A method, device, medium and product for compensating sampling deviation of a satellite terminal

Abstract

This invention relates to the field of communication technology and discloses a sampling deviation compensation method, device, medium, and product for a satellite terminal. The method includes: performing channel estimation based on a demodulation reference signal in the initial frequency domain received signal to obtain a first channel estimate value corresponding to each PTRS subcarrier; performing least squares estimation based on the first channel estimate value to obtain the PTRS phase, and dividing the system bandwidth into multiple frequency domain groups; obtaining each PTRS phase set based on each PTRS phase, and performing least squares fitting processing on each PTRS phase set to obtain a common phase estimate value and a phase slope estimate value corresponding to each frequency domain group; performing phase compensation on the subcarrier frequency domain received signal within the corresponding frequency domain group based on the common phase estimate value and the phase slope estimate value to obtain a target frequency domain received signal, and obtaining output information bits based on the target frequency domain received signal. This method can reduce the implementation complexity and difficulty of sampling deviation compensation.

Description

Technical Field

[0001] This invention relates to the field of communication technology, and in particular to a method, device, medium, and product for compensating sampling deviations in a satellite terminal. Background Technology

[0002] Satellite terminal sampling / timing deviation compensation is a key technical measure to address signal transmission problems caused by long-distance, high-speed movement in satellite communications. In non-terrestrial network satellite communication systems, even if the terminal has completed coarse frequency offset and coarse timing synchronization, residual timing deviations or sampling frequency deviations can cause approximately linear phase rotation in the frequency domain signal. If sampling / timing deviations are not compensated, the linear phase in the frequency domain gradually accumulates with the time of the orthogonal frequency division multiplexing signal, and the further the subcarrier is from the center frequency, the greater the phase error. This leads to significant rotation and spread in the constellation diagram, resulting in an increase in the bit error rate.

[0003] Currently, existing sampling / timing compensation methods typically employ Faro resampling compensation before the Fast Fourier Transform (FFT) to achieve fractional time-domain delay interpolation. However, the computational complexity of this approach is roughly proportional to the number of received sampling points, resulting in high implementation complexity. Summary of the Invention

[0004] This invention provides a sampling deviation compensation method, device, medium, and product for satellite terminals, which can reduce the complexity and difficulty of implementing sampling deviation compensation.

[0005] According to one aspect of the present invention, a sampling deviation compensation method for a satellite terminal is provided, comprising: Acquire the initial frequency domain received signal, and perform channel estimation based on the demodulation reference signal in the initial frequency domain received signal to obtain the first channel estimation value corresponding to each phase tracking reference signal PTRS subcarrier; Least squares estimation is performed based on the first channel estimate to obtain the PTRS phase corresponding to each PTRS subcarrier, and the system bandwidth is divided into multiple frequency domain groups. Based on the PTRS phase corresponding to each PTRS subcarrier, obtain the PTRS phase set corresponding to each frequency domain group, and perform least squares fitting on each PTRS phase set to obtain the common phase estimate and phase slope estimate corresponding to each frequency domain group. Based on the common phase estimate and the phase slope estimate, phase compensation is performed on the subcarrier frequency domain received signal within the corresponding frequency domain group to obtain the target frequency domain received signal, and the output information bits are obtained based on the target frequency domain received signal.

[0006] According to another aspect of the present invention, a sampling deviation compensation device for a satellite terminal is provided, comprising: The channel estimation module is used to acquire the initial frequency domain received signal and perform channel estimation based on the demodulation reference signal in the initial frequency domain received signal to obtain the first channel estimation value corresponding to each phase tracking reference signal PTRS subcarrier. The phase acquisition module is used to perform least squares estimation based on the first channel estimate to obtain the PTRS phase corresponding to each PTRS subcarrier and to divide the system bandwidth into multiple frequency domain groups. The phase fitting module is used to obtain the PTRS phase set corresponding to each frequency domain group based on the PTRS phase corresponding to each PTRS subcarrier, and to perform least squares fitting processing on each PTRS phase set to obtain the common phase estimate and phase slope estimate corresponding to each frequency domain group. The phase compensation module is used to perform phase compensation on the subcarrier frequency domain received signal within the corresponding frequency domain group according to the common phase estimate and the phase slope estimate, so as to obtain the target frequency domain received signal, and obtain the output information bits according to the target frequency domain received signal.

[0007] According to another aspect of the present invention, an electronic device is provided, the electronic device comprising: At least one processor; and A memory communicatively connected to the at least one processor; wherein, The memory stores a computer program that is executed by the at least one processor, which enables the at least one processor to perform the sampling deviation compensation method for a satellite terminal according to any embodiment of the present invention.

[0008] According to another aspect of the present invention, a computer-readable storage medium is provided, the computer-readable storage medium storing a computer program, the computer program being configured to cause a processor to execute and implement the sampling deviation compensation method for a satellite terminal according to any embodiment of the present invention.

