Signal acquisition method, system, apparatus, device, and medium in high dynamic environment

Abstract

The application discloses a signal capturing method, system, device, equipment and medium in a high dynamic environment, and the method comprises the following steps: acquiring a first receiving signal; performing sampling stage sliding correlation processing on the first receiving signal and a local sampling stage 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 capturing signal according to the coarse starting position; performing symbol stage sliding correlation processing on the first-stage coarse capturing signal and a local symbol stage pilot to obtain a second correlation signal; performing fine decision processing on the second correlation signal to determine a fine starting position; and performing frame signal interception according to the fine starting position to obtain a second-stage fine capturing signal. The application can enable a narrowband satellite communication system to maintain 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 ground receivers causes Doppler frequency shifts of up to tens or even hundreds of kHz. This causes narrowband satellite communication systems to operate in highly dynamic environments, severely impacting communication quality and even rendering signal acquisition impossible. Therefore, accurately estimating Doppler frequency shift is crucial for signal reception. Furthermore, in narrowband satellite communication systems, signal acquisition may be disrupted due to uncertainties in the timing of signal transmission and reception. Summary of the Invention

[0003] The present application aims to propose a signal capture method, system, device, equipment and medium for 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 method for capturing signals 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 a 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-stage 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 the 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-related 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, where 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, determining a coarse starting position, and obtaining a first-stage 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] Comparing the first coarse frequency offset value and the second coarse frequency offset value 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] determining a fine sliding range according to the target coarse starting position, and obtaining a second received signal, where the second received signal is the first received signal within the fine sliding range;

[0019] Frequency offset compensation is performed on the second received signal 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-stage coarse acquisition signal according to the coarse starting position includes:

[0021] 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;

[0022] determining a fine sliding range according to the coarse starting position, and obtaining 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 acquisition 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-stage 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, comprising a satellite and a ground receiver, wherein the ground receiver communicates with the satellite through the signal capture method for a high dynamic environment as described in the first aspect.

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

[0033] A signal receiving module, configured 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, configured to perform coarse decision processing on the first correlation signal, determine a coarse starting position, and obtain a first-stage 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, configured to perform fine decision processing on the second correlation signal to determine a fine starting position;

[0038] extracting a frame signal module, configured to extract a frame signal according to the fine start position, to obtain a 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] The processor executes the computer program instructions to implement the signal capture method in a high dynamic environment as described in the first aspect.

[0041] In a fourth aspect, an embodiment of the present application provides a computer readable storage medium, the computer readable storage medium storing computer program instructions, the computer program instructions being executed by a processor to implement the signal capture method in a high dynamic environment as described in the first aspect.

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

[0043] Advantages:

[0044] In the embodiments of the present application, first, a first received signal is acquired; then, a first correlation signal is obtained by performing a sampling stage sliding correlation processing on the first received signal and a local sampling stage pilot; then, a coarse start position is determined by performing a coarse decision processing on the first correlation signal, and a first-level coarse capture signal is obtained according to the coarse start position; then, a second correlation signal is obtained by performing a symbol stage sliding correlation processing on the first-level coarse capture signal according to the local sampling stage pilot; then, a fine start position is determined by performing a fine decision processing on the second correlation signal; finally, a second-level fine capture signal is obtained by extracting a frame signal according to the fine start position. 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 shift multiple times of a symbol rate, so that a narrowband satellite communication system can maintain stable communication in a high dynamic environment.

[0045] Additional aspects and advantages of the present application will be partially given in the following description, partially will become obvious from the following description, or will be understood by practicing the present application. BRIEF DESCRIPTION OF DRAWINGS

[0046] The present application will be further described below in combination with the drawings and embodiments, in which:

[0047] Figure 1 A flowchart of an embodiment of the signal capture method in a high dynamic environment provided by the present application is shown in the figure;

[0048] Figure 2This is a schematic diagram of the physical layer data frame structure in satellite communications in related technologies.

[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 Schematic diagram of the FPGA implementation architecture of the signal capture method for high dynamic environments provided by this application;

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

[0052] Figure 6 This is 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 merely to provide a better understanding of the present application by illustrating the examples of the present application.

[0054] In this document, 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 "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or device comprising 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.

[0056] Figure 1A flow chart of a method for capturing signals in a high-dynamic environment provided by an embodiment of the present application is shown. A method for capturing signals 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 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;

[0060] S104, performing symbol-level sliding correlation processing on the first-stage 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 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. It 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 highly 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 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. Typically, the physical layer data frame structure of a narrowband satellite communication system primarily consists of a pilot and data, and the pilot is used for signal acquisition. The local sampling-level pilot can consist of one or two segments. The sampling-level sliding correlation process is also called a coarse sliding correlation process.

