Signaling method, signal processing method

Abstract

The embodiment of the application provides a signal sending method and a signal processing method, relates to the field of low-orbit satellite communication, and the signal sending method comprises the following steps: acquiring a time delay change rate sent by a signal receiving end, wherein the time delay change rate is calculated by the signal receiving end according to a received synchronization signal and a locally generated synchronization signal; pre-processing a frequency domain signal after resource mapping according to the time delay change rate to obtain a pre-processed frequency domain signal; converting the pre-processed frequency domain signal into a time domain signal, and sending the time domain signal to the signal receiving end. By adopting the technical scheme, the problem that the time delay change rate of a signal in high-speed movement cannot be accurately compensated, thereby affecting demodulation performance, is solved.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the field of low-orbit satellite communication, and in particular, to a signal sending method and a signal processing method. BACKGROUND

[0002] In recent years, with the continuous development of low-orbit satellite communication technology, compared with medium-orbit and high-orbit satellites, low-orbit satellites have the characteristics of low orbit, easy deployment, and low transmission delay, and constructing a communication system for high-speed terminals based on a low-orbit constellation has certain advantages. At present, scholars at home and abroad have relatively mature research results on large frequency offset and large delay estimation and compensation in the low-orbit satellite scenario. However, the estimation and compensation of the time delay rate change between the low-orbit satellite and the terminal due to high-speed movement are still under research.

[0003] In the traditional low-orbit satellite communication scenario, related technologies mostly use extrapolation based on ephemeris information or Doppler frequency offset to calculate the time delay rate for time delay rate estimation. For time delay rate compensation, related technologies mainly use the method of adjusting the subframe-level timing point to complete the compensation of timing advance.

[0004] The above method can estimate and compensate the time and frequency offset in the general scenario, but the method of extrapolating the time delay rate based on ephemeris information is highly dependent on the accuracy of ephemeris information. If the ephemeris information is inaccurate or missing, the time delay rate cannot be estimated. The method of calculating the time delay rate through the Doppler frequency offset is also highly dependent on the accuracy of the Doppler frequency offset. If there is a crystal oscillator or other non-Doppler effect frequency offset, it will greatly interfere with the estimation result. At the same time, considering the high-speed moving scenario, the time delay rate caused by high relative movement causes the timing point of each symbol of the received signal to be offset, and the existing method cannot adjust the timing point of each symbol.

[0005] In related technologies, it is difficult to accurately compensate the time delay rate of the signal in high-speed movement, which affects the demodulation performance. Therefore, an effective solution has not been proposed.

[0006] Therefore, it is necessary to improve the related technologies to overcome the defects in the related technologies. SUMMARY

[0007] Embodiments of the present application provide a signal sending method and a signal processing method to at least solve the problem of difficulty in accurately compensating the time delay rate of the signal in high-speed movement, which affects the demodulation performance.

[0008] According to one embodiment of the present application, a signal sending method is provided, comprising: obtaining a time delay variation rate sent by a signal receiving end, wherein the time delay variation rate is calculated by the signal receiving end according to a received synchronization signal and a locally generated synchronization signal; pre-processing a frequency domain signal mapped with a resource according to the time delay variation rate to obtain a pre-processed frequency domain signal; converting the pre-processed frequency domain signal into a time domain signal, and sending the time domain signal to the signal receiving end.

[0009] According to another embodiment of the present application, a signal processing method is provided, comprising: calculating a time delay variation rate according to a received synchronization signal and a locally generated synchronization signal; and sending the time delay variation rate to a signal sending end, wherein the signal sending end is configured to pre-process a frequency domain signal mapped with a resource according to the time delay variation rate.

[0010] According to another embodiment of the present application, a transceiving signal system is provided, comprising: a signal receiving end configured to calculate a time delay variation rate according to a received synchronization signal and a locally generated synchronization signal, and send the time delay variation rate to a signal sending end; and the signal sending end configured to pre-process a frequency domain signal mapped with a resource according to the time delay variation rate, convert the pre-processed frequency domain signal into a time domain signal, and send the time domain signal to the signal receiving end.

[0011] According to still another embodiment of the present application, a computer readable storage medium is provided, wherein the computer readable storage medium stores a computer program, and the computer program is configured to execute the steps of any of the above method embodiments when running.

[0012] According to still another embodiment of the present application, an electronic device is provided, comprising a memory and a processor, wherein the memory stores a computer program, and the processor is configured to execute the computer program to perform the steps of any of the above method embodiments.

