Methods, apparatus, equipment, storage media and products for signal processing

Abstract

This application provides a signal processing method, apparatus, device, storage medium, and product. The method includes: acquiring signals carried on time-frequency domain resources corresponding to each orthogonal frequency division multiplexing (OFDM) symbol; acquiring header data of each signal; adding the header data as suffix data to the tail of the signal as suffix data of the signal carried on the time-frequency domain resources corresponding to the corresponding OFDM symbol, wherein the suffix data partially or completely covers the cyclic prefix of the next OFDM symbol in the time domain; downsampling and filtering the signal; windowing according to a preset windowing length; and performing a Fourier transform on the downsampled and filtered signal.

Description

Technical Field

[0001] This application relates to the field of mobile communication technology, and in particular to a method, apparatus, device, storage medium and product for signal processing. Background Technology

[0002] Orthogonal Frequency Division Multiplexing (OFDM) technology is widely used in current mobile communication systems. A cyclic prefix (CP) is typically added when using OFDM to help the receiver suppress inter-symbol interference (ISI) caused by multipath channels. However, filtering operations (such as convolution) in the transmitter or receiver of an OFDM system can also introduce ISI. For example, in the digital section of the receiver, many high-order filters are often used to combat aliasing, downsampling, and suppress adjacent channel interference. These operations generate ISI and worsen the error vector magnitude (EVM) in the subcarrier frequency domain. In systems like 5G or Wi-Fi, where higher-order modulation is used, the EVM loss cannot be ignored.

[0003] To address this issue, existing technologies primarily use Fast Fourier Transform (FFT) to advance the timing to avoid the ISI (Intermittent Sequence Inversion) segment in the time domain, thereby improving the frequency domain EVM (Effective Virtual Machine). However, the timing advance used in existing technologies encroaches on the time reserved in the communication system to cope with latency, thus reducing the system's ability to handle signals with large latency extensions. Summary of the Invention

[0004] This application provides a signal processing method, apparatus, device, storage medium, and product that can improve the ability of communication systems to cope with signals with large time delays.

[0005] In a first aspect, this application provides a signal processing method, the method comprising:

[0006] Obtain the signal carried on the time-frequency domain resources corresponding to each orthogonal frequency division multiplexing symbol;

[0007] Obtain the header data of each of the aforementioned signals;

[0008] The header data is added to the end of the signal as suffix data of the signal carried on the time-frequency domain resource corresponding to the orthogonal frequency division multiplexing symbol. The suffix data partially or completely covers the cyclic prefix of the next orthogonal frequency division multiplexing symbol in the time domain.

[0009] The signal is downsampled and filtered;

[0010] Windowing is performed according to the preset windowing length, and Fourier transform is performed on the downsampled and filtered signals.

[0011] The signal processing method described in this application adds the header of the time-domain Orthogonal Frequency Division Multiplexing (OFDM) symbol as a suffix to the tail of the OFDM symbol, allowing subsequent downsampling and filtering operations on the OFDM symbol signal. In this way, the header of the OFDM symbol reappears at the tail of the symbol, and the signal processed by the filter convolution can be considered a periodic signal, transforming the convolution process from linear convolution to cyclic convolution. This ensures signal continuity at the boundaries of the OFDM symbol. When subsequent windowing according to a preset window length and Fourier transform are performed, the signals all originate from the same OFDM symbol. This avoids the involvement of signals from adjacent OFDM symbols during filtering, reducing inter-symbol interference. Therefore, timing advance is unnecessary to avoid the ISI (Inter-Signal Interference) segment in the time domain, thus avoiding encroachment on the cyclic prefix between symbols and fully utilizing the length of the cyclic prefix, i.e., the guard interval, thereby improving the ability to handle signals with large time delay spreads.

[0012] In some possible implementations, the step of windowing according to a preset windowing length and performing a Fourier transform on the downsampled and filtered signal includes:

[0013] In the case of frequency offset of the signal, the Fourier transform window corresponding to the orthogonal frequency division multiplexing symbol in the time domain is advanced according to the preset timing advance length;

[0014] The data corresponding to the first preset windowing length of the Fourier transform window in the suffix corresponding to the orthogonal frequency division multiplexing symbol is superimposed onto the header of the Fourier transform window.

[0015] The above-described method of this application advances the timing of the Fourier transform window when the signal has a frequency offset, and superimposes part of the data in the suffix corresponding to the orthogonal frequency division multiplexing symbol onto the header of the Fourier transform window, ensuring that the data in the Fourier transform window all belong to one orthogonal frequency division multiplexing symbol. In this way, the frequency offset compensation effect can be improved for the frequency offset problem.

[0016] In some possible implementations, before advancing the Fourier transform window corresponding to the orthogonal frequency division multiplexing symbol in the time domain according to a preset timing advance length, the method further includes:

[0017] Obtain the first preset window length corresponding to the timing advance length.

[0018] The specific window length may vary in various practical applications. The method described in this application can obtain an accurate first preset window length by acquiring the first preset window length corresponding to the timing advance length.