[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, where L1 is the pilot length and Ns is the number of sampling points per symbol.

[0067] In the above step S103, the first correlation signal is subjected to coarse decision processing to determine the coarse starting position, and a first-level coarse capture signal is obtained based on the coarse starting position. This refers to identifying the signal after the sampling-level sliding correlation in step S102 to obtain the coarse starting position of the frame signal. The 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 the first-level coarse capture signal.

[0068] In step S104, performing symbol-level sliding correlation processing on the first-stage coarse acquisition signal and the local symbol-level pilot to obtain the second correlation signal refers to performing fine sliding correlation on the first-stage coarse acquisition signal. The specific process of fine sliding correlation is to slide the matched filtered signal by one sample signal at a time, extracting a sample every Ns samples, and obtain L1 symbol-level signals to correlate with the local symbol-level pilot, each time obtaining L1 symbol-level correlation signals. The total number of sliding times for fine sliding correlation is Ns + 1 samples.

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

[0070] S106. The frame signal is intercepted according to the fine starting position to obtain a second-level fine capture signal. This 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 this application, steps S101-S103 achieve first-level coarse capture, and steps S104-S106 achieve second-level fine capture. First-level coarse capture, or blind signal capture, primarily aims to locate the coarse starting position of the frame signal in the received signal and thereby determine the sliding range for second-level fine capture. Second-level fine capture, or explicit capture, primarily aims to locate the fine starting position of the frame signal and thereby complete signal capture. Subsequent processing can include carrier synchronization, demodulation, and decoding of the captured frame signal.

[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, where the first correlation signal includes the first sub-correlation signal and the second sub-correlation signal.

[0076] In this embodiment, two pilot segments 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 a frame signal is L, that is, L symbols, where 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 refers to performing coarse sliding correlation processing on the first received signal. The coarse sliding correlation process slides the received signal according to Ns sample 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, i.e., a first correlation signal. The total number of sliding times of coarse sliding correlation is at least Ns*L-Ns*L2. In this 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. 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. Assume that 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 segments for correlation processing can effectively solve the problem of stable communication when the received signal is incomplete.

[0080] In some embodiments, performing coarse decision processing on the first correlation signal, determining a coarse starting position, and obtaining a first-stage 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] Comparing the first coarse frequency offset value with the second coarse frequency offset value 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;

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

[0085] In this embodiment, a coarse frequency offset estimation process is first performed 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. The first coarse frequency offset value and the second coarse frequency offset value are then compared to obtain target pilot information, a target coarse frequency offset value, and a target coarse starting position. A fine sliding range is then determined based on the target coarse starting position to obtain a second received signal, which is the first received signal within the fine sliding range. Finally, frequency offset compensation is performed on the second received signal based on the target coarse frequency offset value to obtain a first-level coarse capture signal. Using two pilots for coarse decision processing and determining the fine sliding range can effectively solve the problem of stable communication when the received signal is incomplete and reduce the amount of computation required during the capture process.

[0086] The above-mentioned coarse frequency offset estimation processing of the first sub-correlation signal and the second sub-correlation signal 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 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, find the maximum frequency offset Δf estimated by the same pilot segment. 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 them, 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 a fine sliding range based on the target coarse starting position to obtain a second received signal involves determining the fine sliding range based on the target coarse starting position obtained in the above steps and the number of sampling points per symbol during signal transmission, Ns. Specifically, the target coarse starting position is used as a reference, and Ns / 2 points are slid to the left and right of the target coarse starting position, respectively, to extract (Ns+1)*L samples from the received signal for frequency offset compensation. By determining the fine sliding range, this embodiment transforms blind signal acquisition into acquisition within a defined, small range, significantly reducing the computational complexity during implementation and, consequently, hardware resource consumption.

[0090] In some embodiments, performing coarse decision processing on the first correlation signal, determining a coarse starting position, and obtaining a first-stage 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] 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.

[0094] In this implementation, a coarse frequency offset estimation process is first performed on the first correlation signal to obtain a coarse frequency offset value and a coarse starting position corresponding to the local sampling-level pilot. A fine sliding range is then determined based on the coarse starting position to obtain a second received signal, which corresponds to the first received signal within the fine sliding range. Finally, frequency offset compensation is performed on the second received signal based on the coarse frequency offset value to obtain a first-stage coarse acquisition signal. Using a pilot segment for coarse decision-making and determining the fine sliding range reduces the computational complexity during acquisition.

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

[0096] In some embodiments, 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 cumulative value. These second correlation cumulative values ​​are then compared to determine the peak position, which corresponds to the location of the maximum peak value in the second correlation cumulative values. Finally, the fine start position is determined based on the peak position and the local sampling-level pilot signal. This eliminates the effects of random phase offset and effectively reduces the effects of residual frequency offset.

