Satellite orthogonal frequency division multiplexing signal burst frame detection method, device, equipment and medium

Abstract

The application provides a satellite orthogonal frequency division multiplexing signal burst frame detection method, device, equipment and medium, which can be applied to the technical field of signal processing. The method comprises: performing sampling processing on the received satellite orthogonal frequency division multiplexing signal to obtain a discrete orthogonal frequency division multiplexing signal; based on a preset sampling rate, a plurality of first data segments and a plurality of second data segments are extracted from the discrete orthogonal frequency division multiplexing signal, the first data segment comprises a cyclic identifier and at least one repeated sequence associated with the cyclic identifier, and the second data segment comprises a remaining repeated sequence except the at least one repeated sequence and a middle identifier; for any cyclic identifier in the plurality of cyclic identifiers, inner product processing is performed on the first data segment and the second data segment associated with any cyclic identifier to obtain the similarity of the first data segment and the second data segment; and in response to the similarity being greater than a preset similarity threshold, it is determined that the satellite orthogonal frequency division multiplexing signal comprises at least one burst frame.

Description

Technical Field

[0001] This application relates to the field of signal processing technology, and more specifically to a method, apparatus, device and medium for burst frame detection of satellite orthogonal frequency division multiplexing signals. Background Technology

[0002] With the rapid development of satellite internet, low-Earth orbit satellite constellations, represented by Starlink, are being constructed at an accelerated pace, aiming to form a space network capability with full coverage and high throughput. In the field of satellite communication reconnaissance, reliable and efficient burst frame detection is the starting point and main link of the entire signal processing flow. However, the detection accuracy of energy detection methods based on incoherent detection and detection methods based on unique words or synchronization sequences based on coherent detection is relatively low. Summary of the Invention

[0003] In view of the above problems, this application provides a method, apparatus, device, medium and program product for burst frame detection of satellite orthogonal frequency division multiplexing signals.

[0004] According to a first aspect of this application, a method for burst frame detection of a satellite orthogonal frequency division multiplexing (OFDM) signal is provided, comprising: sampling a received satellite OFDM signal to obtain a discrete OFDM signal, wherein the discrete OFDM signal includes multiple sequences consisting of a cyclic identifier and multiple repeating sequences; extracting multiple first data segments and multiple second data segments from the discrete OFDM signal based on a preset sampling rate, wherein the first data segment includes a cyclic identifier and at least one repeating sequence associated with the cyclic identifier, and the second data segment includes the remaining repeating sequences excluding the at least one repeating sequence and an intermediate identifier, wherein the intermediate identifier is determined based on the repeating sequences; performing inner product processing on the first data segment and the second data segment associated with any cyclic identifier among the multiple cyclic identifiers to obtain a similarity between the first data segment and the second data segment; and determining that the satellite OFDM signal includes at least one burst frame in response to a similarity greater than a preset similarity threshold.

[0005] A second aspect of this application provides a burst frame detection device for satellite orthogonal frequency division multiplexing (OFDM) signals, comprising: a sampling module for sampling a received satellite OFDM signal to obtain a discrete OFDM signal, wherein the discrete OFDM signal includes multiple sequences consisting of a cyclic identifier and multiple repeating sequences; an extraction module for extracting multiple first data segments and multiple second data segments from the discrete OFDM signal based on a preset sampling rate, wherein the first data segment includes a cyclic identifier and at least one repeating sequence associated with the cyclic identifier, and the second data segment includes a remaining repeating sequence excluding the at least one repeating sequence and an intermediate identifier, wherein the intermediate identifier is determined based on the repeating sequence; a obtaining module for performing inner product processing on the first data segment and the second data segment associated with any cyclic identifier among the multiple cyclic identifiers to obtain a similarity between the first data segment and the second data segment; and a first determining module for determining that the satellite OFDM signal includes at least one burst frame in response to a similarity greater than a preset similarity threshold.

[0006] A third aspect of this application provides an electronic device comprising: one or more processors; and a memory for storing one or more computer programs, wherein the one or more processors execute the one or more computer programs to implement the steps of the method described above.

[0007] A fourth aspect of this application also provides a computer-readable storage medium having a computer program or instructions stored thereon, which, when executed by a processor, implement the steps of the above-described method.

[0008] The fifth aspect of this application also provides a computer program product, including a computer program or instructions that, when executed by a processor, implement the steps of the above-described method.

[0009] According to the burst frame detection method for satellite orthogonal frequency division multiplexing (OFDM) signals provided in this application, a discrete OFDM signal can be obtained by sampling the satellite OFDM signal. Then, based on a preset sampling rate, a first data segment including a cycle identifier and at least one repeating sequence associated with the cycle identifier, and a second data segment including the remaining repeating sequences other than the at least one repeating sequence and an intermediate identifier are extracted from the discrete OFDM signal. Then, for any cycle identifier, the inner product of the first data segment and the second data segment associated with any cycle identifier is performed to obtain the similarity between the first data segment and the second data segment. The similarity is then compared with a preset similarity threshold. If the similarity is greater than the preset similarity threshold, it can be determined that the satellite OFDM signal includes at least one burst frame. Since data extraction is based on a preset sampling rate, there are no restrictions on the sampling method for discretizing the received satellite orthogonal frequency division multiplexing (OFDM) signal, making the sampling method more flexible. Furthermore, since it is not necessary to know the specific values ​​of the satellite OFDM signal, burst frame detection can be completed simply by knowing the frame structure of the satellite OFDM signal. In other words, it is not sensitive to changes in the values ​​of the satellite OFDM signal and has lower requirements for prior information, thereby improving the detection accuracy of burst frames. Attached Figure Description

[0010] The above-mentioned contents, other objects, features and advantages of this application will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0011] Figure 1 This illustration schematically depicts an application scenario of a burst frame detection method for satellite orthogonal frequency division multiplexing signals according to an embodiment of this application.

[0012] Figure 2 A flowchart illustrating a burst frame detection method for satellite orthogonal frequency division multiplexing signals according to an embodiment of this application is shown schematically.

[0013] Figure 3A A time-domain diagram of a discrete orthogonal frequency division multiplexed signal according to an embodiment of this application is illustrated schematically.

[0014] Figure 3B A spectral analysis diagram of a discrete orthogonal frequency division multiplexed signal according to an embodiment of this application is illustrated schematically.

[0015] Figure 4 This illustration schematically shows a diagram where the start point of the burst frame detector according to an embodiment of the present application is aligned with the start point of the discrete orthogonal frequency division multiplexing signal;

[0016] Figure 5 A schematic diagram illustrating similarity curves according to embodiments of this application is shown.

[0017] Figure 6A flowchart illustrating a burst frame detection method for satellite orthogonal frequency division multiplexing signals according to yet another embodiment of this application is shown.

[0018] Figure 7 This schematically illustrates a structural block diagram of a burst frame detection apparatus for satellite orthogonal frequency division multiplexing signals according to an embodiment of this application; and

[0019] Figure 8 A block diagram schematically illustrates an electronic device suitable for implementing a burst frame detection method for satellite orthogonal frequency division multiplexing signals according to an embodiment of this application. Detailed Implementation

[0020] The embodiments of this application will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of this application. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of this application for ease of explanation. However, it will be apparent that one or more embodiments may be implemented without these specific details. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concepts of this application.

