the opposite order according to the functions involved. For example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0179] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus the necessary general hardware platform. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, or the part that contributes to the relevant technology, can be embodied in the form of a computer software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes a number of instructions for enabling a terminal (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in each embodiment of this application.

[0180] The embodiments of the present application are described above in conjunction with the accompanying drawings, but the present application is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of this application, ordinary technicians in this field can also make many forms without departing from the purpose of this application and the scope of protection of the claims, all of which are within the protection of this application.

[0181] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0182] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and intent of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A signal decoding method based on an OFDM system, characterized in that: include: Acquire a signal-to-noise ratio and bit information of a subcarrier corresponding to a symbol in a valid signal, wherein the valid signal includes a plurality of symbols, and the symbol includes a plurality of the subcarriers; Determining a bit information set based on bit information of the subcarrier corresponding to the symbol, where the bit information in the bit information set corresponds to the same original bit; determining, based on a comparison result between the signal-to-noise ratios corresponding to every two bits of information in the bit information set, whether a ratio between the signal-to-noise ratio corresponding to at least one bit of information and a maximum signal-to-noise ratio does not exceed a target ratio; the maximum signal-to-noise ratio being a maximum value among the signal-to-noise ratios corresponding to each bit of information in the bit information set; If the ratio between the signal-to-noise ratio corresponding to at least one bit information and the maximum signal-to-noise ratio does not exceed the target ratio, removing the at least one bit information from the bit information set, and performing equal-gain combining on the removed bit information set to obtain combined bit information; Channel decoding is performed based on the combined bit information.

2. The signal decoding method based on the OFDM system according to claim 1, characterized in that: The performing diversity combining on the eliminated bit information set to obtain the combined bit information includes: If the bit information set after the elimination includes only one bit information, the one bit information is the merged bit information; if the bit information set after the elimination includes multiple bit information, the multiple bit information are added together to obtain the merged bit information.

3. The signal decoding method based on OFDM system according to claim 1, characterized in that: The performing diversity combining on the bit information set based on a comparison result between signal-to-noise ratios corresponding to every two bit information in the bit information set to obtain combined bit information includes: Based on a comparison result between signal-to-noise ratios corresponding to every two bits of information in the bit information set, the bit information set is divided into a plurality of bit information subsets, or at least one bit information subset and at least one single bit information; the division is aimed at ensuring that each of the bit information subsets meets a similarity condition and that the number of the plurality of bit information subsets, or the sum of the number of the at least one bit information subset and the at least one single bit information, is minimized; the similarity condition is that the ratio of the signal-to-noise ratios corresponding to every two bits of information in the bit information subset is greater than or equal to a target ratio and less than or equal to the inverse of the target ratio; Adding the bit information in each of the bit information subsets to obtain combined bit information corresponding to each of the bit information subsets; The combined bit information corresponding to the multiple bit information subsets is combined at a maximum ratio, or the combined bit information corresponding to the at least one bit information subset is combined at a maximum ratio with the at least one single bit information to obtain the combined bit information.

4. The signal decoding method based on OFDM system according to claim 1, characterized in that: The obtaining of the signal-to-noise ratio and bit information of the subcarrier corresponding to the symbol in the valid signal includes: Performing frame synchronization on a received signal to obtain a pilot symbol in the received signal; Performing channel estimation based on the frequency domain data of the pilot symbol to obtain a channel estimation value of the subcarrier; determining a signal-to-noise ratio of the subcarrier based on a channel estimation value of the subcarrier; Based on the channel estimation value of the subcarrier, the subcarrier is demodulated to obtain bit information of the subcarrier.

5. The signal decoding method based on OFDM system according to claim 4, characterized in that: The determining, based on the channel estimation value of the subcarrier, the signal-to-noise ratio of the subcarrier includes: Performing noise estimation based on the channel estimation value of the subcarrier to obtain noise energy of the subcarrier; A signal-to-noise ratio of the subcarrier is determined based on the noise energy of the subcarrier and the channel estimation value.

6. The signal decoding method based on OFDM system according to claim 5, characterized in that: The performing noise estimation based on the channel estimation value of the subcarrier to obtain the noise energy of the subcarrier includes: performing filtering processing on the channel estimation value of the subcarrier to obtain a filtered channel estimation value of the subcarrier; The noise energy of the subcarrier is determined based on a difference between the channel estimate value and the filtered channel estimate value for the subcarrier.

7. The signal decoding method based on an OFDM system according to any one of claims 1 to 6, characterized in that: The valid signal includes a frame control signal and / or a payload signal.

8. A signal decoding device based on an OFDM system, characterized in that: include: An information acquisition module, configured to acquire a signal-to-noise ratio and bit information of a subcarrier corresponding to a symbol in a valid signal, wherein the valid signal includes a plurality of symbols, and the symbol includes a plurality of the subcarriers; An information processing module, configured to determine a bit information set based on bit information of a subcarrier corresponding to the symbol, wherein the bit information in the bit information set corresponds to the same original bit; a diversity combining module configured to determine, based on a comparison result between the signal-to-noise ratios corresponding to every two bits of information in the bit information set, whether there is at least one bit of information whose ratio between the signal-to-noise ratio corresponding to the bit information set and a maximum signal-to-noise ratio does not exceed a target ratio; the maximum signal-to-noise ratio being the maximum value of the signal-to-noise ratios corresponding to each bit of information in the bit information set; if there is at least one bit of information whose ratio between the signal-to-noise ratio corresponding to the maximum signal-to-noise ratio does not exceed the target ratio, removing the at least one bit of information from the bit information set, and performing equal-gain combining on the removed bit information set to obtain combined bit information; A channel decoding module is configured to perform channel decoding based on the combined bit information.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the signal decoding method based on the OFDM system according to any one of claims 1 to 7 is implemented.

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