OFDM-based power line carrier signal channel estimation method and device

Abstract

The present invention relates to the field of power line carrier communication technology, and specifically provides a power line carrier signal channel estimation method and device based on OFDM. The method includes obtaining initial channel estimation values corresponding to multiple subcarriers based on a target signal of a target channel; performing edge filtering on the initial channel estimation values corresponding to the target subcarriers based on the initial channel estimation values corresponding to the target subcarriers and adjacent initial estimation values to obtain denoised channel estimation values corresponding to the target subcarriers; wherein the target subcarriers are at least part of the multiple subcarriers, the adjacent initial estimation values are initial channel estimation values corresponding to the adjacent subcarriers, and the adjacent subcarriers are subcarriers adjacent to the target subcarriers; and obtaining a channel estimation sequence of the target channel based on the denoised channel estimation values corresponding to the target subcarriers. The present invention effectively improves the accuracy and robustness of the channel estimation results through edge filtering.

Description

Technical Field

[0001] The present invention relates to the technical field of power line carrier communication, and in particular to a power line carrier signal channel estimation method and device based on OFDM. Background Art

[0002] Orthogonal Frequency Division Multiplexing (OFDM), as an efficient multicarrier modulation scheme, significantly improves spectrum efficiency and multipath fading mitigation by transmitting data on multiple orthogonal subcarriers in parallel. In an OFDM system, the receiver must perform channel estimation to accurately obtain channel state information in order to correctly demodulate the data on each subcarrier.

[0003] However, channel estimation in complex channel environments, such as power line carrier communications (PLC), presents significant challenges. As a non-ideal transmission medium, the power line channel is susceptible to interference from the startup and shutdown of surrounding electrical equipment, changes in load impedance, and impulse noise. Existing channel estimation methods are susceptible to significant deviations due to noise and other factors. The results exhibit strong time-varying or frequency-selective fading, resulting in low accuracy. Summary of the Invention

[0004] The OFDM-based power line carrier signal channel estimation method and device provided in the embodiments of the present invention at least solve the problems of large deviation and low accuracy of channel estimation results, and effectively improve the accuracy and robustness of channel estimation results through edge filtering processing.

[0005] In the first aspect, the present invention provides a power line carrier signal channel estimation method based on OFDM, comprising the steps of: obtaining initial channel estimation values corresponding to multiple subcarriers according to a target signal of a target channel; performing edge filtering on the initial channel estimation value corresponding to the target subcarrier according to the initial channel estimation value corresponding to the target subcarrier and the adjacent initial estimation value to obtain a denoised channel estimation value corresponding to the target subcarrier; wherein the target subcarrier is at least part of the multiple subcarriers, the adjacent initial estimation value is the initial channel estimation value corresponding to the adjacent subcarrier, and the adjacent subcarrier is the subcarrier adjacent to the target subcarrier; and obtaining a channel estimation sequence of the target channel according to the denoised channel estimation value corresponding to the target subcarrier.

[0006] In one embodiment of the present invention, edge filtering is performed on the initial channel estimation value corresponding to the target subcarrier according to the initial channel estimation value corresponding to the target subcarrier and the adjacent initial estimation values to obtain a denoised channel estimation value corresponding to the target subcarrier, including the steps of: determining a target filtering value corresponding to the target subcarrier; and multiplying the initial channel estimation value corresponding to the target subcarrier and the adjacent initial estimation values by the corresponding target filtering values, respectively, and then accumulating the resulting values to obtain the denoised channel estimation value.

[0007] In one embodiment of the present invention, determining a target filter value corresponding to the target subcarrier includes the steps of: determining the target filter value based on a position of the target subcarrier in a subcarrier sequence and a preset number of adjacent subcarriers; wherein the subcarrier sequence is obtained by sorting a plurality of subcarriers according to frequency; the target filter value includes a first filter value and a second filter value, and the sum of the first filter value and the second filter value is one; the magnitude of the second filter value is positively correlated with a sequence proximity distance, and the sequence proximity distance is the position distance between the adjacent subcarrier corresponding to the second filter value and the target subcarrier corresponding to the first filter value in the subcarrier sequence.

[0008] In one embodiment of the present invention, the initial channel estimation value corresponding to the target subcarrier and the adjacent initial estimation value are respectively multiplied with the corresponding target filter value and then accumulated to obtain the denoised channel estimation value, which includes at least one of the following steps: multiplying the initial channel estimation value corresponding to the starting subcarrier with the corresponding first filter value, and multiplying the adjacent initial estimation value corresponding to the starting subcarrier with the corresponding second filter value, and accumulating each product to obtain the starting denoised channel estimation value; wherein the starting subcarrier is the subcarrier located at the starting end of the subcarrier sequence; the initial channel estimation value corresponding to the intermediate subcarrier is multiplied with the corresponding first filter value; The estimated value is multiplied by the corresponding first filtered value, and the adjacent initial estimated value corresponding to the intermediate subcarrier is multiplied by the corresponding second filtered value, and each product is accumulated to obtain an intermediate denoised channel estimation value; wherein, the intermediate subcarrier is the subcarrier located in the middle part of the subcarrier sequence; the initial channel estimation value corresponding to the end subcarrier is multiplied by the corresponding first filtered value, and the adjacent initial estimated value corresponding to the end subcarrier is multiplied by the corresponding second filtered value, and each product is accumulated to obtain an end denoised channel estimation value; wherein, the end subcarrier is the subcarrier located in the end part of the subcarrier sequence.

[0009] In one embodiment of the present invention, the second filtering value is smaller than the first filtering value corresponding to the second filtering value.

[0010] In one embodiment of the present invention, before determining the target filter value based on the position of the target subcarrier in the subcarrier sequence and the preset number of adjacent subcarriers, the method further includes the following steps: determining the number of end subcarriers based on the preset number; wherein the end subcarriers include starting subcarriers and end subcarriers, and the number of starting subcarriers and the number of end subcarriers are both related to the preset number; and determining the position of the target subcarrier in the subcarrier sequence based on the number of end subcarriers.

[0011] In one embodiment of the present invention, before edge filtering is performed on the initial channel estimation value corresponding to the target subcarrier based on the initial channel estimation value corresponding to the target subcarrier and the adjacent initial estimation values, the step is further included: when the signal-to-noise ratio value of the subcarrier is less than or equal to a preset threshold, the subcarrier is set as the target subcarrier.

[0012] In one embodiment of the present invention, initial channel estimation values corresponding to multiple subcarriers are obtained based on a target signal of a target channel, including the steps of: performing frame synchronization processing on the target signal to determine a synchronization peak; determining a synchronization symbol of the target signal based on the synchronization peak; and performing channel estimation on the subcarrier based on the synchronization symbol to obtain the initial channel estimation value corresponding to the subcarrier.

[0013] In the second aspect, the present invention also provides an OFDM-based power line carrier signal channel estimation device, comprising a first estimator for obtaining initial channel estimation values corresponding to multiple subcarriers based on a target signal of a target channel; an edge filter for performing edge filtering on the initial channel estimation value corresponding to the target subcarrier based on the initial channel estimation value corresponding to the target subcarrier and the adjacent initial estimation value, so as to obtain a denoised channel estimation value corresponding to the target subcarrier; wherein the target subcarrier is at least part of the multiple subcarriers, the adjacent initial estimation value is the initial channel estimation value corresponding to the adjacent subcarrier, and the adjacent subcarrier is the subcarrier adjacent to the target subcarrier; and a second estimator for obtaining a channel estimation sequence of the target channel based on the denoised channel estimation value corresponding to the target subcarrier.