[0019] In some possible implementations, the method further includes, after superimposing the data corresponding to the first preset windowing length of the Fourier transform window into the header of the Fourier transform window in the suffix corresponding to the orthogonal frequency division multiplexing symbol:

[0020] When the signal-to-noise ratio of the communication signal is lower than a preset value, a portion of the data in the cyclic prefix corresponding to the orthogonal frequency division multiplexing symbol is obtained according to the second preset window length;

[0021] The data is superimposed onto the end of the Fourier transform window.

[0022] The above-described method of this application optimizes the signal under low signal-to-noise ratio conditions by superimposing a portion of the data in the orthogonal frequency division multiplexing symbol cyclic prefix onto the tail of the Fourier transform window based on a second preset window length when the signal-to-noise ratio of the communication signal is lower than a preset value.

[0023] In some possible implementations, before obtaining a portion of the data in the cyclic prefix corresponding to the orthogonal frequency division multiplexing symbol according to the second preset window length, the method further includes:

[0024] Obtain the preset adjustment coefficient and maximum latency spread;

[0025] Calculate the result of multiplying the maximum delay spread of an orthogonal frequency division multiplexing symbol by the adjustment factor;

[0026] The second preset window length is obtained by subtracting the cyclic prefix length of the orthogonal frequency division multiplexing symbol from the result value and the first preset window length.

[0027] The above-described method of this application calculates the second preset window length by obtaining the maximum delay spread and the adjustment coefficient, and can accurately obtain the second preset window length.

[0028] In some possible implementations, before windowing according to a preset windowing length and performing a Fourier transform on the downsampled and filtered signal, the method further includes:

[0029] Get the preset window type;

[0030] The step of windowing according to a preset windowing length and performing Fourier transform on the downsampled and filtered signal includes:

[0031] Windowing is performed according to the preset windowing type and preset windowing length, and Fourier transform is performed on the downsampled and filtered signals.

[0032] The above-described method of this application limits the windowing type during Fourier transform by obtaining a preset windowing type and performing windowing according to the preset windowing type and preset windowing length.

[0033] In some possible implementations, the step of using the header of the time-domain orthogonal frequency division multiplexing symbol as a suffix includes:

[0034] Obtain the maximum latency spread;

[0035] The suffix length is obtained by subtracting the maximum delay spread of the orthogonal frequency division multiplexing symbol from the cyclic prefix length of the orthogonal frequency division multiplexing symbol.

[0036] The signal in the orthogonal frequency division multiplexing symbol header is selected as the suffix based on the suffix length.

[0037] The above-described method of this application obtains the maximum delay spread and then obtains the suffix based on the length of the maximum delay spread, thus obtaining the suffix length more accurately.

[0038] Secondly, this application provides a signal processing apparatus, the apparatus comprising:

[0039] The acquisition module is used to acquire the signals carried on the time-frequency domain resources corresponding to each orthogonal frequency division multiplexing symbol;

[0040] The acquisition module is also used to acquire the header data of each of the signals;

[0041] An adding module is used to add the header data as suffix data of the signal carried on the time-frequency domain resource corresponding to the orthogonal frequency division multiplexing symbol to the tail of the signal. The suffix data partially or completely covers the cyclic prefix of the next orthogonal frequency division multiplexing symbol in the time domain.

[0042] A sampling module is used to downsample and filter the signal;

[0043] The windowing module is used to window the signal according to a preset windowing length and perform Fourier transform on the downsampled and filtered signal.

[0044] Thirdly, embodiments of this application provide a signal processing apparatus, the apparatus comprising: a processor, and a memory storing computer program instructions; the processor reads and executes the computer program instructions to implement the signal processing method as described above.

[0045] Fourthly, embodiments of this application provide a computer-readable storage medium storing computer program instructions, which, when executed by a processor, implement the signal processing method described above.

[0046] Fifthly, embodiments of this application provide a computer program product in which instructions, when executed by a processor of an electronic device, cause the electronic device to perform the signal processing method described above.

[0047] The above-described method of this application adds the header of the time-domain Orthogonal Frequency Division Multiplexing (OFDM) symbol as a suffix to the tail of the OFDM symbol, allowing subsequent downsampling and filtering operations on the signal of the OFDM symbol. In this way, the header of the OFDM symbol reappears at the tail of the symbol, and the signal processed by the filter convolution can be considered a periodic signal, transforming the convolution process from linear convolution to cyclic convolution. This ensures signal continuity at the boundaries of the OFDM symbol. When subsequent windowing according to a preset window length and Fourier transform are performed, the signals all originate from the same OFDM symbol. This avoids the involvement of signals from adjacent OFDM symbols during filtering, reducing inter-symbol interference. Therefore, timing advance is unnecessary to avoid the ISI (Inter-Signal Interference) segment in the time domain, thus avoiding encroachment on the cyclic prefix between symbols and fully utilizing the length of the cyclic prefix, i.e., the guard interval, thereby improving the ability to handle signals with large time delay spreads. Attached Figure Description

[0048] This application can be better understood from the following description of specific embodiments in conjunction with the accompanying drawings, wherein:

[0049] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings, wherein the same or similar reference numerals denote the same or similar features.

