Signal capturing method, system, device and equipment in high dynamic environment and medium

Abstract

The invention discloses a signal capturing method, system and device in a high dynamic environment, equipment and a medium. The method comprises the following steps: acquiring a first receiving signal; performing sampling-level sliding correlation processing according to the first receiving signal and a local sampling-level pilot frequency to obtain a first correlation signal; performing coarse decision processing on the first correlation signal, determining a coarse starting position, and obtaining a first-stage coarse capture signal according to the coarse starting position; performing symbol-level sliding correlation processing according to the first-level coarse capture signal and a local symbol-level pilot frequency to obtain a second correlation signal; performing fine decision processing on the second correlation signal to determine a fine initial position; and intercepting a frame signal according to the fine initial position to obtain a second-stage fine capture signal. According to the invention, the narrow-band satellite communication system can keep stable communication in a high-dynamic environment.

Description

Technical Field

[0001] The present application relates to the field of satellite communications, and in particular to a method, system, device, equipment and medium for capturing signals in a high dynamic environment. Background Art

[0002] In narrowband satellite communication systems, the large relative motion between the satellite and the ground receiver causes a large Doppler frequency shift of up to tens of kHz or even hundreds of kHz, which makes the narrowband satellite communication system work in a highly dynamic environment, seriously affecting the communication quality and even making it impossible to complete signal capture. Therefore, accurate estimation of the Doppler frequency shift is extremely important for signal reception. In addition, in narrowband satellite communication systems, the signal may not be captured normally due to reasons such as uncertainty in the signal transmission and reception time. Summary of the invention

[0003] The present application aims to propose a signal capture method, system, device, equipment and medium in a high dynamic environment, which can enable a narrowband satellite communication system to maintain stable communication in a high dynamic environment.

[0004] In a first aspect, an embodiment of the present application provides a signal capture method in a high dynamic environment, comprising the following steps:

[0005] Acquire a first received signal, where the first received signal is a sampling-level received signal;

[0006] Performing sampling-level sliding correlation processing on the first received signal and the local sampling-level pilot to obtain a first correlation signal;

[0007] Performing coarse decision processing on the first correlation signal to determine a coarse starting position, and obtaining a first-stage coarse acquisition signal according to the coarse starting position;

[0008] Performing symbol-level sliding correlation processing on the first-level coarse acquisition signal and the local symbol-level pilot to obtain a second correlation signal;

[0009] performing fine decision processing on the second correlation signal to determine a fine starting position;

[0010] The frame signal is intercepted according to the fine starting position to obtain a second-level fine capture signal.

[0011] According to some embodiments of the present application, the local sampling level pilot includes a first local sampling level pilot and a second local sampling level pilot, and performing sampling level sliding correlation processing on the first received signal and the local sampling level pilot to obtain a first sampling correlation signal includes:

[0012] Performing sampling-level sliding correlation processing on the first received signal and the first local sampling-level pilot to obtain a first sub-correlation signal;

[0013] Performing sampling-level sliding correlation processing on the first received signal and the second local sampling-level pilot to obtain a second sub-correlation signal;

[0014] A first correlation signal is obtained according to the first sub-correlation signal and the second sub-correlation signal, wherein the first correlation signal includes the first sub-correlation signal and the second sub-correlation signal.

[0015] According to some embodiments of the present application, performing coarse decision processing on the first correlation signal to determine a coarse starting position, and obtaining a first-level coarse acquisition signal according to the coarse starting position includes:

[0016] Performing coarse frequency offset estimation processing on the first sub-correlation signal and the second sub-correlation signal respectively to obtain a first coarse frequency offset value and a first coarse starting position corresponding to a first local sampling level pilot, and a second coarse frequency offset value and a second coarse starting position corresponding to a second local sampling level pilot;

[0017] The first coarse frequency offset value and the second coarse frequency offset value are compared to obtain target pilot information, a target coarse frequency offset value and a target coarse starting position; the target pilot information is the first local sampling level pilot or the second local sampling level pilot for completing coarse synchronization; when the target pilot information is the first local sampling level pilot, the target coarse frequency offset value is the first coarse frequency offset value, and the target coarse starting position is the first coarse starting position; when the target pilot information is the second local sampling level pilot, the target coarse frequency offset value is the second coarse frequency offset value, and the target coarse starting position is the second coarse starting position;

[0018] Determine a fine sliding range according to the target coarse starting position, and obtain a second received signal, where the second received signal is the first received signal within the fine sliding range;

[0019] The second received signal is subjected to frequency offset compensation according to the target coarse frequency offset value to obtain a first-stage coarse acquisition signal.

[0020] According to some embodiments of the present application, performing coarse decision processing on the first correlation signal, determining a coarse starting position, and obtaining a first-level coarse acquisition signal according to the coarse starting position includes:

[0021] Performing a coarse frequency offset estimation process on the first correlation signal to obtain a coarse frequency offset value and a coarse starting position corresponding to the local sampling level pilot;

[0022] Determine a fine sliding range according to the coarse starting position, and obtain a second received signal, where the second received signal is the first received signal within the fine sliding range;

[0023] Frequency offset compensation is performed on the second received signal according to the coarse frequency offset value to obtain a first-stage coarse capture signal.

[0024] According to some embodiments of the present application, performing fine decision processing on the second correlation signal to determine a fine starting position includes:

[0025] performing differential accumulation on the second correlation signal to obtain a second correlation accumulation value;

[0026] Comparing the second correlation accumulated values ​​to obtain a peak position, where the peak position is a position corresponding to a maximum peak in the second correlation accumulated values;

[0027] A fine starting position is determined according to the peak position and the local sampling level pilot.