[0009] According to another aspect of the present invention, a computer program product is provided, comprising a computer program that, when executed by a processor, implements the sampling deviation compensation method for a satellite terminal according to any embodiment of the present invention.

[0010] The technical solution of this invention involves acquiring an initial frequency domain received signal and performing channel estimation based on the demodulation reference signal in the initial frequency domain received signal to obtain a first channel estimate value corresponding to each phase tracking reference signal (PTRS) subcarrier; performing least squares estimation based on the first channel estimate value to obtain the PTRS phase corresponding to each PTRS subcarrier, and dividing the system bandwidth into multiple frequency domain groups; obtaining a PTRS phase set corresponding to each frequency domain group based on the PTRS phase corresponding to each PTRS subcarrier, and performing least squares fitting processing on each PTRS phase set to obtain a common phase estimate corresponding to each frequency domain group. The common phase estimate and phase slope estimate are used to calculate the common phase estimate and phase slope estimate. Based on these estimates, phase compensation is performed on the subcarrier frequency domain received signal within the corresponding frequency domain group to obtain the target frequency domain received signal. Output information bits are then obtained based on the target frequency domain received signal. By dividing the system bandwidth into multiple frequency domain groups and calculating the common phase estimate and phase slope estimate for each frequency domain group, phase compensation is performed on the subcarrier frequency domain received signal within the corresponding frequency domain group based on the estimates. This eliminates the need for high-order interpolation filters and complex polyphase filtering structures, reducing the complexity and difficulty of implementing sampling deviation compensation.

[0011] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a flowchart of a sampling deviation compensation method for a satellite terminal according to Embodiment 1 of the present invention; Figure 2 This is a flowchart of a sampling deviation compensation method for a satellite terminal according to Embodiment 2 of the present invention; Figure 3 This is a schematic diagram of the structure of a sampling deviation compensation device for a satellite terminal according to Embodiment 3 of the present invention; Figure 4 This is a schematic diagram of the structure of an electronic device that implements the sampling deviation compensation method for a satellite terminal according to an embodiment of the present invention. Detailed Implementation

[0014] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0015] It should be noted that the terms "first," "second," "target," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0016] Example 1 Figure 1 This is a flowchart of a sampling deviation compensation method for a satellite terminal according to Embodiment 1 of the present invention. This embodiment is applicable to situations where sampling deviation compensation is performed on a satellite terminal. The method can be executed by a sampling deviation compensation device of the satellite terminal, which can be implemented in hardware and / or software. Typically, the sampling deviation compensation device can be configured in an electronic device, such as a computer or server. Figure 1 As shown, the method includes: S110. Obtain the initial frequency domain received signal, and perform channel estimation based on the demodulation reference signal in the initial frequency domain received signal to obtain the first channel estimation value corresponding to each phase tracking reference signal PTRS subcarrier.

[0017] It should be noted that in Orthogonal Frequency Division Multiplexing (OFDM) systems, sampling frequency deviation or residual timing deviation will manifest as a linear phase ramp on the subcarrier in the frequency domain, i.e. Where m represents the OFDM symbol index and k represents the subcarrier index, Indicates the subcarrier spacing. This represents the sampling or timing bias on the m-th OFDM symbol. This represents the frequency-domain linear phase introduced by sampling or timing deviation. If only timing deviation exists, then... If sampling frequency deviation still exists ,but As OFDM symbol time gradually accumulates, , This represents the time for each OFDM symbol.

[0018] Based on the above principles, firstly, this embodiment can obtain the initial frequency domain received signal after pre-compensation and Fourier transform processing; then, residual synchronization error correction and channel response interpolation are performed based on the demodulation reference signal (DMRS) to obtain the first channel estimate of the subcarrier position of each phase tracking reference signal (PTRS).

[0019] Among them, DMRS is a known reference sequence agreed upon by both the transmitting and receiving ends. It occupies a fixed resource element (RE) in the time-frequency grid, has a clear time-frequency position and a known transmitted symbol, and can be used as a benchmark for synchronization parameter estimation.

[0020] Optionally, acquiring the initial frequency domain received signal may include: The time-domain received signal with ephemeris-assisted Doppler pre-compensation is acquired, and the time-domain received signal is subjected to fast Fourier transform to obtain the initial frequency-domain received signal.

[0021] Ephemeris-assisted Doppler pre-compensation is a unique pre-synchronization technique in non-terrestrial satellite communication systems. Its core function is to pre-compensate the ultra-wide Doppler frequency offset caused by the high-speed relative motion between the satellite and the terminal, providing a foundation for subsequent fine synchronization and demodulation. In this embodiment, firstly, the ephemeris-assisted Doppler pre-compensation method can be used to pre-compensate the ultra-wide Doppler frequency offset of the initial time-domain received signal to obtain the pre-compensated time-domain received signal. Then, a fast Fourier transform is performed on the time-domain received signal to obtain the initial frequency-domain received signal.