[0101] Specifically, the second correlation signal is differentially accumulated to obtain a second correlation cumulative value. Differentiation involves performing a cross product operation on adjacent points of L1 symbol-level correlation signals. This involves conjugating the second and first points, the third and second points, and so on. After differentiation, a total of L1-1 differential signals are obtained. The real parts of these L1-1 differential signals are then accumulated, resulting in Ns+1 cumulative values ​​in the fine capture process. This differentiation process eliminates the influence of random phase offset and effectively reduces the impact of residual frequency offset.

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

[0103] The above method of determining 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 starting position of the frame signal is d f -Ns*(L1+L2).

[0104] It should be understood that after determining the starting position of the frame signal, L symbols are extracted from the signal processed by matched filtering at corresponding positions to complete the frame signal interception, thereby completing the signal capture.

[0105] In some implementations, performing symbol-level sliding correlation processing on the first-stage 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 acquisition signal to obtain a matched filtered coarse acquisition signal;

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

[0108] In this embodiment, the first-stage coarse acquisition signal is first subjected to matched filtering to obtain a matched filtered coarse acquisition signal, and then the matched filtered coarse acquisition signal is subjected to symbol-level sliding correlation processing to obtain a second correlation signal. Matched filtering can achieve the best signal-to-noise ratio.

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

[0110] The following is a flow chart of a specific embodiment of the present application. Figure 3 As shown in the figure, the basic process is that the received signal undergoes a first-stage coarse capture, then a matched filter, and then enters a second-stage 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 at the sampling-level sliding, and then the sampling-related information is frequency offset estimated to obtain the identified pilot information, the estimated coarse frequency offset value and the corresponding coarse synchronization position respectively, and then the corresponding information is subjected to coarse decision processing. According to the ratio of the two coarse frequency offset values, it is judged that one of the pilots has completed coarse synchronization, and then the corresponding parameters are output. The fine sliding range is determined according to the coarse synchronization position output by the coarse decision processing, and then the coarse frequency offset value output by the coarse decision processing is used to compensate the received signal within the fine sliding range for frequency offset, 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 based on 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.

[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 highly dynamic environment and when there is partial loss of the received signal.

[0115] An embodiment of the present application further 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 configured 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 is configured to perform coarse decision processing on the first correlation signal, determine a coarse starting position, and obtain a first-stage coarse acquisition signal according to the coarse starting position;

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

[0122] A fine decision module 205 is 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 FPGA is equipped with the following modules: 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), and frame signal extraction module (EFS). The signal output by the signal receiving module serves as the input of the FPGA, including the in-phase component I_data_i, the orthogonal component I_data_q, and the receive data enable I_data_en of the received data. The FPGA input also includes the reset signal rst and the system clock clk. The specific working process of each module in the 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, taking Ns*L1 signal samples each time and correlating them 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 on the FPGA, Ns*L1 signal samples are taken from the received signal each time and correlated 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, respectively. At the same time, the received signal is stored in a readable and writable register RAM_d1 for use by subsequent modules.

[0127] FFT-based frequency offset estimation module (FFE): This module performs coarse frequency offset estimation. In the overall FPGA design architecture of the two-stage signal capture solution, the FFE module performs frequency offset estimation on the two sets of data after coarse correlation, ccorr1_i, ccorr1_q, and ccorr2_i, ccorr2_q. The estimated frequency offset values ​​and corresponding positions are 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 sequence number information. In the FPGA implementation, this module processes the frequency deviation value and corresponding position calculated by the previous module, finds the maximum frequency deviation value and its corresponding position information through a multi-stage comparator (the number of comparator stages is related to the sliding length), marks the corresponding pilot sequence number, and calculates the coarse position information of the frame signal based on the pilot sequence 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 sequence number information in the read-write register RAM_d2 for subsequent use by other modules.

[0129] Fine Search Module (SRCH): This module transforms blind signal acquisition into acquisition within a defined, small range, defining a fine sliding range. In the overall FPGA design architecture of the two-stage signal acquisition solution, the SRCH uses the frame signal's coarse position idx1, determined by the first frequency offset estimation, as a reference. It slides Ns / 2 points to the left and right of the coarse position, respectively, to define a fine search range of [idx1-Ns / 2, idx1+Ns / 2].

[0130] Data Frequency Offset Compensation (DFC): This module compensates for frequency offsets within a limited range of signals. In the overall FPGA design architecture of the two-stage signal capture solution, the 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 performs matched filtering on the signal after frequency offset compensation. In the FPGA implementation, the output signal of the matched filter is used for fine correlation processing and is stored in the read-write register RAM_d3 for future use.