[0021] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0022] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0023] When using expressions such as "at least one of A, B and C", they should generally be interpreted in accordance with the meaning that is commonly understood by those skilled in the art (e.g., "a system having at least one of A, B and C" should include, but is not limited to, a system having A alone, a system having B alone, a system having C alone, a system having A and B, a system having A and C, a system having B and C, and / or a system having A, B and C, etc.).

[0024] Currently, satellite internet development is booming, with low-Earth orbit satellite constellations, represented by Starlink, being rapidly constructed to achieve full-coverage, high-throughput space network capabilities. In the field of satellite communication reconnaissance, reliable and efficient burst signal detection is the starting point and fundamental link in the entire signal processing flow. It bears the primary task of accurately identifying and capturing target signals from complex electromagnetic environments, and its detection performance determines the feasibility of subsequent demodulation, analysis, and other operations, making it a crucial first step in the entire reconnaissance link. Currently, emerging satellite internet systems, to cope with high throughput and dynamic service demands, have widely adopted Orthogonal Frequency-Division Multiplexing (OFDM) as their core physical layer transmission system. Therefore, research on detection technologies for OFDM-based satellite communication signals is of significant practical importance for achieving effective surveillance and spectrum management of modern satellite internet.

[0025] In non-cooperative satellite communication signal reconnaissance, burst frame detection is a prerequisite for signal interception and analysis. Related technologies primarily employ incoherent and coherent detection methods. Incoherent detection can include energy-based methods, which detect the presence of a signal by detecting a sharp increase in received signal power. This method requires no prior information, is simple to implement, has low computational complexity, and is applicable to various modulated signals. For example, the Tong's Detector (or Energy Double Window Detector) calculates signal energy by sliding a front window and a rear window, and makes a decision based on the statistical characteristics of the energy ratio between the front and rear windows. It is robust under good signal-to-noise ratio (SNR) conditions. However, energy detection methods have poor noise and interference resistance. Under low SNR conditions, noise fluctuations easily lead to false alarms or missed detections, making it difficult to distinguish signal types, and its ability to differentiate between continuous and burst signals is also weak. Coherent detection can include methods based on unique words or synchronization sequences. Many satellite communication standards define specific, known synchronization sequences or unique words in the burst frame structure. This method detects the signal by calculating the cross-correlation between the received signal and a locally stored known sequence, or by employing a Generalized Likelihood Ratio Test (GLRT) framework, utilizing the sharpness of the correlation peak. This method maintains a high detection probability even at low signal-to-noise ratios and achieves accurate symbol timing synchronization. In practical systems, such as when reconnaissance of satellite signals from the DVB-S2 standard, the physical layer frame header contains a fixed 26-symbol physical layer signaling field, which is a known sequence used for synchronization and detection. This method requires the reconnaissance party to know the target signal's synchronization sequence pattern in advance, and its computational complexity is relatively high.

[0026] Therefore, energy detection methods based on incoherent detection suffer from poor noise and interference resistance, and low accuracy in burst detection and burst origin localization. Coherent detection methods based on unique words require prior knowledge of the unique word of the signal to be effective, making them ineffective for blind processing of signals from unknown communication systems and unsuitable for processing communication signals with dynamically changing unique words. Therefore, there is an urgent need for a burst frame detection method that can achieve high accuracy without requiring prior knowledge of the unique word of the signal.

[0027] In view of this, embodiments of this application provide a burst frame detection method for satellite orthogonal frequency division multiplexing (OFDM) signals, comprising: sampling the received satellite OFDM signal to obtain a discrete OFDM signal, wherein the discrete OFDM signal includes multiple sequences composed of a cyclic identifier and multiple repeating sequences; extracting multiple first data segments and multiple second data segments from the discrete OFDM signal based on a preset sampling rate, wherein the first data segment includes a cyclic identifier and at least one repeating sequence associated with the cyclic identifier, and the second data segment includes the remaining repeating sequences excluding the at least one repeating sequence and an intermediate identifier, wherein the intermediate identifier is determined based on the repeating sequences; performing inner product processing on the first data segment and the second data segment associated with any cyclic identifier among the multiple cyclic identifiers to obtain a similarity between the first data segment and the second data segment; and determining that the satellite OFDM signal includes at least one burst frame in response to a similarity greater than a preset similarity threshold.

[0028] Figure 1 The illustration shows an application scenario of the burst frame detection method for satellite orthogonal frequency division multiplexing signals according to an embodiment of this application.

[0029] like Figure 1 As shown, application scenario 100 according to this embodiment may include a first terminal device 101, a second terminal device 102, a third terminal device 103, a network 104, and a server 105. The network 104 serves as a medium for providing a communication link between the first terminal device 101, the second terminal device 102, the third terminal device 103, and the server 105. The network 104 may include various connection types, such as wired or wireless communication links, or fiber optic cables, etc.

[0030] Users can use the first terminal device 101, the second terminal device 102, and the third terminal device 103 to interact with the server 105 via the network 104 to receive or send messages, etc. Various communication client applications can be installed on the first terminal device 101, the second terminal device 102, and the third terminal device 103, such as shopping applications, web browser applications, search applications, instant messaging tools, email clients, social media platform software, etc. (for example only).

[0031] The first terminal device 101, the second terminal device 102, and the third terminal device 103 can be various electronic devices with displays and support web browsing, including but not limited to smartphones, tablets, laptops, and desktop computers.

[0032] Server 105 can be a server that provides various services, such as a backend management server that supports websites browsed by users using the first terminal device 101, the second terminal device 102, and the third terminal device 103 (this is just an example). The backend management server can analyze and process data such as received user requests, and feed back the processing results (such as web pages, information, or data obtained or generated according to user requests) to the terminal devices.

[0033] It should be noted that the burst frame detection method for satellite orthogonal frequency division multiplexing (OFDM) signals provided in this application embodiment can generally be executed by server 105. Correspondingly, the burst frame detection device for satellite OFDM signals provided in this application embodiment can generally be located in server 105. The burst frame detection method for satellite OFDM signals provided in this application embodiment can also be executed by a server or server cluster that is different from server 105 and capable of communicating with the first terminal device 101, the second terminal device 102, the third terminal device 103, and / or server 105. Correspondingly, the burst frame detection device for satellite OFDM signals provided in this application embodiment can also be located in a server or server cluster that is different from server 105 and capable of communicating with the first terminal device 101, the second terminal device 102, the third terminal device 103, and / or server 105.

[0034] It should be understood that Figure 1 The number of first terminal devices, second terminal devices, third terminal devices, networks, and servers shown in the diagram is merely illustrative. Depending on implementation needs, any number of first terminal devices, second terminal devices, third terminal devices, networks, and servers can be included.

[0035] Figure 2 A flowchart illustrating a burst frame detection method for satellite orthogonal frequency division multiplexing signals according to an embodiment of this application is shown.

[0036] like Figure 2 As shown, the burst frame detection method for satellite orthogonal frequency division multiplexing signals in this embodiment includes operations S210 to S240.

[0037] In operation S210, the received satellite orthogonal frequency division multiplexing signal is sampled and processed to obtain a discrete orthogonal frequency division multiplexing signal.

