Signal synchronization method, device, storage medium and node for wireless ad hoc network

Abstract

The present application discloses a signal synchronization method, device, storage medium, and node for a wireless ad hoc network, relating to the field of communications technology. The wireless ad hoc network includes a receiving node and a transmitting node. The receiving node can perform the following operations: receiving a data packet sent by the transmitting node; obtaining a first received sequence from the data packet using a sliding window of a first length; performing frequency domain cross-correlation calculation and analysis on the first received sequence and a local sequence to obtain a rough signal synchronization point; obtaining a second received sequence where the rough signal synchronization point is located using a sliding window of a second length; performing frequency domain cross-correlation calculation and analysis on the second received sequence and the local sequence to obtain a signal starting point, wherein the first length is greater than the second length. The present application can effectively improve the accuracy and efficiency of signal synchronization in wireless ad hoc networks.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a signal synchronization method, device, storage medium and node for a wireless ad hoc network. Background Art

[0002] Taking the drone ad hoc network that combines drone communication with wireless ad hoc network as an example, the relevant ad hoc network protocol usually adopts a fixed preamble sequence structure combining a short training sequence (STF) and a long training sequence (LTF) as the basis for receiving node detection and synchronization. Based on this structure, the receiving node usually finds the signal starting point through the autocorrelation operation of the STF sequence in the time domain and the cross-correlation operation of the LTF sequence in the time domain.

[0003] In the current method, since the length of a single STF sequence is short, it is usually necessary to increase the length of the STF sequence after AGC adjustment to ensure the accuracy of signal detection. However, increasing the length of the STF sequence may cause its autocorrelation value to change significantly, so the accuracy of positioning and synchronization of the signal starting point is still limited. Moreover, the autocorrelation operation of the STF sequence in the time domain usually requires multiple calculations, resulting in poor positioning and synchronization efficiency of the signal starting point. Summary of the Invention

[0004] The embodiments of the present application provide a signal synchronization solution for a wireless ad hoc network, which can effectively improve the accuracy and efficiency of signal synchronization in the wireless ad hoc network.

[0005] The embodiments of this application provide the following technical solutions:

[0006] According to one embodiment of the present application, a signal synchronization method for a wireless ad hoc network is provided, wherein the wireless ad hoc network includes a receiving node and a sending node, and the method is applied to the receiving node, and the method includes: receiving a data packet sent by the sending node; obtaining a first receiving sequence from the data packet using a sliding window of a first length; performing frequency domain cross-correlation calculation and analysis on the first receiving sequence and a local sequence to obtain a rough signal synchronization point; obtaining a second receiving sequence where the rough signal synchronization point is located using a sliding window of a second length; performing frequency domain cross-correlation calculation and analysis on the second receiving sequence and the local sequence to obtain a signal starting point, wherein the first length is greater than the second length.

[0007] In some embodiments of the present application, the data packet is sent by the sending node in accordance with a combined training sequence frame structure, the combined training sequence frame structure includes a preamble sequence and fixed-length control data, the header of the preamble sequence is configured with a signal synchronization sequence, and the local sequence is a pre-configured sequence that is identical to the signal synchronization sequence.

[0008] In some embodiments of the present application, the length of the signal synchronization sequence is N, the first length is greater than the N, and the second length is equal to the N.

[0009] In some embodiments of the present application, the frequency domain cross-correlation calculation and analysis of the first received sequence and the local sequence to obtain a rough signal synchronization point includes: performing the first length point Fourier transform on the first received sequence to obtain a first transform sequence; performing the first length point Fourier transform on the local sequence to obtain a second transform sequence; performing conjugate point multiplication on the first transform sequence and the second transform sequence in the frequency domain to obtain a first conjugate point product sequence; performing the first length point inverse Fourier transform on the first conjugate point product sequence to obtain a first calculation result, which is an absolute value in the time domain; determining whether the maximum peak point in the first calculation result is greater than a first predetermined threshold; if so, determining the position of the maximum peak point in the first calculation result as the rough signal synchronization point.

[0010] In some embodiments of the present application, performing frequency domain cross-correlation calculation and analysis on the second received sequence and the local sequence to obtain a signal starting point includes: performing frequency domain cross-correlation calculation on the second received sequence and the local sequence to obtain a second calculation result; determining whether a maximum peak point in the second calculation result is greater than a second predetermined threshold; and if so, determining the signal starting point in the data packet based on the position of the maximum peak point in the second calculation result.