[0014] In a third aspect, the present invention also provides an electronic device comprising a processor and a memory for storing a program, wherein the program comprises instructions which, when executed by the processor, enable the processor to execute the OFDM-based power line carrier signal channel estimation method as described in any one of the above.

[0015] The above technical solution of the present invention has the following beneficial effects compared with the prior art:

[0016] The OFDM-based power line carrier signal channel estimation method and device described in the present invention performs edge filtering on the initial channel estimation value corresponding to the target subcarrier through the initial channel estimation value corresponding to the target subcarrier and the adjacent initial estimation value to achieve denoising and smoothing, thereby obtaining a denoised channel estimation value, effectively reducing the impact of noise and improving the robustness and accuracy of the final channel estimation result. Compared with the existing technology, the OFDM-based power line carrier signal channel estimation method and device described in the present invention has a wider range of applications, and comprehensively considers the impact of adjacent subcarriers on the target subcarrier, which can effectively reduce the fluctuation of the channel estimation result. It is particularly suitable for low-voltage power line high-speed carrier communication channels based on orthogonal frequency division multiplexing technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without inventive work. In the drawings:

[0018] Figure 1 This is one of the flow charts of the OFDM-based power line carrier signal channel estimation method in the preferred embodiment of the present invention.

[0019] Figure 2 This is the second flow chart of the OFDM-based power line carrier signal channel estimation method in the preferred embodiment of the present invention.

[0020] Figure 3 This is a comparison diagram of the results of the OFDM-based power line carrier signal channel estimation method in the preferred embodiment of the present invention and the prior art method.

[0021] Figure 4 It is a structural diagram of an OFDM-based power line carrier signal channel estimation device in a preferred embodiment of the present invention.

[0022] Figure 5 It is a schematic structural diagram of an electronic device in a preferred embodiment of the present invention.

[0023] The above drawings include the following reference numerals:

[0024] 11. First estimator; 12. Edge filter; 13. Second estimator; 201. Computing unit; 202. ROM; 203. RAM; 204. Bus; 205. I / O interface; 206. Input unit; 207. Output unit; 208. Storage unit; 209. Communication unit. DETAILED DESCRIPTION

[0025] Embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0026] It should be noted that OFDM technology divides the frequency band by orthogonal subcarriers, decomposing high-speed data streams into parallel low-speed subcarrier transmissions, effectively combating the multipath effect and frequency selective fading of the power line channel, and improving spectrum utilization and anti-multipath fading capabilities.

[0027] For example, PLC transmits signals over power line channels. To correctly demodulate the data on each subcarrier, the receiver in an OFDM system must perform channel estimation to accurately obtain channel state information for the power line channel. This channel estimation determines the amplitude attenuation and phase offset of each subcarrier, thereby compensating for channel distortion. In existing technologies, channel estimation typically relies on preamble or pilot symbols.

[0028] However, power line channels are not ideal transmission media. Power line channel characteristics are susceptible to interference from the start-up and shutdown of surrounding electrical equipment, changes in load impedance, and impulse noise. Existing channel estimation methods are susceptible to interference from noise and other factors, resulting in significant deviations. The results exhibit strong time-varying or frequency-selective fading, resulting in low accuracy.

[0029] To solve the above problems, refer to Figure 1 As shown, an embodiment of the present invention provides a power line carrier signal channel estimation method based on OFDM. The power line carrier signal channel estimation method based on OFDM includes the following steps:

[0030] First, initial channel estimation values corresponding to a plurality of subcarriers are obtained according to a target signal of a target channel.

[0031] Secondly, according to the initial channel estimation value corresponding to the target subcarrier and the adjacent initial estimation values, edge filtering is performed on the initial channel estimation value corresponding to the target subcarrier to obtain a denoised channel estimation value corresponding to the target subcarrier.

[0032] The target subcarrier is at least part of the multiple subcarriers, the adjacent initial estimation value is the initial channel estimation value corresponding to the adjacent subcarrier, and the adjacent subcarrier is a subcarrier adjacent to the target subcarrier.

[0033] Finally, the channel estimation sequence of the target channel is obtained according to the denoised channel estimation value corresponding to the target subcarrier.

[0034] In the embodiment of the present invention, the target channel is the power line channel to be estimated. A channel is a medium for signal transmission. After a signal is sent from a transmitting end, the signal is transmitted to a receiving end through the channel, and the receiving end demodulates the received signal.

[0035] Exemplarily, the transmitting end is configured as a network device, such as various forms of macro base stations, micro base stations, relay stations, etc. The receiving end is configured as a user device, mobile device, mobile station, etc., which is located within the coverage area of the transmitting end. The transmitting end can send signals to the receiving end, and the receiving end can receive signals sent by the transmitting end.

[0036] To improve demodulation accuracy, the receiver typically needs to perform channel estimation on the target signal. For example, if the receiver receives a pilot signal transmitted on the target channel, it can use the synchronization symbol in the pilot signal to perform channel estimation. The synchronization symbol is the SYNCP symbol sent by the transmitter. The synchronization symbol consists of multiple subcarriers. In the power line carrier communication protocol, the number of OFDM subcarriers is 512.

[0037] Through channel estimation, the impact of the target channel on the target signal can be determined, and then subsequent data symbols can be compensated according to the channel estimation result.

[0038] For example, a sinusoidal signal For example, it is expressed as:

[0039] ;

[0040] in, is a variable, is the initial amplitude, is the frequency, is the initial phase.

[0041] The transmitter sends a sinusoidal signal , sinusoidal signal Transmitted through a certain power line channel, the sinusoidal signal is interfered by noise and other factors during the transmission process. Amplitude attenuation and phase delay are generated. The signal received by the receiver is , which is expressed as:

[0042] ;

[0043] in, is the amplitude after attenuation, is the delayed phase.

[0044] As can be understood, due to amplitude attenuation and phase delay, the amplitude of the sinusoidal signal is determined by becomes , the phase is determined by becomes If the receiving end determines the characteristics of the power line channel through channel estimation, which will cause the amplitude and phase of the signal to change, then the receiving end can compensate for the received signal accordingly when receiving other signals, thereby restoring the original signal sent by the sending end.

[0045] How to perform channel estimation to obtain the initial channel estimation value corresponding to the subcarrier belongs to the prior art. Those skilled in the art can select an appropriate channel estimation method to perform initial channel estimation on the target channel according to actual needs to obtain the initial channel estimation value.

[0046] There are a large number of subcarriers, and the initial channel estimation values correspond one-to-one to the subcarriers. After completing the initial channel estimation, the multiple initial channel estimation values obtained can form an initial channel estimation sequence, which is usually represented in the form of a broken line graph. The horizontal axis of the broken line graph is the corresponding subcarrier, and the vertical axis is the real part of the initial channel estimation value. Exemplarily, before performing the initial channel estimation, the subcarriers can be sorted according to frequency to obtain a subcarrier sequence. Preferably, the subcarrier sequence arranges the subcarriers in order of frequency, from small to large.