[0013] According to still another embodiment of the present application, a computer program product is provided, comprising a computer program, and the computer program is configured to perform the steps of any of the above method embodiments when executed by a processor. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 is a schematic diagram of a satellite communication system according to an embodiment of the present application;

[0015] Figure 2 is a flowchart of a signal sending method according to an embodiment of the present application;

[0016] Figure 3is a flow chart of a DVRS-OFDM waveform generation according to an embodiment of the present application;

[0017] Figure 4 is a flow chart of a signal processing method according to an embodiment of the present application;

[0018] Figure 5 is a flow chart of a time delay variation rate estimation according to an embodiment of the present application;

[0019] Figure 6 is a structural block diagram of a transceiver system according to an embodiment of the present application;

[0020] Figure 7 is a processing flow diagram of a transceiver system according to an embodiment of the present application;

[0021] Figure 8 is a simulation diagram of a time delay variation rate estimation according to an embodiment of the present application;

[0022] Figure 9 is a diagram of a downlink non-compensated time delay variation rate demodulation performance curve according to an embodiment of the present application;

[0023] Figure 10 is a diagram of a time delay variation rate pre-processed demodulation performance curve according to an embodiment of the present application. DETAILED DESCRIPTION

[0024] Hereinafter, the embodiments of the present application will be described in detail with reference to the accompanying drawings and in conjunction with embodiments.

[0025] It should be noted that the terms "first", "second", and the like in the description and claims of the present application and the above-mentioned accompanying drawings are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence.

[0026] In order to better understand the signal transmission method and signal processing method disclosed in the embodiments of the present disclosure, first, the satellite communication system applicable to the embodiments of the present disclosure will be described.

[0027] Please refer to Figure 1 , Figure 1 is a schematic diagram of an architecture of a satellite communication system provided by an embodiment of the method of the present application. The satellite communication system can include a satellite 101, a terminal 102, and a gateway station 103.

[0028] The satellite 101 in the embodiments of the present disclosure is an entity for transmitting or receiving signals. The embodiments of the present disclosure do not limit the specific technology and specific device form adopted by the satellite.

[0029] The terminal 102 in the embodiments of the present disclosure refers to a processing device in the range of a satellite coverage beam for communication with a satellite. For example, the terminal can be a car, a smart car, a mobile phone, a wearable device, a tablet computer (Pad), etc. with satellite communication function. The embodiments of the present disclosure do not limit the specific technology and specific device form adopted by the terminal.

[0030] It should be noted that, Figure 1 The two terminal devices 102 are taken as examples in the present example.

[0031] In one embodiment of the present disclosure, the gateway station 103 in the present example is connected with the satellite 101.

[0032] The gateway station 103 in the embodiments of the present disclosure is a node on the ground in a satellite communication system for transmitting and receiving data. The embodiments of the present disclosure do not limit the specific technology and specific device form adopted by the gateway station.

[0033] It can be understood that the satellite communication system described in the embodiments of the present disclosure is for more clearly illustrating the technical solutions of the embodiments of the present disclosure, and does not constitute a limitation on the technical solutions provided by the embodiments of the present disclosure. Those skilled in the art can know that, with the evolution of system architecture and the appearance of new business scenarios, the technical solutions provided by the embodiments of the present disclosure are also applicable to similar technical problems.

[0034] In the present embodiment, a signal sending method is provided, applied to a signal sending end, Figure 2 The flow chart of the signal sending method according to the embodiment of the present disclosure is shown in FIG. 2, which includes the following steps S202-S206: Figure 2

[0035] In step S202, a time delay variation rate sent by a signal receiving end is acquired, wherein the time delay variation rate is calculated by the signal receiving end according to a received synchronization signal and a locally generated synchronization signal.

[0036] Optionally, the communication scenario between the signal sending end and the signal receiving end can be a communication scenario between a satellite and a terminal (i.e., the signal sending end is one of the satellite and the terminal, and the signal receiving end is the other one of the satellite and the terminal).

[0037] Optionally, the communication scenario between the signal sending end and the signal receiving end can also be a communication scenario between a satellite and a gateway station (i.e., the signal sending end is one of the satellite and the gateway station, and the signal receiving end is the other one of the satellite and the gateway station).

[0038] In step S204, a frequency domain signal after resource mapping is preprocessed according to the time delay variation rate, to obtain a preprocessed frequency domain signal.​

[0039] Step S206, convert the pre-processed frequency domain signal into a time domain signal, and send the time domain signal to the signal receiving end.

[0040] The above steps accurately compensate the resource-mapped frequency domain signal through the time delay change rate fed back by the receiving end, solving the problem of signal demodulation performance degradation in high-speed mobile scenarios. Based on the comparison between the synchronization signal and the local signal, the signal receiving end can accurately calculate the time delay change rate. After the signal sending end receives the time delay change rate, it directly pre-processes the resource-mapped frequency domain signal. This processing method ensures that the time delay change in the transmission process of the signal is effectively compensated, avoiding the signal timing point drift caused by the time delay change rate. Therefore, when the signal is demodulated at the signal receiving end, the signal quality is significantly improved, enhancing the stability and reliability of data transmission and improving the signal transmission quality in high-speed mobile scenarios.