[0022] Optionally, channel estimation based on the demodulated reference signal in the initial frequency domain received signal to obtain the first channel estimation value corresponding to each phase tracking reference signal (PTRS) subcarrier may include: Based on the demodulation reference signal, the residual time-frequency offset of the initial frequency domain received signal is estimated and compensated to obtain the intermediate frequency domain received signal. Based on the demodulation reference signal, the intermediate frequency domain received signal is subjected to time-frequency domain interpolation filtering to obtain the first channel estimate value corresponding to each PTRS subcarrier.

[0023] In this embodiment, firstly, the received signals of two adjacent DMRS signals at the same subcarrier position in the time domain can be extracted, and their phase difference can be calculated. The ratio of the phase difference to the signal interval duration is the residual carrier frequency offset. Then, based on the estimated residual frequency offset, corresponding phase inversion is applied to the received signals of all subcarriers in the full frequency domain to compensate for the common phase drift introduced by the frequency offset. Next, the received signals of different subcarriers within the same DMRS signal can be extracted, and the phase of each subcarrier can be linearly fitted. The ratio of the phase slope to the subcarrier interval is the residual timing deviation. Then, based on the estimated timing deviation, corresponding linear phase compensation is applied to the frequency domain subcarriers to compensate for the frequency domain phase tilt introduced by the timing deviation. Thus, the estimation and compensation of the residual time-frequency offset can be completed to obtain the intermediate frequency domain received signal.

[0024] Furthermore, least-squares estimation is performed on the DMRS signal after time-frequency offset compensation in the intermediate frequency domain received signal to obtain the discrete channel response value at the RE position where the DMRS is located. Next, frequency domain interpolation filtering is performed. Within a single OFDM symbol, using the discrete channel response value of the DMRS subcarrier as a reference, the channel response of all subcarriers within that symbol is completed using an interpolation algorithm, while simultaneously suppressing estimation noise through filtering. Secondly, time domain interpolation filtering is performed. In the subcarrier dimension, using the channel response of the OFDM symbol where the DMRS is located as a reference, the channel response of all non-DMRS signals (including PTRS, data, etc.) is completed through time-domain interpolation, while simultaneously performing time-domain smoothing filtering. Thus, full-frequency domain channel estimates covering all time-frequency positions can be obtained, including the first channel estimate corresponding to each PTRS subcarrier and the second channel estimate corresponding to each data subcarrier.

[0025] S120. Perform least squares estimation based on the first channel estimate to obtain the PTRS phase corresponding to each PTRS subcarrier, and divide the system bandwidth into multiple frequency domain groups.

[0026] Specifically, the first channel estimate is substituted into the PTRS signal frequency domain expression for least-squares estimation to calculate the PTRS phase corresponding to each PTRS subcarrier. Then, based on a preset bandwidth value, the system bandwidth is divided into multiple consecutive frequency domain groups, each containing the same number of PTRS subcarriers. In this embodiment, the correspondence between the frequency domain groups and the PTRS subcarriers can be determined based on the frequency range corresponding to the frequency domain groups and the frequency corresponding to each PTRS subcarrier.

[0027] S130. Based on the PTRS phase corresponding to each PTRS subcarrier, obtain the PTRS phase set corresponding to each frequency domain group, and perform least squares fitting processing on each PTRS phase set to obtain the common phase estimate and phase slope estimate corresponding to each frequency domain group.

[0028] Specifically, firstly, based on the correspondence between frequency domain groups and PTRS subcarriers, and the PTRS phase corresponding to each PTRS subcarrier, multiple PTRS phases corresponding to each frequency domain group are obtained to form a PTRS phase set for each frequency domain group. Then, within each PTRS phase set, least squares fitting is performed based on each PTRS subcarrier and the center subcarrier to calculate the common phase estimate and phase slope estimate for each frequency domain group.

[0029] For example, dividing the subcarrier set into several groups based on frequency domain grouping is represented as follows: ,in, This is the g-th subcarrier group, where g is the group index. For the group start subcarrier, The packet ending subcarrier. The packet center subcarrier can be defined as... For the g-th PTRS phase set Performing least squares fitting yields the following results. .

[0030] in, This represents the p-th PTRS subcarrier. This represents the common phase error of the m-th symbol and the g-th group, whose main sources include phase noise and residual frequency offset. The frequency domain phase slope of the m-th symbol and g-th group is mainly derived from residual timing error and sampling clock deviation. A common phase estimate is obtained through least-squares fitting. With phase slope estimate .

[0031] S140. Based on the common phase estimate and the phase slope estimate, perform phase compensation on the subcarrier frequency domain received signal within the corresponding frequency domain group to obtain the target frequency domain received signal, and obtain the output information bits based on the target frequency domain received signal.