[0047] Because power line channels are susceptible to noise, the polyline corresponding to the initial channel estimate may not be smooth, resulting in large deviations and low accuracy in the channel estimation results. Therefore, it is necessary to denoise and smooth the initial channel estimation sequence to improve the accuracy and robustness of the final channel estimation results.

[0048] It is worth noting that in the prior art, there are also methods that reconstruct the channel estimation values of the subcarriers at the two ends by selecting the channel estimation values of the subcarriers at the middle. Although this existing method can reduce the error of the channel estimation values of the subcarriers at the end positions to a certain extent, on the one hand, due to the limited reconstruction objects, it cannot reduce the channel estimation error of the subcarriers at the middle position. On the other hand, due to the relatively large distance between the subcarriers at the middle and the subcarriers at the two ends, the mutual influence between them is relatively small, which leads to limited effect on reducing the error of the reconstructed channel estimation value, and cannot meet the needs of scenarios requiring high precision.

[0049] In the embodiments of the present invention, the target subcarriers selected are not limited to those at the two ends. Those skilled in the art can select subcarriers at the two ends, the middle, or multiple locations simultaneously as target subcarriers based on actual needs, and perform edge filtering on these subcarriers to achieve denoising and smoothing, thereby obtaining a denoised channel estimate corresponding to the target subcarrier.

[0050] It is understood that the target subcarrier is at least a portion of the multiple subcarriers. Those skilled in the art can select all subcarriers as target subcarriers to obtain a more accurate channel estimation result; or can select a portion of all subcarriers as target subcarriers to achieve a balance between high accuracy and processing efficiency.

[0051] At the same time, when edge filtering is performed, it is implemented based on the initial channel estimation value corresponding to the target subcarrier and the adjacent initial estimation values corresponding to the adjacent subcarriers adjacent to the target subcarrier.

[0052] Adjacent means close in position. The adjacent subcarrier is close to the target subcarrier in the subcarrier sequence. Those skilled in the art can set an appropriate preset number according to actual needs, that is, set the subcarriers with a preset number before and after the target subcarrier in the subcarrier sequence as adjacent subcarriers.

[0053] Exemplarily, the previous subcarrier and the next subcarrier, the first two subcarriers and the next two subcarriers, or the first three subcarriers and the next three subcarriers of the target subcarrier are set as adjacent subcarriers.

[0054] In signal communications, adjacent subcarriers can influence each other. The OFDM-based power line carrier signal channel estimation method of the present invention selects the initial channel estimate corresponding to the target subcarrier and adjacent initial estimates, performs edge filtering on the initial channel estimate corresponding to the target subcarrier, and takes into account the weight of the influence of adjacent subcarriers on the target subcarrier to obtain a denoised channel estimate. This method can effectively reduce the fluctuation of the final channel estimation result and improve the robustness and accuracy of the final channel estimation result.

[0055] After completing the edge filtering process and obtaining the corresponding denoised channel estimation value, the channel estimation sequence of the target channel, that is, the final channel estimation result, can be obtained based on the denoised channel estimation value corresponding to the target subcarrier.

[0056] The channel estimation sequence obtained varies depending on the number of target subcarriers selected. When all subcarriers are selected as target subcarriers, the denoised channel estimation values are sorted according to the subcarrier sequence to obtain the channel estimation sequence.

[0057] When a portion of all subcarriers is selected as the target subcarrier, the initial channel estimation value corresponding to the target subcarrier in the initial channel estimation sequence is replaced according to the denoised channel estimation value corresponding to the target subcarrier, thereby obtaining a channel estimation sequence. It will be appreciated that in this case, the channel estimation sequence includes the denoised channel estimation value and the initial channel estimation value.

[0058] After obtaining the channel estimation sequence, the impact of the channel on the signal can be determined based on the channel estimation values in the sequence, allowing the receiver to compensate for the subsequent received signals to restore the original signal transmitted by the transmitter.

[0059] The OFDM-based power line carrier signal channel estimation method described in the present invention performs edge filtering on the initial channel estimation value corresponding to the target subcarrier through the initial channel estimation value corresponding to the target subcarrier and the adjacent initial estimation values to achieve denoising and smoothing, thereby obtaining a denoised channel estimation value, effectively reducing the impact of noise and improving the robustness and accuracy of the final channel estimation result. Compared with the existing technology, the OFDM-based power line carrier signal channel estimation method described in the present invention has a wider range of applications, and comprehensively considers the impact of adjacent subcarriers on the target subcarrier, which can effectively reduce the fluctuation of the channel estimation result. It is particularly suitable for low-voltage power line high-speed carrier communication channels based on orthogonal frequency division multiplexing technology.

[0060] In the prior art, there are many methods for channel estimation, such as minimum mean square error channel estimation, pilot-based channel estimation, etc.

[0061] Least Squares (LS) channel estimation offers the advantages of simple computation, rapid implementation, improved overall efficiency, and low computational cost and power consumption. However, due to the influence of noise, LS channel estimation can deviate from the true channel value in noisy environments, resulting in reduced estimation accuracy and poor performance.

[0062] In the OFDM-based power line carrier signal channel estimation method described in the present invention, since the initial channel estimation value is edge filtered to achieve denoising and smoothing, the processed denoised channel estimation value has high accuracy and robustness, which can well compensate for the shortcomings of the least squares channel estimation.

[0063] Therefore, refer to Figure 2 As shown, the OFDM-based power line carrier signal channel estimation method of the present invention, in some embodiments, obtains initial channel estimation values corresponding to multiple subcarriers according to the target signal of the target channel, including the steps of:

[0064] First, the target signal is frame synchronized to determine the synchronization peak.

[0065] The target signal is preferably a preamble signal. Frame synchronization processing belongs to the prior art, and its purpose is to enable the receiving end to accurately identify the start and end positions of each frame signal, thereby achieving correct data reception and processing.

[0066] The basic principle of frame synchronization is that when a transmitter sends a data frame, it inserts a specific synchronization code or sequence into the frame according to a specific format and rules. The receiver detects this synchronization code or sequence to determine the frame boundaries. For example, some communication protocols specify a specific preamble as a frame synchronization indicator. The receiver considers a new frame to have begun only after detecting the complete preamble sequence.

[0067] Secondly, the synchronization symbol of the target signal is determined based on the synchronization peak. The synchronization symbol is the SYNCP symbol sent by the transmitter.

[0068] Finally, the least squares channel estimation process is performed on the subcarrier according to the synchronization symbol to obtain the initial channel estimation value corresponding to the subcarrier.

[0069] The essence of channel estimation is to use the received synchronization symbols and the known local synchronization symbols to perform estimation, and then use the estimation result to compensate for the subsequent data symbols.

[0070] Taking the high-speed carrier physical layer data unit frame structure as an example, it consists of a preamble, frame control, and payload data. The preamble is a periodic sequence, and the number of subcarriers for frame control and payload data per symbol is 512. The preamble includes the received synchronization symbol.