[0041] In an exemplary embodiment, the pre-processing of the resource-mapped frequency domain signal according to the time delay change rate to obtain the pre-processed frequency domain signal can be achieved through the following steps S11-S13:

[0042] Step S11: Construct a pre-processing function for each symbol in the subframe according to the time delay change rate;

[0043] Step S12: Construct a pre-processing matrix of the entire time domain subframe dimension according to the pre-processing function of each symbol;

[0044] Step S13: Divide the frequency domain signal by the phase of the pre-processing matrix to obtain the pre-processed frequency domain signal.

[0045] It should be noted that if the resource-mapped single frame frequency domain signal in the signal sending end is represented as a matrix , the pre-processing formula is as follows:

[0046] ;

[0047] Wherein, is the matrix representation of the pre-processed frequency domain signal, is the pre-processing matrix.

[0048] It should be noted that, first, according to the received time delay variation rate information, a pre-processing function is designed for each OFDM symbol in a subframe, which reflects the change rule of the time delay variation rate over time and allows accurate correction of the phase offset of each symbol. Subsequently, these pre-processing functions for individual symbols are integrated to construct a pre-processing matrix covering the entire time domain subframe, which comprehensively reflects the influence of the time delay variation rate on the subframe timing. Finally, by performing a phase division operation on the frequency domain signal after resource mapping and the pre-processing matrix, in essence, a phase compensation is applied to the signal, eliminating the phase offset caused by the time delay variation rate and ensuring accurate demodulation of the signal at the receiving end. This method not only considers the time characteristics of the time delay variation rate, but also achieves efficient and accurate compensation of the signal, significantly improving the quality and stability of signal transmission in high-speed mobile environments.

[0049] Through the above steps, the influence of the time delay variation rate on the signal demodulation performance can be effectively reduced, especially when serving high-speed mobile terminals in low-orbit satellite communication systems, the signal quality can be significantly improved, thereby ensuring the reliability of data transmission and the continuity of communication. This method avoids the problems of limited estimation accuracy and delayed compensation in traditional schemes, providing strong technical support for high-speed mobile communication scenarios.

[0050] In an exemplary embodiment, the above-mentioned pre-processing function of each symbol in the subframe constructed according to the time delay variation rate can be implemented through the following steps S21-S22:

[0051] Step S21: determining a target total drift sample point number according to the time delay variation rate, the single subframe time length and the sampling interval, wherein the target total drift sample point number is the total drift sample point number caused by the time delay variation rate within a single subframe;

[0052] In an exemplary embodiment, determining the target total drift sample point number according to the time delay variation rate, the single subframe time length and the sampling interval includes: calculating the target total drift sample point number by the following formula:

[0053] ;

[0054] wherein, the target total drift sample point number is the time delay variation rate is the single subframe time length is the sampling interval is

[0055] Step S22: constructing the pre-processing function of each symbol according to the target total drift sample point number, the symbol index of each symbol and the frequency domain subcarrier index.

[0056] It should be noted that, to more accurately compensate for the rate of change of signal delay during high-speed movement, steps S21 and S22 provide a detailed preprocessing mechanism. In step S21, based on the received rate of change of delay information, combined with the system-set single subframe time length and sampling interval, the total number of target drift samples is calculated. This value directly reflects the degree of influence of the rate of change of delay on the signal timing within a single subframe. Step S22 further decomposes this global impact to each OFDM symbol within the subframe. Based on the index position and frequency domain subcarrier distribution of each symbol, a corresponding preprocessing function is constructed to ensure that each signal segment receives tailored compensation measures. In this way, not only is the challenge of the rate of change of delay to the overall signal timing solved, but the differences between different parts of the signal are also considered in detail. Symbol-by-symbol compensation for the impact of the rate of change of signal delay is achieved, significantly improving the accuracy and efficiency of signal processing. Especially in high-speed dynamic scenarios such as low-Earth orbit satellite communication, it can effectively overcome the signal quality degradation caused by delay changes, ensuring the stability and reliability of data transmission.

[0057] In an exemplary embodiment, the preprocessing function for constructing each symbol based on the target total drift sample number, the symbol index of each symbol, and the frequency domain subcarrier index includes: constructing the first symbol in the constructed subframe in the following manner. A preprocessing function for each symbol is used to construct the preprocessing function for each symbol in the subframe:

[0058] ;

[0059] in, The total number of drift samples for the target. For the first Preprocessing functions for each symbol For the first Each symbol index value, S is the total number of symbols contained in the subframe. For frequency domain subcarrier index, , This refers to the number of points used during the Fast Fourier Transform (FFT) process in the modulation phase.