[0028] According to some embodiments of the present application, performing symbol-level sliding correlation processing on the first-level coarse acquisition signal and the local symbol-level pilot to obtain a second correlation signal includes:

[0029] Performing matched filtering on the first-stage coarse acquisition signal to obtain a matched filtered coarse acquisition signal;

[0030] A symbol-level sliding correlation process is performed on the matched filtered coarse acquisition signal and the local symbol-level pilot to obtain a second correlation signal.

[0031] In a second aspect, an embodiment of the present application provides a narrowband satellite communication system, including a satellite and a ground receiver, wherein the ground receiver communicates with the satellite through the signal capture method for a high dynamic environment described in the first aspect.

[0032] In a third aspect, an embodiment of the present application provides a signal capture device in a high dynamic environment, comprising:

[0033] A signal receiving module, used to obtain a first received signal, where the first received signal is a sampling-level received signal;

[0034] a coarse correlation module, configured to perform sampling-level sliding correlation processing on the first received signal and a local sampling-level pilot to obtain a first correlation signal;

[0035] A coarse decision module, used for performing coarse decision processing on the first correlation signal, determining a coarse starting position, and obtaining a first-level coarse acquisition signal according to the coarse starting position;

[0036] A fine correlation module, configured to perform symbol-level sliding correlation processing on the first-level coarse acquisition signal according to a local sampling-level pilot to obtain a second correlation signal;

[0037] A fine decision module, used for performing fine decision processing on the second correlation signal to determine a fine starting position;

[0038] The frame signal extraction module is used to intercept the frame signal according to the fine starting position to obtain the second-level fine capture signal.

[0039] In a fourth aspect, an embodiment of the present application provides an electronic device, the device comprising: a processor and a memory storing computer program instructions;

[0040] When the processor executes the computer program instructions, the signal capture method for a high dynamic environment as described in the first aspect is implemented.

[0041] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium having computer program instructions stored thereon. When the computer program instructions are executed by a processor, the signal capture method for a high dynamic environment as described in the first aspect is implemented.

[0042] The signal capture method, system, device, equipment and medium of the high dynamic environment of the embodiment of the present application at least have the following

[0043] Beneficial effects:

[0044] In the implementation manner of the present application, a first received signal is first acquired; then, a sampling-level sliding correlation process is performed on the first received signal and a local sampling-level pilot to obtain a first correlation signal; then, a coarse decision process is performed on the first correlation signal to determine a coarse starting position, and a first-level coarse capture signal is obtained according to the coarse starting position; then, a symbol-level sliding correlation process is performed on the first-level coarse capture signal according to the local sampling-level pilot to obtain a second correlation signal; then, a fine decision process is performed on the second correlation signal to determine a fine starting position; finally, a frame signal is intercepted according to the fine starting position to obtain a second-level fine capture signal. The present application first completes coarse capture by acquiring a first-level coarse capture signal, and then completes fine capture by acquiring a second-level fine capture signal, and can estimate a large Doppler frequency shift that is several times the symbol rate, so that the narrowband satellite communication system can maintain stable communication in a high dynamic environment.

[0045] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The present application is further described below with reference to the accompanying drawings and embodiments, wherein:

[0047] Figure 1 A schematic diagram of a flow chart of an embodiment of a signal capture method for a high dynamic environment provided by the present application;

[0048] Figure 2It is a schematic diagram of the physical layer data frame structure in satellite communication in the related technology.

[0049] Figure 3 A schematic diagram of the overall process of an embodiment of a signal capture method for a high dynamic environment provided by the present application;

[0050] Figure 4 A schematic diagram of the FPGA implementation architecture of the signal capture method for a high dynamic environment provided in this application;

[0051] Figure 5 A schematic diagram of the structure of a signal capture device for a high dynamic environment provided by the present application;

[0052] Figure 6 A schematic diagram of the structure of the electronic device provided in this application. DETAILED DESCRIPTION

[0053] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application.

[0054] In this article, relational terms such as first and second, etc. are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0055] In order to solve the problems of the prior art, the embodiments of the present application provide a method, system, device, equipment and medium for capturing signals in a high dynamic environment. The method for capturing signals in a high dynamic environment provided by the embodiments of the present application is first introduced below.

[0056] Figure 1A schematic diagram of a process flow of a signal capture method in a high dynamic environment provided by an embodiment of the present application is shown. A signal capture method in a high dynamic environment comprises the following steps:

[0057] S101, obtaining a first received signal, where the first received signal is a sampling-level received signal;

[0058] S102, performing sampling-level sliding correlation processing on the first received signal and the local sampling-level pilot to obtain a first correlation signal;

[0059] S103, performing a coarse decision process on the first correlation signal, determining a coarse starting position, and obtaining a first-level coarse capture signal according to the coarse starting position;

[0060] S104, performing symbol-level sliding correlation processing on the first-level coarse acquisition signal and the local symbol-level pilot to obtain a second correlation signal;

[0061] S105, performing fine decision processing on the second correlation signal to determine a fine starting position;

[0062] S106, intercepting the frame signal according to the fine starting position to obtain a second-level fine capture signal.

[0063] In the implementation mode of the present application, a first received signal is first acquired; then, a sampling-level sliding correlation process is performed on the first received signal and a local sampling-level pilot to obtain a first correlation signal; then, a coarse decision process is performed on the first correlation signal to determine a coarse starting position, and a first-level coarse capture signal is obtained according to the coarse starting position; then, a symbol-level sliding correlation process is performed on the first-level coarse capture signal according to the local sampling-level pilot to obtain a second correlation signal; then, a fine decision process is performed on the second correlation signal to determine a fine starting position; finally, a frame signal is intercepted according to the fine starting position to obtain a second-level fine capture signal. The present application first completes coarse capture by acquiring a first-level coarse capture signal, and then completes fine capture by acquiring a second-level fine capture signal, which can estimate a large Doppler frequency shift that is several times the symbol rate, so that the narrowband satellite communication system can maintain stable communication in a high dynamic environment and when the received signal is partially lost.