[0011] In some embodiments of the present application, determining the signal starting point in the data packet based on the position of the maximum peak point includes: intercepting data in a predetermined range before the maximum peak point in the second calculation result from the two calculation results; and determining the first point in the data in the predetermined range from the beginning to the end that is greater than the second predetermined threshold as the signal starting point.

[0012] In some embodiments of the present application, performing frequency domain cross-correlation calculation on the second received sequence and the local sequence to obtain a second calculation result includes: performing the second length point Fourier transform on the second received sequence to obtain a third transform sequence; performing the second length point Fourier transform on the local sequence to obtain a fourth transform sequence; performing conjugate point multiplication on the third transform sequence and the fourth transform sequence in the frequency domain to obtain a second conjugate point product sequence; performing the second length point inverse Fourier transform on the second conjugate point product sequence to obtain the second calculation result, where the second calculation result is an absolute value in the time domain.

[0013] In some embodiments of the present application, the use of a sliding window of a second length to obtain the second received sequence where the coarse synchronization point of the signal is located includes: backing off a predetermined backoff length from the coarse synchronization point of the signal in the data packet to obtain a backoff point; and using a sliding window of the second length to obtain data starting from the backoff point to obtain the second received sequence.

[0014] In some embodiments of the present application, the predetermined back-off length is greater than the length of a cyclic prefix of an orthogonal frequency division multiplexing symbol.

[0015] According to one embodiment of the present application, a signal synchronization device for a wireless ad hoc network includes a receiving node and a sending node, and the device is applied to the receiving node, and the device includes: a receiving module, used to: receive a data packet sent by the sending node; a first synchronization analysis module, used to: use a sliding window of a first length to obtain a first receiving sequence from the data packet; perform frequency domain cross-correlation calculation and analysis on the first receiving sequence and a local sequence to obtain a rough signal synchronization point; a second synchronization analysis module, used to: use a sliding window of a second length to obtain a second receiving sequence where the rough signal synchronization point is located; perform frequency domain cross-correlation calculation and analysis on the second receiving sequence and the local sequence to obtain a signal starting point, wherein the first length is greater than the second length.

[0016] According to another embodiment of the present application, a storage medium stores a computer program thereon. When the computer program is executed by a processor of a node, the node executes the method described in the embodiment of the present application.

[0017] According to another embodiment of the present application, a node may include: a memory storing a computer program; and a processor reading the computer program stored in the memory to execute the method described in the embodiment of the present application.

[0018] According to another embodiment of the present application, a computer program product or computer program includes computer instructions stored in a computer-readable storage medium. A processor of a node reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the node to perform the methods provided in various optional implementations described in the embodiments of the present application.

[0019] In the signal synchronization method of a wireless ad hoc network in an embodiment of the present application, the wireless ad hoc network includes a receiving node and a sending node, and the receiving node can execute the following: receiving a data packet sent by the sending node; obtaining a first receiving sequence from the data packet using a sliding window of a first length; performing frequency domain cross-correlation calculation and analysis on the first receiving sequence and a local sequence to obtain a rough signal synchronization point; obtaining a second receiving sequence where the rough signal synchronization point is located using a sliding window of a second length; performing frequency domain cross-correlation calculation and analysis on the second receiving sequence and the local sequence to obtain a signal starting point, wherein the first length is greater than the second length.

[0020] In this manner according to the embodiments of the present application, firstly, on the one hand, coarse synchronization processing and fine synchronization processing use sliding windows of different lengths, with the sliding window length of the coarse synchronization processing being greater than the sliding window length of the fine synchronization processing; on the other hand, frequency domain cross-correlation calculation and analysis is performed in the frequency domain during coarse synchronization processing; the combined effect of these two aspects can effectively reduce the number of cross-correlation calculations and shorten the signal synchronization detection time. Furthermore, frequency domain cross-correlation calculation and analysis is performed in the frequency domain with the local sequence during coarse synchronization processing to avoid increasing the length of the short training sequence, which results in a large synchronization error. Therefore, the overall signal synchronization accuracy and efficiency of the wireless ad hoc network can be effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 A flow chart of a signal synchronization method for a wireless ad hoc network according to an embodiment of the present application is shown.

[0023] Figure 2 A schematic diagram of sliding data acquisition according to an example of the present application is shown.

[0024] Figure 3 A schematic diagram of a combined training sequence frame structure according to an example of the present application is shown.

[0025] Figure 4 A flow chart of a coarse synchronization process according to an embodiment of the present application is shown.

[0026] Figure 5 A flowchart of fine synchronization processing according to an embodiment of the present application is shown.