[0071] Specifically, the initial channel estimation value obtained by the least squares channel estimation process is expressed as:

[0072] ;

[0073] in, is the subcarrier sequence The initial channel estimation value corresponding to the subcarriers. and is an integer, is the total number of subcarriers, Also an integer.

[0074] The average result of Fast Fourier Transformation (FFT) of multiple received synchronization symbols during frame synchronization. Fast Fourier Transformation belongs to the existing technology, and its detailed processing steps are not repeated here. Through Fast Fourier Transformation, time domain signals can be converted into frequency domain signals, making signal analysis and processing more convenient. It can be understood that It is a complex number, corresponding to the initial channel estimate Also in plural form.

[0075] The frequency domain data of the synchronization symbol is sent, that is, the frequency domain data of the synchronization symbol stored locally at the receiving end.

[0076] It is worth noting that during channel estimation, there may be unused subcarriers. In this case, the unused subcarrier positions are filled with 0.

[0077] Least squares channel estimation makes it easy to quickly calculate the initial channel estimate, improving overall efficiency and reducing computational cost and power consumption. At the same time, combined with edge filtering, the final denoised channel estimate is highly accurate and robust.

[0078] In the power line carrier communication protocol, there are 512 OFDM subcarriers and corresponding initial channel estimates. If edge filtering is performed on each initial channel estimate, the overall computational complexity is relatively large and the processing efficiency is low.

[0079] In order to reduce the amount of calculation and improve processing efficiency, the OFDM-based power line carrier signal channel estimation method of the present invention, in some embodiments, before edge filtering is performed on the initial channel estimation value corresponding to the target subcarrier based on the initial channel estimation value corresponding to the target subcarrier and the adjacent initial estimation values, further includes the steps of:

[0080] The subcarrier sequence is screened according to preset conditions to determine the target subcarrier.

[0081] By screening the subcarrier sequence according to preset conditions, the computational complexity of edge filtering can be effectively reduced and processing efficiency can be improved. Those skilled in the art can set appropriate preset conditions to achieve subcarrier screening according to actual needs.

[0082] Preferably, refer to Figure 2 As shown, the preset threshold value and the signal-to-noise ratio (SNR) value of the subcarrier can be compared first.

[0083] The signal-to-noise ratio (SNR) is a key parameter that measures the relative strength of the active component and noise component in a signal. It represents the ratio of signal power to noise power. The SNR of a subcarrier can be used to determine the extent to which the subcarrier is affected by noise and other factors. A higher SNR indicates a clearer signal, less noise interference, and more accurate channel estimation. Conversely, a lower SNR indicates a greater signal influence from noise, leading to greater deviation in the channel estimation. Methods for obtaining the SNR are well-known techniques and will not be elaborated upon here.

[0084] Therefore, when the signal-to-noise ratio value of the subcarrier is less than or equal to the preset threshold, the subcarrier is set as the target subcarrier. Conversely, when the signal-to-noise ratio value of the subcarrier is greater than the preset threshold, there is no need to perform edge filtering on the corresponding initial channel estimation value.

[0085] The preset threshold is an empirical value, and those skilled in the art can adjust the value of the preset threshold based on actual communication conditions. Using the preset threshold to filter subcarriers can not only greatly reduce the computational complexity of edge filtering, but also obtain more accurate channel estimation results.

[0086] For example, in a subcarrier sequence, the signal-to-noise ratio values of the first three subcarriers are less than a preset threshold, while the signal-to-noise ratio values of the other subcarriers are all greater than the preset threshold. In this case, only the initial channel estimation values corresponding to the first three subcarriers in the subcarrier sequence need to be edge filtered. Accordingly, the final channel estimation sequence includes the three filtered denoised channel estimation values and the other unfiltered initial channel estimation values, specifically including 、 、 、 、……、 、 ,in, for The corresponding denoised channel estimate.

[0087] In some other embodiments, the subcarrier sequence can be screened according to a preset interval, and the screened subcarriers are set as target subcarriers.

[0088] For example, it is possible to filter at intervals of one subcarrier, and then perform edge filtering on the target subcarriers obtained by filtering, so as to effectively reduce the computational complexity of edge filtering, improve processing efficiency, and save computing resources. Accordingly, the final channel estimation sequence includes a noisy channel estimation value and an initial channel estimation value, for example, including 、 、 、 、……、 、 .

[0089] Of course, in some situations where high accuracy is required, all subcarriers can be set as target subcarriers to obtain more accurate channel estimation results.

[0090] In some embodiments of the OFDM-based power line carrier signal channel estimation method of the present invention, edge filtering is performed on the initial channel estimation value corresponding to the target subcarrier based on the initial channel estimation value corresponding to the target subcarrier and the adjacent initial estimation values to obtain a denoised channel estimation value corresponding to the target subcarrier, comprising the steps of:

[0091] Determine a target filter value corresponding to the target subcarrier.

[0092] The initial channel estimation value corresponding to the target subcarrier and the adjacent initial estimation values are multiplied by the corresponding target filter values and then accumulated to obtain the denoised channel estimation value.

[0093] The correspondence between target subcarriers and target filter values is one-to-many, meaning each target subcarrier corresponds to multiple target filter values. During filtering, the initial channel estimate corresponding to the target subcarrier is multiplied by the corresponding target filter value, and each adjacent initial estimate corresponding to the target subcarrier is multiplied by the corresponding target filter value. These products are then accumulated to obtain the final denoised channel estimate. Those skilled in the art can select an appropriate target filter value based on actual needs and multiply it by the corresponding initial channel estimate.

[0094] In this way, the influence of different adjacent subcarriers on the target subcarrier is fully considered, so as to effectively reduce the volatility of the channel estimation result, reduce the influence of noise, and improve the accuracy of channel estimation.

[0095] The target filtering value corresponding to each target subcarrier is related to the position of the target subcarrier in the subcarrier sequence and the preset number of adjacent subcarriers corresponding to the target subcarrier.

[0096] Furthermore, the OFDM-based power line carrier signal channel estimation method of the present invention determines the target filter value corresponding to the target subcarrier, including the steps of:

[0097] The target filtering value is determined according to the position of the target subcarrier in the subcarrier sequence and the preset number of adjacent subcarriers.

[0098] The subcarrier sequence is obtained by sorting multiple subcarriers according to frequency. Preferably, the subcarrier sequence is arranged in ascending order.

[0099] Adjacent subcarriers are a preset number of subcarriers before and after the target subcarrier in the subcarrier sequence. The preset number is an empirical value, and those skilled in the art can set it based on actual needs, for example, to 1, 2, 3, 4, 5, 6, etc., and the present invention is not limited thereto.

[0100] For example, when the second subcarrier in the subcarrier sequence is selected as the target subcarrier and the preset number is 3, the adjacent initial estimation values include initial channel estimation values corresponding to subcarriers with subcarrier numbers 0, 2, 3, and 4, respectively.

[0101] The target filter value includes a first filter value and a second filter value. The first filter value corresponds to the initial channel estimate of the target subcarrier. The number of second filter values is the same as the actual number of adjacent subcarriers, and each second filter value corresponds to the adjacent initial estimate of each adjacent subcarrier. The sum of the first filter value and the second filter value is one to ensure that the final denoised channel estimate is less than the initial channel estimate.

