Signal synchronization method, system, and storage medium

Abstract

This invention provides a signal synchronization method, system, and storage medium, relating to the field of communication technology and applicable to signal synchronization systems. The signal synchronization system includes a main control module, multiple acquisition modules, and multiple synchronization modules, which are cascaded sequentially. The signal synchronization method includes: a main control module distributing a unified reference clock and a unified reference time to the acquisition modules; acquisition modules acquiring sampled data from air signals, generating data streams based on the sampled data, and distributing the data streams step-by-step to the next acquisition module or the next synchronization module; and synchronization modules selecting at least one data stream from the received multiple data streams as the data to be synchronized and performing synchronization processing on it. This invention distributes data from each module step-by-step to the next level module, effectively avoiding the overload problem caused by centralized synchronization processing, thereby ensuring signal synchronization accuracy in complex scenarios.

Description

Technical Field

[0001] This invention relates to the field of communication technology, and in particular to a signal synchronization method, system, and storage medium. Background Technology

[0002] In modern wireless communication, the prerequisite for data transmission between the transmitting and receiving parties is synchronization (generally referred to as cell search in civilian communication). Synchronization involves obtaining the pre-agreed transmission and reception time and location (time frame location) and simultaneously acquiring broadcast control interaction parameter messages. Using a single antenna for reception or location-restricted reception (where the transmitting and receiving antennas are not in the same direction) can lead to synchronization failure or malfunction.

[0003] Existing synchronization methods typically combine distributed acquisition with centralized synchronization to process communication data. However, in wide-area coverage or complex scenarios, centralized synchronization can lead to excessive processing load and reduced synchronization accuracy. Summary of the Invention

[0004] This invention provides a signal synchronization method, system, and storage medium to solve the technical problem in the prior art where centralized synchronization leads to excessive synchronization processing load and reduced synchronization accuracy in wide-area coverage or complex scenarios.

[0005] This invention provides a signal synchronization method applicable to a signal synchronization system. The signal synchronization system includes a main control module, multiple acquisition modules, and multiple synchronization modules, wherein the acquisition modules and synchronization modules are cascaded sequentially. The signal synchronization method includes: The main control module distributes a unified reference clock and a unified reference time to the acquisition module. The acquisition module acquires sampling data from air signals, generates a data stream based on the sampling data, and distributes the data stream to the next acquisition module or the next synchronization module level by level. The synchronization module selects at least one data stream from the received multiple data streams as the data to be synchronized, and performs synchronization processing on the data to be synchronized.

[0006] According to the signal synchronization method provided by the present invention, the step of acquiring sampling data from air signals and generating a data stream based on the sampling data includes: Sampling data is obtained based on a unified reference clock, and a timestamp is inserted into the sampling data to generate a data stream; wherein the timestamp is generated based on the unified reference time.

[0007] According to the signal synchronization method provided by the present invention, the step of distributing the data stream to the next acquisition module or the next synchronization module in stages includes: At least one data stream from the nth acquisition module, and at least one data stream received by the nth acquisition module from the (n-1)th acquisition module, are distributed to the (n+1)th acquisition module; where n is greater than or equal to 1. At least one data stream from the (n+1)th acquisition module, and at least one data stream received by the (n+1)th acquisition module from the nth acquisition module, are distributed to the first synchronization module.

[0008] According to the signal synchronization method provided by the present invention, selecting at least one data stream from the received multiple data streams as the data to be synchronized includes: It receives and responds to the configuration instructions from the main control module, and selects at least one data stream from multiple data streams as the data to be synchronized.

[0009] According to the signal synchronization method provided by the present invention, the synchronization processing of the data to be synchronized includes: A synchronization search algorithm is used to determine the time frame position from the data to be synchronized, and broadcast information is extracted from the data to be synchronized based on the time frame position; The time frame position and the broadcast information are used as the synchronization output result.

[0010] According to the signal synchronization method provided by the present invention, the step of using a synchronization search algorithm to determine the time frame position from the data to be synchronized includes: The data to be synchronized is channelized to divide it into several sub-band signals. The center frequency of the preset target synchronization signal in the sub-band signal is shifted to zero frequency to obtain a zero-frequency baseband signal; The sampling rate of the zero-frequency baseband signal is down-converted to be consistent with the baseband sampling frequency of the preset target synchronization signal to obtain a low sampling rate baseband signal; The local known synchronization sequence is correlated with the baseband sequence of the low sampling rate baseband signal by sliding correlation to obtain the correlation energy sequence; The peak position of the relevant energy sequence is detected based on the dynamic threshold, and the time frame position is calculated by combining the peak position and the timestamp.

[0011] According to the signal synchronization method provided by the present invention, the step of performing a sliding correlation between the locally known synchronization sequence and the baseband sequence of the low sampling rate baseband signal to calculate the correlation energy sequence includes: Using the locally known synchronization sequence as a sliding window, the system slides sequentially across the baseband sequence from the initial position. After each slide, the sum of the products of the synchronization sequence and the corresponding points of the baseband sequence within the current window is calculated, and the square of the sum of the products modulo the sum is taken to obtain the relevant energy value at the current sliding position. After traversing all sliding positions, the relevant energy sequence is obtained.

[0012] According to the signal synchronization method provided by the present invention, the step of detecting the peak position of the relevant energy sequence based on a dynamic threshold and calculating the time frame position by combining the peak position and the timestamp includes: The first position in the relevant energy sequence that exceeds the dynamic threshold and has the largest amplitude is determined as the peak position. The timestamp carried by the data to be synchronized is obtained. The peak position is multiplied by the sampling period to obtain the time offset. The timestamp and the time offset are added to obtain the time frame position.

