Frame synchronization detection method, device, equipment and medium

Abstract

The invention relates to a frame synchronization detection method, device and equipment and a medium, and the method comprises the steps: carrying out the frequency offset pre-compensation of a received satellite signal; setting N different frequency offset grades, and adopting the N different frequency offset grades to perform secondary frequency offset pre-compensation on the satellite signals subjected to frequency offset pre-compensation to obtain N satellite signals subjected to secondary frequency offset pre-compensation; performing frame synchronization detection on each satellite signal subjected to secondary frequency offset pre-compensation by adopting a frame synchronization detection algorithm to obtain N detection results; and screening out a final frame synchronization detection result by adopting a preset rule based on the N detection results. According to the method, the frame synchronization detection performance can be improved, and the detection performance can meet the system design index requirement.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a frame synchronization detection method, device, equipment and medium. Background Art

[0002] Since the satellite terminal does not know the corresponding information of the signal frame header starting position and carrier frequency deviation before accessing the network, the terminal first needs to perform frame synchronization to detect the accurate frame header position in the presence of interference such as carrier frequency deviation, and then perform bit synchronization and subsequent channel estimation, equalization and decoding. Therefore, the performance of frame synchronization detection is very critical and determines the performance of the entire satellite communication system.

[0003] In satellite communication networks, how to perform frame synchronization in the presence of frequency deviation, predecessors have proposed many detection algorithms: such as full correlation algorithm, segmented correlation algorithm and differential correlation algorithm, etc. These algorithms can reduce the impact of frequency deviation on frame synchronization detection performance to a certain extent. However, when the frequency deviation reaches about 0.01 relative to the system sampling rate, the correlation peak of the existing frame synchronization algorithm will drop sharply, resulting in an unclear peak and difficulty in capturing the accurate frame header position. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a frame synchronization detection method and device, which can improve the frame synchronization detection performance so that the detection performance can meet the system design index requirements.

[0005] The technical solution adopted by the present invention to solve the technical problem is: to provide a frame synchronization detection method, comprising the following steps:

[0006] Perform frequency deviation pre-compensation on the received satellite signal;

[0007] Setting N different frequency offset bins, using the N different frequency offset bins to perform secondary frequency offset pre-compensation on the satellite signals after the frequency offset pre-compensation, to obtain N secondary frequency offset pre-compensated satellite signals;

[0008] Using a frame synchronization detection algorithm to perform frame synchronization detection on each satellite signal pre-compensated for the secondary frequency offset, to obtain N detection results;

[0009] Based on the N detection results, a preset rule is used to filter out the final frame synchronization detection result.

[0010] The satellite signal after frequency offset pre-compensation is expressed as: y′(n)=y(n)·e -j2πΔfn , y′(n) is the satellite signal after frequency offset pre-compensation, y(n) is the received satellite signal, Δf is the pre-compensated frequency offset, and n is an integer greater than 0.

[0011] The i-th quadratic frequency offset pre-compensated satellite signal among the N quadratic frequency offset pre-compensated satellite signals is expressed as: Among them, y i-1 (n) is the satellite signal after the i-th secondary frequency offset pre-compensation, y′(n) is the satellite signal after the frequency offset pre-compensation, f i-1 is the ith frequency deviation bin, and n is an integer greater than 0.

[0012] The frame synchronization detection algorithm is a full correlation algorithm, a segmented correlation algorithm or a differential correlation algorithm.

[0013] The method of obtaining the final frame synchronization detection result based on the N detection results by using a preset rule specifically includes:

[0014] Find P detection results that successfully capture the frame header from N detection results;

[0015] Calculate the signal-to-noise ratio of each detection result of the successfully captured frame header according to the maximum cross-correlation value obtained during frame synchronization detection and the cumulative average of the cross-correlation results after removing the maximum cross-correlation value;

[0016] The detection result of the successfully captured frame header with the largest signal-to-noise ratio is taken as the final frame synchronization detection result.

[0017] The signal-to-noise ratio of the detection result of the successfully captured frame header is expressed by SNR p =corr max / σ 2 Calculated, where SNR p is the signal-to-noise ratio of the detection result of the pth successfully captured frame header, corr max is the maximum cross-correlation value obtained during frame synchronization detection corresponding to the detection result of the pth successfully captured frame header, σ 2 It is the cumulative average of the cross-correlation results after removing the maximum cross-correlation value obtained during the frame synchronization detection corresponding to the detection result of the p-th successfully captured frame header.