[0102] The magnitude of the second filter value is positively correlated with the sequence proximity distance. The sequence proximity distance is the distance between the adjacent subcarrier corresponding to the second filter value and the target subcarrier corresponding to the first filter value in the subcarrier sequence. As can be understood, the closer the adjacent subcarrier is to the target subcarrier, the larger the corresponding second filter value.

[0103] This step can be understood as filtering, which essentially processes the initial channel estimation results. This step comprehensively considers the impact of adjacent subcarriers on the target subcarrier, thereby reducing the problem of large fluctuations in the channel estimation results caused by noise interference or other factors. It smoothes the channel estimation results, reduces the impact of noise, and improves the robustness and accuracy of the final channel estimation results.

[0104] Preferably, in the OFDM-based power line carrier signal channel estimation method of the present invention, each second filter value is smaller than the first filter value corresponding to the second filter value.

[0105] It is understandable that although adjacent subcarriers will affect the target subcarrier, the channel estimation value corresponding to the target subcarrier has the strongest correlation with the target subcarrier itself. On this basis, by setting the first filter value to the maximum value among the target filter values, it is possible to ensure that the target subcarrier dominates the denoised channel estimation value after edge filtering, making the resulting denoised channel estimation value closer to the original value, thereby further improving the accuracy of the final channel estimation result.

[0106] Considering that the first filter value and the second filter value are decimals, in order to avoid floating-point operations during actual calculation, each target filter value may be amplified by a certain multiple before calculation.

[0107] It is worth noting that the preset number is only a theoretical number. The number of adjacent subcarriers corresponding to different target subcarriers is not necessarily equal to twice the preset number. When the target subcarrier is an end subcarrier, the actual number of adjacent initial estimates will be less than the preset number.

[0108] Exemplarily, when the first subcarrier in the subcarrier sequence is selected as the target subcarrier, there are only adjacent subcarriers on one side of the first subcarrier.

[0109] When the second subcarrier in the subcarrier sequence is selected as the target subcarrier, although there are adjacent subcarriers on both sides, the actual number of adjacent subcarriers on both sides may vary depending on the preset number. For example, if the preset number is 3, the target subcarrier may have 1 adjacent subcarrier on one side and 3 adjacent subcarriers on the other side. In other words, the actual number of adjacent subcarriers (4) will be less than the theoretical number (6).

[0110] On this basis, the OFDM-based power line carrier signal channel estimation method of the present invention further includes the following steps before determining the target filtering value based on the position of the target subcarrier in the subcarrier sequence and the preset number of adjacent subcarriers:

[0111] The number of end subcarriers is determined according to a preset number.

[0112] The position of the target subcarrier in the subcarrier sequence is determined according to the number of end subcarriers.

[0113] Specifically, each subcarrier in the subcarrier sequence can be divided into end subcarriers and middle subcarriers.

[0114] The end subcarriers are the subcarriers at both ends of the subcarrier sequence. As can be understood, the subcarrier sequence includes a start end and an end end, and accordingly, the end subcarriers can be further divided into a start subcarrier and an end subcarrier.

[0115] The starting subcarrier is the subcarrier at the beginning of the subcarrier sequence, the middle subcarrier is the subcarrier in the middle of the subcarrier sequence, and the end subcarrier is the subcarrier at the end of the subcarrier sequence. The number of starting subcarriers and the number of end subcarriers are both related to the preset number.

[0116] Preferably, the number of starting subcarriers, the number of ending subcarriers, and the preset number are equal. That is, in this embodiment of the present invention, the starting subcarriers, middle subcarriers, and ending subcarriers in the subcarrier sequence are defined by the preset number of adjacent subcarriers.

[0117] Specifically, the first preset number of subcarriers in the subcarrier sequence are set as the starting subcarriers, the last preset number of subcarriers are set as the end subcarriers, and the other subcarriers are set as the middle subcarriers.

[0118] For example, taking the low voltage power line high speed carrier communication channel as an example, the preset number is set to 3. In this case, among the 512 subcarriers, the first 3 subcarriers, i.e. The subcarriers 0, 1 and 2 are the starting subcarriers; the last three subcarriers, namely The subcarriers 509, 510 and 511 are the end subcarriers; the remaining subcarriers, namely The subcarriers from 3 to 508 are middle subcarriers.

[0119] It can be understood that at this time, there are 3 starting subcarriers and 3 ending subcarriers, the number of end subcarriers is 6, and the number of middle subcarriers is 506.

[0120] The target subcarrier can be selected from end subcarriers, middle subcarriers, and end subcarriers. For example, after filtering subcarriers based on the signal-to-noise ratio value, the filtered subcarriers may include end subcarriers, middle subcarriers, and end subcarriers, or may only include middle subcarriers and end subcarriers.

[0121] Depending on the location of the target subcarrier, the number of adjacent subcarriers will vary. Furthermore, subcarriers at the beginning and end of the channel are more susceptible to the influence of adjacent noise frequencies. Therefore, different target filter values must be selected for the target subcarriers at the beginning and end to smooth the channel estimation results and reduce the impact of noise.

[0122] By predetermining the position of the target subcarrier, different edge filtering processing steps can be adopted for target subcarriers at different positions during subsequent processing, thereby accurately and efficiently implementing edge filtering processing on the target subcarrier, thereby improving the accuracy of the final estimation result and the overall efficiency.

[0123] Furthermore, the OFDM-based power line carrier signal channel estimation method of the present invention multiplies the initial channel estimation value corresponding to the target subcarrier and the adjacent initial estimation values by the corresponding target filter values and then accumulates them to obtain a denoised channel estimation value, comprising at least one of the following steps:

[0124] (I) Multiply the initial channel estimate corresponding to the starting subcarrier by the corresponding first filtered value to obtain a first starting value. Also, multiply the adjacent initial estimate corresponding to the starting subcarrier by the corresponding second filtered value to obtain a second starting value. Finally, the first starting value and the second starting value are added together to obtain the starting denoised channel estimate.

[0125] (II) Multiplying the initial channel estimate corresponding to the middle subcarrier by the corresponding first filtered value to obtain a first intermediate value. Furthermore, multiplying the adjacent initial estimate corresponding to the middle subcarrier by the corresponding second filtered value to obtain a second intermediate value. Finally, summing the first intermediate value and the second intermediate value to obtain an intermediate denoised channel estimate.

[0126] (III) Multiplying the initial channel estimate corresponding to the terminal subcarrier by the corresponding first filtered value to obtain a first terminal value. Furthermore, multiplying the adjacent initial estimate corresponding to the terminal subcarrier by the corresponding second filtered value to obtain a second terminal value. Finally, summing the first terminal value and the second terminal value to obtain a terminal denoised channel estimate.

[0127] Those skilled in the art can first calculate the product of the initial channel estimation value and the first filtered value, or first calculate the product of the adjacent initial estimation value and the second filtered value according to actual needs.

[0128] Depending on the location of the target subcarrier and the preset number, the number of the second starting value, the second intermediate value, and the second end value may also vary. Preferably, the preset number is set to multiple to ensure that the number of the second starting value, the second intermediate value, and the second end value is also multiple, thereby improving the accuracy of the final result.