[0013] The present invention also provides a signal synchronization system, including a main control module, multiple acquisition modules and multiple synchronization modules, wherein the multiple acquisition modules and multiple synchronization modules are cascaded in sequence; The main control module distributes a unified reference clock and a unified reference time to the acquisition module. The acquisition module acquires sampling data from air signals, generates a data stream based on the sampling data, and distributes the data stream to the next acquisition module or the next synchronization module level by level. The synchronization module selects at least one data stream from the received multiple data streams as the data to be synchronized, and performs synchronization processing on the data to be synchronized.

[0014] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the signal synchronization method described above.

[0015] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the signal synchronization method as described above.

[0016] The present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the signal synchronization method as described above.

[0017] This invention distributes data from each module to the next level module through a hierarchical distribution method. The chain-like cascaded structure ensures that each node communicates only with its adjacent nodes, and the data stream is broadcast hierarchically. Furthermore, it can perform synchronization processing on data requiring synchronization based on actual needs, effectively avoiding the excessive load problem caused by centralized synchronization processing. This ensures signal synchronization accuracy in wide-area coverage or complex scenarios. When it is necessary to expand the coverage area or acquisition density, only additional acquisition or synchronization modules need to be added to the chain-like cascaded structure, thereby effectively improving the applicability of signal synchronization.

[0018] Furthermore, the synchronization module of the present invention only selects the data stream specified by the main control module for processing, avoiding the execution of synchronization algorithms on all multi-channel data, significantly reducing the consumption of computing resources, thereby effectively improving the synchronization processing efficiency. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a flowchart illustrating the signal synchronization method provided in an embodiment of the present invention.

[0021] Figure 2 This is a schematic diagram of the acquisition module provided in an embodiment of the present invention.

[0022] Figure 3 This is a schematic diagram of the data flow structure provided in an embodiment of the present invention.

[0023] Figure 4 This is a schematic diagram of the data distribution process provided in an embodiment of the present invention.

[0024] Figure 5 This is a schematic diagram of the synchronous output process provided in an embodiment of the present invention.

[0025] Figure 6 This is a schematic diagram of energy detection provided in an embodiment of the present invention.

[0026] Figure 7 This is a schematic diagram of broadcast signal extraction provided in an embodiment of the present invention.

[0027] Figure 8 This is a schematic diagram of the signal synchronization system provided in an embodiment of the present invention.

[0028] Figure 9 This is a schematic diagram of the physical structure of the electronic device provided in an embodiment of the present invention. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0030] Figure 1 This is a flowchart illustrating the signal synchronization method provided by the present invention. The signal synchronization method of this embodiment is applicable to a signal synchronization system, which includes a main control module, multiple acquisition modules, and multiple synchronization modules, wherein the multiple acquisition modules and multiple synchronization modules are cascaded sequentially. Figure 1 As shown, the method includes the following: S1. The main control module distributes a unified reference clock and a unified reference time to the acquisition module; The main control module provides a unified reference clock and a unified reference time. The unified reference clock is a highly stable clock source distributed to all acquisition and synchronization modules via wired or wireless means, ensuring strict alignment of the analog-to-digital converter sampling times across all modules and eliminating clock drift. The unified reference time is absolute time information (e.g., year, month, day, hour, minute, second), used to generate timestamps, ensuring consistency in the time stamps applied by different acquisition modules. The main control module is also responsible for configuring the operating parameters of each module, such as selecting the number of data channels and the target signal frequency.

[0031] S2. The acquisition module acquires air signals to obtain sampled data, generates a data stream based on the sampled data, and distributes the data stream to the next acquisition module or the next synchronization module level by level. In this embodiment of the invention, the airborne signal refers to the electromagnetic wave signal radiated into space by communication equipment (such as base stations and terminals), including synchronization sequences, broadcast information, and user data. The acquisition module of this embodiment receives the airborne signal through a distributed antenna array and samples it using an analog-to-digital converter to obtain sampled data. The sampled data is a discrete digital I / Q (I, In-phase; Q, Quadrature) complex signal, with a sampling rate preset by the system (e.g., 500MHz). To facilitate subsequent processing, the acquisition module can package continuous sampled data into packets of a certain length and attach timestamps to form a data stream. The generation of timestamps depends on a unified reference time provided by the main control module. The data stream refers to a sequence of sampled data packets with timestamps. Each data packet contains a segment of sampled data and its corresponding absolute timestamp. The data stream is distributed level by level through a high-speed distribution network; that is, each acquisition module or synchronization module, while using the data locally, forwards all received data streams to the next level module, forming a chained broadcast. This hierarchical distribution acquisition method ensures that all synchronization modules can obtain the same set of raw data, laying the foundation for parallel processing, enabling wide-area signal acquisition and low-latency sharing, and avoiding the bottleneck caused by centralized processing.

[0032] In this embodiment of the invention, based on a unified reference clock, the acquisition modules synchronously sample the air signal at the same sampling time to obtain the original sampled data. Then, a high-precision timestamp is generated based on the unified reference time. This timestamp contains the absolute time and a sampling period count (e.g., a counter in 2ns units), and the timestamp is inserted into the header or tail of the sampled data packet to generate a data stream with a time stamp. The timestamp is obtained by the main control module distributing the reference time, and each acquisition module maintains a local time counter, latching the count value at the moment of sampling. The purpose of the timestamp is to mark the absolute acquisition time of each data segment. Subsequent synchronization modules can use this to align data from different antennas and calculate the signal transmission delay and frame start position in the air. The overall effect of this step is to ensure that the multi-channel acquired data is time-traceable and alignable.

[0033] S3. The synchronization module selects at least one data stream from the received multiple data streams as the data to be synchronized, and performs synchronization processing on the data to be synchronized.