[0050] Figure 1 This is a schematic flowchart of a signal processing method provided in one embodiment of this application;

[0051] Figure 2 This is a schematic diagram of time-domain processing in a high-order modulation scenario according to one embodiment of this application;

[0052] Figure 3 This is a schematic diagram of time-domain processing in a scenario with frequency offset in one embodiment of this application;

[0053] Figure 4 This is a schematic diagram of a time-domain processing graph in a low signal-to-noise ratio scenario according to one embodiment of this application;

[0054] Figure 5 This is a schematic diagram of the structure of a signal processing apparatus provided in one embodiment of this application;

[0055] Figure 6 This is a schematic diagram of the hardware structure of the signal processing device provided in the embodiments of this application. Detailed Implementation

[0056] The features and exemplary embodiments of various aspects of this application will now be described in detail. Numerous specific details are set forth in the following detailed description to provide a comprehensive understanding of this application. However, it will be apparent to those skilled in the art that this application can be implemented without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of this application by illustrating examples. This application is by no means limited to any specific configurations and algorithms presented below, but covers any modifications, substitutions, and improvements to elements, components, and algorithms without departing from the spirit of this application. Well-known structures and techniques are not shown in the accompanying drawings and the following description in order to avoid unnecessary obfuscation of this application.

[0057] Inter-carrier interference (ICI): In an orthogonal frequency division multiplexing system, interference caused when subcarriers lose orthogonality.

[0058] Inter-symbol interference (ISI) refers to the interference caused by the overlapping of the same signal at the receiver due to multipath propagation.

[0059] Cyclic Prefix (CP): A prefix formed by copying the signal from the tail of an orthogonal frequency division multiplexing symbol to the head.

[0060] Orthogonal Frequency Division Multiplexing (OFDM) technology is widely used in current mobile communication systems. A cyclic prefix (CP) is typically added when using OFDM to help the receiver suppress inter-symbol interference (ISI) caused by multipath channels. However, filtering operations (such as convolution) in the transmitter or receiver of an OFDM system can also introduce ISI. For example, in the digital section of the receiver, many high-order filters are often used to combat aliasing, downsampling, and suppress adjacent channel interference. These operations generate ISI and worsen the error vector magnitude (EVM) in the subcarrier frequency domain. In systems like 5G or Wi-Fi, where higher-order modulation is used, the EVM loss cannot be ignored.

[0061] To address this issue, existing technologies primarily use Fast Fourier Transform (FFT) to advance the timing to avoid the ISI (Intermittent Sequence Inversion) segment in the time domain, thereby improving the frequency domain EVM (Effective Virtual Machine). However, the timing advance used in existing technologies encroaches on the time reserved in the communication system to cope with latency, thus reducing the system's ability to handle signals with large latency extensions.

[0062] In OFDM systems, frequency offset disrupts the orthogonality between subcarriers, leading to inter-carrier interference (ICI). Existing technologies typically use frequency offset estimation compensation to mitigate ICI; however, the accuracy and stability of frequency offset estimation methods are limited, resulting in less than ideal compensation effects.

[0063] The inventors, in their research addressing the aforementioned problems, discovered that existing technologies, in order to avoid the ISI (Intermittent Separation) segment in the time domain, need to encroach on the time reserved in the communication system to cope with latency, thus reducing the system's ability to handle signals with large latency spreads. However, if ISI is avoided during the filtering process, there is no need for timing advance, and therefore, the system's ability to handle signals with large latency spreads is not reduced.

[0064] In one embodiment of the signal processing method of this application, reference can be made to Figure 1 In this embodiment, the method can be executed by the signal processing device described above, and the method includes the following steps S101 to S105.

[0065] Step S101: Obtain the signal carried on the time-frequency domain resources corresponding to each orthogonal frequency division multiplexing symbol.

[0066] In practical implementation, when preparing to transmit a signal, each different orthogonal frequency division multiplexing (OFDM) symbol corresponds to a different signal. Therefore, it is necessary to obtain the signal corresponding to the time-frequency domain resources of the OFDM symbol in advance. For example, the data to be transmitted is modulated and converted into a digital signal to be transmitted. Then, the digital signal is encoded (such as error correction coding) to generate a bit stream to be transmitted. This bit stream is then divided into signals corresponding to different OFDM symbols.

[0067] Step S102: Obtain the header data of each signal.

[0068] In practice, after determining the signals corresponding to different orthogonal frequency division multiplexing symbols, the header data of each transmission frame can be accurately extracted.

[0069] Step S103: Add the header data as suffix data to the end of the signal as the signal carried on the time-frequency domain resource corresponding to the orthogonal frequency division multiplexing symbol. The suffix data partially or completely covers the cyclic prefix of the next orthogonal frequency division multiplexing symbol in the time domain.

[0070] In the specific implementation, the acquired header data is converted into suffix data. The length of the suffix data in the time domain is the same as that of the acquired header data, and is less than or equal to the length of the cyclic prefix. The generated suffix data is directly appended to the end of the OFDM symbol, so that part or all of the suffix data will cover the cyclic prefix of the next OFDM symbol.

[0071] Step S104: Downsample and filter the signal.

[0072] Downsampling refers to sampling a high-sampling-rate signal at a lower sampling rate to reduce the amount of data and improve processing efficiency.

[0073] In the actual implementation, a filter is pre-designed, which can be applied to the signal through convolution operations or frequency domain filtering. Then, sampling can be performed according to a set downsampling factor.