[0060] It should be noted that since the main effect of time delay on frequency domain signals is phase shift, this application considers constructing a preprocessing matrix using the estimated time delay change rate, and using this matrix to preprocess the time delay change rate at the signal transmission end. Because the operation is performed on frequency domain signals, this step is performed after resource mapping and before OFDM modulation. The symbol time domain index is constructed as follows: The frequency domain subcarrier index is Its construction formula is shown above.

[0061] It should be noted that since the center frequency point of the signal is shifted to both ends of the signal after the fft shift, when constructing the subcarrier index , the high frequency and low frequency parts are embodied according to the criteria in the above formula. Since the phase deflection caused by the time delay to the frequency domain signal is proportional to the time domain symbol index and the frequency domain subcarrier index, the pre-processing function of the first symbol is represented as the above . .

[0062] In an exemplary embodiment, the pre-processing matrix of the entire time domain subframe dimension is constructed according to the pre-processing function of each symbol, including: the pre-processing matrix is constructed by :

[0063] .

[0064] In an exemplary embodiment, the above converting the pre-processed frequency domain signal into a time domain signal includes: the pre-processed frequency domain signal is inverse Fourier transformed by column to obtain the time domain signal:

[0065] ;

[0066] wherein, is the converted time domain signal, is the pre-processed frequency domain signal, , is the number of points used in the fast Fourier transform in the modulation process, n is the time sampling point, m is the subcarrier, and k is the symbol.

[0067] It should be noted that the matrix of the pre-processed frequency domain signal is inverse Fourier transformed by column to convert to the time domain, and the signal waveform after inverse Fourier transform is a DVRS-OFDM waveform, and the time delay variation rate can be effectively suppressed by sending the above time domain signal at the signal sending end.

[0068] For better understanding, Figure 3 is a flowchart of a DVRS-OFDM waveform generated according to an embodiment of the present application, including:

[0069] Step 1: construct the symbol index vector in the subframe and the subcarrier index vector in the frequency domain, and save them in the register respectively;

[0070] that is, the symbol time domain index , and the frequency domain subcarrier index .

[0071] Step two: single symbol dimension preprocessing function construction, preprocessing function construction in single symbol dimension by using symbol index vector in subframe, subcarrier index vector in frequency domain and time delay rate estimation value;

[0072] i.e. constructing the preprocessing function of the first symbol: .

[0073] Step three: time delay rate preprocessing matrix construction, extending the single symbol dimension preprocessing function to the entire time domain symbol dimension to complete the construction of the time delay rate preprocessing matrix;

[0074] i.e. extending from a single symbol to the entire time domain to obtain the preprocessing matrix as follows:

[0075] .

[0076] Step four: preprocessing, dividing the frequency domain signal by the preprocessing matrix to complete the preprocessing step of the signal for the time delay rate.

[0077] In an exemplary embodiment, before preprocessing the frequency domain signal mapped by the resource according to the time delay rate, the method further comprises: generating original data to be transmitted, and channel encoding the original data to obtain encoded data; scrambling the encoded data, and performing discrete Fourier transform conversion on the scrambled data to obtain a frequency domain signal; performing resource mapping on the frequency domain signal to obtain the resource mapped frequency domain signal.

[0078] The following will be described in combination with Figure 7 , specifically, the signal sending end comprises:

[0079] Data generation module: the signal sending end receives original data to be transmitted from the application layer or the transmission layer. These data may include but are not limited to text, image, voice or video information, etc. The data generation module is responsible for converting these high layer data into a format suitable for physical layer transmission to form the original data to be transmitted.

[0080] Channel encoding module: channel encoding is a key step to improve data transmission reliability. It adds redundant information to the original data, so that even if the data is interfered or lost to a certain extent during transmission, the original data can be recovered through decoding at the receiving end. Common channel encoding techniques include Turbo encoding, LDPC (low density parity check) encoding, convolutional encoding, etc. These encoding techniques can adjust the encoding rate according to the channel characteristics to achieve the best transmission efficiency and error protection capability.

[0081] ​Scrambling module: the channel encoded data stream is further sent to a scrambling module for processing. Scrambling can be performed by applying a pseudo-random sequence to shuffle the order of the data stream, aiming to reduce the peak-to-average power ratio (PAPR) of the signal, reduce the non-linear distortion in wireless transmission, and improve the security of the signal, so that even without encryption, the signal is not easy to be demodulated by a third party.

[0082] DFT (Discrete Fourier Transform) conversion module: the scrambled data stream enters the DFT conversion module. DFT conversion converts the data stream into a signal representation in the frequency domain, preparing for subsequent frequency domain resource allocation and OFDM modulation. This conversion decomposes the original data stream into a series of signals in the frequency domain, each corresponding to a different frequency component.