[0034] In this embodiment of the invention, the synchronization module can receive multiple data streams (e.g., 8-channel, 16-channel, etc.) from all acquisition modules via a high-speed distribution network. Due to system resource or task requirements, the synchronization module does not need to process all data streams. Instead, based on the configuration commands issued by the main control module (e.g., specifying processing channels ①~④), it selects the data stream of the corresponding channel from the received multiple data streams as the data to be synchronized. The selection method of the data to be synchronized is dynamically configured by the main control module, which can achieve load balancing or targeted search. Synchronization processing refers to performing a series of algorithms on the data to be synchronized, such as channelization, mixing and shifting, downsampling, sliding correlation, dynamic threshold detection, time frame position estimation, and broadcast information parsing, to finally obtain the time frame position (i.e., the absolute time boundary agreed upon by the sender and receiver) and broadcast information (such as cell ID, system bandwidth, etc.). The role of synchronization processing is to extract the synchronization parameters required for communication from the original sampled data, and to complete the time alignment and system information acquisition between the receiver and the sender. The overall role of this step is to achieve high-precision, high-parallel synchronization search, providing a foundation for subsequent data demodulation, multi-antenna combining, and other operations.

[0035] This invention distributes data from each module to the next level module through a hierarchical distribution method. The chain-like cascaded structure ensures that each node communicates only with its adjacent nodes, and the data stream is broadcast hierarchically. Furthermore, it can perform synchronization processing on data requiring synchronization based on actual needs, effectively avoiding the excessive load problem caused by centralized synchronization processing. This ensures signal synchronization accuracy in wide-area coverage or complex scenarios. When it is necessary to expand the coverage area or acquisition density, only additional acquisition or synchronization modules need to be added to the chain-like cascaded structure, thereby effectively improving the applicability of signal synchronization.

[0036] Please see Figure 2 In one embodiment, a schematic diagram of the acquisition module is provided. Figure 2 As shown, the acquisition module includes a radio frequency processing unit and an analog-to-digital conversion unit. The acquisition module acquires air information based on the reference clock information configured by the main control module, obtains sampled data, inserts timestamps into the sampled data packets based on the reference time information configured by the main control module, generates a data stream, and then distributes the data.

[0037] Please see Figure 3 This is a schematic diagram of a data flow structure provided in an embodiment of the present invention. Figure 3 Each data stream shown consists of sampled data and a timestamp.

[0038] In one embodiment, step S2, acquiring sampling data from air signals and generating a data stream based on the sampling data, includes: Sampling data is obtained based on a unified reference clock, and a timestamp is inserted into the sampling data to generate a data stream; wherein the timestamp is generated based on the unified reference time.

[0039] In this embodiment of the invention, the unified reference clock refers to a high-stability clock signal (e.g., 100MHz or 500MHz) generated by the main control module and distributed to all acquisition modules. Its function is to ensure that acquisition modules in different geographical locations sample air signals at the same time, eliminating inconsistencies in sampling time caused by clock drift or crystal oscillator deviation. The generation of timestamps depends on the unified reference time, i.e., the global absolute time reference provided by the main control module, such as through GNSS (Global Navigation Satellite System) or PTP (Precision Time Protocol) synchronization. The data stream refers to a structured data packet sequence formed by packaging continuous sampled data into fixed lengths and appending timestamps to the header or tail of the packets, which facilitates transmission and subsequent processing in the distribution network.

[0040] In this embodiment of the invention, the main control module can distribute a unified reference clock and a unified reference time to all acquisition modules via a dedicated clock interface or network protocol. Each acquisition module maintains a local time counter, which is initialized with the unified reference time and automatically increments by the period of the unified reference clock. When the ADC (Analog-to-Digital Converter) samples, the acquisition module latches the current counter value and generates a timestamp corresponding to the sampling point or sampled data block. Then, the acquisition module concatenates the sampled data and the timestamp according to a predefined format, such as 8 bytes of absolute time + 4 bytes of sample count + sampled data block, and encapsulates them into a data stream. Finally, this data stream is pushed to the high-speed distribution network and forwarded level by level to the next acquisition module or synchronization module.

[0041] The embodiments of the present invention generate data streams by coordinating a unified reference clock and a unified reference time, which enables high-precision synchronous sampling and data time traceability of distributed antenna arrays. This effectively improves the alignment of sampled data and the consistency of time reference, thereby effectively improving the accuracy and reliability of signal synchronization.

[0042] In one embodiment, step S2, distributing the data stream step by step to the next acquisition module, includes: S21. Distribute at least one data stream from the nth acquisition module, and at least one data stream received by the nth acquisition module from the (n-1)th acquisition module, to the (n+1)th acquisition module; where n is greater than or equal to 1. In this embodiment of the invention, each acquisition module is used to acquire and generate its own data stream, as well as receive the data stream forwarded by the upstream module, and then merge the two data streams and forward them to the downstream module.

[0043] S22. Distribute at least one data stream from the (n+1)th acquisition module and at least one data stream received by the (n+1)th acquisition module from the nth acquisition module to the first synchronization module.

[0044] In this embodiment of the invention, the data stream distribution method can be a process of copying the data stream from the current module to the next level module via a high-speed bus such as a serial link or Ethernet. In the hierarchical distribution, each module also acts as a repeater to achieve data broadcasting. The nth acquisition module represents any node in the chain topology, where n increases from 1. The first acquisition module has no upstream module, so when n=1, the first acquisition module only forwards its own data stream. The (n-1)th acquisition module is the upstream module of the nth module, and its distributed data stream already contains data from all the preceding acquisition modules. The (n+1)th acquisition module is the downstream module of the nth module. The first synchronization module refers to the first synchronization module in the chain topology. Although the synchronization module is not an acquisition module, it also has the ability to receive and forward data. When the number of acquisition modules is n+1, the data stream of the (n+1)th acquisition module is distributed to the first synchronization module, and the mth synchronization module distributes the received data stream to the (m+1)th synchronization module.

[0045] In one embodiment, four acquisition modules and two synchronization modules are configured. Each acquisition module can use two antennas to acquire data, for a total of eight data channels. Each synchronization module can process four data channels. Each module is numbered from low to high according to the cascading order, and the distribution direction is also numbered from low to high, i.e., C1--->C2--->……--->Cx. Each channel can transmit one wideband signal or multiple narrowband signals sampled by the ADC (Analog-to-Digital Converter). The distribution process is as follows: C1 uses distribution channels ① and ②, while C2 to Cx all forward channels ① and ②. C2 uses distribution channels ③ and ④, while C3 to Cx all forward channels ①, ②, ③, and ④.