[0129] It can be understood that the denoised channel estimation value includes at least one of a starting denoised channel estimation value, an ending denoised channel estimation value, and a middle denoised channel estimation value.

[0130] Correspondingly, (I) the initial channel estimation value corresponding to the starting subcarrier is multiplied by the corresponding first filtered value to obtain a first starting value; and, the adjacent initial estimation value corresponding to the starting subcarrier is multiplied by the corresponding second filtered value to obtain a second starting value; finally, the first starting value and the second starting value are accumulated to obtain a starting denoised channel estimation value; (II) the initial channel estimation value corresponding to the middle subcarrier is multiplied by the corresponding first filtered value to obtain a first intermediate value; and, the adjacent initial estimation value corresponding to the middle subcarrier is multiplied by the corresponding second filtered value to obtain a second intermediate value; finally, the first intermediate value and the second intermediate value are accumulated to obtain a middle denoised channel estimation value; (III) the initial channel estimation value corresponding to the end subcarrier is multiplied by the corresponding first filtered value to obtain a first end value; and, the adjacent initial estimation value corresponding to the end subcarrier is multiplied by the corresponding second filtered value to obtain a second end value; finally, the first end value and the second end value are accumulated to obtain a end denoised channel estimation value; the above steps can be used individually, in pairs, or in combination.

[0131] When the preset number of adjacent subcarriers changes, the number of subcarriers in different parts of the subcarrier sequence and the target filter value corresponding to each target subcarrier may change. For ease of understanding, the following description assumes that the preset number is set to 3 and all subcarriers are set as target subcarriers.

[0132] When the preset number of adjacent subcarriers is set to 3, in the subcarrier sequence, the first three subcarriers are the starting subcarriers, the last three subcarriers are the end subcarriers, and the rest are middle subcarriers.

[0133] The initial channel estimation value corresponding to the starting subcarrier is multiplied by the corresponding first filtered value, and the adjacent initial estimation value corresponding to the starting subcarrier is multiplied by the corresponding second filtered value, and the products are accumulated to obtain the starting denoised channel estimation value, which is expressed as:

[0134] ;

[0135] ;

[0136] ;

[0137] The initial channel estimation value corresponding to the middle subcarrier is multiplied by the corresponding first filtered value, and the adjacent initial estimation value corresponding to the middle subcarrier is multiplied by the corresponding second filtered value, and the products are accumulated to obtain the middle denoised channel estimation value, which is expressed as:

[0138] ;

[0139] The initial channel estimation value corresponding to the end subcarrier is multiplied by the corresponding first filtered value, and the adjacent initial estimation value corresponding to the end subcarrier is multiplied by the corresponding second filtered value, and the products are accumulated to obtain the end denoised channel estimation value, which is expressed as:

[0140] ;

[0141] ;

[0142] ;

[0143] in, is the subcarrier sequence The initial channel estimation value corresponding to the subcarriers. and is an integer, and is an integer, is the total number of subcarriers, Also an integer. for The corresponding denoised channel estimate. to 、 to 、 to ,as well as to are the target filter values corresponding to the corresponding subcarriers. Specifically, is the first filtered value, and the rest are the second filtered values.

[0144] in, , .

[0145] , .

[0146] , .

[0147] .

[0148] In power line carrier communication, by setting the preset number to three, the channel estimation results can be effectively smoothed, the impact of noise can be reduced, and the robustness and accuracy of the final channel estimation results can be improved. At the same time, the amount of calculation can be controlled within an appropriate range to improve processing efficiency and keep computing costs and power consumption low.

[0149] Considering that the subcarriers on both sides of the middle subcarrier have similar effects, the target filter value is preferably to The size of satisfies the relationship:

[0150] .

[0151] By setting the second filter values corresponding to two adjacent initial estimation values to be equal in size, the accuracy of the final channel estimation result can be further improved, while also reducing the amount of calculation to a certain extent.

[0152] Reference Figure 3 As shown, Figure 3 The following figure shows the comparison of channel estimation results, where the horizontal axis represents the subcarrier and the vertical axis represents the real part of the channel estimation result.

[0153] Figure 3 In the figure, the dashed line shows the channel estimation result of a low-voltage power line high-speed carrier communication channel using a conventional channel estimation method, without edge filtering. The solid line shows the channel estimation result of a low-voltage power line high-speed carrier communication channel using the OFDM-based power line carrier signal channel estimation method described in an embodiment of the present invention.

[0154] According to the comparison diagram, it can be seen that after edge filtering is performed on the initial channel estimation value, the obtained channel estimation sequence is smoother and more accurate.

[0155] Reference Figure 4 As shown, an embodiment of the present invention further provides an OFDM-based power line carrier signal channel estimation device, comprising a first estimator 11 , an edge filter 12 and a second estimator 13 .

[0156] The first estimator 11 is configured to obtain initial channel estimation values corresponding to a plurality of subcarriers according to a target signal of a target channel.

[0157] The edge filter 12 is configured to perform edge filtering on the initial channel estimate corresponding to the target subcarrier based on the initial channel estimate corresponding to the target subcarrier and the adjacent initial estimate values to obtain a denoised channel estimate corresponding to the target subcarrier. The target subcarrier is at least part of a plurality of subcarriers, the adjacent initial estimate values are initial channel estimate values corresponding to adjacent subcarriers, and the adjacent subcarriers are subcarriers adjacent to the target subcarrier.

[0158] The second estimator 13 is configured to obtain a channel estimation sequence of the target channel according to the denoised channel estimation value corresponding to the target subcarrier.

[0159] The OFDM-based power line carrier signal channel estimation device described in the present invention performs edge filtering on the initial channel estimation value corresponding to the target subcarrier through the initial channel estimation value corresponding to the target subcarrier and the adjacent initial estimation value to achieve denoising and smoothing, thereby obtaining a denoised channel estimation value, effectively reducing the impact of noise and improving the robustness and accuracy of the final channel estimation result. Compared with the prior art, the OFDM-based power line carrier signal channel estimation device described in the present invention has a wider range of applications, and comprehensively considers the impact of adjacent subcarriers on the target subcarrier, which can effectively reduce the fluctuation of the channel estimation result. It is particularly suitable for low-voltage power line high-speed carrier communication channels based on orthogonal frequency division multiplexing technology.

[0160] In some embodiments of the OFDM-based power line carrier signal channel estimation device of the present invention, the first estimator 11 obtains initial channel estimation values corresponding to multiple subcarriers based on the target signal of the target channel, specifically including:

[0161] First, the target signal is frame synchronized to determine the synchronization peak.

[0162] Secondly, the synchronization symbol of the target signal is determined based on the synchronization peak.

[0163] Finally, the least squares channel estimation process is performed on the subcarrier according to the synchronization symbol to obtain the initial channel estimation value corresponding to the subcarrier.

[0164] In some embodiments, the OFDM-based power line carrier signal channel estimation device of the present invention further includes a target filter. The target filter is configured to compare a preset threshold with the signal-to-noise ratio (SNR) of a subcarrier before edge filter 12 performs edge filtering, and to set the subcarrier as a target subcarrier if the SNR of the subcarrier is less than or equal to the preset threshold.