[0032] Specifically, based on the common phase estimate and phase slope estimate of each frequency domain group, phase inversion compensation is performed on the received signal of each subcarrier within that frequency domain group to obtain the corresponding target frequency domain received signal. The subcarrier frequency domain received signal can be the frequency domain data of an effective subcarrier (such as a data subcarrier). Finally, the target frequency domain received signal undergoes subsequent processing, such as demodulation and decoding, to obtain the final output information bits.

[0033] The technical solution of this invention involves acquiring an initial frequency domain received signal and performing channel estimation based on the demodulation reference signal in the initial frequency domain received signal to obtain a first channel estimate value corresponding to each phase tracking reference signal (PTRS) subcarrier; performing least squares estimation based on the first channel estimate value to obtain the PTRS phase corresponding to each PTRS subcarrier, and dividing the system bandwidth into multiple frequency domain groups; obtaining a PTRS phase set corresponding to each frequency domain group based on the PTRS phase corresponding to each PTRS subcarrier, and performing least squares fitting processing on each PTRS phase set to obtain a common phase estimate corresponding to each frequency domain group. The common phase estimate and phase slope estimate are used to calculate the common phase estimate and phase slope estimate. Based on these estimates, phase compensation is performed on the subcarrier frequency domain received signal within the corresponding frequency domain group to obtain the target frequency domain received signal. Output information bits are then obtained based on the target frequency domain received signal. By dividing the system bandwidth into multiple frequency domain groups and calculating the common phase estimate and phase slope estimate for each frequency domain group, phase compensation is performed on the subcarrier frequency domain received signal within the corresponding frequency domain group based on the estimates. This eliminates the need for high-order interpolation filters and complex polyphase filtering structures, reducing the complexity and difficulty of implementing sampling deviation compensation.

[0034] Example 2 Figure 2 This is a flowchart of a sampling deviation compensation method for a satellite terminal provided in Embodiment 2 of the present invention. This embodiment is a further refinement of the above technical solution, and the technical solution in this embodiment can be combined with one or more of the above implementation methods. Figure 2 As shown, the method includes: S210. Obtain the initial frequency domain received signal, and perform channel estimation based on the demodulation reference signal in the initial frequency domain received signal to obtain the first channel estimation value corresponding to each phase tracking reference signal (PTRS) subcarrier, and obtain the second channel estimation value corresponding to each data subcarrier.

[0035] The PTRS subcarrier carries a fixed reference sequence pre-agreed upon by both the transmitting and receiving ends. It is a known signal to the receiver, with the corresponding transmission symbols pre-stored locally, and does not carry random service information. The data subcarrier carries coded and modulated user service data or control signaling. It is an unknown signal to the receiver, and its transmission content changes dynamically with the transmitted information; it is the core carrier of the communication.

[0036] In this embodiment, a full-frequency domain channel estimate can be obtained based on the DMRS signal, and a first channel estimate corresponding to the PTRS subcarrier and a second channel estimate corresponding to the data subcarrier can be extracted from the full-frequency domain channel estimate.

[0037] For example, consider a non-terrestrial network system with a 400 MHz bandwidth and 120 kHz subcarriers. Assume a fixed sampling deviation of 1 / 10,000,000, a PTRS frequency domain density of 2, a time domain density of 1, and frequency domain grouping of 8 resource blocks. If a sampling frequency of 491.52 MHz is used, a sampling deviation of 1 / 10,000,000 corresponds to a sampling rate error of 4915.2 Hz. This means that the received sampling clock, relative to the ideal sampling clock, will experience an increment or decrement of 0.6 sampling points within each 125 microsecond time slot. This sampling deviation causes the subcarrier's frequency domain phase to exhibit a linear slope, and the phase slope changes slowly across different OFDM symbols. Without compensation for the sampling or timing deviation, inter-carrier interference will occur, thus degrading demodulation performance.

[0038] S220. Perform least squares estimation based on the first channel estimate to obtain the PTRS phase corresponding to each PTRS subcarrier, and divide the system bandwidth into multiple frequency domain groups.

[0039] Optionally, performing least-squares estimation based on the first channel estimate to obtain the PTRS phase corresponding to each PTRS subcarrier may include: The PTRS transmitted symbols and the PTRS received symbols in the initial frequency domain received signal are obtained, and least squares estimation is performed based on the first channel estimate, the PTRS transmitted symbols and the PTRS received symbols to obtain the PTRS phase corresponding to each PTRS subcarrier.

[0040] Among them, at the PTRS subcarrier position The frequency domain received signal can be represented as follows: .in, Indicates the received symbol on the PTRS RE. This represents the PTRS transmitted symbol, which is a known quantity. Represents the actual channel response. This represents the residual phase error to be estimated. Indicates noise. Assume PTRS subcarrier positions. First channel estimate It is accurate; the least squares estimation of the PTRS RE position yields the PTRS phase observations. , Finally, based on the formula Extract the PTRS phase corresponding to the PTRS subcarrier Here, arg represents taking the principal argument of the complex number.