[0046] In this embodiment of the invention, it should be noted that when the chain topology extends to the last acquisition module (e.g., C4), the next node is the first synchronization module (e.g., C5). At this time, the (n+1)th acquisition module merges at least one of its own data streams (e.g., channels ⑦ and ⑧) with the data streams received from the upstream nth acquisition module (including all channels ①②③④⑤⑥ of C1, C2, and C3), and distributes them all to the first synchronization module. In this way, the first synchronization module C5 obtains all the data streams from all acquisition modules, and similarly, the second synchronization module C6 will also receive data streams ①②③④⑤⑥⑦⑧.

[0047] This invention employs a hierarchical forwarding mechanism, where each acquisition module merges its own data with upstream data and transmits it downwards. Ultimately, this enables the first synchronization module to receive all data streams from all acquisition modules, and each synchronization module receives all data streams from all acquisition modules. This eliminates the need for a central switch or aggregation node. The synchronization module only needs to perform synchronization processing on any one or more data streams according to configuration instructions or actual needs, thereby effectively reducing the data processing load and improving synchronization processing capability and signal synchronization accuracy.

[0048] Please see Figure 4 This is a schematic diagram of a data distribution process provided by an embodiment of the present invention. Figure 4 As shown, the acquisition module distributes the multiple data streams from all acquisition modules to the first synchronization module in a hierarchical manner. Then, the first synchronization module distributes the multiple data streams to the next synchronization module in a hierarchical manner to achieve distributed distribution.

[0049] In one embodiment, step S3, selecting at least one data stream from the received multiple data streams as the data to be synchronized, includes: It receives and responds to the configuration instructions from the main control module, and selects at least one data stream from multiple data streams as the data to be synchronized.

[0050] In this embodiment of the invention, the main control module is the central control node of the signal synchronization system, responsible for issuing configuration parameters, operating modes, and task assignment instructions to all acquisition modules and synchronization modules. The configuration instruction is a structured control message containing at least the following information: the channel number of the data stream to be processed (e.g., "channel ①, ②"), the center frequency, bandwidth, baseband symbol rate of the target synchronization signal, the type of the locally known synchronization sequence, and the dynamic threshold coefficient. The configuration instruction can be transmitted via a separate control bus or in-band signaling shared with the data streams. Multiple data streams refer to the sequence of timestamped data packets received by the synchronization module from all acquisition modules through a high-speed distribution network, such as the eight data streams (channels ① to ⑧) received by synchronization module C5. Data to be synchronized refers to the one or more data streams selected by the synchronization module according to the configuration instruction, from which the synchronization search algorithm will be executed.

[0051] In this embodiment of the invention, after power-on initialization, the synchronization module can continuously monitor the control channel from the main control module. The main control module generates a configuration command based on system task requirements, such as needing to search for signals in a specific cell, and sends it to the designated synchronization module via the control interface. Upon receiving the configuration command, the synchronization module parses the data stream path number list within it. Simultaneously, the synchronization module maintains a data stream buffer internally, storing all data streams received from the distribution network. Based on the parsed path number list, the synchronization module selects the corresponding data stream from the buffer and marks it as data to be synchronized. If the configuration command requires processing multiple data streams (e.g., for aggregation and merging), multiple streams are selected; if only one stream is required, only one stream is selected. After selection, the synchronization module prepares to perform subsequent synchronization processing on the data, such as channelization and frequency shifting.

[0052] The synchronization module in this embodiment of the invention only selects the data stream specified by the main control module for processing, avoiding the execution of synchronization algorithms on all multi-channel data, significantly reducing the consumption of computing resources, and thus effectively improving the efficiency of synchronization processing.

[0053] In one embodiment, step S3, synchronizing the data to be synchronized, includes: S31. Using a synchronization search algorithm, determine the time frame position from the data to be synchronized, and extract broadcast information from the data to be synchronized based on the time frame position; S32. The time frame position and the broadcast information are used as the synchronization output result.

[0054] In this embodiment of the invention, the broadcast information includes cell identifier and system bandwidth, etc., which is obtained based on the analysis of the broadcast signal. The broadcast signal is a modulated signal carrying system parameters sent by the transmitting end in a fixed time slot, and its original form is I / Q complex sampled data.

[0055] In this embodiment of the invention, after obtaining the synchronization output result, the starting position of the data time slot can be located based on the time frame position of the synchronization output and the system parameters (such as bandwidth, frame structure, modulation and coding scheme) in the broadcast information, and the subsequent user service data can be demodulated and decoded. Alternatively, multiple data from different acquisition modules can be aligned using a unified timestamp, and combined with the time frame position of the synchronization output, the multiple signals at the same time can be combined by maximum ratio, equal gain, or the best antenna signal can be selected to improve the signal reception quality.

[0056] The embodiments of the present invention determine the time frame position by using a synchronization search algorithm, and then extract broadcast information from the data to be synchronized based on the time frame position. This enables precise time alignment at the sampling period level in wide-area coverage and complex scenarios, thereby significantly improving signal synchronization accuracy.

[0057] In one embodiment, S32, using a synchronization search algorithm to determine the time frame position from the data to be synchronized, includes: S321. Channelize the data to be synchronized to divide it into several sub-band signals. In this embodiment of the invention, the data to be synchronized can be a broadband signal. Channelization processing is a digital signal processing technique that divides the broadband signal into multiple narrowband sub-signals, or sub-signals, according to frequency. Each sub-band signal is a narrowband signal obtained after channelization, and its bandwidth is much smaller than that of the original broadband signal. Each sub-band corresponds to a continuous frequency range.