[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 starting from the first point. If pilot 2 is used, fine sliding correlation is performed starting from the Ns*(L1+L2)+1th point. In the FPGA implementation, the FCORR fine correlation retrieves the received signal for fine sliding correlation from register RAM_d1 based on 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 register reg_p1 (or reg_p2) is 0 or 1. This operation uses a ternary operator on the received signal to complete the correlation processing, obtaining fine correlation signals fcorr_i and fcorr_q.

[0133] Differential summation module (DSUM): This module performs differential and cumulative operations on the fine correlation results. In the FPGA implementation, this module first performs a conjugate multiplication operation on 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 stages of comparators (the number of comparator stages is related to Ns) to find the maximum peak and its corresponding position. Combined with the pilot information identified by the coarse decision, the fine starting position fidx of the frame signal can be determined.

[0135] Extraction frame signal module (EFS): This module completes the extraction of frame signals. In the FPGA implementation, this module extracts the 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. Where appropriate, the memory 302 may include removable or non-removable (or fixed) media. Where appropriate, 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 read-only memory (ROM), random access memory (RAM), magnetic disk storage media devices, optical storage media devices, flash memory devices, electrical, optical, or other physical / tangible memory storage devices. Thus, generally, the memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., memory devices) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the method according to an aspect of the present disclosure.

[0141] The processor 301 reads and executes 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 can further include a communication interface 303 and a bus 310. As shown in Figure 3 the processor 301, the memory 302, and the communication interface 303 are connected through the bus 310 and complete communication therebetween.

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

[0144] The bus 310 includes hardware, software or both to couple components of the online data traffic billing device to each other in a known manner. By way of example, and not limitation, the bus can include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), a HyperTransport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an InfiniBand interconnect, a Low Pin Count (LPC) bus, a memory bus, a Micro Channel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association local (VLB) bus, or another suitable bus or a combination of two or more of these. Where suitable, the bus 310 can include one or more buses. Although particular buses are described and shown in the embodiments of the present application, the present application contemplates any suitable bus or interconnect.

[0145] In addition, in combination with the signal capturing method in the high dynamic environment in the above-described embodiments, the embodiments of the present application can provide a computer storage medium to implement. The computer storage medium has computer program instructions stored thereon; the computer program instructions are executed by a processor to implement any one of the signal capturing methods in the high dynamic environment in the above-described embodiments.

[0146] It needs to be clear that the present application is not limited to the specific configurations and processes described above and shown in the drawings. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above-described embodiments, several specific steps are described and shown as examples. However, the method processes of the present application are 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 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, they can be, for example, electronic circuits, application specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of 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 that can store or transmit information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROMs, flash memories, erasable ROMs (EROMs), 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. In other words, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0149] Aspects of the present disclosure have been described above 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 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 is also understood that each box in the block diagram and / or flowchart and the combination of the boxes in the block diagram and / or flowchart can also be implemented by dedicated hardware that performs the specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions.

[0150] The above description is only a specific embodiment of the present application. Those skilled in the art will clearly understand that for the convenience and brevity 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 scope of protection of the present application is not limited thereto. Any person skilled in the art can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the scope of protection of the present 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 a 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-stage 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; Intercepting the frame signal according to the fine starting position to obtain a second-level fine capture signal; 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 correlation signal to obtain a coarse frequency offset value and a coarse starting position corresponding to the local sampling-level pilot; determining a fine sliding range according to the coarse starting position, and obtaining 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 acquisition 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-related 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, where 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-stage coarse acquisition signal according to the coarse starting position, includes: 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; Comparing the first coarse frequency offset value and the second coarse frequency offset value 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; determining a fine sliding range according to the target coarse starting position, and obtaining 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 target coarse frequency offset value to obtain a first-stage coarse acquisition signal.

4. The signal capture method for a high dynamic environment according to claim 1, characterized in that: The performing fine decision processing on the second correlation signal to determine the 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.

5. The signal capture method for 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.

6. A narrowband satellite communication system, characterized in that: The method 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 5.

7. A signal capture device for a high dynamic environment, characterized in that: include: A signal receiving module, configured 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, configured to perform coarse decision processing on the first correlation signal, determine a coarse starting position, and obtain a first-level coarse acquisition signal based on the coarse starting position; the coarse decision processing on the first correlation signal, determining a coarse starting position, and obtaining the first-level coarse acquisition signal based on the coarse starting position comprising: 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; determining a fine sliding range based on the coarse starting position to obtain a second received signal, the second received signal being the first received signal within the fine sliding range; and performing frequency offset compensation on the second received signal based on the coarse frequency offset value to obtain the first-level coarse acquisition signal; 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, configured to perform 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.

8. An electronic device, characterized in that: The device includes: 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 according to any one of claims 1 to 5 is implemented.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer program instructions, which, when executed by a processor, implement the signal capture method for a high-dynamic environment according to any one of claims 1 to 5.

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