[0083] Resource mapping module: the frequency domain signal is then sent to the resource mapping module. In the resource mapping module, the signal is allocated to a specific frequency domain resource block. Resource mapping is the mapping of signals to physical resource blocks composed of subcarriers and time slots according to communication protocols and link configuration information.

[0084] The functions of the time delay variation preprocessing module and the OFDM adjustment module have been described in detail above and will not be repeated here.

[0085] In this embodiment, a signal processing method is also provided, which is applied to a signal receiving end, Figure 4 is a flowchart of a signal processing method according to an embodiment of the present application, as shown in the figure, the flow includes the following steps S402-S404: Figure 4

[0086] Step S402: calculating the time delay variation rate according to the received synchronization signal and the locally generated synchronization signal;

[0087] Step S404: sending the time delay variation rate to the signal sending end, wherein the signal sending end is used to pre-process the frequency domain signal after resource mapping according to the time delay variation rate.

[0088] ​It should be noted that by accurately comparing the received synchronization signal with the locally generated synchronization signal, the time delay variation rate in the signal transmission process can be calculated in real time, and this calculation process fully considers the dynamic change of signal time delay caused by high-speed movement, and has higher accuracy and robustness compared with traditional ephemeris information or frequency offset estimation. In addition, the time delay variation rate information is fed back to the signal sending end, and the frequency domain signal after resource mapping is preprocessed according to the time delay variation rate, and the influence of the time delay variation rate is compensated directly at the signal source, avoiding the timing point drift caused by time delay variation when the signal reaches the signal receiving end, and significantly improving the demodulation performance of the signal. This method realizes accurate synchronization and compensation of the signal in the high-speed moving environment by introducing real-time time delay variation rate feedback, enhances the adaptability and stability of the communication system, especially in complex scenarios such as low-orbit satellite communication, which can effectively overcome the dynamic challenges of signal processing and ensure the high quality and continuity of data transmission.

[0089] In an exemplary embodiment, the above-mentioned calculation of the time delay variation rate according to the received synchronization signal and the locally generated synchronization signal can be realized by the following steps S31-S33:

[0090] Step S31: In the case of receiving M synchronization signals, the timing offset between each pair of synchronization signals in the P pairs of synchronization signals in the M synchronization signals is calculated to obtain P timing offsets, wherein M is an integer greater than or equal to 2, the timing offset between the pth pair of synchronization signals in the P pairs of synchronization signals is equal to the difference between the timing estimation values of the two synchronization signals in the pth pair of synchronization signals, and the timing estimation value of the target synchronization signal in the pth pair of synchronization signals is calculated according to the locally generated synchronization signal corresponding to the target synchronization signal;

[0091] Optionally, assuming that the M synchronization signals are the first synchronization signal, the second synchronization signal and the third synchronization signal, the P pairs of synchronization signals are (the first synchronization signal, the second synchronization signal), (the second synchronization signal, the third synchronization signal) and (the first synchronization signal, the third synchronization signal).

[0092] If the timing estimation value of the first synchronization signal is , the timing estimation value of the first synchronization signal is , and the timing estimation value of the third synchronization signal is , then the P timing offsets can be , and .

[0093] Step S32: Calculate P reference time delay variation rates according to the P timing offsets, wherein the pth reference time delay variation rate in the P reference time delay variation rates is equal to the pth timing offset divided by the hop beam period between the pth pair of synchronization signals.

[0094] Optionally, assuming P timing offsets are , and , the P reference time delay variation rates are respectively: , wherein, is the beam hopping period.

[0095] Step S33: Weighted sum of the P reference time delay variation rates is obtained to obtain the time delay variation rate.

[0096] Optionally, the time delay variation rate .

[0097] Optionally, in the case of P equal to M, there are timing deviations between the P synchronization signals , which can be flexibly configured according to the beam hopping period, and the time delay variation rate , when the final signal receiving end receives the Pth synchronization signal, the estimated value of the time delay variation rate calculated is :

[0098] .

[0099] In an exemplary embodiment, the method further comprises: calculating the timing estimation value of the target synchronization signal in the Pth pair of synchronization signals by the following steps S41-S42;

[0100] Step S41: The target synchronization signal is slidingly conjugated with the locally generated synchronization signal corresponding to the target synchronization signal to obtain a sliding conjugate correlation result.

[0101] It should be noted that if the PSS synchronization signal sent by the signal sending end is . After completing the initial time-frequency synchronization, the received synchronization signal is considered to be , wherein is the timing point drift caused by the time delay variation rate. Here, it is considered that the time-frequency synchronization has compensated the Doppler frequency offset and the time delay, and only the influence of the time delay variation rate on the signal is considered. The sliding conjugate correlation of the PSS synchronization signal and the local PSS synchronization signal to find the peak value can obtain the timing point drift of this downlink frame :

[0102] ;

[0103] wherein, ​is the length of the synchronization signal, is the sliding conjugate correlation result, is the local generated synchronization signal corresponding to the target synchronization signal.