[0038] In operation S220, based on a preset sampling rate, multiple first data segments and multiple second data segments are extracted from the discrete orthogonal frequency division multiplexing signal.

[0039] In operation S230, for any one of the multiple cycle identifiers, the inner product of the first data segment and the second data segment associated with any cycle identifier is performed to obtain the similarity between the first data segment and the second data segment.

[0040] In operation S240, in response to the similarity being greater than a preset similarity threshold, it is determined that the satellite orthogonal frequency division multiplexing signal includes at least one burst frame.

[0041] Satellite Orthogonal Frequency-Division Multiplexing (OFDM) signals can characterize radio frequency transmission signals that combine orthogonal frequency division multiplexing modulation technology with the characteristics of satellite communication links. Satellite OFDM signals can be non-cooperative signals.

[0042] Discrete orthogonal frequency division multiplexing (OFDM) signals can be obtained by sampling the received satellite OFDM signals. For example, zero-IF sampling or bandpass sampling methods can be used to sample the satellite OFDM signals.

[0043] In one implementation, the Discrete Orthogonal Frequency Division Multiplexing (DFO) signal can be a non-cooperative signal with a known frame structure. In another implementation, the DFO signal can include multiple OFDM frames with known frame structures, and one OFDM frame can include multiple OFDM symbols. The known frame structure of the DFO signal can be called the OFDM frame structure, or the burst frame structure. The DFO signal satisfies the following formula (1).

[0044] (1);

[0045] in, Indicates the index of the OFDM frame. This represents the first OFDM symbol in the m-th OFDM frame. This represents the second OFDM symbol in the m-th OFDM frame. This represents the 3rd OFDM symbol in the m-th OFDM frame, ... This represents the 302nd OFDM symbol in the m-th OFDM frame. This represents the 303rd OFDM symbol in the m-th OFDM frame.

[0046] The first OFDM symbol in the m-th OFDM frame can be called the Primary Synchronization Sequence (PSS), the second OFDM symbol in the m-th OFDM frame can be called the Secondary Synchronization Sequence (SSS), the third to 302nd OFDM symbols in the m-th OFDM frame can be used to transmit communication content, and the 303rd OFDM symbol in the m-th OFDM frame can be called the Coda Synchronization Sequence (CSS).

[0047] In one implementation, the baseband signal transmitted from the satellite to the ground terminal can be obtained by down-converting the received satellite orthogonal frequency division multiplexing signal. The continuous-time expression of the baseband signal is given by... As shown in formula (2).

[0048] (2);

[0049] in, This represents the time delay from transmission to reception. Indicates time, This represents the carrier frequency deviation parameter. Indicates the center frequency of the signal transmitted by the satellite. This indicates the center frequency set by the receiver of the ground terminal. Indicates additive noise. This indicates multiple frames of signals transmitted by the satellite.

[0050] In one implementation, the multi-frame signal transmitted by the satellite is the result of stitching together multiple OFDM frames in chronological order. The continuous-time expression is shown in formula (3).

[0051] (3);

[0052] in, This represents the set of indices for OFDM frames. This indicates the length of one OFDM frame. Indicates the first The signal of one OFDM frame This represents the rectangular window corresponding to one OFDM frame.

[0053] In one implementation, a rectangular window corresponds to one OFDM frame. Satisfying the following formula (4), a single OFDM frame is the result of splicing multiple OFDM symbols in chronological order, the first... Continuous-time expression of OFDM frames As shown in formula (5).

[0054] (4);

[0055] (5);

[0056] in, This indicates the number of OFDM symbols in one OFDM frame. Indicates the index of the OFDM symbol in the OFDM frame. This represents the length of one OFDM symbol. This represents the signal of the i-th OFDM symbol in the m-th OFDM frame. Represents a rectangular window corresponding to one OFDM symbol.

[0057] In one implementation, a rectangular window corresponds to one OFDM symbol. It satisfies the following formula (6).

[0058] (6);

[0059] Figure 3A A time-domain diagram of a discrete orthogonal frequency division multiplexed signal according to an embodiment of this application is illustrated. Figure 3B The diagram illustrates the spectral analysis of a discrete orthogonal frequency division multiplexed signal according to an embodiment of this application.

[0060] In one implementation, the Discrete Orthogonal Frequency Division Multiplexing (DIFM) signal may include at least one burst frame. The main synchronization sequence of each burst frame may include a cycle identifier and multiple repeating sequences. That is, the DIFM signal may include multiple sequences composed of cycle identifiers and multiple repeating sequences. The parameters of the DIFM signal are shown in Table 1 below, and the frequency domain diagram of the DIFM signal is shown below. Figure 3A As shown, the horizontal axis represents the preset number of sampling points (number of points), and the vertical axis represents the amplitude of the discrete orthogonal frequency division multiplexed signal. The spectrum analysis diagram of the discrete orthogonal frequency division multiplexed signal is shown below. Figure 3B As shown, the horizontal axis represents the frequency of the discrete orthogonal frequency division multiplexed signal, and the vertical axis represents the amplitude of the discrete orthogonal frequency division multiplexed signal.

[0061] Table 1

[0062]

[0063] In one implementation, the expression for the discrete orthogonal frequency division multiplexed signal is as follows (7).

[0064] (7);

[0065] in, This represents a discrete orthogonal frequency division multiplexed signal. Indicates the sampling period. , Indicates the preset sampling frequency. This represents the index of a discrete orthogonal frequency division multiplexed signal that includes a sequence consisting of a cyclic identifier and multiple repeating sequences.

[0066] In one implementation, the continuous-time expression of the primary synchronization sequence (PSS sequence) in the satellite orthogonal frequency division multiplexing signal is... As shown in formula (8).

[0067] (8);

[0068] in, Indicates the bandwidth of the PSS sequence. This indicates the number of the first preset sampling points for the cyclic identifier under this bandwidth. This indicates the second preset number of sampling points for the effective portion of one OFDM symbol within that bandwidth. Indicates the index of the modulation symbol of the PSS sequence. Represents the PSS sequence's first... One modulation symbol, Indicates based on pseudo-random sequence generate intermediate variables, This represents an exponential function.

[0069] In one implementation, the PSS sequence's first... modulation symbols The exponential function satisfies the following formula (9). Satisfying the following formula (10), based on the pseudo-random sequence generate intermediate variables It satisfies the following formula (11).

[0070] (9);

[0071] (10);

[0072] (11);

[0073] in, A set representing the indices of modulation symbols. , This represents the second preset number of sampling points for the effective portion of one OFDM symbol. Represents a set of integers. Represents a pseudo-random sequence. This represents the modulo operation. The bit index representing the pseudo-random sequence.

[0074] In some implementations, satellite orthogonal frequency division multiplexing (OFDM) signals may include multiple master synchronization sequences, while discrete OFDM signals may include multiple sequences consisting of cyclic identifiers and multiple repeating sequences.

[0075] A first data segment, including a cycle identifier and at least one repeating sequence associated with the cycle identifier, can be extracted from a discrete orthogonal frequency division multiplexing (DFM) signal based on a preset sampling rate. Alternatively, a second data segment, including the remaining repeating sequence excluding at least one repeating sequence and an intermediate identifier, can be extracted from the DFM signal based on the repeating sequence. Specifically, the intermediate identifier is the tail of the preceding repeating sequence contained in the second data segment, and the length of its tail is the same as the length of the cycle identifier. In one implementation, the lengths of the first and second data segments are the same.