[0027] Figure 6A block diagram of a signal synchronization device for a wireless ad hoc network according to an embodiment of the present application is shown.

[0028] Figure 7 A block diagram of a node according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0029] The present disclosure will be further described in detail below in conjunction with the accompanying drawings and examples. It should be understood that the examples provided herein are merely for explaining the present disclosure and are not intended to limit the present disclosure. In addition, the examples provided below are partial examples for implementing the present disclosure, rather than providing all examples for implementing the present disclosure. In the absence of conflict, the technical solutions described in the examples of the present disclosure may be implemented in any combination.

[0030] It should be noted that, in the embodiments of the present disclosure, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a method or apparatus comprising a series of elements includes not only the elements explicitly stated, but also other elements not explicitly listed, or also includes elements inherent to the implementation of the method or apparatus. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other related elements (such as steps in the method or units in the apparatus, for example, a unit may be part of a circuit, part of a processor, part of a program or software, etc.) in the method or apparatus comprising the element.

[0031] For example, the signal synchronization method for a wireless ad hoc network provided in an embodiment of the present disclosure includes a series of steps, but the signal synchronization method for a wireless ad hoc network provided in an embodiment of the present disclosure is not limited to the recorded steps. Similarly, the signal synchronization device for a wireless ad hoc network provided in an embodiment of the present disclosure includes a series of units, but the device provided in an embodiment of the present disclosure is not limited to including the units explicitly recorded, and may also include units that need to be set up to obtain relevant information or perform processing based on information.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present disclosure pertains. The terms used herein are for the purpose of describing specific embodiments only and are not intended to limit the present disclosure.

[0033] It is understandable that in the specific implementation of this application, relevant data is involved. When the embodiments in this application are applied to specific products or technologies, user permission or consent is required, and the collection, use and processing of relevant data must comply with relevant laws, regulations and standards of relevant countries and regions.

[0034] Figure 1A flowchart schematically illustrates a signal synchronization method for a wireless ad hoc network according to one embodiment of the present application. The wireless ad hoc network includes a receiving node and a transmitting node. The receiving node and the transmitting node can each be any node in the wireless ad hoc network, such as a drone, a vehicle-mounted terminal, a mobile phone, a smartwatch, or the like. In a specific embodiment of the present application, the node in the wireless ad hoc network is specifically a drone.

[0035] The receiving node in the wireless ad hoc network can perform the following Figure 1 The steps of the signal synchronization method shown are as follows: Figure 1 The signal synchronization method of the wireless ad hoc network may include steps S110 to S150.

[0036] Step S110, receiving a data packet sent by a sending node;

[0037] Step S120, obtaining a first received sequence from the data packet using a sliding window of a first length;

[0038] Step S130, performing frequency domain cross-correlation calculation and analysis on the first received sequence and the local sequence to obtain a rough signal synchronization point;

[0039] Step S140, using a sliding window of a second length to obtain a second received sequence where a rough synchronization point of the signal is located;

[0040] Step S150 , performing frequency domain cross-correlation calculation and analysis on the second received sequence and the local sequence to obtain a signal starting point, wherein the first length is greater than the second length.

[0041] The receiving node in the wireless ad hoc network can receive the data packets sent by the sending node (i.e. Figure 2 Received data 210 shown).

[0042] The receiving node first performs a coarse synchronization process, specifically: using a sliding window of a first length (i.e. Figure 2 The coarse synchronization window 220 shown in FIG2 is used to obtain the first received sequence from the data packet, and then the first received sequence is subjected to frequency domain cross-correlation calculation and analysis with the local sequence to obtain the rough synchronization point of the signal (ie, Figure 2 coarse synchronization point 230 shown).

[0043] The receiving node then performs fine synchronization processing, specifically: using a sliding window of the second length (ie, Figure 2 The fine synchronization window 240 shown in the figure obtains the second received sequence where the signal coarse synchronization point is located, and then performs frequency domain cross-correlation calculation and analysis on the second received sequence and the local sequence to obtain the signal starting point, wherein the first length is greater than the second length.

[0044] In this manner, the coarse and fine synchronization processes utilize sliding windows of different lengths, with the coarse synchronization process utilizing a larger sliding window than the fine synchronization process. Furthermore, frequency-domain cross-correlation calculations and analysis are performed in the frequency domain during coarse synchronization. These two combined effects effectively reduce the number of cross-correlation calculations and shorten signal synchronization detection time. Furthermore, frequency-domain cross-correlation calculations and analysis with the local sequence are performed in the frequency domain during coarse synchronization, avoiding the significant synchronization errors caused by increasing the length of the short training sequence (STF sequence). Consequently, the overall signal synchronization accuracy and efficiency of wireless ad hoc networks can be effectively improved.