[0104] Step S42: The timing estimation value corresponding to the peak point after the sliding conjugate correlation result is taken modulo is determined as the timing estimation value of the target synchronization signal.

[0105] It should be noted that the sliding conjugate correlation result is taken modulo, and the peak point is found, and the timing estimation value under the synchronization signal is calculated through the peak point:

[0106] ;

[0107] wherein, is the timing estimation value of the target synchronization signal.

[0108] In order to better understand, Figure 5 is a flowchart of time delay rate estimation according to an embodiment of the present application, comprising:

[0109] Step 1: PSS synchronization signal receiving and processing, receiving and storing 3 synchronization signals in 3 continuous beam hopping periods, and sliding correlating them with the local synchronization signal;

[0110] Step 2: synchronization and timing offset calculation, reading the local PSS synchronization signal storage module and the synchronization signal receiving module, performing sliding correlation and peak detection;

[0111] Step 3: rough estimation of time delay rate, reading the sliding correlation and peak detection result to find the timing point, and calculating the time delay rate of a single frame PSS synchronization signal through the beam hopping period;

[0112] Step 4: multi-frame time delay rate calculation, reading the historical storage in the synchronization timing result, performing multi-frame weighted calculation, and feeding the result back to the transmitter side for processing.

[0113] In the present embodiment, a transceiving signal system is also provided, Figure 6 is a structural block diagram of a transceiving signal system according to an embodiment of the present application, as shown in the figure, the system comprises: Figure 6

[0114] a signal receiving end 602, configured to calculate the time delay rate according to the received synchronization signal and the local generated synchronization signal, and send the time delay rate to the signal sending end;

[0115] ​The signal sending end 604 is configured to preprocess the frequency domain signal after resource mapping according to the time delay variation rate, convert the preprocessed frequency domain signal into a time domain signal, and send the time domain signal to the signal receiving end.

[0116] The above system can calculate the time delay variation rate in the signal transmission process in real time by accurately comparing the received synchronization signal with the locally generated synchronization signal, which fully considers the dynamic change of signal time delay caused by high-speed movement and has higher accuracy and robustness compared with traditional ephemeris information or frequency offset estimation. In addition, the time delay variation rate information is fed back to the signal sending end, and the signal sending end pre-processes the frequency domain signal after resource mapping according to the time delay variation rate, directly compensating for the influence of the time delay variation rate at the signal source, avoiding the timing point drift caused by the time delay variation when the signal reaches the signal receiving end, and significantly improving the demodulation performance of the signal. This method realizes accurate synchronization and compensation of the signal in a high-speed moving environment by introducing real-time time delay variation rate feedback, enhances the adaptability and stability of the communication system, and effectively overcomes the dynamic challenges of signal processing in complex scenarios such as low-orbit satellite communication, thereby ensuring the high quality and continuity of data transmission.

[0117] In order to better understand, Figure 7 is a processing flow diagram of a transceiver signal system according to an embodiment of the application.

[0118] As Figure 7 shown, a time delay variation rate estimation module is added to the signal receiving end side in addition to the normal processing flow, and the time delay variation rate estimation value is input to the signal sending end for processing. A time delay variation rate preprocessing module is added to the signal sending end side in addition to the normal processing flow, and a matrix is constructed according to the time delay variation rate estimation value to pre-process the transmitted signal. After the signal passes through the preprocessing and OFDM modulation module, a new DVRS-OFDM waveform is formed. The time delay variation rate preprocessing module added to the signal sending end and the time delay variation rate estimation module added to the signal receiving end have been described in detail above, and will not be described here.

[0119] It should be noted that the method of the application has high precision, can support multiple time delay variation rates, and can support high-speed mobile situations with large bandwidth. On the other hand, the scheme can support the estimation of the time delay variation rate in the case where there is no ephemeris information or the ephemeris information is inaccurate, effectively solving the time and frequency synchronization problem in the case of GNSS denial and outdated ephemeris information.

[0120] The transceiver for suppressing the time delay variation rate is simulated, and the simulation setting parameters are shown in Table 1:

[0121] Table 1

[0122]

[0123] It should be noted that the simulation results of the time delay change rate estimation of the present application are as shown in Figure 8 , wherein, microsecond per second (us / s) means how many microseconds the signal time delay changes per second.

[0124] It should be noted that the time delay change rate is calculated from the timing offset and the beam hopping period, and when the timing offset is used to calculate the time delay change rate, the error of the timing offset is an integer multiple of the sampling period. When the time delay change rate is calculated by the 20ms beam hopping period, since the error of the timing offset is about 1 sample point, according to the formula , it can be known that the accuracy of the time delay change rate estimation is 0.1017us / s.