[0076] In one implementation, the cyclic identifier can characterize a cyclic prefix included in the discrete orthogonal frequency division multiplexing (DFM) signal. In another implementation, the DFM signal can include multiple sequences consisting of eight repeating sequences and a cyclic prefix. Based on a preset sampling rate, the DFM signal can be extracted to include the cyclic identifier and four repeating sequences associated with the cyclic identifier; that is, the first data segment includes the cyclic identifier, a first repeating sequence, a second repeating sequence, a third repeating sequence, and a fourth repeating sequence. Alternatively, based on a preset sampling rate, the remaining four repeating sequences (excluding the aforementioned four repeating sequences) and an intermediate identifier can be extracted from the DFM signal. The intermediate identifier is the tail of the fourth repeating sequence, and its length is the same as the length of the cyclic identifier.

[0077] In one implementation, for any one of a plurality of cyclic identifiers, a vector inner product operation can be performed on the first data segment and the second data segment associated with any cyclic identifier to obtain the similarity between the first data segment and the second data segment.

[0078] If the similarity between the first data segment and the second data segment is greater than a preset similarity threshold, it can be determined that the satellite orthogonal frequency division multiplexing signal includes at least one burst frame.

[0079] By sampling the satellite orthogonal frequency division multiplexing (OFDM) signal, a discrete OFDM signal can be obtained. Based on a preset sampling rate, a first data segment including a cycle identifier and at least one repeating sequence associated with the cycle identifier, and a second data segment including the remaining repeating sequences other than the at least one repeating sequence and an intermediate identifier are extracted from the discrete OFDM signal. Then, for any cycle identifier, the inner product of the first data segment and the second data segment associated with any cycle identifier is performed to obtain the similarity between the first data segment and the second data segment. The similarity is then compared with a preset similarity threshold. If the similarity is greater than the preset similarity threshold, it can be determined that the satellite OFDM signal includes at least one burst frame. Since data extraction is based on a preset sampling rate, there are no restrictions on the sampling method for discretizing the received satellite orthogonal frequency division multiplexing (OFDM) signal, making the sampling method more flexible. Furthermore, since it is not necessary to know the specific values ​​of the satellite OFDM signal, burst frame detection can be completed simply by knowing the frame structure of the satellite OFDM signal. In other words, it is not sensitive to changes in the values ​​of the satellite OFDM signal and has lower requirements for prior information, thereby improving the detection accuracy of burst frames.

[0080] Since satellite orthogonal frequency division multiplexing (OFDM) signals can include PSS sequences with known frame structures, the burst frame detection method for satellite OFDM signals can also be called the burst frame detection method for OFDM satellite internet signals based on the characteristics of the synchronization sequence structure.

[0081] Based on a preset sampling rate, multiple first data segments and multiple second data segments are extracted from the discrete orthogonal frequency division multiplexing signal, including: mapping the number of first preset sampling points of the cyclic identifier and the number of second preset sampling points of the repeating sequence based on the preset sampling rate to obtain a first data segment extraction window and a second data segment extraction window; extracting the first data segment from the discrete orthogonal frequency division multiplexing signal based on the first data segment extraction window; and extracting the second data segment from the discrete orthogonal frequency division multiplexing signal based on the second data segment extraction window.

[0082] Based on a preset sampling rate, the first preset sampling point count of the loop identifier and the second preset sampling point count of the repeating sequence are mapped to obtain a first data segment extraction window and a second data segment extraction window. This includes: reducing the first preset sampling point count of the loop identifier by a factor of the preset sampling rate to obtain the duration of the loop identifier; reducing the second preset sampling point count of the repeating sequence by a factor of the preset sampling rate to obtain the duration of the repeating sequence; summing the duration of the loop identifier and the duration of at least one repeating sequence associated with the loop identifier to obtain a first extraction duration; using the duration of the remaining repeating sequence segments determined based on the duration of the repeating sequence as the second extraction duration; and mapping the first extraction duration and the second extraction duration based on the preset sampling rate to obtain a first data segment extraction window and a second data segment extraction window.

[0083] In one implementation, the duration of the loop identifier can be obtained by dividing the first preset number of sampling points of the loop identifier by a preset sampling rate. The duration of the repeating sequence can be obtained by dividing the second preset number of sampling points of the repeating sequence by the second preset number of sampling points.

[0084] The first extraction duration can be obtained by summing the duration of the cycle identifier and the duration of at least one repeating sequence associated with the cycle identifier. The second extraction duration can be the duration of the remaining repeating sequences determined based on the duration of the repeating sequences. In one implementation, the PSS sequence can consist of a cycle prefix and 8 repeating sequences. In this case, the first extraction duration can be the sum of the duration of the cycle prefix and the duration of 4 repeating sequences, and the second extraction duration can be the sum of the duration of the remaining 4 repeating sequences and the duration of the intermediate identifier.

[0085] Based on a preset sampling rate, the first extraction duration and the second extraction duration can be mapped respectively to obtain the first data segment extraction window that satisfies the following formula (12). and the second data segment extraction window based on the following formula (13) .

[0086] (12);

[0087] (13);

[0088] in, Indicates the duration of the loop identifier. Indicates the duration of the repeating sequence. The index represents the sequence in a discrete orthogonal frequency division multiplexed signal that consists of a cyclic identifier and multiple repeating sequences. This represents the index of the sequence corresponding to the starting point of the first data segment extraction window. This indicates the preset sampling frequency.

[0089] The range indicated by the first data segment extraction window and the range indicated by the second data segment extraction window can be used as a burst frame detector. The range indicated by the first data segment extraction window and the range indicated by the second data segment extraction window have the same length.

[0090] In some implementations, the range indicated by the first data segment extraction window or the range indicated by the second data segment extraction window can be set to... ~ Any value within.

[0091] Multiple first data segments can be extracted from a discrete orthogonal frequency division multiplexing (DFM) signal based on a first data segment extraction window. Multiple second data segments can be extracted from a DFM signal based on a second data segment extraction window.

[0092] The discrete orthogonal frequency division multiplexing (DFM) signal may include multiple sampling points. Specifically, based on the second data segment extraction window, multiple second data segments can be extracted from the discrete orthogonal frequency division multiplexing signal. This can include sliding the second data segment extraction window on the discrete orthogonal frequency division multiplexing signal point by point until the second data segment extraction window slides to the position of the last sampling point, thereby obtaining multiple second data segments.

[0093] The sum of the lengths of the first and second data segment extraction windows is equal to the length of a PSS sequence. By sliding the first and second data segment extraction windows, the first and second data segment extraction windows can be slid across the discrete orthogonal frequency division multiplexed signal point by point. When the second data segment extraction window slides to the position of the last sampling point, multiple second data segments can be obtained.