[0064] In the above step S101, a first received signal is obtained. The first received signal refers to a satellite signal received by a receiver, and the signal is a sampling-level signal.

[0065] In the above step S102, a sampling level sliding correlation process is performed on the first received signal and the local sampling level pilot to obtain a first correlation signal. The local sampling level pilot refers to local pilot information. Usually, the physical layer data frame structure of a narrowband satellite communication system is mainly composed of a pilot and data, and the pilot is used for signal capture. The local sampling level pilot can be one segment or two segments. The sampling level sliding correlation can also be called a coarse sliding correlation.

[0066] Performing sampling-level sliding correlation processing on the first received signal and the local sampling-level pilot refers to performing coarse sliding correlation processing on the first received signal. In the coarse sliding correlation process, the received signal slides according to Ns sample point signals each time, and Ns*L1 signal sample points are correlated with the local sampling-level pilot each time to obtain a sampling-level correlation signal, i.e., a first correlation signal, wherein L1 is the pilot length and Ns is the number of sampling points for each symbol.

[0067] In the above step S103, a coarse decision process is performed on the first correlation signal to determine a coarse starting position, and a first-level coarse capture signal is obtained based on the coarse starting position. This means that the signal after the sampling-level sliding correlation in step S102 is identified to obtain a coarse starting position of the frame signal, and a fine sliding range is determined by combining the coarse starting position of the frame signal obtained by the coarse decision and the number of sampling points Ns of each symbol when the signal is sent. Then, the signal is captured based on the fine sliding range to obtain a first-level coarse capture signal.

[0068] In the above step S104, the second correlation signal is obtained by performing symbol-level sliding correlation processing on the first-level coarse acquisition signal and the local symbol-level pilot, which means that the first-level coarse acquisition signal is subjected to fine sliding correlation. The specific process of fine sliding correlation is to slide the signal after matched filtering processing according to 1 sample signal each time, extract a sample point every Ns sample points to obtain L1 symbol-level signals and correlate them with the local symbol-level pilot, and obtain L1 symbol-level correlation signals each time. The total number of sliding times of fine sliding correlation is Ns+1 sample points.

[0069] In the above step S105, performing fine decision processing on the second correlation signal to determine a fine starting position refers to identifying the second correlation signal in combination with the pilot signal to determine a fine starting position of the frame signal.

[0070] S106, intercepting the frame signal according to the fine starting position to obtain a second-level fine capture signal, means that after determining the fine starting position of the frame signal, L symbols of the second related signal are extracted at corresponding position points to complete the frame signal interception, thereby completing the signal capture.

[0071] In the present application, the first-level coarse capture is realized by steps S101-S103, and the second-level fine capture is realized by steps S104-S106. The first-level coarse capture is the signal blind capture, and its main purpose is to find the coarse starting position of the frame signal in the received signal and then determine the sliding range of the second-level fine capture. The second-level fine capture is the bright capture, and its main purpose is to find the fine starting position of the frame signal and then complete the signal capture. In the subsequent processing, the captured frame signal can be subjected to carrier synchronization and demodulation and decoding processing.

[0072] In some implementations, the local sampling level pilot includes a first local sampling level pilot and a second local sampling level pilot, and performing sampling level sliding correlation processing on the first received signal and the local sampling level pilot to obtain a first correlation signal may include:

[0073] Performing sampling-level sliding correlation processing on the first received signal and the first local sampling-level pilot to obtain a first sub-correlation signal;

[0074] Performing sampling-level sliding correlation processing on the first received signal and the second local sampling-level pilot to obtain a second sub-correlation signal;

[0075] A first correlation signal is obtained according to the first sub-correlation signal and the second sub-correlation signal, and the first correlation signal includes the first sub-correlation signal and the second sub-correlation signal.

[0076] In this implementation, two-segment pilot signals are used to perform sampling-level sliding correlation processing, so that stable communication can be maintained even when a portion of the received signal is lost.

[0077] Exemplary, reference Figure 2 As shown, taking the physical layer data frame of the satellite communication system as an example, the total length of one frame signal is L, that is, L symbols, wherein the length of pilot 1 and pilot 2 is L1, pilot 1 is the first local sampling level pilot, pilot 2 is the second local sampling level pilot, and the length of data 1 and data 2 is L2.

[0078] It should be noted that when only one pilot is used, for example, only pilot 1 is used, if the received signal is incomplete in practice, that is, pilot 1 is not received, the frame data may be discarded, causing unstable communication; if only pilot 2 is used, the performance may be degraded due to the insufficient length of pilot 2.

[0079] Specifically, sampling-level sliding correlation processing is performed on the first received signal and the first local sampling-level pilot, and sampling-level sliding correlation processing is performed on the first received signal and the second local sampling-level pilot; it means that coarse sliding correlation processing is performed on the first received signal, and the coarse sliding correlation process slides the received signal according to Ns sample point signals each time, and takes Ns*L1 signal samples each time to correlate with the local sampling-level pilot to obtain a sampling-level correlation signal, that is, a first correlation signal. The total number of sliding times of coarse sliding correlation is at least Ns*L-Ns*L2. In the present application, pilot 1 and pilot 2 are both subjected to sampling-level sliding correlation processing with the first received signal to obtain sampling-level correlation signal 1 and sampling-level correlation signal 2, wherein sampling-level correlation signal 1 is the first sub-correlation signal, and sampling-level correlation signal 2 is the second sub-correlation signal. By performing sampling-level processing on the signal through coarse sliding correlation, the receiver can quickly complete coarse capture of the signal under high dynamic conditions, and at the same time can greatly improve the coarse frequency offset estimation range. Assuming the symbol rate of the frame signal is f s , this application uses sampling level processing, and the frequency offset estimation range is (-Ns*f s / 2,Ns*f s / 2); and using two pilot signals for correlation processing can effectively solve the problem of stable communication when the received signal is incomplete.