[0041] Optionally, the system bandwidth can be divided into multiple frequency domain groups, which may include: Obtain the total number of resource blocks corresponding to the system bandwidth, and obtain multiple frequency domain groups based on the total number of resource blocks and the preset number of grouped resource blocks.

[0042] In this embodiment, the system bandwidth can be divided into multiple frequency domain groups using resource blocks as the unit of division. Specifically, a bandwidth value corresponding to each resource block is preset, and the total number of resource blocks corresponding to the system bandwidth is determined based on this bandwidth value. Then, the total number of resource blocks is divided by the preset number of resource blocks in each group to obtain the quotient value as the number of groups. The system bandwidth is then divided based on this number of groups to obtain multiple frequency domain groups. The preset number of resource blocks in each group can be a preset number of resource blocks corresponding to each group.

[0043] In a specific example, the system bandwidth is 400 MHz, corresponding to 264 resource blocks. The preset number of resource blocks per group is 8, so the 264 resource blocks are divided into 33 groups, that is, 33 frequency domain groups. If the PTRS frequency domain density (the number of resource blocks corresponding to each PTRS subcarrier) is 2, then there are 4 PTRS subcarriers in each frequency domain group.

[0044] It should be noted that, due to the sampling frequency deviation, the frequency domain phase slope over the entire bandwidth may not satisfy a global linear model. In this embodiment, phase estimation and compensation are performed separately in each frequency domain group, which can enhance the local phase estimation performance and improve the accuracy of phase compensation.

[0045] S230. Based on the PTRS phase corresponding to each PTRS subcarrier, obtain the PTRS phase set corresponding to each frequency domain group, and perform least squares fitting processing on each PTRS phase set to obtain the common phase estimate and phase slope estimate corresponding to each frequency domain group.

[0046] S240. Based on the common phase estimate and the phase slope estimate, perform phase compensation on the subcarrier frequency domain received signal within the corresponding frequency domain group to obtain the target frequency domain received signal.

[0047] Optionally, based on the common phase estimate and the phase slope estimate, phase compensation is performed on the subcarrier frequency domain received signal within the corresponding frequency domain group to obtain the target frequency domain received signal, which may include: Based on the common phase estimate and the phase slope estimate, the estimated phase corresponding to each subcarrier in each frequency domain group is obtained, and the phase compensation of the subcarrier frequency domain received signal corresponding to each subcarrier is performed based on the estimated phase corresponding to each subcarrier to obtain the target frequency domain received signal.

[0048] In this embodiment, it can be based on the common phase estimate. With phase slope estimate Construct the estimated phase on any subcarrier k within this frequency domain group. , Then, it can be done through the formula. According to this estimated phase Receive signal in the corresponding subcarrier frequency domain Phase compensation is performed to obtain the target frequency domain received signal. .

[0049] Among them, under a fixed sampling frequency deviation, the frequency domain linear phase introduced by the sampling or timing deviation. It will gradually accumulate over OFDM symbol time, therefore, It will also change slowly with the symbol index m.

[0050] S250. The target frequency domain received signal is equalized, demodulated and decoded according to each of the second channel estimates to obtain the output information bits.

[0051] Specifically, zero-forced equalization or minimum mean square error equalization methods can be used to perform frequency domain equalization on the target frequency domain received signal based on the second channel estimate to obtain an equalized frequency domain received signal. Then, the equalized frequency domain received signal can be demodulated according to the modulation scheme agreed upon with the transmitter to obtain the bit sequence. Finally, rate matching, channel decoding, and cyclic redundancy check are performed on the bit sequence to obtain the final output information bits.

[0052] The technical solution in this embodiment has the advantages of low complexity, ease of implementation, and suitability for residual compensation. If PTRS is already configured in the system, it is not necessary to change the frame structure at the transmitting end or occupy additional time-frequency resources. Only the PTRS frequency domain group compensation processing algorithm needs to be added to the receiver side to achieve the correction of sampling or timing deviations. PTRS frequency domain group compensation can utilize existing PTRS resources for estimation, and use sampling or timing deviations to introduce frequency domain linear phase characteristics to correct frequency domain common phase errors and linear phase slopes. This reduces the impact of residual sampling deviations and timing drift on OFDM subcarriers, improves constellation convergence, error vector amplitude, block error rate, and link reliability. It has low complexity, high compatibility, and ease of implementation, especially in scenarios with small to medium residual sampling or timing deviations.