[0058] In this embodiment of the invention, the synchronization module can read the data to be synchronized, such as an I / Q complex sampling sequence, from its internal buffer and send it to a digital channelizer. The channelizer decomposes the input data into N complex signals in parallel, each corresponding to a sub-band, according to a preset number of sub-bands N and filter coefficients. In this embodiment of the invention, the center frequency and bandwidth of the sub-bands are determined by the filter bank design.

[0059] This invention decomposes a broadband signal into multiple narrowband sub-bands, making it easier to select only the sub-band containing the target synchronization signal for subsequent processing, reducing single-channel processing bandwidth and computational complexity, while supporting parallel processing of multiple sub-bands.

[0060] S322. Shift the center frequency of the preset target synchronization signal in the sub-band signal to zero frequency to obtain a zero-frequency baseband signal; In this embodiment of the invention, the preset target synchronization signal is a specific synchronization signal configured by the main control module and required to be detected. It includes a synchronization sequence and a broadcast channel, and has a known center frequency, bandwidth, and training sequence. The center frequency is the carrier frequency of the preset target synchronization signal in the spectrum, for example, 2.6 GHz. The zero-frequency baseband signal is a complex signal obtained after shifting, with a center frequency of 0 Hz, but still maintaining the original high sampling rate.

[0061] In this embodiment of the invention, a sub-band containing the center frequency of a preset target synchronization signal configured by the main control module can be selected from multiple sub-band signals. A complex carrier with a frequency equal to the center frequency of the preset target synchronization signal is generated by a numerically controlled oscillator in the synchronization module. The selected sub-band signal is multiplied by the carrier, and then filtered out by a low-pass filter to remove high-frequency images, thereby obtaining a zero-frequency baseband signal.

[0062] This invention converts the preset target synchronization signal from bandpass form to baseband form, which facilitates subsequent downsampling and sliding correlation processing.

[0063] S323. The sampling rate of the zero-frequency baseband signal is downconverted to be consistent with the baseband sampling frequency of the preset target synchronization signal to obtain a low sampling rate baseband signal; In this embodiment of the invention, the zero-frequency baseband signal can be fed into a digital down-converter (DDC). The DDC first filters out out-of-band noise and aliasing components through a low-pass filter, and then decimates the signal according to an integer multiple of the decimation factor D (D = original sampling rate / target baseband sampling rate), outputting a low sampling rate baseband signal. The decimation factor is configured by the main controller or preset by the system.

[0064] This invention reduces the data rate and the computational load of subsequent sliding correlation and peak detection by downconverting the sampling rate of the zero-frequency baseband signal to match the baseband sampling frequency of the preset target synchronization signal.

[0065] S324. Perform a sliding correlation between the locally known synchronization sequence and the baseband sequence of the low sampling rate baseband signal to calculate the correlation energy sequence; In this embodiment of the invention, the locally known synchronization sequence is a training sequence pre-stored at the receiving end, and this locally known synchronization sequence is exactly the same as the sequence used in the synchronization header at the transmitting end. The baseband sequence is a time-discrete sampling point sequence of a low-sampling-rate baseband signal.

[0066] In this embodiment of the invention, the sliding correlation processing can be performed by sliding the known sequence and the baseband sequence point by point from the starting position and calculating the correlation value; the correlation energy sequence is the sequence obtained by taking the square of the modulus of each correlation value.

[0067] This invention can read a known sequence (PN_DATA) specified by the master controller from local memory. Simultaneously, it reads the baseband sequence (RX_DATA) of the low-sampling-rate baseband signal. Then, through a hardware correlator or software loop, it calculates the dot product of all sliding positions and the modulus squared to generate a correlation energy sequence.

[0068] S325. Detect the peak position of the relevant energy sequence according to the dynamic threshold, and calculate the time frame position by combining the peak position and the timestamp.

[0069] In this embodiment of the invention, the dynamic threshold is a threshold that can be adaptively adjusted according to the energy of the received signal itself.

[0070] In this embodiment of the invention, the process for determining the time frame position can be as follows: The baseband sequence obtained by the receiver after downsampling is RX_DATA, with a length of N. The known training sequence (i.e., the locally known synchronization sequence) used by the transmitter is PN_DATA, with a length of L. The correlation operation involves using PN_DATA as a template and sliding it point by point on RX_DATA, calculating the correlation value at each sliding position, i.e., Corr(RX_DATA, PN_DATA). The correlation operation is defined as multiplying corresponding points and then summing them. Specifically: Corr(0) = RX_DATA(0) PN_DATA(0)+RX_DATA(1) PN_DATA(1)+…+RX_DATA(L-1) PN_DATA(L-1); Corr(1) = RX_DATA(1) PN_DATA(0)+RX_DATA(2) PN_DATA(1)+…+RX_DATA(L) PN_DATA(L-1); Corr(2) = RX_DATA(2) PN_DATA(0)+RX_DATA(3) PN_DATA(1)+…+RX_DATA(L+1) PN_DATA(L-1); … Corr(NL) = RX_DATA(NL) PN_DATA(0)+RX_DATA(N-L+1) PN_DATA(1)+…+RX_DATA(N-1) PN_DATA(L-1); Where n is the index of the sliding position, and the value range is 0, 1, 2, ..., NL. Each correlation value Corr(n) is a complex number. In order to obtain the intensity of the correlation energy, the correlation energy sequence is further calculated: Corr_Power=abs(Corr(n))^2.

[0071] In this embodiment of the invention, the real energy value is obtained by taking the square modulo of each correlation value, which is the correlation energy sequence. The correlation energy sequence reflects the degree of matching of the received signal at position n with the local training sequence. When n exactly corresponds to the starting position of the synchronization sequence in the received signal, Corr_Power(n) will have a peak value.