[0074] Step S105: Window the signal according to the preset windowing length, and perform Fourier transform on the downsampled and filtered signal.

[0075] In practical implementation, the window length is predetermined based on specific needs and application scenarios. Generally, the window length is the same as the length of an OFDM symbol. This window length determines the size of the window used to truncate the signal in the time domain. The downsampled and filtered signal is truncated according to the preset window length, and then a Fourier transform is performed on the windowed signal to complete signal processing.

[0076] The signal processing method described in this application adds the header of the time-domain Orthogonal Frequency Division Multiplexing (OFDM) symbol as a suffix to the tail of the OFDM symbol, allowing subsequent downsampling and filtering operations on the OFDM symbol signal. In this way, the header of the OFDM symbol reappears at the tail of the symbol, and the signal processed by the filter convolution can be considered a periodic signal, transforming the convolution process from linear convolution to cyclic convolution. This ensures signal continuity at the boundaries of the OFDM symbol. When subsequent windowing according to a preset window length and Fourier transform are performed, the signals all originate from the same OFDM symbol. This avoids the involvement of signals from adjacent OFDM symbols during filtering, reducing inter-symbol interference. Therefore, timing advance is unnecessary to avoid the ISI (Inter-Signal Interference) segment in the time domain, thus avoiding encroachment on the cyclic prefix between symbols and fully utilizing the length of the cyclic prefix, i.e., the guard interval, thereby improving the ability to handle signals with large time delay spreads.

[0077] In some implementations, the step of windowing according to a preset windowing length and performing a Fourier transform on the downsampled and filtered signal includes:

[0078] In the case of frequency offset of the signal, the Fourier transform window corresponding to the orthogonal frequency division multiplexing symbol in the time domain is advanced according to the preset timing advance length.

[0079] Frequency offset refers to the difference between the actual frequency of a signal and its theoretical frequency. For example, when the receiver is moving at high speed, the Doppler effect causes a change in the signal frequency.

[0080] In the specific implementation, the timing advance length is predetermined based on specific needs and application scenarios. The timing advance length determines the size of the window for advancing the signal in the time domain. Then, the Fourier transform window corresponding to the orthogonal frequency division multiplexing symbol is advanced according to the timing advance length.

[0081] The data corresponding to the first preset windowing length of the Fourier transform window in the suffix corresponding to the orthogonal frequency division multiplexing symbol is superimposed onto the header of the Fourier transform window.

[0082] In the specific implementation, the preset window length for the Fourier transform window is first determined. Based on the preset window length, the length of data to be extracted from the orthogonal frequency division multiplexing symbol suffix is ​​determined. Corresponding to the window length, this part of the data will be superimposed on the header of the Fourier transform window.

[0083] The above-described method of this application advances the timing of the Fourier transform window when the signal has a frequency offset, and superimposes part of the data in the suffix corresponding to the orthogonal frequency division multiplexing symbol onto the header of the Fourier transform window, ensuring that the data in the Fourier transform window all belong to one orthogonal frequency division multiplexing symbol. In this way, the frequency offset compensation effect can be improved for the frequency offset problem.

[0084] In some embodiments, before advancing the Fourier transform window corresponding to the orthogonal frequency division multiplexing symbol in the time domain according to a preset timing advance length, the method further includes:

[0085] Obtain the first preset window length corresponding to the timing advance length.

[0086] In the specific implementation, firstly, the required timing advance length needs to be determined. The timing advance length refers to the window size for advancing the signal in the time domain. Then, the first preset window length is determined as the timing advance length.

[0087] The specific window length may vary in various practical applications. The method described in this application can obtain an accurate first preset window length by acquiring the first preset window length corresponding to the timing advance length.

[0088] In some implementations, the method further includes superimposing the data corresponding to the first preset windowing length of the Fourier transform window into the header of the Fourier transform window in the suffix corresponding to the orthogonal frequency division multiplexing symbol.

[0089] When the signal-to-noise ratio of the communication signal is lower than a preset value, a portion of the data in the cyclic prefix corresponding to the orthogonal frequency division multiplexing symbol is obtained according to the second preset window length.

[0090] In the specific implementation, it is first necessary to determine the signal-to-noise ratio of the communication signal. If the signal-to-noise ratio of the communication signal is lower than a preset value, a second preset window length is determined. Then, according to the second preset window length, data of the corresponding length is extracted from the cyclic prefix of the orthogonal frequency division multiplexing symbol.

[0091] The data is superimposed onto the end of the Fourier transform window.

[0092] In the actual implementation, after obtaining the data to be overlaid, the newly obtained data is directly connected to the end of the window.

[0093] The above-described method of this application optimizes the signal under low signal-to-noise ratio conditions by superimposing a portion of the data in the orthogonal frequency division multiplexing symbol cyclic prefix onto the tail of the Fourier transform window based on a second preset window length when the signal-to-noise ratio of the communication signal is lower than a preset value.

[0094] In some embodiments, before obtaining a portion of the data in the cyclic prefix corresponding to the orthogonal frequency division multiplexing symbol according to the second preset window length, the method further includes:

[0095] Obtain the preset adjustment coefficient and the maximum delay spread.

[0096] In practice, the preset adjustment coefficient is usually a parameter determined in advance based on the system design or signal characteristics. It is used for adjustment and correction in subsequent signal processing to obtain the maximum time delay spread and preset adjustment coefficient in the system.