[0045] Described below Figure 1 When performing signal synchronization of a wireless ad hoc network under the embodiment, further optional specific embodiments are provided for each step performed.

[0046] In one embodiment, the data packet is sent by the sending node according to a combined training sequence frame structure, the combined training sequence frame structure includes a preamble sequence and fixed-length control data, the header of the preamble sequence is configured with a signal synchronization sequence, and the local sequence is a pre-configured sequence that is the same as the signal synchronization sequence.

[0047] See Figure 3 In an embodiment of the present application, a new combined training sequence frame structure is further provided. The combined training sequence frame structure includes a preamble sequence 310 and fixed-length control data 320. The head of the preamble sequence 310 is configured with a signal synchronization sequence 311. The preamble sequence 310 may also include a short training sequence (STF) 312 and a long training sequence (LTF) 313. The fixed-length control data 320 may include a signaling field 321, a high-throughput short training sequence (HTSTF) 322, and a high-throughput long training sequence (HTLTF) 323. In one example, the signal synchronization sequence 311 may specifically be a ZC (Zadoff-Chu) sequence.

[0048] In addition, a local sequence identical to the signal synchronization sequence configured in the sending node is pre-configured locally at the receiving node. Based on this combined training sequence frame structure and this local sequence, the signal starting point positioning synchronization is performed through the aforementioned coarse synchronization processing and fine synchronization processing, which can further improve the signal synchronization accuracy of the wireless self-organizing network, especially under low signal-to-noise ratio and multipath channel conditions.

[0049] In the related art, autocorrelation operation is performed on the STF sequence and cross-correlation operation is performed on the LTF sequence and the local LTF sequence to perform signal starting point positioning synchronization, which is very susceptible to low signal-to-noise ratio and multipath channel conditions, resulting in poor signal synchronization accuracy.

[0050] Furthermore, in one embodiment, the length of the signal synchronization sequence is N, the first length is greater than the N, and the second length is equal to the N.

[0051] By setting the length of the signal synchronization sequence to N, setting the first length M1 of the sliding window for the coarse synchronization process to be greater than N, and setting the second length M2 of the sliding window for the fine synchronization process to N, the accuracy of signal synchronization can be further ensured. In one example, the first length can be specifically equal to 2N.

[0052] In one embodiment, see Figure 4 In step S130, performing frequency domain cross-correlation calculation and analysis on the first received sequence and the local sequence to obtain a rough signal synchronization point may include:

[0053] Step S410, performing a first length-point Fourier transform on the first received sequence to obtain a first transformed sequence;

[0054] Step S420, performing a first length-point Fourier transform on the local sequence to obtain a second transformed sequence;

[0055] Step S430, performing conjugate point product on the first transformed sequence and the second transformed sequence in the frequency domain to obtain a first conjugate point product sequence;

[0056] Step S440, performing a first-length point inverse Fourier transform on the first conjugate point product sequence to obtain a first calculation result, where the first calculation result is an absolute value in the time domain;

[0057] Step S450, determining whether the maximum peak point in the first calculation result is greater than a first predetermined threshold;

[0058] Step S460: If yes, the position of the maximum peak point in the first calculation result is determined as the rough synchronization point of the signal.

[0059] In this embodiment, specifically, first, a first length (M1) point Fourier transform is performed on the first received sequence to obtain a first transformed sequence; a first length (M1) point Fourier transform is performed on the local sequence to obtain a second transformed sequence; and a conjugate point product is performed on the first transformed sequence and the second transformed sequence in the frequency domain to obtain a first conjugate point product sequence.

[0060] Then, the first conjugate point multiplication sequence is subjected to a first length point inverse Fourier transform to obtain a first calculation result, which is an absolute value in the time domain; it is determined whether the maximum peak point in the first calculation result is greater than a first predetermined threshold (SS1); if the maximum peak point in the first calculation result is greater than the first predetermined threshold (SS1), the position of the maximum peak point in the first calculation result is determined as a rough synchronization point of the signal.

[0061] By performing frequency domain cross-correlation calculation and analysis on the first received sequence and the local sequence, a rough synchronization point of the signal can be accurately and efficiently located.

[0062] In one embodiment, obtaining the second received sequence where the rough synchronization point of the signal is located using a sliding window of a second length may include:

[0063] A predetermined backoff length is backed off from a rough synchronization point of the signal in the data packet to obtain a backoff point; and data is retrieved starting from the backoff point using a sliding window of a second length to obtain a second received sequence.