[0080] In some implementations, performing a coarse decision process on the first correlation signal, determining a coarse starting position, and obtaining a first-level coarse acquisition signal according to the coarse starting position may include:

[0081] Performing coarse frequency offset estimation processing on the first sub-correlation signal and the second sub-correlation signal respectively, to obtain a first coarse frequency offset value and a first coarse starting position corresponding to the first local sampling level pilot, and a second coarse frequency offset value and a second coarse starting position corresponding to the second local sampling level pilot;

[0082] The first coarse frequency offset value and the second coarse frequency offset value are compared to obtain target pilot information, target coarse frequency offset value and target coarse starting position; the target pilot information is the first local sampling level pilot or the second local sampling level pilot for completing coarse synchronization; when the target pilot information is the first local sampling level pilot, the target coarse frequency offset value is the first coarse frequency offset value, and the target coarse starting position is the first coarse starting position; when the target pilot information is the second local sampling level pilot, the target coarse frequency offset value is the second coarse frequency offset value, and the target coarse starting position is the second coarse starting position;

[0083] Determine a fine sliding range according to the target coarse starting position, and obtain a second received signal, where the second received signal is the first received signal within the fine sliding range;

[0084] The frequency offset of the second received signal is compensated according to the target coarse frequency offset value to obtain a first-stage coarse capture signal.

[0085] In this implementation, firstly, the first sub-correlation signal and the second sub-correlation signal are respectively subjected to coarse frequency deviation estimation processing to obtain the first coarse frequency deviation value and the first coarse starting position corresponding to the first local sampling level pilot, and the second coarse frequency deviation value and the second coarse starting position corresponding to the second local sampling level pilot; then the first coarse frequency deviation value and the second coarse frequency deviation value are compared to obtain the target pilot information, the target coarse frequency deviation value and the target coarse starting position; then the fine sliding range is determined according to the target coarse starting position to obtain the second received signal, which is the first received signal within the fine sliding range; finally, the second received signal is subjected to frequency deviation compensation according to the target coarse frequency deviation value to obtain the first level coarse capture signal. The use of two-segment pilots for coarse decision processing and determination of the fine sliding range can effectively solve the problem of stable communication when the received signal is incomplete and reduce the amount of calculation in the capture process.

[0086] The above-mentioned coarse frequency offset estimation processing of the first sub-correlation signal and the second sub-correlation signal respectively refers to the frequency offset estimation of the first sub-correlation signal and the second sub-correlation signal respectively. In this embodiment, the frequency domain frequency offset estimation method based on FFT is used to calculate the frequency offset value Δf 1i and its corresponding position d 1i , and calculate the second sub-correlation signal to calculate the frequency deviation value Δf 2i and its corresponding position d 1i and d 2i , i=1,2,...,L-L1.

[0087] The above-mentioned comparison of the first coarse frequency offset value and the second coarse frequency offset value to obtain the target pilot information, the target coarse frequency offset value and the target coarse starting position refers to processing the frequency offset value and the corresponding position calculated in the previous step, first finding the maximum frequency offset Δf estimated by the same pilot segment respectively. 1max and Δf 2max and its corresponding position d 1max and d 2max , and then compare Δf 1max and Δf 2max Find the maximum frequency deviation value Δf max and its corresponding position d max , frequency deviation value Δf max is Δf 1max and Δf 2max The larger one among the two, the pilot with the larger maximum frequency deviation is considered to have completed coarse synchronization, and the corresponding pilot number is identified.

[0088] If the pilot sequence number is 1, the target coarse frequency offset value is the first coarse frequency offset value, and the target coarse starting position is the first coarse starting position. At this time, the target coarse starting position, that is, the coarse starting position of the frame signal is d maxIf the pilot number is 2, the target coarse frequency offset value is the second coarse frequency offset value, and the target coarse starting position is the second coarse starting position. At this time, the target coarse starting position, that is, the coarse starting position of the frame signal is d max -Ns*(L1+L2).

[0089] Determining the fine sliding range according to the target coarse starting position to obtain the second received signal refers to determining the fine sliding range according to the target coarse starting position obtained in the above steps and the number of sampling points Ns for each symbol when the signal is sent, that is, the target coarse starting position is used as a reference, and Ns / 2 points are slid to the left and right of it respectively, that is, (Ns+1)*L sampling points of the received signal are intercepted for frequency offset compensation. This embodiment changes the signal capture from blind capture to capture within a certain small range by determining the fine sliding range, which can greatly reduce the amount of calculation in the implementation process, thereby reducing the consumption of hardware resources.

[0090] In some implementations, performing a coarse decision process on the first correlation signal, determining a coarse starting position, and obtaining a first-level coarse acquisition signal according to the coarse starting position may include:

[0091] Performing coarse frequency offset estimation processing on the first correlation signal to obtain a coarse frequency offset value and a coarse starting position corresponding to the local sampling level pilot;

[0092] Determine a fine sliding range according to the coarse starting position, and obtain a second received signal, where the second received signal is the first received signal within the fine sliding range;

[0093] The frequency offset of the second received signal is compensated according to the coarse frequency offset value to obtain a first-stage coarse capture signal.