[0097] The result of multiplying the maximum delay spread of an orthogonal frequency division multiplexing symbol by the adjustment factor is calculated.

[0098] In the specific implementation, the obtained maximum delay spread is multiplied by the preset adjustment coefficient to obtain a product value.

[0099] The second preset window length is obtained by subtracting the cyclic prefix length of the orthogonal frequency division multiplexing symbol from the result value and the first preset window length.

[0100] In the specific implementation, the length of the cyclic prefix in each OFDM symbol and the previously obtained preset first window length are determined. Then, the cyclic prefix length is subtracted from the previously calculated result, and then the first preset window length is subtracted to obtain the second preset window length.

[0101] The above-described method of this application calculates the second preset window length by obtaining the maximum delay spread and the adjustment coefficient, and can accurately obtain the second preset window length.

[0102] In some embodiments, before windowing according to a preset windowing length and performing a Fourier transform on the downsampled and filtered signal, the method further includes:

[0103] Get the preset window type.

[0104] In practice, parameters representing preset windowing types are set in the system or algorithm. After obtaining the preset windowing type parameter, the software will make a selection judgment based on the value or identifier of the parameter to determine which preset windowing type to use.

[0105] The step of windowing according to a preset windowing length and performing Fourier transform on the downsampled and filtered signal includes:

[0106] Windowing is performed according to the preset windowing type and preset windowing length, and Fourier transform is performed on the downsampled and filtered signals.

[0107] In the specific implementation, windowing is performed according to the preset windowing type and preset windowing length. After windowing, the input signal is multiplied or convolved with the corresponding windowing coefficients to achieve signal filtering. Downsampling can also be performed on the windowed signal to reduce the signal sampling rate.

[0108] The above-described method of this application limits the windowing type during Fourier transform by obtaining a preset windowing type and performing windowing according to the preset windowing type and preset windowing length.

[0109] In some implementations, using the header of the time-domain orthogonal frequency division multiplexing symbol as a suffix includes:

[0110] Obtain the maximum latency spread.

[0111] The suffix length is obtained by subtracting the maximum delay spread of the orthogonal frequency division multiplexing (OFDM) symbol from the cyclic prefix length of the OFDM symbol.

[0112] In the specific implementation, the cyclic prefix length and maximum delay spread of each OFDM symbol are obtained in advance, and then the suffix length is determined to be equal to the cyclic prefix length minus the maximum delay spread.

[0113] The signal in the orthogonal frequency division multiplexing symbol header is selected as the suffix based on the suffix length.

[0114] In practice, after determining the suffix length, consecutive signal samples can be selected as suffixes in each OFDM symbol based on the determined suffix length. These signal samples are usually located in the head of the symbol.

[0115] The above-described method of this application obtains the maximum delay spread and then obtains the suffix based on the length of the maximum delay spread, thus obtaining the suffix length more accurately.

[0116] As another implementation of this application, in high-order modulation scenarios, such as when the user terminal is in a mobile communication network with high data throughput requirements, such as in a 5G network, after receiving the signal, during time-domain preprocessing, a suffix is ​​added to the OFDM symbol in the time domain before downsampling and filtering, covering the CP header of subsequent symbols, such as... Figure 2 As shown.

[0117] In this way, the signals before and after the subsequent Fast Fourier Transform (FFT) window are from the same symbol, and the signals are continuous at the symbol boundaries. The filtering operation of the OFDM symbols is changed from linear convolution to circular convolution. This reduces the signal participation of adjacent symbols when performing filtering, thus reducing ISI.

[0118] In this case, the FFT window timing is not advanced; that is, the FFT begins at the beginning of the OFDM symbol, thus making full use of the CP length. The suffix length can be selected based on the maximum delay spread obtained from channel estimation, for example: suffix length = CP length - maximum delay spread.

[0119] In cases of frequency offset, such as when the user terminal is moving at high speed or when the power of a neighboring cell is significantly higher than that of the serving cell, causing interference, the FFT timing window is advanced based on the above operations. This involves superimposing the data after the FFT window onto the data at the beginning of the FFT window. Figure 3 As shown.

[0120] This also ensures signal continuity at OFDM symbol boundaries, thus suppressing ISI and consequently ICI. Specific windowing types can be chosen, such as raised cosine windows or exponential windows. The additional part of the FFT window, i.e., the first window length, can be selected according to the rule: first window length = timing advance length.

[0121] In low signal-to-noise ratio scenarios, such as when the signal received by the user terminal is weak, the FFT window is further advanced based on the above operations, and a portion of the data from the second window length, which is further advanced before the FFT window, is superimposed on the data at the end of the FFT window. For example... Figure 4 As shown.

[0122] This allows for full utilization of the CP portion of the signal for time-domain combining in low signal-to-noise ratio (SNR) scenarios, achieving time diversity gain. The window type can be selected from raised cosine windows, exponential windows, etc. The selection rule for the second window length can be: Window length 0 + Window length 1 = CP length - Maximum delay spread * Adjustment coefficient, where the adjustment coefficient is determined through link simulation. Choosing an appropriate adjustment coefficient can achieve the best demodulation performance in multipath channels and low SNR scenarios.