[0064] See Figure 2 , after determining the rough synchronization point of the signal through rough synchronization processing (i.e. Figure 2 After the rough synchronization point 230 shown in FIG, the signal is backed off from the rough synchronization point in the data packet by a predetermined backoff length (ie, as shown in FIG. Figure 2 A backoff length Q is shown in FIG. ), resulting in backoff point 250. Then, a sliding window of a second length is used to extract data starting from the backoff point to obtain a second received sequence. When the intercepted second received sequence is used for fine synchronization, the predetermined backoff length can serve as a guard interval, further improving the accuracy of positioning synchronization at the signal starting point.

[0065] Furthermore, in one embodiment, the predetermined backoff length is greater than the cyclic prefix length of an Orthogonal Frequency Division Multiplexing (OFDM) symbol. This can further ensure the accuracy of the positioning synchronization of the signal starting point. Orthogonal Frequency Division Multiplexing (OFDM) is a modulation technology used in digital communications that divides a data stream into multiple subcarriers for transmission. Orthogonal Frequency Division Multiplexing can be used to transmit data packets in wireless ad hoc networks.

[0066] In one embodiment, see Figure 5 In step S150, frequency domain cross-correlation calculation and analysis is performed on the second received sequence and the local sequence to obtain a signal starting point, including:

[0067] Step S510, performing frequency domain cross-correlation calculation on the second received sequence and the local sequence to obtain a second calculation result;

[0068] Step S520, determining whether the maximum peak point in the second calculation result is greater than a second predetermined threshold;

[0069] Step S530: If yes, determine the signal starting point in the data packet according to the position of the maximum peak point in the second calculation result.

[0070] Specifically, in this embodiment, a frequency-domain cross-correlation calculation is first performed on the second received sequence and the local sequence to obtain a second calculation result. A determination is then made as to whether the maximum peak value in the second calculation result is greater than a second predetermined threshold value (SS2). If the maximum peak value in the second calculation result is greater than the second predetermined threshold value (SS2), the signal starting point is determined based on the position of the maximum peak value in the second calculation result.

[0071] By performing frequency domain cross-correlation calculation and analysis on the second received sequence and the local sequence, the signal starting point can be accurately and efficiently located.

[0072] Furthermore, in one embodiment, determining the signal starting point in the data packet based on the position of the maximum peak point includes:

[0073] From the second calculation result, data in a predetermined range before the maximum peak point in the second calculation result is intercepted; and the first point in the predetermined range of data from the beginning to the end that is greater than a second predetermined threshold is determined as the signal starting point.

[0074] In this embodiment, the position of the maximum peak point in the second calculation result is not directly determined as the signal starting point (optionally, in other embodiments, the position of the maximum peak point in the second calculation result can be directly determined as the signal starting point). Instead, data in a predetermined range before the maximum peak point in the second calculation result is further intercepted from the second calculation result, and then, each point in the predetermined range of data is traversed from beginning to end, and the first point traversed from beginning to end that is greater than the second predetermined threshold is determined as the signal starting point.

[0075] Due to multipath effects in real-world communication environments, the sequence selected by the receiving node using the sliding window will inevitably contain signals from other sub-paths. The final result is that when the frequency domain cross-correlation between the sequence selected by the sliding window and the local sequence is calculated, multiple correlation peaks will appear that meet the judgment criteria. Considering this, a special multipath channel scenario is considered: the signal power of the first path is lower than that of the other paths. In this case, the signal starting point output by the fine synchronization process is incorrect, causing inter-symbol interference in the service data domain. This embodiment designs a method to address this special multipath channel. This method uses correlation values within a certain range of the fine synchronization result (i.e., the maximum peak point in the second calculation result) to traverse and independently determine the relationship between the value and the second predetermined threshold. Finally, the signal starting point is determined. This process effectively suppresses the impact of multipath effects on the synchronization result, further improving the accuracy of signal starting point positioning and synchronization.

[0076] Furthermore, in one embodiment, performing frequency domain cross-correlation calculation on the second received sequence and the local sequence to obtain a second calculation result may include: performing a second-length point Fourier transform on the second received sequence to obtain a third transformed sequence; performing a second-length point Fourier transform on the local sequence to obtain a fourth transformed sequence; performing conjugate point product on the third transformed sequence and the fourth transformed sequence in the frequency domain to obtain a second conjugate point product sequence; performing a second-length point inverse Fourier transform on the second conjugate point product sequence to obtain a second calculation result, where the second calculation result is an absolute value in the time domain.