[0094] In this implementation, the first correlation signal is first subjected to a coarse frequency offset estimation process to obtain a coarse frequency offset value and a coarse starting position corresponding to the local sampling level pilot; then a fine sliding range is determined according to the coarse starting position to obtain a second received signal, which is the first received signal within the fine sliding range; finally, the second received signal is subjected to frequency offset compensation according to the coarse frequency offset value to obtain a first level coarse capture signal. Using a section of pilot for coarse decision processing and determining a fine sliding range can reduce the amount of calculation in the capture process.

[0095] This implementation uses one segment of pilot to perform coarse decision processing and determine a fine sliding range. The working principle and process are similar to those of two segments. The two segments of pilot can be replaced by one segment, which will not be described in detail here.

[0096] In some implementations, performing fine decision processing on the second correlation signal to determine the fine starting position may include:

[0097] Performing differential accumulation on the second correlation signal to obtain a second correlation accumulation value;

[0098] Comparing the second correlation accumulated values ​​to obtain a peak position, where the peak position is a position corresponding to a maximum peak in the second correlation accumulated values;

[0099] The fine starting position is determined based on the peak position and the local sampling level pilot.

[0100] In this implementation, the second correlation signal is first differentially accumulated to obtain a second correlation accumulation value; then the second correlation accumulation value is compared to obtain a peak position, which is the position corresponding to the maximum peak in the second correlation accumulation value; finally, the fine start position is determined according to the peak position and the local sampling level pilot. This can eliminate the influence of random phase deviation and effectively reduce the influence of residual frequency deviation.

[0101] Specifically, the second correlation signal is differentially accumulated to obtain the second correlation cumulative value. The differential is to perform a cross product operation on adjacent points of L1 symbol-level correlation signals, that is, the second and the first conjugate multiplication, the third and the second conjugate multiplication, and so on. After the differential, a total of L1-1 differential signals are obtained, and then the real parts of these L1-1 differential signals are accumulated. The fine capture process can obtain Ns+1 cumulative values. The differential process can eliminate the influence of random phase deviation and effectively reduce the influence of residual frequency deviation.

[0102] The above-mentioned comparison of the second correlation accumulated values ​​to obtain the peak position means that the position d corresponding to the maximum peak is selected by comparing Ns+1 accumulated values. f .

[0103] The above-mentioned determination of the fine starting position based on the peak position and the local sampling level pilot means that the fine starting position of the frame signal can be determined by combining the target pilot information identified by the coarse decision. If the target pilot information is pilot 1, the fine starting position of the frame signal is d f If the target pilot signal is pilot 2, the fine start position of the frame signal is d f -Ns*(L1+L2).

[0104] It should be understood that after determining the fine starting position of the frame signal, extracting L symbols from the signal processed by matched filtering at corresponding position points completes frame signal interception, thereby completing signal capture.

[0105] In some implementations, performing symbol-level sliding correlation processing on the first-level coarse acquisition signal according to the local sampling-level pilot to obtain the second correlation signal may include:

[0106] Performing matched filtering on the first-stage coarse capture signal to obtain a matched filtered coarse capture signal;

[0107] The matched filtering coarse capture signal is subjected to symbol-level sliding correlation processing to obtain a second correlation signal.

[0108] In this embodiment, the first level coarse acquisition signal is firstly processed by matched filtering to obtain a matched filtered coarse acquisition signal, and then the matched filtered coarse acquisition signal is processed by symbol level sliding correlation to obtain a second correlation signal. Matched filtering can make the signal reach the best signal-to-noise ratio state.

[0109] It should be noted that symbol-level sliding correlation can also be called fine sliding correlation. If two-segment pilots are used, the pilot information identified by the coarse decision determines whether to use pilot 1 or pilot 2 to perform symbol-level sliding correlation on the matched filter coarse capture signal. If pilot 1 is used, fine sliding correlation is performed from the first point. If pilot 2 is used, symbol-level sliding correlation is performed from the Ns*(L1+L2)+1th point. The specific process is to slide the signal processed by the matched filter according to 1 sample signal each time, extract a sample every Ns sample points, and take L1 symbol-level signals to correlate with the local symbol-level pilot, and obtain L1 symbol-level correlation signals each time. The total number of sliding times for symbol-level sliding correlation is Ns+1 sample points.

[0110] The following is a flow chart of a specific embodiment of the present application. Figure 3 As shown, the basic process is that the received signal is captured in the first stage, then goes through matched filtering, and then enters the second stage of fine capture.

[0111] The first-level coarse capture process is as follows: first, the received sampling-level signal is correlated with the local sampling-level pilot 1 and the local sampling-level pilot 2 by sampling-level sliding correlation, and then the sampling-related information is frequency-biased estimated to obtain the identified pilot information, the estimated coarse frequency deviation value and the corresponding coarse synchronization position, and then the corresponding information is coarsely decided, and it is judged that one of the pilots has completed coarse synchronization based on the ratio of the two coarse frequency deviation values, and then the corresponding parameters are output, and the fine sliding range is determined based on the coarse synchronization position output by the coarse decision processing, and then the coarse frequency deviation value output by the coarse decision processing is used to compensate the received signal within the fine sliding range for frequency deviation, thus completing the first-level coarse capture.

[0112] The coarsely captured signal enters the matched filter and then undergoes secondary fine capture processing.

[0113] The secondary fine capture process is as follows: first, the signal after matched filtering is subjected to symbol-level sliding correlation according to the pilot information identified by the coarse decision processing in the coarse capture, and then enters the fine decision processing after differential accumulation. After determining the fine synchronization position, the frame signal is intercepted, and then the frame signal is subjected to carrier synchronization, demodulation and decoding processing.

[0114] Through the above two-stage acquisition scheme, a large Doppler frequency shift several times the symbol rate can be estimated, allowing the narrowband satellite communication system to maintain stable communication in a high dynamic environment and when there is partial loss of the received signal.