[0018] If the detection result of successfully capturing the frame header among the N detection results is zero, the frame synchronization detection fails.

[0019] The technical solution adopted by the present invention to solve the technical problem is: to provide a frame synchronization detection device, comprising:

[0020] A frequency offset pre-compensation module, used for performing frequency offset pre-compensation on received satellite signals;

[0021] A secondary frequency offset pre-compensation module is used to set N different frequency offset grades, and use the N different frequency offset grades to perform secondary frequency offset pre-compensation on the satellite signals after the frequency offset pre-compensation, so as to obtain N satellite signals after the secondary frequency offset pre-compensation;

[0022] A frame synchronization detection module, used for performing frame synchronization detection on each satellite signal pre-compensated for the secondary frequency offset using a frame synchronization detection algorithm to obtain N detection results;

[0023] The screening module is used to screen out the final frame synchronization detection result based on N detection results using preset rules.

[0024] The technical solution adopted by the present invention to solve its technical problem is: to provide an electronic device, including a memory, a processor and a computer program stored in the memory and executable on the processor, and the processor implements the steps of the above-mentioned frame synchronization detection method when executing the computer program.

[0025] The technical solution adopted by the present invention to solve its technical problem is: providing a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above-mentioned frame synchronization detection method are implemented.

[0026] Beneficial Effects

[0027] Due to the adoption of the above-mentioned technical scheme, the present invention has the following advantages and positive effects compared with the prior art: the present invention adds multiple frequency deviation divisions, performs multiple time domain secondary frequency deviation compensations, and then attempts multiple frame synchronization detections, and obtains the final frame header detection result according to certain selection and judgment criteria based on the results of the multiple detections, thereby greatly improving the frame header capture performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a flowchart of the frame synchronization detection method according to the first embodiment of the present invention. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0030] The first embodiment of the present invention relates to a frame synchronization detection method, such as Figure 1 As shown, the following steps are included:

[0031] Step 1: pre-compensate the received satellite signal for frequency offset. In this step, the received satellite signal is y(n), n is an integer greater than 0, the pre-compensated frequency offset is Δf, and the satellite signal after frequency offset pre-compensation is y′(n), expressed as: y′(n)=y(n)·e -j2πΔfn .

[0032] Step 2, setting N different frequency offset bins, using N different frequency offset bins to perform secondary frequency offset precompensation on the satellite signals after frequency offset precompensation, to obtain N secondary frequency offset precompensated satellite signals. In this step, the set N different frequency offset bins are represented as: {f0, f1, ..., f N-1}, the satellite signal after secondary frequency offset pre-compensation is expressed as:

[0033]

[0034] Step 3: Use a frame synchronization detection algorithm to perform frame synchronization detection on each satellite signal pre-compensated for the secondary frequency offset to obtain N detection results. The frame synchronization detection algorithm in this step can be a full correlation algorithm, a segmented correlation algorithm, a differential correlation algorithm, or other frame synchronization algorithms.

[0035] This implementation method uses a segmented correlation algorithm to perform frame synchronization detection on each satellite signal pre-compensated for secondary frequency offset, specifically as follows:

[0036] First, the satellite signal with secondary frequency offset precompensation needs to be processed by sliding segmentation to obtain d q (n), and then perform cross-correlation operation with the local sequence s(n), where the local sequence is divided into M segments, each of which has a length of L, that is, the signal data after sliding segmentation is cross-correlated with the segmented local sequence; then, the obtained cross-correlation results of each segment are squared, accumulated and averaged to obtain the cross-correlation result of this sliding offset, and then the satellite signal with secondary frequency offset pre-compensation is sliding segmented, and the above process is repeated to obtain the cross-correlation result of the next sliding offset, until Q cross-correlation results are obtained. The maximum value (peak value) among the Q cross-correlation results is recorded as corr max , and then calculate and remove the maximum cross-correlation value corr max The cumulative average value of the cross-correlation results after 2 . Then use the maximum value corr max and the cumulative mean σ 2 Perform peak search (i.e. search for the frame header position), as follows:

[0037] (1) First, let the peak threshold PeakMax = 0; when the peak search begins, if the maximum value corr max is less than the peak threshold PeakMax, it is judged as an invalid peak; if the peak corr max and the cumulative mean value σ 2 The quotient is greater than the peak search threshold, and the peak corr max If it is greater than the peak value threshold PeakMax, it is determined to be a valid peak value, and the peak value threshold PeakMax is updated to corr maxAt the beginning, it is necessary to perform the decision search segment by segment until the first valid peak is found.