[0123] The above-described methods of this application employ different time-domain preprocessing techniques to optimize signal quality and improve demodulation performance for signal problems in high-order modulation scenarios, high-speed scenarios, strong adjacent channel interference scenarios, and low SNR scenarios.

[0124] Based on the signal processing method provided in the above embodiments, this application also provides specific implementations of a signal processing apparatus. Please refer to the following embodiments.

[0125] First see Figure 5 The signal processing apparatus 400 provided in this application embodiment includes the following modules:

[0126] The acquisition module 401 is used to acquire the signals carried on the time-frequency domain resources corresponding to each orthogonal frequency division multiplexing symbol.

[0127] The acquisition module 401 is also used to acquire the header data of each of the signals.

[0128] The addition module 402 is used to add the header data as suffix data of the signal carried on the time-frequency domain resource corresponding to the orthogonal frequency division multiplexing symbol to the end of the signal. The suffix data partially or completely covers the cyclic prefix of the next orthogonal frequency division multiplexing symbol in the time domain.

[0129] The sampling module 403 is used to downsample and filter the signal.

[0130] The windowing module 404 is used to window the signal according to a preset windowing length and to perform Fourier transform on the downsampled and filtered signal.

[0131] The signal processing method described in this application adds the header of the time-domain Orthogonal Frequency Division Multiplexing (OFDM) symbol as a suffix to the tail of the OFDM symbol, allowing subsequent downsampling and filtering operations on the OFDM symbol signal. In this way, the header of the OFDM symbol reappears at the tail of the symbol, and the signal processed by the filter convolution can be considered a periodic signal, transforming the convolution process from linear convolution to cyclic convolution. This ensures signal continuity at the boundaries of the OFDM symbol. When subsequent windowing according to a preset window length and Fourier transform are performed, the signals all originate from the same OFDM symbol. This avoids the involvement of signals from adjacent OFDM symbols during filtering, reducing inter-symbol interference. Therefore, timing advance is unnecessary to avoid the ISI (Inter-Signal Interference) segment in the time domain, thus avoiding encroachment on the cyclic prefix between symbols and fully utilizing the length of the cyclic prefix, i.e., the guard interval, thereby improving the ability to handle signals with large time delay spreads.

[0132] As one implementation of this application, the signal processing apparatus 400 further includes:

[0133] The advance module is used to advance the Fourier transform window corresponding to the orthogonal frequency division multiplexing symbol in the time domain according to a preset timing advance length when the signal has a frequency offset.

[0134] The overlay module is used to overlay the data in the suffix corresponding to the orthogonal frequency division multiplexing symbol, which corresponds to the first preset windowing length of the Fourier transform window, onto the header of the Fourier transform window.

[0135] The above-described method of this application advances the timing of the Fourier transform window when the signal has a frequency offset, and superimposes part of the data in the suffix corresponding to the orthogonal frequency division multiplexing symbol onto the header of the Fourier transform window, ensuring that the data in the Fourier transform window all belong to one orthogonal frequency division multiplexing symbol. In this way, the frequency offset compensation effect can be improved for the frequency offset problem.

[0136] As one implementation of this application, the signal processing apparatus 400 further includes:

[0137] The acquisition module is used to acquire the first preset window length corresponding to the timing advance length.

[0138] The specific window length may vary in various practical applications. The method described in this application can obtain an accurate first preset window length by acquiring the first preset window length corresponding to the timing advance length.

[0139] As one implementation of this application, the signal processing apparatus 400 further includes:

[0140] The acquisition module is used to acquire a portion of the data in the cyclic prefix corresponding to the orthogonal frequency division multiplexing symbol according to a second preset window length when the signal-to-noise ratio of the communication signal is lower than a preset value.

[0141] The overlay module is used to overlay the data onto the tail of the Fourier transform window.

[0142] The above-described method of this application optimizes the signal under low signal-to-noise ratio conditions by superimposing a portion of the data in the orthogonal frequency division multiplexing symbol cyclic prefix onto the tail of the Fourier transform window based on a second preset window length when the signal-to-noise ratio of the communication signal is lower than a preset value.

[0143] As one implementation of this application, the signal processing apparatus 400 further includes:

[0144] The acquisition module is used to obtain the preset adjustment coefficient and the maximum delay spread.

[0145] The calculation module is used to calculate the result of multiplying the maximum delay spread of an orthogonal frequency division multiplexing symbol by the adjustment coefficient.

[0146] The calculation module is also used to subtract the result value and the first preset windowing length from the cyclic prefix length of the orthogonal frequency division multiplexing symbol to obtain the second preset windowing length.

[0147] The above-described method of this application calculates the second preset window length by obtaining the maximum delay spread and the adjustment coefficient, and can accurately obtain the second preset window length.

[0148] As one implementation of this application, the signal processing apparatus 400 further includes:

[0149] The acquisition module is used to acquire preset window types.

[0150] The windowing module is used to window the signal according to the preset windowing type and preset windowing length, and to perform Fourier transform on the downsampled and filtered signal.

[0151] The above-described method of this application limits the windowing type during Fourier transform by obtaining a preset windowing type and performing windowing according to the preset windowing type and preset windowing length.