[0115] An embodiment of the present application also provides a narrowband satellite communication system, including a satellite and a ground receiver, wherein the ground receiver communicates with the satellite through the signal capture method for a high dynamic environment of the above embodiment.

[0116] The narrowband satellite communication system of the embodiment of the present application is used to execute the signal capture method for a high dynamic environment in the above embodiment. Its specific signal capture processing process is the same as the signal capture method for a high dynamic environment in the above embodiment, and will not be repeated here.

[0117] Based on the signal capture method for a high dynamic environment provided by the above embodiment, the present application also provides a specific implementation of a signal capture device for a high dynamic environment. Figure 5 As shown, a signal capture device 200 for a high dynamic environment includes:

[0118] The signal receiving module 201 is used to obtain a first received signal, where the first received signal is a sampling-level received signal;

[0119] A coarse correlation module 202, configured to perform a sampling-level sliding correlation process on the first received signal and a local sampling-level pilot to obtain a first correlation signal;

[0120] A coarse decision module 203, configured to perform coarse decision processing on the first correlation signal, determine a coarse starting position, and obtain a first-level coarse acquisition signal according to the coarse starting position;

[0121] A fine correlation module 204, configured to perform symbol-level sliding correlation processing on the first-level coarse acquisition signal according to a local sampling-level pilot to obtain a second correlation signal;

[0122] A fine decision module 205, configured to perform fine decision processing on the second correlation signal to determine a fine starting position;

[0123] The frame signal extraction module 206 is used to intercept the frame signal according to the fine starting position to obtain a second-level fine capture signal.

[0124] Specifically, refer to Figure 4 As shown, the signal capture device 200 for a high dynamic environment of the present application can be implemented by FPGA. The signal capture device 200 for a high dynamic environment of the present application is described in detail below based on a specific FPGA architecture, as follows:

[0125] The following modules are set up in FPGA: coarse correlation module (CCORR), frequency offset estimation module (FFE), coarse decision module (CDEC), fine search module (SRCH), data frequency offset compensation module (DFC), matched filter module (MF), fine correlation (FCORR), differential summation module (DSUM), fine decision module (FDEC), frame signal extraction module (EFS), among which the signal receiving module outputs the signal as the input of FPGA, including the in-phase component I_data_i, orthogonal component I_data_q and receiving data enable I_data_en of the received data, and the input of FPGA also includes reset signal rst and system clock clk. The specific working process of each module in FPGA is as follows:

[0126] Coarse correlation module (CCORR): This module performs coarse sliding correlation processing on the received signal; in the overall FPGA design architecture of the two-stage signal capture solution, this module slides the received signal according to Ns sample points each time, and takes Ns*L1 signal samples each time to correlate with the local sampling level pilot 1 and sampling level pilot 2, respectively, to obtain sampling level correlation signal 1 and sampling level correlation signal 2. When implemented in FPGA, Ns*L1 signal samples are taken from the received signal each time to correlate with the local sampling level pilot reg_pc1 and sampling level pilot reg_pc2, respectively, to obtain coarse correlation values ​​ccorr1_i, ccorr1_q and ccorr2_i, ccorr2_q; at the same time, the received signal is stored in a readable and writable register RAM_d1 for use by subsequent modules;

[0127] Frequency offset estimation module (FFE) based on FFT: This module completes the rough frequency offset estimation function; in the overall FPGA design architecture of the two-stage signal capture solution, the FFE module estimates the frequency offset of the two groups of data ccorr1_i, ccorr1_q and ccorr2_i, ccorr2_q after rough correlation, and obtains the estimated frequency offset values ​​and corresponding positions as freq1, idx1 and freq2, idx2 respectively;

[0128] Coarse decision module (CDEC): This module is used to obtain the frequency deviation value, the coarse starting position of the frame signal, and the pilot number information; in the FPGA implementation, this module processes the frequency deviation value and the corresponding position calculated by the previous module, finds the frequency deviation value through a multi-stage comparator (the number of comparator stages is related to the sliding length), finds the maximum frequency deviation value and its corresponding position information, marks the corresponding pilot number, and calculates the coarse position information of the frame signal through the pilot number information. The coarse decision module sends the coarse position information of the frame signal to the fine search (SRCH) module, and stores the frequency deviation value and pilot number information in the readable and writable register RAM_d2 for subsequent use by other modules;

[0129] Fine search module (SRCH): This module is used to change the signal capture from blind capture to capture within a certain small range, that is, to determine the fine sliding range; in the overall FPGA design architecture of the two-stage signal capture solution, SRCH takes the coarse position idx1 of the frame signal determined by the first frequency offset estimation as a reference, slides Ns / 2 points on its left and right, and determines the fine search range as [idx1-Ns / 2,idx1+Ns / 2];

[0130] Data frequency offset compensation module (DFC): This module completes the frequency offset compensation for signals within a limited range; in the overall FPGA design architecture of the two-stage signal capture solution, DFC uses the fine frequency offset value obtained by the second fine frequency offset estimation FFE module to compensate for the frequency offset of the frame signal extracted by the EFS module.