[0038] (2) If the next peak value is less than or equal to the previous peak value, it is considered that the correlation peak value is found (because the previous correlation peak value is the largest, the index corresponding to the correlation peak value corresponding to the previous correlation peak value is taken as the frame header position), thereby finding the frame header position and achieving frame synchronization;

[0039] (3) If the next peak value is greater than the previous peak value, continue to look for the next segment until the conditions in step (2) are met.

[0040] By respectively detecting the N secondary frequency offset pre-compensated satellite signals in this implementation manner through the above-mentioned segmented correlation algorithm, N detection results can be obtained.

[0041] Step 4: Based on the N detection results, a final frame synchronization detection result is screened out using a preset rule. The specific process of this step is as follows:

[0042] First, find the detection result of successfully capturing the frame header from the N detection results; if the detection result of successfully capturing the frame header is zero among the N detection results, the frame synchronization detection fails. If the number of detection results of successfully capturing the frame header is P among the N detection results, the preset rules are used to filter out the final frame synchronization detection result from the P detection results of successfully capturing the frame header. During the screening, the signal-to-noise ratio of each detection result of successfully capturing the frame header is calculated, and the detection result of successfully capturing the frame header with the largest signal-to-noise ratio is used as the final frame synchronization detection result. The signal-to-noise ratio is calculated as follows: SNR p =corr max / σ 2 , where SNR p is the signal-to-noise ratio of the detection result of the pth successfully captured frame header, corr max is the maximum cross-correlation value obtained during the frame synchronization detection corresponding to the detection result of the pth successfully captured frame header, σ 2 It is the cumulative average of the cross-correlation results after removing the maximum cross-correlation value obtained during the frame synchronization detection corresponding to the detection result of the p-th successfully captured frame header.

[0043] It is not difficult to find that the present invention greatly improves the frame header capture performance by adding multiple frequency deviation divisions, performing multiple time domain secondary frequency deviation compensations, and then attempting multiple frame synchronization detections, and obtaining the final frame header detection result according to certain selection and judgment criteria for the results of multiple detections.

[0044] A second embodiment of the present invention relates to a frame synchronization detection device, comprising:

[0045] A frequency offset pre-compensation module, used for performing frequency offset pre-compensation on received satellite signals;

[0046] A secondary frequency offset pre-compensation module is used to set N different frequency offset grades, and use the N different frequency offset grades to perform secondary frequency offset pre-compensation on the satellite signals after the frequency offset pre-compensation, so as to obtain N satellite signals after the secondary frequency offset pre-compensation;

[0047] A frame synchronization detection module, used for performing frame synchronization detection on each satellite signal pre-compensated for the secondary frequency offset using a frame synchronization detection algorithm to obtain N detection results;

[0048] The screening module is used to screen out the final frame synchronization detection result based on N detection results using preset rules.

[0049] The satellite signal after frequency offset pre-compensation is expressed as: y′(n)=y(n)·e -j2πΔfn , y′(n) is the satellite signal after frequency offset pre-compensation, y(n) is the received satellite signal, Δf is the pre-compensated frequency offset, and n is an integer greater than 0.

[0050] The i-th quadratic frequency offset pre-compensated satellite signal among the N quadratic frequency offset pre-compensated satellite signals is expressed as: Among them, y i-1 (n) is the satellite signal after the i-th secondary frequency offset pre-compensation, y′(n) is the satellite signal after the frequency offset pre-compensation, f i-1 is the ith frequency deviation bin, and n is an integer greater than 0.

[0051] The frame synchronization detection algorithm adopted by the frame synchronization detection module is a full correlation algorithm, a segmented correlation algorithm or a differential correlation algorithm.

[0052] The screening module comprises:

[0053] A search unit, used to find P detection results that successfully capture the frame header from the N detection results;

[0054] A calculation unit, used to calculate the signal-to-noise ratio of each detection result of successfully capturing the frame header according to the maximum cross-correlation value obtained during frame synchronization detection and the cumulative average value of the cross-correlation result after removing the maximum cross-correlation value;

[0055] The first determining unit is used to use the detection result of the successfully captured frame header with the largest signal-to-noise ratio as the final frame synchronization detection result.