[0094] In one implementation, starting from the first sampling point of the discrete orthogonal frequency division multiplexing (DFM) signal, data truncation is performed point by point according to the first data segment extraction window and the second data segment extraction window. That is, the starting point of the first data segment extraction window is aligned with the starting point of the DFM signal, i.e., ... Extract the window based on the first data segment. Second data segment extraction window The indicated range is used to extract the discrete orthogonal frequency division multiplexed signal, and obtain a first data segment consisting of a cycle identifier and at least one repeating sequence associated with the cycle identifier. The second data segment consists of the remaining repeating sequences excluding at least one repeating sequence and intermediate identifiers. First data segment Second data segment The formulas are (14) and (15) respectively.

[0095] (14);

[0096] (15);

[0097] By mapping the number of first preset sampling points of the cyclic identifier and the number of second preset sampling points of the repeating sequence based on a preset sampling rate, a first data segment extraction window and a second data segment extraction window can be obtained. Then, based on the first data segment extraction window and the second data segment extraction window, sample-by-sample data extraction is performed on the discrete orthogonal frequency division multiplexing signal to obtain multiple first data segments and multiple second data segments. That is, by utilizing the repeating structure of the PSS sequence, the detection accuracy of burst frames can be improved. Specifically, when burst frames exist in the satellite orthogonal frequency division multiplexing signal, the data extracted by the first data segment extraction window and the second data segment extraction window exhibit high autocorrelation because they contain repeating sequences. When there are no burst frames in the satellite orthogonal frequency division multiplexing signal, the correlation between the data extracted by the first data segment extraction window and the second data segment extraction window approaches 0. Therefore, judging burst frames by autocorrelation can eliminate false triggering caused by noise and interference and significantly reduce the false detection rate.

[0098] Figure 4 The illustration shows a schematic diagram of the start point of the burst frame detector according to an embodiment of the present application being aligned with the start point of the discrete orthogonal frequency division multiplexing signal.

[0099] like Figure 4 As shown, when the PSS sequence consists of a cyclic prefix and 8 repeating sequences, when the starting point of the burst frame detector is aligned with the starting point of the PSS sequence in the discrete orthogonal frequency division multiplexing signal, the similarity between the two data segments corresponding to the two data extraction windows before and after the burst frame detector will reach the maximum value in the region. At this time, the positional relationship between the burst frame detector and the PSS sequence in the discrete orthogonal frequency division multiplexing signal is as follows: the range indicated by the first data segment extraction window (window 1) can include the cyclic prefix and the first 4 repeating sequences (segment 1 to segment 4), and the range indicated by the second data segment extraction window (window 2) can include the last 4 repeating sequences (segment 5 to segment 8) and the tail of segment 4. The length of the tail of segment 4 is the same as the length of the cyclic prefix.

[0100] For any one of multiple cyclic identifiers, perform an inner product operation on the first data segment and the second data segment associated with that cyclic identifier to obtain the similarity between the first data segment and the second data segment. This includes: for any one of the multiple cyclic identifiers, inverting the cyclic identifier to obtain the target cyclic identifier; concatenating the target cyclic identifier with at least one repeating sequence associated with the cyclic identifier to obtain the first intermediate data segment; and performing an inner product operation on the first intermediate data segment and the second data segment to obtain the similarity.

[0101] Since the header of each OFDM symbol is a cyclic prefix, which is generated by inverting the last small segment of data in the valid part of the OFDM symbol, the target cyclic identifier can be obtained by inverting any cyclic identifier among multiple cyclic identifiers. Then, the target cyclic identifier is concatenated with at least one repeating sequence associated with the cyclic identifier to obtain the first intermediate data segment. It satisfies the following formula (16).

[0102] (16);

[0103] The similarity can be obtained by performing an inner product operation on the first intermediate data segment and the second data segment. In one implementation, the similarity is... and Perform the vector dot product operation, that is, multiply the elements at the same position and then sum them to obtain the similarity. It satisfies the following formula (17).

[0104] (17);

[0105] in, express and The preset number of sampling points.

[0106] In one implementation, the preset number of sampling points may include the sum of a first preset number of sampling points for the cycle identifier and a second preset number of sampling points for each of the repeating sequences.

[0107] The length of a discrete orthogonal frequency division multiplexed signal can be Based on this, by shifting the starting point of the first data segment extraction window point by point, that is, sequentially setting... Extract the window based on the first data segment. Second data segment extraction window The range of indication is used to extract data from the discrete orthogonal frequency division multiplexing signal, and the cyclic identifier of the first data segment is inverted to obtain multiple first data segments as shown in the following formula (18). and multiple second data segments of the following formula (19) .

[0108] (18);

[0109] (19);

[0110] in, This represents the number of sampling points by which the starting point of the first data segment extraction window has moved relative to the starting point of the discrete orthogonal frequency division multiplexing signal; its value is related to... same.

[0111] Furthermore, calculating the starting point of the extraction window for the first data segment at different positions for each sampling point... and The dot product of vectors can yield multiple similarity values. It satisfies the following formula (20).

[0112] (20);

[0113] For any cyclic identifier, the target cyclic identifier can be obtained by inverting the cyclic identifier. Then, the target cyclic identifier and at least one repeating sequence associated with the cyclic identifier are concatenated to obtain the first intermediate data segment. The first intermediate data segment and the second data segment are then processed by inner product to obtain the similarity. That is, for multiple cyclic identifiers, multiple similarities can be calculated point by point when the starting point of the first data segment extraction window is at different positions of the discrete orthogonal frequency division multiplexing signal. Thus, the peak values ​​of multiple similarities can be determined to determine that the satellite orthogonal frequency division multiplexing signal includes at least one burst frame, thereby improving the detection accuracy of burst frames.

[0114] In response to a similarity greater than a preset similarity threshold, determining that the satellite orthogonal frequency division multiplexing signal includes at least one burst frame includes: generating a similarity curve by classifying multiple similarities according to similarity identifiers; dividing the similarity curve into at least one similarity region in response to a similarity greater than the preset similarity threshold; arranging at least two similarities included in the at least one similarity region in descending order; and determining the first similarity in the at least one similarity region as the burst frame of the satellite orthogonal frequency division multiplexing signal.

[0115] Similarity identifiers can be indexes of similarity generated based on the order of sampling points. Multiple similarities can be grouped according to their similarity identifiers to generate a similarity vector, satisfying the following formula (21). Based on the similarity vector... It can generate similarity curves.

[0116] (twenty one);

[0117] in, This represents the total number of sampling points that the first data segment extraction window and the second data segment extraction window pause and slide on the discrete orthogonal frequency division multiplexing signal, that is, the number of similarity scores generated for the first data segment and the second data segment extracted by the first data segment extraction window and the second data segment extraction window respectively.

[0118] Similarity vector Its index sequence Using these variables as dependent and independent variables respectively, a similarity curve is generated for subsequent multi-peak point detection.

[0119] Since discrete orthogonal frequency division multiplexing signals may contain multiple burst frames, burst frame detection and starting point localization can be transformed into a problem of multi-peak detection based on similarity curves.

[0120] A preset similarity threshold can be set empirically to filter out regions in the similarity curve whose amplitude exceeds the preset similarity threshold, resulting in only one less similar region. In one implementation, in the case of including In the case of similarity regions, the similarity in each similarity region can form an array, satisfying the following formula (22).

[0121] (twenty two);

[0122] in, This represents an array consisting of the similarity scores within the first similarity region. This represents an array consisting of similarity scores within the second similarity region. Indicates the first An array consisting of the similarity scores of each similarity region.