[0053] The technical solution of this invention involves acquiring an initial frequency domain received signal, performing channel estimation based on the demodulation reference signal in the initial frequency domain received signal to obtain a first channel estimate value corresponding to each phase tracking reference signal (PTRS) subcarrier, and acquiring a second channel estimate value corresponding to each data subcarrier; performing least squares estimation based on the first channel estimate value to obtain the PTRS phase corresponding to each PTRS subcarrier, and dividing the system bandwidth into multiple frequency domain groups; acquiring the PTRS phase set corresponding to each frequency domain group based on the PTRS phase corresponding to each PTRS subcarrier, and performing least squares fitting processing on each PTRS phase set to obtain the PTRS phase set corresponding to each frequency domain group. The common phase estimate and phase slope estimate corresponding to the frequency domain group are obtained. Based on the common phase estimate and phase slope estimate, phase compensation is performed on the subcarrier frequency domain received signal within the corresponding frequency domain group to obtain the target frequency domain received signal. Equalization, demodulation and decoding processing is performed on the target frequency domain received signal based on each second channel estimate to obtain the output information bits. By obtaining the first channel estimate corresponding to the PTRS subcarrier and the second channel estimate corresponding to each data subcarrier at the same time, and realizing the final equalization, demodulation and decoding processing based on each second channel estimate, a complete back-end process can be realized, which can improve the accuracy of obtaining the output information bits.

[0054] This invention utilizes PTRS to construct frequency-domain phase observations, dividing the system bandwidth into several frequency-domain groups. Within each group, the PTRS phase is linearly fitted, and the common phase error and frequency-domain phase slope are jointly estimated. This slope corresponds to the residual sampling or timing deviation. Then, phase inversion compensation is applied to the data subcarriers within each group, thereby reducing the impact of sampling / timing deviations on demodulation performance without using a Faroe fractional delay filter.

[0055] Compared to traditional sampling / timing deviation compensation, which uses time-domain Faro filtering to achieve fractional delay compensation in the time domain, this embodiment employs PTRS frequency-domain grouping compensation. This method utilizes the linear phase characteristics in the frequency domain to correct residual sampling frequency deviation and timing drift. Its implementation primarily involves complex multiplication operations, eliminating the need for high-order interpolation filters and complex polyphase filter structures. This method is less complex and easier to implement than traditional Faro filtering. Furthermore, since satellite channels may exhibit frequency selectivity, Doppler residuals, phase noise, and estimation errors, frequency-domain grouping estimation can flexibly adjust the group size based on the signal-to-noise ratio, the frequency density of the PTRS schedule, and the Doppler change rate of the satellite channel, thereby improving the accuracy of phase estimation and compensation.

[0056] Example 3 Figure 3 This is a schematic diagram of a sampling deviation compensation device for a satellite terminal provided in Embodiment 3 of the present invention. Figure 3 As shown, the module comprises a channel estimation module 310, a phase acquisition module 320, a phase fitting module 330, and a phase compensation module 340; wherein, The channel estimation module 310 is used to acquire the initial frequency domain received signal and perform channel estimation based on the demodulation reference signal in the initial frequency domain received signal to obtain the first channel estimation value corresponding to each phase tracking reference signal PTRS subcarrier. Phase acquisition module 320 is used to perform least squares estimation based on the first channel estimation value to obtain the PTRS phase corresponding to each PTRS subcarrier and divide the system bandwidth into multiple frequency domain groups. The phase fitting module 330 is used to obtain the PTRS phase set corresponding to each frequency domain group based on the PTRS phase corresponding to each PTRS subcarrier, and to perform least squares fitting processing on each PTRS phase set to obtain the common phase estimate and phase slope estimate corresponding to each frequency domain group. The phase compensation module 340 is used to perform phase compensation on the subcarrier frequency domain received signal in the corresponding frequency domain group according to the common phase estimate and the phase slope estimate, so as to obtain the target frequency domain received signal, and obtain the output information bits according to the target frequency domain received signal.

[0057] The technical solution of this invention involves acquiring an initial frequency domain received signal and performing channel estimation based on the demodulation reference signal in the initial frequency domain received signal to obtain a first channel estimate value corresponding to each phase tracking reference signal (PTRS) subcarrier; performing least squares estimation based on the first channel estimate value to obtain the PTRS phase corresponding to each PTRS subcarrier, and dividing the system bandwidth into multiple frequency domain groups; obtaining a PTRS phase set corresponding to each frequency domain group based on the PTRS phase corresponding to each PTRS subcarrier, and performing least squares fitting processing on each PTRS phase set to obtain a common phase estimate corresponding to each frequency domain group. The common phase estimate and phase slope estimate are used to calculate the common phase estimate and phase slope estimate. Based on these estimates, phase compensation is performed on the subcarrier frequency domain received signal within the corresponding frequency domain group to obtain the target frequency domain received signal. Output information bits are then obtained based on the target frequency domain received signal. By dividing the system bandwidth into multiple frequency domain groups and calculating the common phase estimate and phase slope estimate for each frequency domain group, phase compensation is performed on the subcarrier frequency domain received signal within the corresponding frequency domain group based on the estimates. This eliminates the need for high-order interpolation filters and complex polyphase filtering structures, reducing the complexity and difficulty of implementing sampling deviation compensation.