[0077] Specifically, in this embodiment, the second received sequence is first subjected to a second-length (M2) point Fourier transform to obtain a third transformed sequence; the local sequence is subjected to a second-length (M2) point Fourier transform to obtain a fourth transformed sequence; the third transformed sequence and the fourth transformed sequence are subjected to a conjugate point multiplication in the frequency domain to obtain a second conjugate point product sequence. The second conjugate point product sequence is then subjected to a second-length (M2) point inverse Fourier transform to obtain a second calculation result, which is an absolute value in the time domain. This second calculation result can be used to accurately locate the starting point of the synchronization signal.

[0078] To facilitate better implementation of the signal synchronization method for a wireless ad hoc network provided in an embodiment of the present application, an embodiment of the present application also provides a signal synchronization device for a wireless ad hoc network based on the aforementioned signal synchronization method for a wireless ad hoc network. The meanings of the terms herein are the same as those in the aforementioned signal synchronization method for a wireless ad hoc network. For specific implementation details, please refer to the description in the method embodiment. Figure 6 A block diagram of a signal synchronization device for a wireless ad hoc network according to an embodiment of the present application is shown.

[0079] Wireless ad hoc networks include receiving nodes and sending nodes, such as Figure 6The signal synchronization device 600 of the wireless self-organizing network shown is applied to the receiving node, and the signal synchronization device 600 of the wireless self-organizing network may include: a receiving module 610 can be used to: receive the data packet sent by the sending node; a first synchronization analysis module 620 can be used to: use a sliding window of a first length to obtain a first receiving sequence from the data packet; perform frequency domain cross-correlation calculation and analysis on the first receiving sequence and the local sequence to obtain a rough signal synchronization point; a second synchronization analysis module 630 can be used to: use a sliding window of a second length to obtain a second receiving sequence where the rough signal synchronization point is located; perform frequency domain cross-correlation calculation and analysis on the second receiving sequence and the local sequence to obtain a signal starting point, wherein the first length is greater than the second length.

[0080] In some embodiments of the present application, the data packet is sent by the sending node in accordance with a combined training sequence frame structure, the combined training sequence frame structure includes a preamble sequence and fixed-length control data, the header of the preamble sequence is configured with a signal synchronization sequence, and the local sequence is a pre-configured sequence that is identical to the signal synchronization sequence.

[0081] In some embodiments of the present application, the length of the signal synchronization sequence is N, the first length is greater than the N, and the second length is equal to the N.

[0082] In some embodiments of the present application, the first synchronization analysis module 620 can be used to: perform the first length point Fourier transform on the first received sequence to obtain a first transform sequence; perform the first length point Fourier transform on the local sequence to obtain a second transform sequence; perform conjugate point multiplication on the first transform sequence and the second transform sequence in the frequency domain to obtain a first conjugate point product sequence; perform the first length point inverse Fourier transform on the first conjugate point product sequence to obtain a first calculation result, which is an absolute value in the time domain; determine whether the maximum peak point in the first calculation result is greater than a first predetermined threshold; if so, determine the position of the maximum peak point in the first calculation result as the rough synchronization point of the signal.

[0083] In some embodiments of the present application, the second synchronization analysis module 630 can be used to: perform frequency domain cross-correlation calculation on the second received sequence and the local sequence to obtain a second calculation result; determine whether the maximum peak point in the second calculation result is greater than a second predetermined threshold; if so, determine the signal starting point in the data packet based on the position of the maximum peak point in the second calculation result.

[0084] In some embodiments of the present application, the second synchronization analysis module 630 can be used to: intercept data in a predetermined range before the maximum peak point in the second calculation result from the two calculation results; and determine the first point in the data in the predetermined range from the beginning to the end that is greater than the second predetermined threshold as the signal starting point.

[0085] In some embodiments of the present application, the second synchronization analysis module 630 can be used to: perform the second length point Fourier transform on the second received sequence to obtain a third transform sequence; perform the second length point Fourier transform on the local sequence to obtain a fourth transform sequence; perform conjugate point multiplication on the third transform sequence and the fourth transform sequence in the frequency domain to obtain a second conjugate point product sequence; perform the second length point inverse Fourier transform on the second conjugate point product sequence to obtain the second calculation result, which is the absolute value in the time domain.

[0086] In some embodiments of the present application, the second synchronization analysis module 630 can be used to: back off a predetermined backoff length from the rough synchronization point of the signal in the data packet to obtain a backoff point; and use a sliding window of the second length to obtain data starting from the backoff point to obtain the second received sequence.