[0123] At least two similarities within at least one similarity region can be arranged in descending order; then the first similarity in at least one similarity region is determined as the burst frame of the satellite orthogonal frequency division multiplexing signal, that is, the largest similarity in the similarity region is determined as a burst frame.

[0124] In one implementation, Automatic Multiscale-based Peak Detection (APMD) can be used to determine the maximum similarity from at least one similarity region.

[0125] Satellite orthogonal frequency division multiplexing signals are usually transmitted continuously in multiple burst frames. By comparing the similarity region with a preset similarity threshold, similarity regions with a similarity greater than the preset similarity threshold can be filtered out. Then, the maximum similarity in the similarity region is determined as the burst frame, which realizes the detection of at least one burst frame at a time and improves the detection efficiency.

[0126] In one implementation, including In the case of similarity regions, the similarity scores within each similarity region can form an array; that is, there will be... There are n arrays, each with a maximum similarity score; that is, there will be n arrays. A burst frame.

[0127] The above-mentioned method for detecting burst frames of satellite orthogonal frequency division multiplexing signals may further include: for any similarity region in at least one similarity region, the similarity identifier associated with the first similarity can be determined as the starting position information of the burst frame.

[0128] The similarity identifier can characterize the number of points by which the starting point of the first data segment extraction window corresponding to the first similarity has moved relative to the starting point of the discrete orthogonal frequency division multiplexing (DFM) signal. In one implementation, for any similarity region in at least one similarity region, the similarity identifier associated with the first similarity, i.e., the number of points by which the starting point of the first data segment extraction window corresponding to the maximum similarity in that similarity region has moved relative to the starting point of the DFM signal, can be determined as the starting position information of the burst frame.

[0129] In one implementation, the satellite orthogonal frequency division multiplexing signal includes In the case of a burst frame The starting position information of each burst frame satisfies the following formula (23).

[0130] (twenty three);

[0131] in, This indicates the starting position information of the first burst frame. This indicates the start position information of the second burst frame, ... Indicates the first The start position information of each burst frame.

[0132] By determining the starting point of the burst frame as the number of points the starting point of the extraction window of the first data segment corresponding to the first similarity in the similarity region moves relative to the starting point of the discrete orthogonal frequency division multiplexing signal, the positioning accuracy of the starting position of the burst frame is improved.

[0133] In one implementation, based on the structural characteristics of the PSS sequence, which consists of a cyclic prefix and eight repeating sequences, a burst frame detector structure for satellite orthogonal frequency division multiplexing (OFDM) signals can be designed. Two data extraction windows before and after the burst detector extract data from the discrete OFDM signal. The cyclic prefix portion of the extracted first data segment is inverted, and a vector inner product operation is performed on the two data segments to obtain a similarity. By sliding the starting point of the burst frame detector, a similarity vector is generated. By finding the peak value of the similarity vector, the detection of at least one burst frame of the satellite OFDM signal and the accurate positioning of the burst frame's starting position information can be achieved.

[0134] Figure 5 A schematic diagram of similarity curves according to an embodiment of this application is shown.

[0135] like Figure 5 As shown, the horizontal axis represents the location identifier of the burst frame detector's starting point, and the vertical axis represents the similarity magnitude. It can be seen that 4986 represents the starting location information of the burst frame, and 3797440000 represents the similarity magnitude corresponding to this starting location information. Verification shows that the burst starting point location information obtained using the above-described burst frame detection method for satellite orthogonal frequency division multiplexing signals is the same as the actual location, demonstrating the effectiveness of this method.

[0136] Figure 6 A flowchart illustrating a burst frame detection method for satellite orthogonal frequency division multiplexing signals according to yet another embodiment of this application is shown.

[0137] like Figure 6 As shown, the burst frame detection method for satellite orthogonal frequency division multiplexing signals in this embodiment includes operations S610 to S670.

[0138] In operation S610, the received satellite orthogonal frequency division multiplexing signal with a known frame structure is sampled and processed to obtain a discrete orthogonal frequency division multiplexing signal.

[0139] In operation S620, the burst frame detector is initialized according to the known frame structure and preset sampling rate to obtain the first data segment extraction window and the second data segment extraction window.

[0140] When operating the S630, the starting point of the burst frame detector is aligned with the starting point of the discrete orthogonal frequency division multiplexing (DFM) signal, and the DFM signal is extracted using two data extraction windows.

[0141] In operation S640, the cyclic prefix of the first data segment is inverted, and then the inner product operation is performed on the two data segments.

[0142] In operation of S650, the starting point of the burst frame detector is slid along the sampling point, and the data segment extraction and data segment inner product operation are repeatedly performed until the end point of the burst frame detector is aligned with the end point of the discrete orthogonal frequency division multiplexing signal.

[0143] When operating the S660, the similarity of the burst frame detector at each location is calculated, and a similarity curve is plotted.

[0144] During operation of S670, the maximum value of the similarity curve is detected, and the similarity identifier corresponding to the maximum similarity is determined as the starting position information of the burst frame.

[0145] Based on the aforementioned method for burst frame detection of satellite orthogonal frequency division multiplexing (OFDM) signals, this application also provides a device for burst frame detection of satellite OFDM signals. The following will be combined with... Figure 7 The device is described in detail.

[0146] Figure 7 The schematic diagram illustrates the structural block diagram of a burst frame detection apparatus for satellite orthogonal frequency division multiplexing signals according to an embodiment of this application.

[0147] like Figure 7 As shown, the burst frame detection device 700 for satellite orthogonal frequency division multiplexing signals in this embodiment includes a sampling module 710, an extraction module 720, an acquisition module 730, and a first determination module 740.

[0148] The sampling module 710 is used to sample and process the received satellite orthogonal frequency division multiplexing (OFDM) signal to obtain a discrete OFDM signal. The discrete OFDM signal includes multiple sequences consisting of a cyclic identifier and multiple repeating sequences. In one embodiment, the sampling module 710 can be used to perform the operation S210 described above, which will not be repeated here.

[0149] Extraction module 720 is used to extract multiple first data segments and multiple second data segments from a discrete orthogonal frequency division multiplexing signal based on a preset sampling rate. Each first data segment includes a cycle identifier and at least one repeating sequence associated with the cycle identifier. Each second data segment includes the remaining repeating sequences excluding the at least one repeating sequence and an intermediate identifier, which is determined based on the repeating sequences. In one embodiment, extraction module 720 can be used to perform the operation S220 described above, which will not be repeated here.

[0150] The obtaining module 730 is used to perform inner product processing on a first data segment and a second data segment associated with any one of a plurality of cycle identifiers to obtain the similarity between the first data segment and the second data segment. In one embodiment, the obtaining module 730 can be used to perform the operation S230 described above, which will not be repeated here.

[0151] The first determining module 740 is configured to determine, in response to a similarity greater than a preset similarity threshold, that the satellite orthogonal frequency division multiplexing signal includes at least one burst frame. In one embodiment, the first determining module 740 may be used to perform the operation S240 described above, which will not be repeated here.