[0058] Optionally, the channel estimation module 310 is specifically used to acquire the time-domain received signal with ephemeris-assisted Doppler pre-compensation, and to perform a fast Fourier transform on the time-domain received signal to obtain the initial frequency-domain received signal.

[0059] Optionally, the channel estimation module 310 is further configured to estimate and compensate for the residual time-frequency offset of the initial frequency domain received signal based on the demodulation reference signal, so as to obtain the intermediate frequency domain received signal. Based on the demodulation reference signal, the intermediate frequency domain received signal is subjected to time-frequency domain interpolation filtering to obtain the first channel estimate value corresponding to each PTRS subcarrier.

[0060] Optionally, the phase acquisition module 320 is specifically used to acquire the PTRS transmitted symbols and the PTRS received symbols in the initial frequency domain received signal, and to perform least squares estimation based on the first channel estimate, the PTRS transmitted symbols and the PTRS received symbols to obtain the PTRS phase corresponding to each PTRS subcarrier.

[0061] Optionally, the phase acquisition module 320 is further configured to acquire the total number of resource blocks corresponding to the system bandwidth, and acquire multiple frequency domain groups based on the total number of resource blocks and the preset number of grouped resource blocks.

[0062] Optionally, the phase compensation module 340 is specifically used to obtain the estimated phase corresponding to each subcarrier in each frequency domain group based on the common phase estimate and the phase slope estimate, and to perform phase compensation on the subcarrier frequency domain received signal corresponding to each subcarrier based on the estimated phase corresponding to each subcarrier, so as to obtain the target frequency domain received signal.

[0063] Optionally, the channel estimation module 310 is also used to obtain the second channel estimation value corresponding to each data subcarrier; The phase compensation module 340 is further configured to perform equalization, demodulation and decoding processing on the target frequency domain received signal according to each of the second channel estimates, so as to obtain the output information bits.

[0064] The sampling deviation compensation device for satellite terminals provided in this embodiment of the invention can execute the sampling deviation compensation method for satellite terminals provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects of the method.

[0065] The collection, storage, use, processing, transmission, provision, and disclosure of user personal information involved in the technical solution disclosed herein comply with the provisions of relevant laws and regulations and do not violate public order and good morals.

[0066] Example 4 Figure 4 A schematic diagram of an electronic device 40 that can be used to implement embodiments of the present invention is shown. The electronic device 40 is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device 40 can also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (such as helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0067] like Figure 4As shown, the electronic device 40 includes at least one processor 41 and a memory, such as a read-only memory (ROM) 42 or a random access memory (RAM) 43, communicatively connected to the at least one processor 41. The memory stores computer programs executable by the at least one processor. The processor 41 can perform various appropriate actions and processes based on the computer program stored in the read-only memory 42 or loaded from the storage unit 48 into the random access memory 43. The RAM 43 can also store various programs and data required for the operation of the electronic device 40. The processor 41, ROM 42, and RAM 43 are interconnected via a bus 44. An input / output (I / O) interface 45 is also connected to the bus 44.

[0068] Multiple components in electronic device 40 are connected to I / O interface 45, including: input unit 46, such as keyboard, mouse, etc.; output unit 47, such as various types of monitors, speakers, etc.; storage unit 48, such as disk, optical disk, etc.; and communication unit 49, such as network card, modem, wireless transceiver, etc. Communication unit 49 allows electronic device 40 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0069] Processor 41 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 41 include, but are not limited to, central processing units, graphics processing units, various special-purpose artificial intelligence computing chips, various processors running machine learning model algorithms, digital signal processors, and any suitable processor, controller, microcontroller, etc. Processor 41 performs the various methods and processes described above, such as the sampling bias compensation method for a satellite terminal.

[0070] In some embodiments, the sampling bias compensation method for a satellite terminal may be implemented as a computer program tangibly contained in a computer-readable storage medium, such as storage unit 48. In some embodiments, part or all of the computer program may be loaded into and / or installed on electronic device 40 via ROM 42 and / or communication unit 49. When the computer program is loaded into RAM 43 and executed by processor 41, one or more steps of the sampling bias compensation method for a satellite terminal described above may be performed. Alternatively, in other embodiments, processor 41 may be configured to perform the sampling bias compensation method for a satellite terminal by any other suitable means (e.g., by means of firmware).