[0152] As one implementation of this application, the signal processing apparatus 400 further includes:

[0153] The acquisition module is used to obtain the maximum latency spread.

[0154] The calculation module is used to subtract the maximum delay spread of the orthogonal frequency division multiplexing symbol from the cyclic prefix length of the orthogonal frequency division multiplexing symbol to obtain the suffix length.

[0155] The selection module is used to select the signal of the orthogonal frequency division multiplexing symbol header as the suffix according to the suffix length.

[0156] The above-described method of this application obtains the maximum delay spread and then obtains the suffix based on the length of the maximum delay spread, thus obtaining the suffix length more accurately.

[0157] Each module in the signal processing apparatus provided in this application embodiment can implement each step in the above-described signal processing method and achieve the corresponding effect. For the sake of brevity, it will not be described in detail here.

[0158] Figure 6 A schematic diagram of the hardware structure for signal processing provided in an embodiment of this application is shown.

[0159] The signal processing device may include a processor 501 and a memory 502 storing computer program instructions.

[0160] Specifically, the processor 501 may include a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits that can be configured to implement the embodiments of this application.

[0161] Memory 502 may include mass storage for data or instructions. For example, and not limitingly, memory 502 may include a hard disk drive (HDD), floppy disk drive, flash memory, optical disk, magneto-optical disk, magnetic tape, or Universal Serial Bus (USB) drive, or a combination of two or more of these. Where appropriate, memory 502 may include removable or non-removable (or fixed) media. Where appropriate, memory 502 may be internal or external to the integrated gateway disaster recovery device. In a particular embodiment, memory 502 is non-volatile solid-state memory.

[0162] Memory may include read-only memory (ROM), random access memory (RAM), disk storage media devices, optical storage media devices, flash memory devices, and electrical, optical, or other physical / tangible memory storage devices. Therefore, typically, memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., memory devices) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the signal processing methods according to any embodiment of this disclosure.

[0163] The processor 501 implements any of the signal processing methods described in the above embodiments by reading and executing computer program instructions stored in the memory 502.

[0164] In one example, the signal processing device may further include a communication interface 503 and a bus 510. Wherein, as Figure 6 As shown, the processor 501, memory 502, and communication interface 503 are connected through bus 510 and complete communication with each other.

[0165] The communication interface 503 is mainly used to realize communication between various modules, devices, units and / or equipment in the embodiments of this application.

[0166] Bus 510 includes hardware, software, or both, that couples components of an online data traffic metering device together. For example, and not limitingly, the bus may include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), HyperTransport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an Infinite Bandwidth Interconnect, a Low Pin Count (LPC) bus, a memory bus, a Microchannel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local (VLB) bus, or other suitable buses, or combinations of two or more of these. Where appropriate, bus 510 may include one or more buses. Although specific buses are described and illustrated in embodiments of this application, any suitable bus or interconnect is contemplated herein.

[0167] Furthermore, in conjunction with the signal processing methods described in the above embodiments, this application embodiment can provide a computer storage medium for implementation. The computer storage medium stores computer program instructions; when these computer program instructions are executed by a processor, they implement any of the signal processing methods described in the above embodiments.

[0168] However, it should be clarified that this application is not limited to the specific configurations and processes described above and shown in the figures. Furthermore, for the sake of brevity, detailed descriptions of known methods and techniques are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of this application is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of this application.

[0169] The functional blocks shown in the above-described structural diagram can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this application are programs or code segments used to perform the required tasks. Programs or code segments can be stored on a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried on a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, fiber optic media, radio frequency (RF) links, etc. Code segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0170] It should also be noted that the exemplary embodiments mentioned in this application describe methods or systems based on a series of steps or apparatus. However, this application is not limited to the order of the above steps; that is, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0171] The aspects of this application have been described above with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It should be understood that each block in the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that these instructions, executable via the processor of the computer or other programmable data processing apparatus, enable the implementation of the functions / actions specified in one or more blocks of the flowchart illustrations and / or block diagrams. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field-programmable logic circuit. It is also understood that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can also be implemented by dedicated hardware performing the specified functions or actions, or can be implemented by a combination of dedicated hardware and computer instructions.

[0172] This application may be implemented in other specific forms without departing from its spirit and essential characteristics. For example, the algorithm described in a particular embodiment may be modified without departing from the basic spirit of this application. Therefore, the present embodiments are to be regarded as exemplary rather than limiting in all respects, and the scope of this application is defined by the appended claims rather than the foregoing description, and all changes falling within the meaning and scope of the claims and their equivalents are thus included within the scope of this application.

[0173] Those skilled in the art will understand that the above embodiments are exemplary and not restrictive. Different technical features appearing in different embodiments can be combined to achieve beneficial effects. Based on a study of the drawings, specification, and claims, those skilled in the art should be able to understand and implement other variations of the disclosed embodiments. In the claims, the term "comprising" does not exclude other means or steps; the indefinite article "a" does not exclude a plurality; the terms "first" and "second" are used to identify names and not to indicate any particular order. No reference numerals in the claims should be construed as limiting the scope of protection. The functionality of multiple parts appearing in the claims can be implemented by a single hardware or software module. The appearance of certain technical features in different dependent claims does not mean that these technical features cannot be combined to achieve beneficial effects.