[0087] In some embodiments of the present application, the predetermined back-off length is greater than the length of a cyclic prefix of an orthogonal frequency division multiplexing symbol.

[0088] It should be noted that, although several modules or units of the device for action execution are mentioned in the above detailed description, this division is not mandatory. In fact, according to the embodiment of the application, the features and functions of two or more modules or units described above can be concretized in one module or unit. On the contrary, the features and functions of one module or unit described above can be further divided into multiple modules or units to be concretized.

[0089] In addition, the embodiment of the present application also provides a node, such as Figure 7 As shown, Figure 7 A block diagram of a node according to an embodiment of the present application is shown, specifically:

[0090] The node may include one or more processing core processors 701, one or more computer readable storage media memories 702 and other components. Those skilled in the art will understand that Figure 7 The node structure shown in the figure does not constitute a limitation of the node, and may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently.

[0091] Processor 701 is the control center of the node, connecting the various components of the entire computer device using various interfaces and lines. By running or executing software programs and / or modules stored in memory 702 and accessing data stored in memory 702, it performs various computer device functions and processes data, thereby providing overall monitoring of the node. Optionally, processor 701 may include one or more processing cores; preferably, processor 701 may integrate an application processor and a modem processor, wherein the application processor primarily processes the operating system, user interfaces, and application programs, while the modem processor primarily handles wireless communications. It is understood that the modem processor may not be integrated into processor 701.

[0092] Memory 702 can be used to store software programs and modules. Processor 701 executes various functional applications and data processing by running the software programs and modules stored in memory 702. Memory 702 may primarily include a program storage area and a data storage area. The program storage area may store an operating system and at least one application required for a function (such as sound playback or image playback); the data storage area may store data generated based on the use of the computer device. Furthermore, memory 702 may include high-speed random access memory and non-volatile memory, such as at least one disk storage device, flash memory device, or other volatile solid-state storage device. Accordingly, memory 702 may also include a memory controller to provide processor 701 with access to memory 702.

[0093] Although not shown, the node may also include a display unit, etc., which will not be described in detail here. Specifically, in this embodiment, the processor 701 in the node will load the executable files corresponding to one or more computer program processes into the memory 702 according to the following instructions, and the processor 701 will run the computer program stored in the memory 702, thereby realizing the various functions in the aforementioned embodiments of this application.

[0094] For example, the processor 701 may execute the following steps:

[0095] Receive a data packet sent by the sending node; obtain a first received sequence from the data packet using a sliding window of a first length; perform frequency domain cross-correlation calculation and analysis on the first received sequence and a local sequence to obtain a rough signal synchronization point; obtain a second received sequence where the rough signal synchronization point is located using a sliding window of a second length; perform frequency domain cross-correlation calculation and analysis on the second received sequence and the local sequence to obtain a signal starting point, wherein the first length is greater than the second length.

[0096] Those skilled in the art will appreciate that all or part of the steps in the various methods of the above embodiments may be accomplished by a computer program, or by controlling related hardware through a computer program. The computer program may be stored in a computer-readable storage medium and loaded and executed by a processor.

[0097] To this end, an embodiment of the present application further provides a storage medium storing a computer program, which can be loaded by a processor to execute the steps of any method provided in the embodiment of the present application.

[0098] The storage medium may be a computer-readable storage medium, and the storage medium may include a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0099] Since the computer program stored in the storage medium can execute the steps of any method provided in the embodiments of the present application, the beneficial effects that can be achieved by the method provided in the embodiments of the present application can be achieved. Please refer to the previous embodiments for details and will not be repeated here.

[0100] Those skilled in the art will readily conceive of other embodiments of the present application after considering the specification and practicing the embodiments disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present application that follow the general principles of this application and include common knowledge or customary techniques in the art that are not disclosed herein.

[0101] It should be understood that the present application is not limited to the embodiments that have been described above and shown in the accompanying drawings, but various modifications and changes may be made without departing from the scope thereof.

Claims

1. A signal synchronization method for a wireless ad hoc network, characterized in that: The wireless ad hoc network includes a receiving node and a sending node, and the method is applied to the receiving node, and the method includes: receiving a data packet sent by the sending node, where the data packet is sent by the sending node according to a combined training sequence frame structure, where the combined training sequence frame structure includes a preamble sequence and fixed-length control data, and a signal synchronization sequence is configured at the head of the preamble sequence; Obtaining a first received sequence from the data packet using a sliding window of a first length; Performing frequency domain cross-correlation calculation and analysis on the first received sequence and a local sequence in the frequency domain to obtain a rough signal synchronization point, wherein the local sequence is a pre-configured sequence that is the same as the signal synchronization sequence; Using a sliding window of a second length to obtain a second received sequence where the rough synchronization point of the signal is located; Perform frequency domain cross-correlation calculation and analysis on the second received sequence and the local sequence to obtain a signal starting point, wherein the first length is greater than the second length, the length of the signal synchronization sequence is N, the first length is greater than the N, and the second length is equal to the N.