[0071] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays, application-specific integrated circuits (ASICs), application-specific standard products (ASICs), system-on-a-chip (SoCs), complex programmable logic devices, computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0072] Computer programs used to implement the methods of the present invention can be written in any combination of one or more programming languages. These computer programs can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs can be executed entirely on a machine, partially on a machine, as a standalone software package partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0073] In the context of this invention, a computer-readable storage medium can be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory, read-only memory, erasable programmable read-only memory, optical fibers, portable compact disk read-only memory, optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0074] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device 40, which includes: a display device (e.g., a cathode ray tube or liquid crystal display) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the electronic device 40. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0075] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or computing systems that include middleware components (e.g., application servers), or computing systems that include frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), blockchain networks, and the Internet.

[0076] A computing system can include clients and servers. Clients and servers are generally located far apart and typically interact via a communication network. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server.

[0077] This embodiment may also include a computer program product, which includes a computer program that, when executed by a processor, implements the sampling deviation compensation method for satellite terminals provided in any embodiment of the present invention.

[0078] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0079] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for compensating sampling deviation in a satellite terminal, characterized in that, include: Acquire the initial frequency domain received signal, and perform channel estimation based on the demodulation reference signal in the initial frequency domain received signal to obtain the first channel estimation value corresponding to each phase tracking reference signal PTRS subcarrier; Least squares estimation is performed based on the first channel estimate to obtain the PTRS phase corresponding to each PTRS subcarrier, and the system bandwidth is divided into multiple frequency domain groups. Based on the PTRS phase corresponding to each PTRS subcarrier, obtain the PTRS phase set corresponding to each frequency domain group, and perform least squares fitting on each PTRS phase set to obtain the common phase estimate and phase slope estimate corresponding to each frequency domain group. Based on the common phase estimate and the phase slope estimate, phase compensation is performed on the subcarrier frequency domain received signal within the corresponding frequency domain group to obtain the target frequency domain received signal, and the output information bits are obtained based on the target frequency domain received signal.

2. The method according to claim 1, characterized in that, Acquire the initial frequency domain received signal, including: The time-domain received signal with ephemeris-assisted Doppler pre-compensation is acquired, and the time-domain received signal is subjected to fast Fourier transform to obtain the initial frequency-domain received signal.

3. The method according to claim 1, characterized in that, Channel estimation is performed based on the demodulated reference signal in the initial frequency domain received signal to obtain the first channel estimation value corresponding to each phase tracking reference signal (PTRS) subcarrier, including: Based on the demodulation reference signal, the residual time-frequency offset of the initial frequency domain received signal is estimated and compensated to obtain the intermediate frequency domain received signal. Based on the demodulation reference signal, the intermediate frequency domain received signal is subjected to time-frequency domain interpolation filtering to obtain the first channel estimate value corresponding to each PTRS subcarrier.

4. The method according to claim 1, characterized in that, Least squares estimation is performed based on the first channel estimate to obtain the PTRS phase corresponding to each PTRS subcarrier, including: The PTRS transmitted symbols and the PTRS received symbols in the initial frequency domain received signal are obtained, and least squares estimation is performed based on the first channel estimate, the PTRS transmitted symbols and the PTRS received symbols to obtain the PTRS phase corresponding to each PTRS subcarrier.

5. The method according to claim 1, characterized in that, The system bandwidth is divided into multiple frequency domain groups, including: Obtain the total number of resource blocks corresponding to the system bandwidth, and obtain multiple frequency domain groups based on the total number of resource blocks and the preset number of grouped resource blocks.

6. The method according to claim 1, characterized in that, Based on the common phase estimate and the phase slope estimate, phase compensation is performed on the subcarrier frequency domain received signal within the corresponding frequency domain group to obtain the target frequency domain received signal, including: Based on the common phase estimate and the phase slope estimate, the estimated phase corresponding to each subcarrier in each frequency domain group is obtained, and the phase compensation of the subcarrier frequency domain received signal corresponding to each subcarrier is performed based on the estimated phase corresponding to each subcarrier to obtain the target frequency domain received signal.

7. The method according to claim 1, characterized in that, After performing channel estimation based on the demodulated reference signal in the initial frequency domain received signal to obtain the first channel estimation value corresponding to each phase tracking reference signal PTRS subcarrier, the method further includes: Obtain the second channel estimate value corresponding to each data subcarrier; Obtaining output information bits based on the target frequency domain received signal includes: The target frequency domain received signal is equalized, demodulated, and decoded based on each of the second channel estimates to obtain the output information bits.

8. An electronic device, characterized in that, The electronic device includes: At least one processor, and A memory communicatively connected to the at least one processor; wherein, The memory stores a computer program that is executed by the at least one processor, which enables the at least one processor to perform the sampling deviation compensation method for the satellite terminal according to any one of claims 1-7.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that enables a processor to execute the sampling deviation compensation method for the satellite terminal according to any one of claims 1-7.

10. A computer program product, characterized in that, It includes a computer program that, when executed by a processor, implements the sampling deviation compensation method for the satellite terminal according to any one of claims 1-7.

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