[0125] The following simulates the preprocessing effect of the downlink time delay change rate. First, the demodulation performance curve is simulated when the downlink time delay change rate is not compensated, as shown in Figure 9 , wherein, bit error rate (BER), signal-to-noise ratio (SNR), and dB are decibels. The demodulation performance curve after adopting the DVRS-OFDM waveform in the present application is as shown in Figure 10 .

[0126] It can be obtained from Figure 9 and Figure 10 that the large time delay change rate has a great influence on the demodulation performance, and when the time delay change rate is less than 15us / s, the performance loss of different DMRS is 1-3dB, the performance loss of POS1 and POS2 is more, and the performance of POS3 is better than that of POS1 and POS2; after the signal sending end uses the DVRS-OFDM waveform, the performance is obviously improved.

[0127] It should be noted that the present application mainly serves the time frequency tracking and compensation after the initial time frequency synchronization is completed, and when the beam hopping mode is served, a large time delay and frequency offset will be accumulated during the adjacent two beam revisit periods, which affects the demodulation performance. On the other hand, the maximum time delay change rate of 50us / s caused by the high-speed movement of the terminal will cause the drift of the timing point of each OFDM symbol, which will greatly affect the signal demodulation.

[0128] The embodiment of the present application also provides a computer readable storage medium, and the computer readable storage medium stores a computer program, wherein the computer program is set to execute the steps in any one of the method embodiments when running.

[0129] In an example embodiment, the computer readable storage medium described above can include, but is not limited to, a U disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a mobile hard disk, a magnetic disk or an optical disk, and various media that can store computer programs.

[0130] Embodiments of the present application also provide an electronic device including a memory and a processor, the memory storing a computer program, and the processor being configured to execute the computer program to perform the steps in any of the method embodiments described above.

[0131] In an example embodiment, the electronic device described above can further include a transmission device connected to the processor and an input / output device connected to the processor.

[0132] The specific examples in the present embodiment can refer to the examples described in the above embodiments and example implementations, and the present embodiment will not be described here again.

[0133] Embodiments of the present application also provide a computer program product including a computer program, the computer program being executed by a processor to implement the steps in any of the method embodiments described above.

[0134] Embodiments of the present application also provide another computer program product including a non-volatile computer readable storage medium, the non-volatile computer readable storage medium storing a computer program, the computer program being executed by a processor to implement the steps in any of the method embodiments described above.

[0135] Embodiments of the present application also provide a computer program including computer instructions stored in a computer readable storage medium; a processor of a computer device reads the computer instructions from the computer readable storage medium, and executes the computer instructions, so that the computer device performs the steps in any of the method embodiments described above.

[0136] It should be apparent to those skilled in the art that the modules or steps of the application described above can be implemented with general computing devices, which can be centralized on a single computing device or distributed on a network of multiple computing devices, which can be implemented with program codes executable by the computing devices, so that they can be stored in storage devices and executed by the computing devices, and in some cases, the steps shown or described can be executed in different orders than shown, or made into individual integrated circuit modules, or made into a single integrated circuit module. Thus, the application is not limited to any particular combination of hardware and software.

[0137] The preferred embodiments of the application described above are intended to be merely exemplary and those skilled in the art will recognize that many changes and modifications can be made to the application without departing from the spirit and scope of the application. Any modifications, equivalent substitutions, improvements, etc. made within the principles of the application should be included in the protection scope of the application.

Claims

1. A signal transmission method, characterized in that, include: The delay change rate transmitted by the signal receiver is obtained, wherein the delay change rate is calculated by the signal receiver based on the received synchronization signal and the locally generated synchronization signal; The frequency domain signal after resource mapping is preprocessed according to the time delay change rate to obtain the preprocessed frequency domain signal. The preprocessed frequency domain signal is converted into a time domain signal and then sent to the signal receiving end. The time delay change rate is calculated by the signal receiver as follows: When M synchronization signals are received, the timing offset between each pair of synchronization signals in the P pairs of synchronization signals is calculated to obtain P timing offsets, where M is an integer greater than or equal to 2. The timing offset between the p-th pair of synchronization signals in the P pairs of synchronization signals is equal to the difference in timing estimates of the two synchronization signals in the p-th pair of synchronization signals. The timing estimate of the target synchronization signal in the p-th pair of synchronization signals is calculated based on the locally generated synchronization signal corresponding to the target synchronization signal. P reference time delay change rates are calculated based on the P timing offsets, where the p-th reference time delay change rate is equal to the p-th timing offset divided by the beam-hopping period between the p-th pairs of synchronization signals. The P reference time delay change rates are then weighted and summed to obtain the time delay change rate.