[0165] In the OFDM-based power line carrier signal channel estimation device of the present invention, in some embodiments, the edge filter 12 includes a filter determiner and a filter calculator.

[0166] The filter determiner is used to determine a target filter value corresponding to a target subcarrier.

[0167] The filter calculator is used to multiply the initial channel estimation value corresponding to the target subcarrier and the adjacent initial estimation values by the corresponding target filter values respectively and then accumulate them to obtain a denoised channel estimation value.

[0168] Furthermore, in some embodiments of the OFDM-based power line carrier signal channel estimation device of the present invention, the filter determiner determines the target filter value corresponding to the target subcarrier, specifically including:

[0169] The target filtering value is determined according to the position of the target subcarrier in the subcarrier sequence and the preset number of adjacent subcarriers.

[0170] The subcarrier sequence is obtained by sorting multiple subcarriers according to frequency.

[0171] The target filter value includes a first filter value and a second filter value, and the sum of the first filter value and the second filter value is one.

[0172] The magnitude of the second filter value is positively correlated with the sequence proximity distance, which is the position distance between the adjacent subcarrier corresponding to the second filter value and the target subcarrier corresponding to the first filter value in the subcarrier sequence.

[0173] Furthermore, in some embodiments, the OFDM-based power line carrier signal channel estimation device of the present invention further includes a position determiner.

[0174] The position determiner is used to determine the number of end subcarriers according to a preset number before the filter determiner determines the target filter value corresponding to the target subcarrier, and to determine the position of the target subcarrier in the subcarrier sequence according to the number of end subcarriers.

[0175] Furthermore, in some embodiments of the OFDM-based power line carrier signal channel estimation device of the present invention, the filter calculator includes at least one of a starting calculator, an intermediate calculator, and an end calculator.

[0176] The starting-end calculator is configured to multiply an initial channel estimate corresponding to a starting subcarrier by a corresponding first filtered value, and to multiply an adjacent initial estimate corresponding to the starting subcarrier by a corresponding second filtered value, and to accumulate the products to obtain a starting-end denoised channel estimate. The starting subcarrier is a subcarrier located at the starting end of the subcarrier sequence.

[0177] The intermediate calculator is configured to multiply the initial channel estimate corresponding to the intermediate subcarrier by the corresponding first filtered value, and to multiply the adjacent initial estimate corresponding to the intermediate subcarrier by the corresponding second filtered value, and to accumulate the products to obtain an intermediate denoised channel estimate. The intermediate subcarrier is a subcarrier located in the middle of the subcarrier sequence.

[0178] The terminal calculator is configured to multiply the initial channel estimate corresponding to the terminal subcarrier by the corresponding first filtered value, and multiply the adjacent initial estimate corresponding to the terminal subcarrier by the corresponding second filtered value, and accumulate the products to obtain the terminal denoised channel estimate. The terminal subcarrier is the subcarrier at the end of the subcarrier sequence.

[0179] Furthermore, in some embodiments of the OFDM-based power line carrier signal channel estimation device of the present invention, the second filtering value is smaller than the first filtering value corresponding to the second filtering value.

[0180] An embodiment of the present invention further provides a non-transitory machine-readable medium storing a computer program, wherein the computer program, when executed by a processor of a computer, causes the computer to execute the OFDM-based power line carrier signal channel estimation method described in any one of the above embodiments.

[0181] An embodiment of the present invention further provides a computer program product, including a computer program, wherein when executed by a processor of a computer, the computer program is used to cause the computer to execute the OFDM-based power line carrier signal channel estimation method described in any one of the above embodiments.

[0182] An embodiment of the present invention further provides an electronic device, comprising at least one processor and a memory communicatively connected to the at least one processor. The memory stores a computer program executable by the at least one processor, and when executed by the at least one processor, the computer program causes the electronic device to perform the OFDM-based power line carrier signal channel estimation method described in any of the above embodiments.

[0183] Reference Figure 5 As shown, a block diagram of an electronic device that can be used as a server or client of an embodiment of the present invention will now be described, which is an example of a hardware device that can be applied to various aspects of the present invention. The electronic device is intended to represent various forms of digital electronic computer devices, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0184] Reference Figure 5 As shown, the electronic device includes a computing unit 201, which can perform various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) 202 or a computer program loaded from a storage unit 208 into a random access memory (RAM) 203. Various programs and data required for the operation of the electronic device can also be stored in the RAM 203. The computing unit 201, ROM 202, and RAM 203 are connected to each other via a bus 204. An input / output (I / O) interface 205 is also connected to the bus 204.

[0185] Multiple components within the electronic device are connected to the I / O interface 205, including an input unit 206, an output unit 207, a storage unit 208, and a communication unit 209. The input unit 206 can be any type of device capable of inputting information into the electronic device. The input unit 206 can receive input numeric or character information and generate key signal inputs related to user settings and / or function control of the electronic device. The output unit 207 can be any type of device capable of presenting information and can include, but is not limited to, a display, a speaker, a video / audio output terminal, a vibrator, and / or a printer. The storage unit 208 can include, but is not limited to, a magnetic disk or an optical disk. The communication unit 209 allows the electronic device to exchange information / data with other devices via a computer network such as the Internet and / or various telecommunication networks, and can include, but is not limited to, a modem, a network card, an infrared communication device, and / or a wireless communication transceiver, such as a Bluetooth device, a WiFi device, a WiMax device, a cellular communication device, and / or the like.

[0186] The computing unit 201 can be any general-purpose and / or specialized processing component with processing and computing capabilities. Some examples of the computing unit 201 include, but are not limited to, a CPU, a graphics processing unit (GPU), various specialized artificial intelligence (AI) computing units, various computing units that run machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. The computing unit 201 performs the various methods and processes described above. For example, in some embodiments, method embodiments of the present invention may be implemented as a computer program tangibly embodied in a machine-readable medium, such as the storage unit 208. In some embodiments, part or all of the computer program may be loaded and / or installed onto the electronic device via the ROM 202 and / or the communication unit 209. In some embodiments, the computing unit 201 may be configured to perform the above-described methods by any other suitable means (e.g., via firmware).

[0187] The computer programs for implementing the methods of the embodiments of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer programs are executed by the processor or controller, the functions / operations specified in the flowcharts and / or block diagrams are implemented. The computer programs may be executed entirely on the machine, partially on the machine, as a stand-alone software package, partially on the machine and partially on a remote machine, or entirely on a remote machine or server.

[0188] In the context of embodiments of the present invention, a machine-readable medium may be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable signal medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, or infrared system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of machine-readable storage media may include an electrical connection based on one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), optical fibers, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0189] It should be noted that the term "including" and its variations used in the embodiments of the present invention are open inclusions, that is, "including but not limited to". The term "based on" means "based at least in part on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; and the term "some embodiments" means "at least some embodiments". The modifications of "one" and "a plurality of" mentioned in the embodiments of the present invention are illustrative and non-restrictive. Those skilled in the art should understand that unless the context clearly indicates otherwise, they should be understood as "one or more".

[0190] The various steps described in the method implementation schemes provided in the embodiments of the present invention may be performed in different orders and / or in parallel. In addition, the method implementation schemes may include additional steps and / or omit the steps shown. The scope of protection of the present invention is not limited in this respect.