[0072] In this embodiment of the invention, to avoid missed detections or false alarms caused by using a fixed threshold in environments with fluctuating signal strength or interference, the invention employs a dynamic threshold based on the energy of the received signal itself in real time. The specific calculation method is as follows: First, a sliding autocorrelation is performed on the received baseband sequence RX_DATA to calculate the signal energy Corr_data(n) within each sliding window. The value of n ranges from 0, 1, 2, ..., NL-1 (the last window guarantees complete coverage of L points). The autocorrelation operation uses conjugate multiplication: Corr_data(0)=RX_DATA(0) CONJ(RX_DATA(0))+RX_DATA(1) CONJ(RX_DATA(1))+…+RX_DATA(L-1) CONJ(RX_DATA(L-1)); Corr_data(1)=RX_DATA(1) CONJ(RX_DATA(2))+RX_DATA(3) CONJ(RX_DATA(4))+…+RX_DATA(L) CONJ(RX_DATA(L)); Corr_data(2)=RX_DATA(2) CONJ(RX_DATA(3))+RX_DATA(4) CONJ(RX_DATA(5))+…+RX_DATA(L+1) CONJ(RX_DATA(L+1)); … Corr_data(NL-1)=RX_DATA(NL-1) CONJ(RX_DATA(NL-1))+RX_DATA(NL) CONJ(RX_DATA(NL))+…+RX_DATA(N-1) CONJ(RX_DATA(N-1)).

[0073] Where CONJ is the conjugate operation, and the data energy is defined as: Corr_data_Power=abs(Corr_data(n))^2. n=0, 1, 2, 3,…, N-1.

[0074] Final threshold = Corr_data_Power threshold_coe, where threshold_coe is an unsigned number less than or equal to 1. The larger the factor, the higher the threshold.

[0075] In this embodiment of the invention, the synchronization module scans all sliding positions n and finds the first or the n value with the largest energy that satisfies the following condition: Corr_Power(n) > Threshold(n) Where Corr_Power(n) is the correlation energy value calculated at the sliding position n; Threshold(n) is the threshold at the sliding position n; the value of n is the detected peak position, denoted as n_peak, which represents the offset of the starting sampling point of the synchronization sequence in RX_DATA.

[0076] Then, combining the timestamp T0 and sampling period Ts carried in the data packet, the absolute time of the start of the time frame is calculated: T_frame = T0 + n_peak × Ts Among them, the absolute time T_frame is the instantaneous frame position. This time frame position is the data frame start boundary agreed upon by both the sender and receiver, and is used for subsequent extraction of broadcast signals and demodulation of user data.

[0077] In one embodiment, step S324, performing a sliding correlation between the locally known synchronization sequence and the baseband sequence of the low sampling rate baseband signal to calculate the correlation energy sequence, includes: Using the locally known synchronization sequence as a sliding window, the system slides sequentially across the baseband sequence from the initial position. After each slide, the sum of the products of the synchronization sequence and the corresponding points of the baseband sequence within the current window is calculated, and the square of the sum of the products modulo the sum is taken to obtain the relevant energy value at the current sliding position. After traversing all sliding positions, the relevant energy sequence is obtained.

[0078] The embodiments of the present invention use sliding correlation calculation to perform point-by-point multiplication and accumulation of the local known synchronization sequence and the received baseband sequence and take the modulus square. This can effectively suppress noise and interference by utilizing the autocorrelation of the known sequence, making the correlation energy at the synchronization signal position significantly higher than that at the asynchronous position. Thus, peaks can still be accurately identified in low signal-to-noise ratio environments, improving the reliability of synchronization detection.

[0079] In one embodiment, step S325, detecting the peak position of the relevant energy sequence based on a dynamic threshold, and calculating the time frame position by combining the peak position and the timestamp, includes: The first position in the relevant energy sequence that exceeds the dynamic threshold and has the largest amplitude is determined as the peak position. The timestamp carried by the data to be synchronized is obtained. The peak position is multiplied by the sampling period to obtain the time offset. The timestamp and the time offset are added to obtain the time frame position.

[0080] The embodiments of the present invention use dynamic threshold adaptive detection of relevant energy peaks and combine high-precision timestamps to convert sampling point offsets into absolute time frame positions, which can effectively eliminate the influence of signal strength fluctuations and noise interference on peak decision, thereby obtaining a high-precision time frame synchronization reference even in complex channel environments, significantly improving the accuracy and robustness of synchronization.

[0081] Please see Figure 5 In one embodiment, a schematic diagram of a synchronous output process is provided. For example... Figure 5 As shown, the synchronization module can select one or more data streams for synchronization processing according to configuration instructions. The selected data streams include broadband signals or narrowband signals. If it is a broadband signal, it performs N-channel conversion, selects one phase data based on the preset target synchronization signal, and then performs mixing frequency shifting and down-conversion processing. After related processing and related energy detection, it determines the time frame structure or time frame position based on the related energy and the accompanying timestamp, extracts the broadcast signal and parses it to obtain the broadcast information, and finally achieves synchronous output. If it is a narrowband signal, it can directly perform down-conversion operation and subsequent synchronization processing operations on the narrowband signal.

[0082] Please see Figure 6 This invention provides a schematic diagram of related energy detection. For example... Figure 6 As shown, the horizontal axis 0, 1, 2, …, N-2, N-1 represents the starting position index of the sliding correlation, and the vertical axis represents the correlation energy value. Figure 6 The curves in the diagram represent the correlation energy calculated at each sliding position, and the horizontal line represents the dynamic threshold determined based on the signal's own energy and the threshold coefficient. When the correlation energy at a certain position exceeds the threshold and forms a peak, it is determined to be the peak position (the starting offset of the synchronization sequence), which is used to subsequently calculate the time frame position by combining the timestamp.

[0083] Please see Figure 7 This invention provides a schematic diagram for extracting broadcast signals. Figure 7The structure of the timestamp in the sampled data packet is shown. The timestamp contains the absolute time (year, month, day, hour, minute, second) and an internal counter within the second (sampling period count value), and is encapsulated together with the sampled data (Sn, Sn+1, ...) in the data packet, with the packet tail indicating the end of the data. This structure is used to mark the precise acquisition time of each segment of sampled data, facilitating the calculation of the time frame position during subsequent synchronization processing.