[0131] Matched filter module (MF): This module completes the matched filtering function of the signal after frequency offset compensation; in the FPGA implementation, the matched filter output signal is used for fine correlation processing on the one hand, and is stored in the readable and writable register RAM_d3 for use on the other hand;

[0132] Fine correlation module (FCORR): This module performs fine sliding correlation processing on the received signal; in the overall FPGA design architecture of the two-stage signal capture solution, this module determines whether to use pilot 1 or pilot 2 to perform fine sliding correlation on the signal output by the matched filter based on the pilot information identified by the coarse decision. If pilot 1 is used, fine sliding correlation is performed from the first point, and if pilot 2 is used, fine sliding correlation is performed from the Ns*(L1+L2)+1th point. In the FPGA implementation, the FCORR fine correlation takes out the received signal for fine sliding correlation from the register RAM_d1 according to the fine sliding range. The correlation process can determine whether to perform an inversion operation on the received signal based on whether the sequence value stored in the register reg_p1 (or reg_p2) is 0 or 1. This operation uses a ternary operator to complete the correlation processing on the received signal, and obtains fine correlation signals fcorr_i and fcorr_q;

[0133] Differential summation module (DSUM): This module performs differential and then accumulation operations on the fine correlation results. In the FPGA implementation, this module first completes the conjugate multiplication operation of two adjacent points of the fine correlation signals fcorr_i and fcorr_q, and then accumulates the real part of the conjugate multiplication result to obtain dsum_i.

[0134] Fine decision module (FDEC): This module is used to determine the fine starting position of the frame signal. In the FPGA implementation, this module uses several levels of comparators (the number of comparator levels is related to Ns) to find the maximum peak and its corresponding position, and combines the pilot information identified by the coarse decision to determine the fine starting position fidx of the frame signal.

[0135] Extraction frame signal module (EFS): This module completes the extraction of frame signals; in the FPGA implementation, this module extracts frame signals frm_i and frm_q from register RAM_d3 according to the frame structure based on the fine starting position fidx of the frame signal obtained by the fine decision module, which can be used for subsequent carrier synchronization and demodulation and decoding processing.

[0136] Figure 6 A schematic diagram of the hardware structure of an electronic device provided in an embodiment of the present application is shown.

[0137] The electronic device may include a processor 301 and a memory 302 storing computer program instructions.

[0138] Specifically, the processor 301 may include a central processing unit (CPU), or an application specific integrated circuit (ASIC), or may be configured to implement one or more integrated circuits of the embodiments of the present application.

[0139] The memory 302 may include a large capacity memory for data or instructions. By way of example and not limitation, the memory 302 may include a hard disk drive (HDD), a floppy disk drive, a flash memory, an optical disk, a magneto-optical disk, a magnetic tape, or a universal serial bus (USB) drive or a combination of two or more of these. In appropriate cases, the memory 302 may include a removable or non-removable (or fixed) medium. In appropriate cases, the memory 302 may be inside or outside the integrated gateway disaster recovery device. In a specific embodiment, the memory 302 is a non-volatile solid-state memory.

[0140] In some embodiments, the memory 302 may include a read-only memory (ROM), a random access memory (RAM), a magnetic disk storage medium device, an optical storage medium device, a flash memory device, an electrical, optical or other physical / tangible memory storage device. Thus, in general, the memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., a memory device) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the method according to an aspect of the present disclosure.

[0141] The processor 301 reads and executes the computer program instructions stored in the memory 302 to implement any one of the signal capture methods in a high dynamic environment in the above embodiments.

[0142] In one example, the electronic device may further include a communication interface 303 and a bus 310. Figure 3 As shown, the processor 301, the memory 302, and the communication interface 303 are connected via a bus 310 and communicate with each other.

[0143] The communication interface 303 is mainly used to implement communication between various modules, devices, units and / or equipment in the embodiments of the present application.

[0144] Bus 310 includes hardware, software or both, and the parts of online data flow billing equipment are coupled to each other. For example, but not limitation, bus may include accelerated graphics port (AGP) or other graphics bus, enhanced industrial standard architecture (EISA) bus, front-end bus (FSB), hypertransport (HT) interconnection, industrial standard architecture (ISA) bus, infinite bandwidth interconnection, low pin count (LPC) bus, memory bus, micro channel architecture (MCA) bus, peripheral component interconnection (PCI) bus, PCI-Express (PCI-X) bus, serial advanced technology attachment (SATA) bus, video electronics standard association local (VLB) bus or other suitable bus or two or more of these combinations. In appropriate cases, bus 310 may include one or more buses. Although the present application embodiment describes and shows a specific bus, the present application considers any suitable bus or interconnection.

[0145] In addition, in combination with the signal capture method for a high dynamic environment in the above embodiment, the embodiment of the present application can provide a computer storage medium for implementation. The computer storage medium stores computer program instructions; when the computer program instructions are executed by a processor, any one of the signal capture methods for a high dynamic environment in the above embodiment is implemented.

[0146] It should be clear that the present application is not limited to the specific configuration and processing described above and shown in the figures. For the sake of simplicity, a detailed description of the known method is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present application is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present application.

[0147] The functional blocks shown in the above-described block diagram can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, it can be, for example, an electronic circuit, an application specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, etc. When implemented in software, the elements of the present application are programs or code segments that are used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link by a data signal carried in a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, optical fiber media, radio frequency (RF) links, etc. The code segment can be downloaded via a computer network such as the Internet, an intranet, etc.

[0148] It should also be noted that the exemplary embodiments mentioned in this application describe some methods or systems based on a series of steps or devices. However, this application is not limited to the order of the above steps, that is, the steps can be performed in the order mentioned in the embodiment, or in a different order from the embodiment, or several steps can be performed simultaneously.

[0149] Aspects of the present disclosure are described above with reference to the flowchart and / or block diagram of the method, device (system) and computer program product according to the embodiment of the present disclosure. It should be understood that each box in the flowchart and / or block diagram and the combination of each box 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, or other programmable data processing device to produce a machine so that these instructions executed by the processor of the computer or other programmable data processing device enable the implementation of the function / action specified in one or more boxes of the flowchart and / or block diagram. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field programmable logic circuit. It can also be understood that each box in the block diagram and / or flowchart and the combination of boxes in the block diagram and / or flowchart can also be implemented by dedicated hardware that performs a specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions.