[0152] According to an embodiment of this application, the obtaining module 730 includes: a first obtaining submodule, used to invert any one of the multiple cycle identifiers to obtain a target cycle identifier; a second obtaining submodule, used to concatenate the target cycle identifier and at least one repeating sequence associated with the cycle identifier to obtain a first intermediate data segment; and a third obtaining submodule, used to perform inner product processing on the first intermediate data segment and the second data segment to obtain a similarity.

[0153] According to an embodiment of this application, the extraction module 720 includes: a first extraction submodule, configured to map the number of first preset sampling points of the cyclic identifier and the number of second preset sampling points of the repeating sequence based on a preset sampling rate, respectively, to obtain a first data segment extraction window and a second data segment extraction window; a second extraction submodule, configured to extract multiple first data segments from the discrete orthogonal frequency division multiplexing signal based on the first data segment extraction window; and a third extraction submodule, configured to extract multiple second data segments from the discrete orthogonal frequency division multiplexing signal based on the second data segment extraction window.

[0154] According to an embodiment of this application, a first extraction submodule includes: a first extraction unit, configured to reduce the number of first preset sampling points of the loop identifier by a preset sampling rate to obtain the duration of the loop identifier; a second extraction unit, configured to reduce the number of second preset sampling points of the repeating sequence by a preset sampling rate to obtain the duration of the repeating sequence; a third extraction unit, configured to sum the duration of the loop identifier and the duration of at least one repeating sequence associated with the loop identifier to obtain a first extraction duration; a fourth extraction unit, configured to use the duration of the remaining repeating sequence determined according to the duration of the repeating sequence as a second extraction duration; and a fifth extraction unit, configured to map the first extraction duration and the second extraction duration based on a preset sampling rate to obtain a first data segment extraction window and a second data segment extraction window.

[0155] According to an embodiment of this application, the discrete orthogonal frequency division multiplexing signal includes multiple sampling points. The third extraction submodule includes: a sixth extraction unit, used to slide the second data segment extraction window on the discrete orthogonal frequency division multiplexing signal point by point until the second data segment extraction window slides to the position of the last sampling point to obtain multiple second data segments.

[0156] According to an embodiment of this application, the first determining module 740 includes: a first determining submodule, used to generate a similarity curve by assigning multiple similarities to similarity identifiers, wherein the similarity identifier is an index of similarities generated based on the sampling point order; a second determining submodule, used to divide the similarity curve into at least one similarity region in response to a similarity greater than a preset similarity threshold; a third determining submodule, used to arrange at least two similarities included in the at least one similarity region in descending order; and a fourth determining submodule, used to determine the first similarity in the at least one similarity region as a burst frame of a satellite orthogonal frequency division multiplexing signal.

[0157] According to an embodiment of this application, the above-mentioned burst frame detection device 700 for satellite orthogonal frequency division multiplexing signals further includes: a second determining module, used to determine, for any similarity region in at least one similarity region, the similarity identifier associated with the first similarity as the start position information of the burst frame.

[0158] According to embodiments of this application, any multiple modules among the sampling module 710, extraction module 720, obtaining module 730, and first determining module 740 can be combined into one module, or any one of these modules can be split into multiple modules. Alternatively, at least part of the functionality of one or more of these modules can be combined with at least part of the functionality of other modules and implemented in one module. According to embodiments of this application, at least one of the sampling module 710, extraction module 720, obtaining module 730, and first determining module 740 can be at least partially implemented as hardware circuitry, such as a field-programmable gate array (FPGA), a programmable logic array (PLA), a system-on-a-chip, a system-on-a-substrate, a system-on-package, an application-specific integrated circuit (ASIC), or implemented in hardware or firmware by any other reasonable means of integrating or packaging the circuitry, or implemented in software, hardware, or firmware, or in any suitable combination of any of these three implementation methods. Alternatively, at least one of the sampling module 710, extraction module 720, obtaining module 730 and first determining module 740 may be implemented at least partially as a computer program module, which can perform corresponding functions when the computer program module is run.

[0159] Figure 8 A block diagram schematically illustrates an electronic device suitable for implementing a burst frame detection method for satellite orthogonal frequency division multiplexing signals according to an embodiment of this application.

[0160] like Figure 8 As shown, an electronic device 800 according to an embodiment of this application includes a processor 801, which can perform various appropriate actions and processes according to a program stored in ROM 802 or a program loaded from storage portion 808 into RAM 803. The processor 801 may include, for example, a general-purpose microprocessor (e.g., a CPU), an instruction set processor and / or an associated chipset and / or a special-purpose microprocessor (e.g., an application-specific integrated circuit (ASIC)), etc. The processor 801 may also include onboard memory for caching purposes. The processor 801 may include a single processing unit or multiple processing units for performing different actions of the method flow according to an embodiment of this application.

[0161] RAM 803 stores various programs and data required for the operation of electronic device 800. Processor 801, ROM 802, and RAM 803 are interconnected via bus 804. Processor 801 executes various operations of the method flow according to embodiments of this application by executing programs in ROM 802 and / or RAM 803. It should be noted that the programs may also be stored in one or more memories other than ROM 802 and RAM 803. Processor 801 may also execute various operations of the method flow according to embodiments of this application by executing programs stored in said one or more memories.

[0162] According to embodiments of this application, the electronic device 800 may further include an input / output (I / O) interface 805, which is also connected to a bus 804. The electronic device 800 may also include one or more of the following components connected to the input / output (I / O) interface 805: an input section 806 including a keyboard, mouse, etc.; an output section 807 including a cathode ray tube (CRT), liquid crystal display (LCD), etc., and a speaker, etc.; a storage section 808 including a hard disk, etc.; and a communication section 809 including a network interface card such as a LAN card, modem, etc. The communication section 809 performs communication processing via a network such as the Internet. A drive 810 is also connected to the input / output (I / O) interface 805 as needed. A removable medium 811, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., is installed on the drive 810 as needed so that computer programs read from it can be installed into the storage section 808 as needed.

[0163] This application also provides a computer-readable storage medium, which may be included in the device / apparatus / system described in the above embodiments; or it may exist independently and not assembled into the device / apparatus / system. The computer-readable storage medium carries one or more programs, which, when executed, implement the method according to the embodiments of this application.

[0164] According to embodiments of this application, the computer-readable storage medium can be a non-volatile computer-readable storage medium, such as including but not limited to: portable computer disks, hard disks, RAM (Random Access Memory), ROM (Read Only Memory), erasable programmable read-only memory (EPROM or flash memory), portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this application, the computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. For example, according to embodiments of this application, the computer-readable storage medium may include ROM 802 and / or RAM 803 and / or one or more memories other than ROM 802 and RAM 803 described above.

[0165] Embodiments of this application also include a computer program product comprising a computer program containing program code for performing the methods shown in the flowchart. When the computer program product is run on a computer system, the program code enables the computer system to implement the burst frame detection method for satellite orthogonal frequency division multiplexing signals provided in the embodiments of this application.

[0166] When the computer program is executed by the processor 801, it performs the functions defined in the system / apparatus of this application embodiment. According to the embodiments of this application, the systems, apparatuses, modules, units, etc., described above can be implemented by computer program modules.