[0084] Implementing the embodiments of the present invention has the following beneficial effects: This invention distributes data from each module to the next level module through a hierarchical distribution method. The chain-like cascaded structure ensures that each node communicates only with its adjacent nodes, and the data stream is broadcast hierarchically. Furthermore, it can perform synchronization processing on data requiring synchronization based on actual needs, effectively avoiding the excessive load problem caused by centralized synchronization processing. This ensures signal synchronization accuracy in wide-area coverage or complex scenarios. When it is necessary to expand the coverage area or acquisition density, only additional acquisition or synchronization modules need to be added to the chain-like cascaded structure, thereby effectively improving the applicability of signal synchronization.

[0085] Furthermore, in this embodiment of the invention, the synchronization module only selects the data stream specified by the main control module for processing, avoiding the execution of synchronization algorithms on all multi-channel data, significantly reducing the consumption of computing resources, and thus effectively improving the efficiency of synchronization processing.

[0086] The signal synchronization system provided by the present invention is described below. The signal synchronization system described below and the signal synchronization method described above can be referred to in correspondence.

[0087] Please see Figure 8 A signal synchronization system provided in this embodiment of the invention includes a main control module, multiple acquisition modules and multiple synchronization modules, wherein the multiple acquisition modules and multiple synchronization modules are cascaded in sequence. The main control module 810 distributes a unified reference clock and a unified reference time to the acquisition module; The acquisition module 820 acquires air signals to obtain sampled data, generates a data stream based on the sampled data, and distributes the data stream to the next acquisition module or the next synchronization module level by level. The synchronization module 830 selects at least one data stream from the received multiple data streams as the data to be synchronized, and performs synchronization processing on the data to be synchronized.

[0088] In one embodiment, the step of acquiring sampling data from air signals and generating a data stream based on the sampling data includes: Sampling data is obtained based on a unified reference clock, and a timestamp is inserted into the sampling data to generate a data stream; wherein the timestamp is generated based on the unified reference time.

[0089] In one embodiment, distributing the data stream step-by-step to the next acquisition module or the next synchronization module includes: At least one data stream from the nth acquisition module, and at least one data stream received by the nth acquisition module from the (n-1)th acquisition module, are distributed to the (n+1)th acquisition module; where n is greater than or equal to 1. At least one data stream from the (n+1)th acquisition module, and at least one data stream received by the (n+1)th acquisition module from the nth acquisition module, are distributed to the first synchronization module.

[0090] In one embodiment, selecting at least one data stream from the received multiple data streams as the data to be synchronized includes: It receives and responds to the configuration instructions from the main control module, and selects at least one data stream from multiple data streams as the data to be synchronized.

[0091] In one embodiment, the synchronization process for the data to be synchronized includes: A synchronization search algorithm is used to determine the time frame position from the data to be synchronized, and broadcast information is extracted from the data to be synchronized based on the time frame position; The time frame position and the broadcast information are used as the synchronization output result.

[0092] In one embodiment, determining the time frame position from the data to be synchronized using a synchronization search algorithm includes: The data to be synchronized is channelized to divide it into several sub-band signals. The center frequency of the preset target synchronization signal in the sub-band signal is shifted to zero frequency to obtain a zero-frequency baseband signal; The sampling rate of the zero-frequency baseband signal is down-converted to be consistent with the baseband sampling frequency of the preset target synchronization signal to obtain a low sampling rate baseband signal; The local known synchronization sequence is correlated with the baseband sequence of the low sampling rate baseband signal by sliding correlation to obtain the correlation energy sequence; The peak position of the relevant energy sequence is detected based on the dynamic threshold, and the time frame position is calculated by combining the peak position and the timestamp.

[0093] In one embodiment, the step of performing a sliding correlation between the locally known synchronization sequence and the baseband sequence of the low sampling rate baseband signal to calculate the correlation energy sequence includes: Using the locally known synchronization sequence as a sliding window, the system slides sequentially across the baseband sequence from the initial position. After each slide, the sum of the products of the synchronization sequence and the corresponding points of the baseband sequence within the current window is calculated, and the square of the sum of the products modulo the sum is taken to obtain the relevant energy value at the current sliding position. After traversing all sliding positions, the relevant energy sequence is obtained.

[0094] In one embodiment, the step of detecting the peak position of the relevant energy sequence based on a dynamic threshold and calculating the time frame position by combining the peak position and the timestamp includes: The first position in the relevant energy sequence that exceeds the dynamic threshold and has the largest amplitude is determined as the peak position. The timestamp carried by the data to be synchronized is obtained. The peak position is multiplied by the sampling period to obtain the time offset. The timestamp and the time offset are added to obtain the time frame position.

[0095] Figure 9 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 9 As shown, the electronic device may include: a processor 910, a communication interface 920, a memory 930, and a communication bus 940, wherein the processor 910, the communication interface 920, and the memory 930 communicate with each other through the communication bus 940. The processor 910 can call logical instructions in the memory 930 to execute a signal synchronization method. This method is applicable to a signal synchronization system, which includes a main control module, multiple acquisition modules, and multiple synchronization modules, with the acquisition modules and synchronization modules cascaded sequentially. The signal synchronization method includes: The main control module distributes a unified reference clock and a unified reference time to the acquisition module. The acquisition module acquires sampling data from air signals, generates a data stream based on the sampling data, and distributes the data stream to the next acquisition module or the next synchronization module level by level. The synchronization module selects at least one data stream from the received multiple data streams as the data to be synchronized, and performs synchronization processing on the data to be synchronized.