[0191] The term "embodiment" in this specification refers to specific features, structures, or characteristics described in conjunction with the embodiment that can be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily mean the same embodiment, nor does it mean that it is mutually exclusive with other embodiments and is independent or optional. The various embodiments in this specification are described in a related manner, and the same or similar parts between the various embodiments are referenced to each other. In particular, for the embodiments of the device, equipment, and system, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts are referred to the partial description of the method embodiment.

[0192] The above-described embodiments merely illustrate several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of protection. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A power line carrier signal channel estimation method based on OFDM, characterized in that: Including steps: Obtaining initial channel estimation values corresponding to a plurality of subcarriers according to a target signal of a target channel; Performing edge filtering on the initial channel estimation value corresponding to the target subcarrier according to the initial channel estimation value corresponding to the target subcarrier and adjacent initial estimation values to obtain a denoised channel estimation value corresponding to the target subcarrier; The method includes determining a target filter value corresponding to the target subcarrier based on the position of the target subcarrier in the subcarrier sequence and a preset number of adjacent subcarriers; the target filter value includes a first filter value corresponding to the target subcarrier and a second filter value corresponding to the adjacent subcarriers; multiplying the initial channel estimation value corresponding to the target subcarrier by the corresponding first filter value, and multiplying the adjacent initial estimation value corresponding to the adjacent subcarrier by the corresponding second filter value, and accumulating the products to obtain the denoised channel estimation value; the target subcarrier is at least part of the plurality of subcarriers, the adjacent initial estimation value is the initial channel estimation value corresponding to the adjacent subcarrier, and the adjacent subcarrier is the subcarrier adjacent to the target subcarrier; the subcarrier sequence is obtained by sorting the plurality of subcarriers according to frequency; the sum of the first filter value and the second filter value is one, and the second filter value is the same as the number of the adjacent subcarriers; the magnitude of the second filter value is positively correlated with a sequence proximity distance, which is the position distance between the adjacent subcarrier corresponding to the second filter value and the target subcarrier corresponding to the first filter value in the subcarrier sequence; A channel estimation sequence of the target channel is obtained according to the denoised channel estimation value corresponding to the target subcarrier.

2. The OFDM-based power line carrier signal channel estimation method according to claim 1, characterized in that: Multiplying the initial channel estimate corresponding to the target subcarrier by the corresponding first filtered value, and multiplying the adjacent initial estimate corresponding to the adjacent subcarrier by the corresponding second filtered value, and accumulating the products to obtain the denoised channel estimate, comprises at least one of the following steps: multiplying the initial channel estimation value corresponding to the starting subcarrier by the corresponding first filtered value, and multiplying the adjacent initial estimation value corresponding to the starting subcarrier by the corresponding second filtered value, and accumulating the products to obtain a starting-end denoised channel estimation value; wherein the starting subcarrier is the subcarrier located at the starting end of the subcarrier sequence; multiplying the initial channel estimation value corresponding to the middle subcarrier by the corresponding first filtered value, and multiplying the adjacent initial estimation value corresponding to the middle subcarrier by the corresponding second filtered value, and accumulating the products to obtain a middle denoised channel estimation value; wherein the middle subcarrier is the subcarrier located in the middle of the subcarrier sequence; Multiplying the initial channel estimation value corresponding to the terminal subcarrier by the corresponding first filtered value, and multiplying the adjacent initial estimation value corresponding to the terminal subcarrier by the corresponding second filtered value, and accumulating the products to obtain a terminal denoised channel estimation value; wherein the terminal subcarrier is the subcarrier located at the terminal part of the subcarrier sequence.

3. The OFDM-based power line carrier signal channel estimation method according to claim 1, characterized in that: The second filtering value is smaller than the first filtering value corresponding to the second filtering value.

4. The OFDM-based power line carrier signal channel estimation method according to claim 1, characterized in that: Before determining the target filtering value according to the position of the target subcarrier in the subcarrier sequence and the preset number of adjacent subcarriers, the method further includes the following steps: Determining the number of end subcarriers according to the preset number; wherein the end subcarriers include a starting subcarrier and an end subcarrier, and the number of the starting subcarriers and the number of the end subcarriers are both related to the preset number; The position of the target subcarrier in the subcarrier sequence is determined according to the number of the end subcarriers.

5. The OFDM-based power line carrier signal channel estimation method according to any one of claims 1 to 4, characterized in that: Before edge filtering is performed on the initial channel estimation value corresponding to the target subcarrier according to the initial channel estimation value corresponding to the target subcarrier and the adjacent initial estimation values, the method further includes the steps of: When the signal-to-noise ratio value of the subcarrier is less than or equal to a preset threshold, the subcarrier is set as the target subcarrier.

6. The OFDM-based power line carrier signal channel estimation method according to any one of claims 1 to 4, characterized in that: Obtaining initial channel estimation values corresponding to a plurality of subcarriers according to a target signal of a target channel, comprising the steps of: Performing frame synchronization processing on the target signal to determine a synchronization peak; determining a synchronization symbol of the target signal according to the synchronization peak; Channel estimation is performed on the subcarrier according to the synchronization symbol to obtain the initial channel estimation value corresponding to the subcarrier.

7. A power line carrier signal channel estimation device based on OFDM, characterized in that: include: A first estimator, configured to obtain initial channel estimation values corresponding to a plurality of subcarriers based on a target signal of a target channel; an edge filter, configured to perform edge filtering on the initial channel estimation value corresponding to the target subcarrier based on the initial channel estimation value corresponding to the target subcarrier and adjacent initial estimation values, to obtain a denoised channel estimation value corresponding to the target subcarrier; The method includes determining a target filter value corresponding to the target subcarrier based on the position of the target subcarrier in the subcarrier sequence and a preset number of adjacent subcarriers; the target filter value includes a first filter value corresponding to the target subcarrier and a second filter value corresponding to the adjacent subcarriers; multiplying the initial channel estimation value corresponding to the target subcarrier by the corresponding first filter value, and multiplying the adjacent initial estimation value corresponding to the adjacent subcarrier by the corresponding second filter value, and accumulating the products to obtain the denoised channel estimation value; the target subcarrier is at least part of the plurality of subcarriers, the adjacent initial estimation value is the initial channel estimation value corresponding to the adjacent subcarrier, and the adjacent subcarrier is the subcarrier adjacent to the target subcarrier; the subcarrier sequence is obtained by sorting the plurality of subcarriers according to frequency; the sum of the first filter value and the second filter value is one, and the second filter value is the same as the number of the adjacent subcarriers; the magnitude of the second filter value is positively correlated with a sequence proximity distance, which is the position distance between the adjacent subcarrier corresponding to the second filter value and the target subcarrier corresponding to the first filter value in the subcarrier sequence; as well as, The second estimator is configured to obtain a channel estimation sequence of the target channel according to the denoised channel estimation value corresponding to the target subcarrier.

8. An electronic device comprising a processor and a memory for storing a program, characterized in that: The program includes instructions that, when executed by the processor, cause the processor to perform the OFDM-based power line carrier signal channel estimation method according to any one of claims 1 to 7.

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