Claims

1. A signal processing method, characterized in that, The method includes: Obtain the signal carried on the time-frequency domain resources corresponding to each orthogonal frequency division multiplexing symbol; Obtain the header data of each of the aforementioned signals; The header data is added to the end of the signal as suffix data of the signal carried on the time-frequency domain resource corresponding to the orthogonal frequency division multiplexing symbol. The suffix data partially or completely covers the cyclic prefix of the next orthogonal frequency division multiplexing symbol in the time domain. The signal is downsampled and filtered; Windowing is performed according to the preset windowing length, and Fourier transform is performed on the downsampled and filtered signals; The step of windowing according to a preset windowing length and performing Fourier transform on the downsampled and filtered signal includes: when the signal has a frequency offset, advancing the Fourier transform window corresponding to the orthogonal frequency division multiplexing symbol in the time domain according to a preset timing advance length; and superimposing the data in the suffix corresponding to the orthogonal frequency division multiplexing symbol that corresponds to the first preset windowing length of the Fourier transform window advance onto the header of the Fourier transform window. The method further includes: when the signal-to-noise ratio of the signal is lower than a preset value, obtaining a portion of the data in the cyclic prefix corresponding to the orthogonal frequency division multiplexing symbol according to a second preset window length; and superimposing the portion of the data in the cyclic prefix corresponding to the orthogonal frequency division multiplexing symbol onto the tail of the Fourier transform window.

2. The signal processing method according to claim 1, characterized in that, Before advancing the Fourier transform window corresponding to the orthogonal frequency division multiplexing symbol in the time domain according to the preset timing advance length, the method further includes: Obtain the first preset window length corresponding to the timing advance length.

3. The signal processing method according to claim 1, characterized in that, Before obtaining a portion of the data in the cyclic prefix corresponding to the orthogonal frequency division multiplexing symbol according to the second preset window length, the method further includes: Obtain the preset adjustment coefficient and maximum latency spread; Calculate the result of multiplying the maximum delay spread of an orthogonal frequency division multiplexing symbol by the adjustment factor; The second preset window length is obtained by subtracting the cyclic prefix length of the orthogonal frequency division multiplexing symbol from the result value and the first preset window length.

4. The signal processing method according to any one of claims 1 to 3, characterized in that, Before windowing according to a preset windowing length and performing a Fourier transform on the downsampled and filtered signal, the method further includes: Get the preset window type; The step of windowing according to a preset windowing length and performing Fourier transform on the downsampled and filtered signal includes: Windowing is performed according to the preset windowing type and preset windowing length, and Fourier transform is performed on the downsampled and filtered signals.

5. The signal processing method according to any one of claims 1 to 3, characterized in that, The method of adding the header data as suffix data of the signal carried on the time-frequency domain resource corresponding to the orthogonal frequency division multiplexing symbol to the tail of the signal further includes: Obtain the maximum latency spread; The suffix length is obtained by subtracting the maximum delay spread of the orthogonal frequency division multiplexing symbol from the cyclic prefix length of the orthogonal frequency division multiplexing symbol. The signal in the orthogonal frequency division multiplexing symbol header is selected as the suffix based on the suffix length.

6. A signal processing apparatus, characterized in that, The device includes: The acquisition module is used to acquire the signals carried on the time-frequency domain resources corresponding to each orthogonal frequency division multiplexing symbol; The acquisition module is also used to acquire the header data of each of the signals; An adding module is used to add the header data as suffix data of the signal carried on the time-frequency domain resource corresponding to the orthogonal frequency division multiplexing symbol to the tail of the signal. The suffix data partially or completely covers the cyclic prefix of the next orthogonal frequency division multiplexing symbol in the time domain. A sampling module is used to downsample and filter the signal; The windowing module is used to window the signal according to a preset windowing length and perform Fourier transform on the downsampled and filtered signal. Wherein, in the case of frequency offset in the signal, the device further includes: The advance module is used to advance the Fourier transform window corresponding to the orthogonal frequency division multiplexing symbol in the time domain according to the preset advance time. The overlay module is used to overlay the data in the suffix corresponding to the orthogonal frequency division multiplexing symbol, which corresponds to the first preset windowing length of the Fourier transform window, onto the header of the Fourier transform window. After the superposition module superimposes the data corresponding to the first preset windowing length of the Fourier transform window into the header of the Fourier transform window in the suffix corresponding to the orthogonal frequency division multiplexing symbol, if the signal-to-noise ratio of the signal is lower than a preset value, the acquisition module is further used to acquire part of the data in the cyclic prefix corresponding to the orthogonal frequency division multiplexing symbol according to the second preset windowing length. The overlay module is also used to overlay a portion of the data in the cyclic prefix corresponding to the orthogonal frequency division multiplexing symbol onto the tail of the Fourier transform window.

7. A signal processing device, characterized in that, The device includes: a processor and a memory storing computer program instructions; the processor reads and executes the computer program instructions to implement the signal processing method as described in any one of claims 1-5.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer program instructions that, when executed by a processor, implement the signal processing method as described in any one of claims 1-5.

9. A computer program product, characterized in that, When the instructions in the computer program product are executed by the processor of the electronic device, the electronic device causes the electronic device to perform the signal processing method as described in any one of claims 1-5.

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