[0150] The above is only a specific implementation of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in this application, and these modifications or replacements should be included in the protection scope of this application.

Claims

1. A signal capture method for a high dynamic environment, characterized in that: The following steps are involved: Acquire a first received signal, where the first received signal is a sampling-level received signal; Performing sampling-level sliding correlation processing on the first received signal and the local sampling-level pilot to obtain a first correlation signal; Performing coarse decision processing on the first correlation signal to determine a coarse starting position, and obtaining a first-stage coarse acquisition signal according to the coarse starting position; Performing symbol-level sliding correlation processing on the first-level coarse acquisition signal and the local symbol-level pilot to obtain a second correlation signal; performing fine decision processing on the second correlation signal to determine a fine starting position; The frame signal is intercepted according to the fine starting position to obtain a second-level fine capture signal.

2. The signal capture method for a high dynamic environment according to claim 1, characterized in that: The local sampling level pilot includes a first local sampling level pilot and a second local sampling level pilot, and performing sampling level sliding correlation processing on the first received signal and the local sampling level pilot to obtain a first sampling correlation signal includes: Performing sampling-level sliding correlation processing on the first received signal and the first local sampling-level pilot to obtain a first sub-correlation signal; Performing sampling-level sliding correlation processing on the first received signal and the second local sampling-level pilot to obtain a second sub-correlation signal; A first correlation signal is obtained according to the first sub-correlation signal and the second sub-correlation signal, wherein the first correlation signal includes the first sub-correlation signal and the second sub-correlation signal.

3. The signal capture method for a high dynamic environment according to claim 2, characterized in that: The performing coarse decision processing on the first correlation signal to determine a coarse starting position, and obtaining a first-level coarse acquisition signal according to the coarse starting position, comprises: Performing coarse frequency offset estimation processing on the first sub-correlation signal and the second sub-correlation signal respectively to obtain a first coarse frequency offset value and a first coarse starting position corresponding to a first local sampling level pilot, and a second coarse frequency offset value and a second coarse starting position corresponding to a second local sampling level pilot; The first coarse frequency offset value and the second coarse frequency offset value are compared to obtain target pilot information, a target coarse frequency offset value and a target coarse starting position; the target pilot information is the first local sampling level pilot or the second local sampling level pilot for completing coarse synchronization; when the target pilot information is the first local sampling level pilot, the target coarse frequency offset value is the first coarse frequency offset value, and the target coarse starting position is the first coarse starting position; when the target pilot information is the second local sampling level pilot, the target coarse frequency offset value is the second coarse frequency offset value, and the target coarse starting position is the second coarse starting position; Determine a fine sliding range according to the target coarse starting position, and obtain a second received signal, where the second received signal is the first received signal within the fine sliding range; The second received signal is subjected to frequency offset compensation according to the target coarse frequency offset value to obtain a first-stage coarse acquisition signal.

4. The signal capture method in a high dynamic environment according to claim 1, characterized in that: The method of performing a coarse decision process on the first correlation signal to determine a coarse starting position and obtaining a first-level coarse acquisition signal according to the coarse starting position includes: Performing a coarse frequency offset estimation process on the first correlation signal to obtain a coarse frequency offset value and a coarse starting position corresponding to the local sampling level pilot; Determine a fine sliding range according to the coarse starting position, and obtain a second received signal, where the second received signal is the first received signal within the fine sliding range; Frequency offset compensation is performed on the second received signal according to the coarse frequency offset value to obtain a first-stage coarse capture signal.

5. The signal capture method in a high dynamic environment according to claim 1, characterized in that: The performing fine decision processing on the second correlation signal to determine a fine starting position includes: performing differential accumulation on the second correlation signal to obtain a second correlation accumulation value; Comparing the second correlation accumulated values ​​to obtain a peak position, where the peak position is a position corresponding to a maximum peak in the second correlation accumulated values; A fine starting position is determined according to the peak position and the local sampling level pilot.

6. The signal capture method in a high dynamic environment according to claim 1, characterized in that: The performing symbol-level sliding correlation processing on the first-level coarse acquisition signal and the local symbol-level pilot to obtain a second correlation signal includes: Performing matched filtering on the first-stage coarse acquisition signal to obtain a matched filtered coarse acquisition signal; A symbol-level sliding correlation process is performed on the matched filtered coarse acquisition signal and the local symbol-level pilot to obtain a second correlation signal.

7. A narrowband satellite communication system, characterized in that: It comprises a satellite and a ground receiver, wherein the ground receiver communicates with the satellite through the signal acquisition method for a high dynamic environment according to any one of claims 1 to 6.

8. A signal capture device for a high dynamic environment, characterized in that: include: A signal receiving module, used to obtain a first received signal, where the first received signal is a sampling-level received signal; a coarse correlation module, configured to perform sampling-level sliding correlation processing on the first received signal and a local sampling-level pilot to obtain a first correlation signal; A coarse decision module, used for performing coarse decision processing on the first correlation signal, determining a coarse starting position, and obtaining a first-level coarse acquisition signal according to the coarse starting position; A fine correlation module, configured to perform symbol-level sliding correlation processing on the first-level coarse acquisition signal according to a local sampling-level pilot to obtain a second correlation signal; A fine decision module, used for performing fine decision processing on the second correlation signal to determine a fine starting position; The frame signal extraction module is used to intercept the frame signal according to the fine starting position to obtain the second-level fine capture signal.

9. An electronic device, characterized in that: The device comprises: a processor and a memory storing computer program instructions; When the processor executes the computer program instructions, the signal capture method for a high dynamic environment as described in any one of claims 1 to 6 is implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer program instructions, and when the computer program instructions are executed by a processor, the signal capture method for a high dynamic environment as described in any one of claims 1 to 6 is implemented.

Images