[0096] Furthermore, the logical instructions in the aforementioned memory 930 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0097] On the other hand, the present invention also provides a computer program product, the computer program product comprising a computer program, the computer program being able to be stored on a non-transitory computer-readable storage medium, the computer program being executed by a processor, the computer being able to execute the signal synchronization method provided by the above methods, the method being applicable to a signal synchronization system, the signal synchronization system comprising a main control module, multiple acquisition modules and multiple synchronization modules, the multiple acquisition modules and the multiple synchronization modules being cascaded sequentially; the signal synchronization method comprising: The main control module distributes a unified reference clock and a unified reference time to the acquisition module. The acquisition module acquires sampling data from air signals, generates a data stream based on the sampling data, and distributes the data stream to the next acquisition module or the next synchronization module level by level. The synchronization module selects at least one data stream from the received multiple data streams as the data to be synchronized, and performs synchronization processing on the data to be synchronized.

[0098] In another aspect, the present invention also provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the signal synchronization method provided by the methods described above. This method is applicable to a signal synchronization system, the signal synchronization system comprising a main control module, multiple acquisition modules, and multiple synchronization modules, wherein the multiple acquisition modules and multiple synchronization modules are cascaded sequentially; the signal synchronization method includes: The main control module distributes a unified reference clock and a unified reference time to the acquisition module. The acquisition module acquires sampling data from air signals, generates a data stream based on the sampling data, and distributes the data stream to the next acquisition module or the next synchronization module level by level. The synchronization module selects at least one data stream from the received multiple data streams as the data to be synchronized, and performs synchronization processing on the data to be synchronized.

[0099] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0100] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A signal synchronization method, characterized in that, Applicable to a signal synchronization system, the signal synchronization system includes a main control module, multiple acquisition modules and multiple synchronization modules, wherein the multiple acquisition modules and multiple synchronization modules are cascaded in sequence; The signal synchronization method includes: The main control module distributes a unified reference clock and a unified reference time to the acquisition module. The acquisition module acquires sampling data from air signals, generates a data stream based on the sampling data, and distributes the data stream to the next acquisition module or the next synchronization module level by level. The synchronization module selects at least one data stream from the received multiple data streams as the data to be synchronized, and performs synchronization processing on the data to be synchronized.

2. The signal synchronization method as described in claim 1, characterized in that, The process of acquiring sampling data from air signals and generating a data stream based on the sampling data includes: Sampling data is obtained based on a unified reference clock, and a timestamp is inserted into the sampling data to generate a data stream; wherein the timestamp is generated based on the unified reference time.

3. The signal synchronization method as described in claim 1, characterized in that, The step of distributing the data stream to the next acquisition module or the next synchronization module includes: At least one data stream from the nth acquisition module, and at least one data stream received by the nth acquisition module from the (n-1)th acquisition module, are distributed to the (n+1)th acquisition module; where n is greater than or equal to 1. At least one data stream from the (n+1)th acquisition module, and at least one data stream received by the (n+1)th acquisition module from the nth acquisition module, are distributed to the first synchronization module.

4. The signal synchronization method as described in claim 1, characterized in that, The step of selecting at least one data stream from the received multiple data streams as the data to be synchronized includes: It receives and responds to the configuration instructions from the main control module, and selects at least one data stream from multiple data streams as the data to be synchronized.

5. The signal synchronization method as described in claim 2, characterized in that, The synchronization process for the data to be synchronized includes: A synchronization search algorithm is used to determine the time frame position from the data to be synchronized, and broadcast information is extracted from the data to be synchronized based on the time frame position; The time frame position and the broadcast information are used as the synchronization output result.

6. The signal synchronization method as described in claim 5, characterized in that, The step of using a synchronization search algorithm to determine the time frame position from the data to be synchronized includes: The data to be synchronized is channelized to divide it into several sub-band signals. The center frequency of the preset target synchronization signal in the sub-band signal is shifted to zero frequency to obtain a zero-frequency baseband signal; The sampling rate of the zero-frequency baseband signal is down-converted to be consistent with the baseband sampling frequency of the preset target synchronization signal to obtain a low sampling rate baseband signal; The local known synchronization sequence is correlated with the baseband sequence of the low sampling rate baseband signal by sliding correlation to obtain the correlation energy sequence; The peak position of the relevant energy sequence is detected based on the dynamic threshold, and the time frame position is calculated by combining the peak position and the timestamp.

7. The signal synchronization method as described in claim 6, characterized in that, The step of performing a sliding correlation between the locally known synchronization sequence and the baseband sequence of the low sampling rate baseband signal to calculate the correlation energy sequence includes: Using the locally known synchronization sequence as a sliding window, the system slides sequentially across the baseband sequence from the initial position. After each slide, the sum of the products of the synchronization sequence and the corresponding points of the baseband sequence within the current window is calculated, and the square of the sum of the products modulo the sum is taken to obtain the relevant energy value at the current sliding position. After traversing all sliding positions, the relevant energy sequence is obtained.

8. The signal synchronization method as described in claim 6, characterized in that, The step of detecting the peak position of the relevant energy sequence based on a dynamic threshold, and calculating the time frame position by combining the peak position and the timestamp, includes: The first position in the relevant energy sequence that exceeds the dynamic threshold and has the largest amplitude is determined as the peak position. The timestamp carried by the data to be synchronized is obtained. The peak position is multiplied by the sampling period to obtain the time offset. The timestamp and the time offset are added to obtain the time frame position.

9. A signal synchronization system, characterized in that, It includes a main control module, multiple acquisition modules and multiple synchronization modules, with the multiple acquisition modules and multiple synchronization modules cascaded in sequence; The main control module distributes a unified reference clock and a unified reference time to the acquisition module. The acquisition module acquires sampling data from air signals, generates a data stream based on the sampling data, and distributes the data stream to the next acquisition module or the next synchronization module level by level. The synchronization module selects at least one data stream from the received multiple data streams as the data to be synchronized, and performs synchronization processing on the data to be synchronized.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the signal synchronization method as described in any one of claims 1 to 8.

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