[0167] In one embodiment, the computer program may rely on a tangible storage medium such as an optical storage device or a magnetic storage device. In another embodiment, the computer program may also be transmitted and distributed in the form of signals over a network medium, and may be downloaded and installed via the communication section 809, and / or installed from a removable medium 811. The program code contained in the computer program can be transmitted using any suitable network medium, including but not limited to: wireless, wired, etc., or any suitable combination thereof.

[0168] In such an embodiment, the computer program can be downloaded and installed from a network via the communication section 809, and / or installed from the removable medium 811. When the computer program is executed by the processor 801, it performs the functions defined in the system of this application embodiment. According to the embodiments of this application, the systems, devices, apparatuses, modules, units, etc., described above can be implemented by computer program modules.

[0169] According to embodiments of this application, program code for executing the computer programs provided in the embodiments of this application can be written in any combination of one or more programming languages. Specifically, these computational programs can be implemented using high-level procedural and / or object-oriented programming languages, and / or assembly / machine languages. Programming languages ​​include, but are not limited to, languages ​​such as Java, C++, Python, "C", or similar programming languages. The program code can be executed entirely on the user's computing device, partially on the user's device, partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0170] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram or flowchart, and combinations of blocks in a block diagram or flowchart, may be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0171] Those skilled in the art will understand that the features described in the various embodiments of this application can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in this application. In particular, the features described in the various embodiments of this application can be combined and / or combined in various ways without departing from the spirit and teachings of this application. All such combinations and / or combinations fall within the scope of this application.

[0172] The embodiments of this application have been described above. However, these embodiments are merely illustrative and not intended to limit the scope of this application. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. Without departing from the scope of this application, those skilled in the art can make various substitutions and modifications, all of which should fall within the scope of this application.

Claims

1. A method for burst frame detection of satellite orthogonal frequency division multiplexing signals, characterized in that, The method includes: The received satellite orthogonal frequency division multiplexing signal is sampled and processed to obtain a discrete orthogonal frequency division multiplexing signal, wherein the discrete orthogonal frequency division multiplexing signal includes multiple sequences consisting of a cyclic identifier and multiple repeating sequences; Based on a preset sampling rate, multiple first data segments and multiple second data segments are extracted from the discrete orthogonal frequency division multiplexing signal, wherein the first data segment includes a cycle identifier and at least one repeating sequence associated with the cycle identifier, and the second data segment includes the remaining repeating sequence excluding the at least one repeating sequence and an intermediate identifier, wherein the intermediate identifier is determined based on the repeating sequence; For any one of the plurality of cycle identifiers, perform inner product processing on the first data segment and the second data segment associated with the any one cycle identifier to obtain the similarity between the first data segment and the second data segment; In response to the similarity being greater than a preset similarity threshold, it is determined that the satellite orthogonal frequency division multiplexing signal includes at least one burst frame.

2. The method according to claim 1, characterized in that, The step of performing inner product processing on the first data segment and the second data segment associated with any one of the plurality of cycle identifiers to obtain the similarity between the first data segment and the second data segment includes: For any one of the multiple cycle identifiers, Invert any of the loop identifiers to obtain the target loop identifier; The target cycle identifier and at least one repeating sequence associated with the cycle identifier are concatenated to obtain a first intermediate data segment; The similarity is obtained by performing inner product processing on the first intermediate data segment and the second data segment.

3. The method according to claim 2, characterized in that, The step of extracting multiple first data segments and multiple second data segments from the discrete orthogonal frequency division multiplexing signal based on a preset sampling rate includes: Based on the preset sampling rate, the first preset sampling point number of the loop identifier and the second preset sampling point number of the repeating sequence are mapped to obtain the first data segment extraction window and the second data segment extraction window. Based on the first data segment extraction window, multiple first data segments are extracted from the discrete orthogonal frequency division multiplexing signal; Based on the second data segment extraction window, multiple second data segments are extracted from the discrete orthogonal frequency division multiplexing signal.

4. The method according to claim 3, characterized in that, The method of mapping the first preset sampling point number of the cycle identifier and the second preset sampling point number of the repeating sequence based on a preset sampling rate to obtain a first data segment extraction window and a second data segment extraction window includes: The duration of the loop identifier is obtained by multiplying the number of the first preset sampling points of the loop identifier by the preset sampling rate. The duration of the repeating sequence is obtained by multiplying the number of the second preset sampling points of the repeating sequence by a factor of the preset sampling rate. The duration of the cycle identifier and the duration of at least one repeating sequence associated with the cycle identifier are summed to obtain the first extraction duration; The duration of the remaining segment of the repeating sequence, determined based on the duration of the repeating sequence, is used as the second extraction duration; Based on the preset sampling rate, the first extraction duration and the second extraction duration are mapped to obtain the first data segment extraction window and the second data segment extraction window.

5. The method according to claim 4, characterized in that, The discrete orthogonal frequency division multiplexed signal includes multiple sampling points, wherein, The extraction of multiple second data segments from the discrete orthogonal frequency division multiplexing signal based on the second data segment extraction window includes: The second data segment extraction window is slid across the discrete orthogonal frequency division multiplexing signal, point by point, until the second data segment extraction window reaches the position of the last sampling point, thus obtaining multiple second data segments.

6. The method according to claim 5, characterized in that, The response that the similarity is greater than a preset similarity threshold determines that the satellite orthogonal frequency division multiplexing signal includes at least one burst frame, including: A similarity curve is generated by assigning similarity identifiers to multiple similarities, wherein the similarity identifiers are indexes of the similarities generated based on the order of sampling points; In response to the similarity being greater than a preset similarity threshold, the similarity curve is divided into at least one similarity region; Arrange at least two similarities within the at least one similarity region in descending order; The first similarity in the at least one similarity region is determined as the burst frame of the satellite orthogonal frequency division multiplexing signal.

7. The method according to claim 6, characterized in that, The method further includes: For any similarity region in the at least one similarity region, the similarity identifier associated with the first similarity is determined as the starting position information of the burst frame.

8. A burst frame detection device for satellite orthogonal frequency division multiplexing signals, characterized in that, The device includes: The sampling module is used to sample and process the received satellite orthogonal frequency division multiplexing signal to obtain a discrete orthogonal frequency division multiplexing signal, wherein the discrete orthogonal frequency division multiplexing signal includes multiple sequences composed of a cycle identifier and multiple repeating sequences; An extraction module is used to extract multiple first data segments and multiple second data segments from the discrete orthogonal frequency division multiplexing signal based on a preset sampling rate. The first data segment includes a cycle identifier and at least one repeating sequence associated with the cycle identifier. The second data segment includes a remaining repeating sequence excluding the at least one repeating sequence and an intermediate identifier, wherein the intermediate identifier is determined based on the repeating sequence. The module is configured to perform inner product processing on a first data segment and a second data segment associated with any one of the plurality of cycle identifiers to obtain the similarity between the first data segment and the second data segment. The first determining module is used to determine, in response to the similarity being greater than a preset similarity threshold, that the satellite orthogonal frequency division multiplexing signal includes at least one burst frame.

9. An electronic device, comprising: One or more processors; Memory, used to store one or more computer programs. The characteristic feature is that the one or more processors execute the one or more computer programs to implement the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program or instructions stored thereon, characterized in that, When the computer program or instructions are executed by a processor, they implement the steps of the method according to any one of claims 1 to 7.

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