2. The method according to claim 1, characterized in that The performing frequency domain cross-correlation calculation and analysis on the first received sequence and the local sequence in the frequency domain to obtain a rough signal synchronization point includes: Performing a first length-point Fourier transform on the first received sequence to obtain a first transformed sequence; Performing a first length-point Fourier transform on the local sequence to obtain a second transformed sequence; performing a conjugate point product on the first transformed sequence and the second transformed sequence in the frequency domain to obtain a first conjugate point product sequence; Performing a first-length point inverse Fourier transform on the first conjugate point product sequence to obtain a first calculation result, where the first calculation result is an absolute value in the time domain; Determining whether a maximum peak point in the first calculation result is greater than a first predetermined threshold; If so, the position of the maximum peak point in the first calculation result is determined as the rough synchronization point of the signal.

3. The method according to claim 1, characterized in that The performing frequency domain cross-correlation calculation and analysis on the second received sequence and the local sequence to obtain a signal starting point includes: Perform frequency domain cross-correlation calculation on the second received sequence and the local sequence to obtain a second calculation result; Determining whether the maximum peak point in the second calculation result is greater than a second predetermined threshold; If so, the signal starting point in the data packet is determined according to the position of the maximum peak point in the second calculation result.

4. The method according to claim 3, characterized in that Determining the signal starting point in the data packet according to the position of the maximum peak point includes: From the two calculation results, extracting data in a predetermined range before the maximum peak point in the second calculation result; The first point in the data of the predetermined range that is greater than the second predetermined threshold from the beginning to the end is determined as the signal starting point.

5. The method according to claim 3, characterized in that The performing frequency domain cross-correlation calculation on the second received sequence and the local sequence to obtain a second calculation result includes: Performing a second length-point Fourier transform on the second received sequence to obtain a third transformed sequence; Performing a second length-point Fourier transform on the local sequence to obtain a fourth transformed sequence; performing a conjugate point product on the third transformed sequence and the fourth transformed sequence in the frequency domain to obtain a second conjugate point product sequence; Perform a second length point inverse Fourier transform on the second conjugate point product sequence to obtain the second calculation result, which is an absolute value in the time domain.

6. The method according to claim 1, characterized in that The step of using a sliding window of a second length to obtain a second received sequence where the rough synchronization point of the signal is located includes: Backing off a predetermined backoff length from the rough synchronization point of the signal in the data packet to obtain a backoff point; The sliding window of the second length is used to obtain data starting from the backoff point to obtain the second received sequence.

7. The method according to claim 6, characterized in that The predetermined back-off length is greater than the length of a cyclic prefix of an orthogonal frequency division multiplexing symbol.

8. A signal synchronization device for a wireless ad hoc network, characterized in that: The wireless ad hoc network includes a receiving node and a sending node, and the device is applied to the receiving node, and the device includes: a receiving module, configured to: receive a data packet sent by the sending node, wherein the data packet is sent by the sending node according to a combined training sequence frame structure, wherein the combined training sequence frame structure includes a preamble sequence and fixed-length control data, and a signal synchronization sequence is configured at the head of the preamble sequence; a first synchronization analysis module, configured to: obtain a first received sequence from the data packet using a sliding window of a first length; perform frequency domain cross-correlation calculation and analysis on the first received sequence and a local sequence in the frequency domain to obtain a rough signal synchronization point, wherein the local sequence is a pre-configured sequence identical to the signal synchronization sequence; The second synchronization analysis module is configured to: use a sliding window of a second length to obtain a second received sequence where the coarse synchronization point of the signal is located; and perform frequency domain cross-correlation calculation and analysis on the second received sequence and the local sequence to obtain a signal starting point, wherein the first length is greater than the second length, the length of the signal synchronization sequence is N, the first length is greater than N, and the second length is equal to N.

9. A storage medium, characterized in that: A computer program is stored thereon, which, when executed by a processor of a node, causes the node to execute the method according to any one of claims 1 to 7.

10. A node, characterized in that: include: a memory storing a computer program; A processor reads a computer program stored in a memory to execute the method according to any one of claims 1 to 7.

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