[0056] The calculation unit uses SNR p =corr max / σ 2 Calculate the signal-to-noise ratio of the detection result of the successfully captured frame header, where SNR p is the signal-to-noise ratio of the detection result of the pth successfully captured frame header, corr maxis the maximum cross-correlation value obtained during the frame synchronization detection corresponding to the detection result of the pth successfully captured frame header, σ 2 It is the cumulative average of the cross-correlation results after removing the maximum cross-correlation value obtained during the frame synchronization detection corresponding to the detection result of the p-th successfully captured frame header.

[0057] The screening module further includes: a second determination unit, configured to determine that the frame synchronization detection fails when the detection result of successfully capturing the frame header is zero among the N detection results.

[0058] The third embodiment of the present invention relates to an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the frame synchronization detection method of the first embodiment when executing the computer program.

[0059] A fourth embodiment of the present invention relates to a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the frame synchronization detection method of the first embodiment are implemented.

[0060] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) that contain computer-usable program code.

[0061] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0062] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction method, which is implemented in the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0063] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0064] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A frame synchronization detection method, characterized in that: The following steps are involved: Perform frequency deviation pre-compensation on the received satellite signal; Setting N different frequency offset bins, using the N different frequency offset bins to perform secondary frequency offset pre-compensation on the satellite signals after the frequency offset pre-compensation, to obtain N secondary frequency offset pre-compensated satellite signals; Using a frame synchronization detection algorithm to perform frame synchronization detection on each satellite signal pre-compensated for the secondary frequency offset, to obtain N detection results; Based on the N detection results, a preset rule is used to filter out the final frame synchronization detection result.

2. The frame synchronization detection method according to claim 1, characterized in that: The satellite signal after frequency offset pre-compensation is expressed as: y′(n)=y(n)·e -j2 πΔ fn , y′(n) is the satellite signal after frequency offset pre-compensation, y(n) is the received satellite signal, Δf is the pre-compensated frequency offset, and n is an integer greater than 0.

3. The frame synchronization detection method according to claim 1, characterized in that: The i-th quadratic frequency offset pre-compensated satellite signal among the N quadratic frequency offset pre-compensated satellite signals is expressed as: Among them, y i-1 (n) is the satellite signal after the i-th secondary frequency offset pre-compensation, y′(n) is the satellite signal after the frequency offset pre-compensation, f i-1 is the ith frequency deviation bin, and n is an integer greater than 0.

4. The frame synchronization detection method according to claim 1, characterized in that: The frame synchronization detection algorithm is a full correlation algorithm, a segmented correlation algorithm or a differential correlation algorithm.

5. The frame synchronization detection method according to claim 1, characterized in that: The method of obtaining the final frame synchronization detection result based on the N detection results by using a preset rule specifically includes: Find P detection results that successfully capture the frame header from N detection results; Calculate the signal-to-noise ratio of each detection result of the successfully captured frame header according to the maximum cross-correlation value obtained during frame synchronization detection and the cumulative average of the cross-correlation results after removing the maximum cross-correlation value; The detection result of the successfully captured frame header with the largest signal-to-noise ratio is taken as the final frame synchronization detection result.

6. The frame synchronization detection method according to claim 5, characterized in that: The signal-to-noise ratio of the detection result of the successfully captured frame header is expressed by SNR p =corr max / σ 2 Calculated, where SNR p is the signal-to-noise ratio of the detection result of the pth successfully captured frame header, corr max is the maximum cross-correlation value obtained during the frame synchronization detection corresponding to the detection result of the pth successfully captured frame header, σ 2 It is the cumulative average of the cross-correlation results after removing the maximum cross-correlation value obtained during the frame synchronization detection corresponding to the detection result of the p-th successfully captured frame header.

7. The frame synchronization detection method according to claim 5, characterized in that: If the detection result of successfully capturing the frame header among the N detection results is zero, the frame synchronization detection fails.

8. A frame synchronization detection device, characterized in that: include: A frequency offset pre-compensation module, used for performing frequency offset pre-compensation on received satellite signals; A secondary frequency offset pre-compensation module is used to set N different frequency offset grades, and use the N different frequency offset grades to perform secondary frequency offset pre-compensation on the satellite signals after the frequency offset pre-compensation, so as to obtain N satellite signals after the secondary frequency offset pre-compensation; A frame synchronization detection module, used for performing frame synchronization detection on each satellite signal pre-compensated for the secondary frequency offset using a frame synchronization detection algorithm to obtain N detection results; The screening module is used to screen out the final frame synchronization detection result based on N detection results using preset rules.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the frame synchronization detection method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the frame synchronization detection method according to any one of claims 1 to 7 are implemented.

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