2. The method according to claim 1, characterized in that, The frequency domain signal after resource mapping is preprocessed according to the time delay change rate to obtain the preprocessed frequency domain signal, including: Construct a preprocessing function for each symbol in the subframe based on the said delay change rate; A preprocessing matrix for the entire temporal subframe dimension is constructed based on the preprocessing function of each symbol; The frequency domain signal is divided bitwise by the preprocessing matrix to obtain the preprocessed frequency domain signal.

3. The method according to claim 2, characterized in that, Constructing a preprocessing function for each symbol in a subframe based on the said delay change rate, including: The total number of target drift samples is determined based on the delay change rate, the duration of a single subframe, and the sampling interval, wherein the total number of target drift samples is the total number of drift samples caused by the delay change rate within a single subframe; Based on the total number of drift samples of the target, the preprocessing function for each symbol is constructed using the symbol index and frequency domain subcarrier index of each symbol.

4. The method according to claim 3, characterized in that, The total number of target drift samples is determined based on the time delay change rate, the duration of a single subframe, and the sampling interval, including: The total number of drift points of the target is calculated using the following formula: ； in, The total number of drift samples for the target. The time delay change rate, The duration of a single subframe. The sampling interval is denoted as .

5. The method according to claim 3, characterized in that, Based on the total number of target drift samples, a preprocessing function is constructed for each symbol using the symbol index and frequency domain subcarrier index, including: The first subframe in the construction is constructed in the following manner. A preprocessing function for each symbol is used to construct the preprocessing function for each symbol in the subframe: ； in, The total number of drift samples for the target. For the first Preprocessing functions for each symbol For the first Each symbol index value, S is the total number of symbols contained in the subframe. For frequency domain subcarrier index, , This refers to the number of points used during the Fast Fourier Transform (FFT) process in the modulation phase.

6. The method according to claim 5, characterized in that, Based on the preprocessing function of each symbol, a preprocessing matrix is ​​constructed for the entire temporal subframe dimension, including: The preprocessing matrix is ​​constructed in the following manner. : 。 7. The method according to claim 1, characterized in that, Converting the preprocessed frequency domain signal into a time domain signal includes: The time-domain signal is obtained by performing an inverse Fourier transform on each column of the preprocessed frequency-domain signal in the following manner: ； in, The converted time-domain signal, The preprocessed frequency domain signal, , n represents the number of points used during the Fast Fourier Transform (FFT) in the modulation process, where n is the time sampling point, m is the subcarrier, and k is the symbol.

8. The method according to claim 1, characterized in that, Before preprocessing the frequency domain signal after resource mapping according to the time delay change rate, the method further includes: Generate the raw data to be transmitted, and perform channel coding on the raw data to obtain the encoded data; The encoded data is scrambled, and the scrambled data is then subjected to a discrete Fourier transform to obtain a frequency domain signal. The frequency domain signal is mapped to resources to obtain the frequency domain signal after resource mapping.

9. A signal processing method, characterized in that, include: The delay rate is calculated based on the received synchronization signal and the locally generated synchronization signal. The time delay change rate is sent to the signal transmitting end, wherein the signal transmitting end is used to preprocess the frequency domain signal after resource mapping according to the time delay change rate; The calculation of the delay change rate based on the received synchronization signal and the locally generated synchronization signal includes: When M synchronization signals are received, the timing offset between each pair of synchronization signals in the P pairs of synchronization signals is calculated to obtain P timing offsets, where M is an integer greater than or equal to 2. The timing offset between the p-th pair of synchronization signals in the P pairs of synchronization signals is equal to the difference between the timing estimates of the two synchronization signals in the p-th pair of synchronization signals. The timing estimate of the target synchronization signal in the p-th pair of synchronization signals is calculated based on the locally generated synchronization signal corresponding to the target synchronization signal. P reference delay change rates are calculated based on the P timing offsets, wherein the p-th reference delay change rate among the P reference delay change rates is equal to the p-th timing offset divided by the beam skipping period between the p-th pairs of synchronization signals. The time delay change rate is obtained by weighted summation of the P reference time delay change rates.

10. The method according to claim 9, characterized in that, The method further includes: The timing estimate of the target synchronization signal in the p-th pair of synchronization signals is calculated in the following manner; The target synchronization signal is subjected to sliding conjugation with the locally generated synchronization signal corresponding to the target synchronization signal to obtain the sliding conjugation correlation result; The timing estimate corresponding to the peak point after taking the modulus of the sliding conjugate correlation result is determined as the timing estimate of the target synchronization signal.

11. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, wherein the computer program, when executed by a processor, implements the steps of the method described in any one of claims 1 to 10.

12. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method described in any one of claims 1 to 10.

13. A computer program product comprising a computer program that, when executed by a processor, implements the steps of the method described in any one of claims 1 to 10.

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