WO2021098612A1 - Signal synchronization method and apparatus, and computer storage medium - Google Patents

Abstract

Disclosed in the embodiments of the present application are a signal synchronization method and apparatus, and a computer storage medium. The method comprises: receiving a spread spectrum preamble signal, the spread spectrum preamble signal comprising N sequences, wherein N is a positive integer greater than or equal to 1; separately performing first correlation processing with a local signal on each sequence in the spread spectrum preamble signal to determine N first processing results corresponding to the spread spectrum preamble signal; performing second correlation processing with the local signal on two adjacent first processing results among the N first processing results to determine second processing results corresponding to the spread spectrum preamble signal; if the second processing results are greater than a preset threshold, then querying the maximum value of the second processing results in a correlation window; and on the basis of the maximum value, determining synchronization information of the spread spectrum preamble signal, and implementing synchronization tracking of the spread spectrum preamble signal according to the synchronization information.

Description

Signal synchronization method, device and computer storage medium

Cross-references to related applications

This application is based on a Chinese patent application with an application number of 201911147089.3 and an application date of November 21, 2019, and claims the priority of the Chinese patent application. The entire content of the Chinese patent application is hereby incorporated into this application by way of introduction.

Technical field

This application relates to the field of communication technology, and in particular to a signal synchronization method, device, and computer storage medium.

Background technique

Chirp Spread Spectrum (CSS) is a spread spectrum technology used in communication systems, and it can also be called wideband chirp modulation (Chirp Modulation). In CSS modulation, the transmitted radio frequency pulse signal changes linearly in the frequency of its carrier frequency within one cycle. Because its frequency changes in a wider frequency band, correspondingly, the frequency band of the signal is also expanded, so it is called spread spectrum technology.

The CSS spread spectrum technology can greatly increase the carrier-to-noise ratio threshold of the receiver's demodulation, and the sensitivity of the receiver's demodulation can be improved again through the Hamming code. However, the premise of demodulation by the receiver is to discover and identify the random access preamble of the transmitter and synchronize with it. As the preamble code is recognized as a fixed format, encoding and decoding cannot be performed, so that the receiver has high requirements on power consumption and time for the judgment and synchronization of the preamble code, and the too weak signal cannot be identified and synchronized in the preamble code. .

Summary of the invention

The embodiments of the present application propose a signal synchronization method, device, and computer storage medium, which can not only save power consumption and operation time, but also achieve time domain and frequency domain synchronization of the preamble code in the CSS spread spectrum signal.

The technical solution of this application is realized as follows:

In the first aspect, an embodiment of the present application provides a signal synchronization method, which includes:

Receiving a spread-spectrum preamble signal, where the spread-spectrum preamble signal includes N sequences, where N is a positive integer greater than or equal to 1;

Perform first correlation processing on each sequence in the spread-spectrum preamble signal and a local signal respectively, and determine N first processing results corresponding to the spread-spectrum preamble signal;

Performing second correlation processing on two first processing results before and after the N first processing results and the local signal to determine a second processing result corresponding to the spread-spectrum preamble signal;

If the second processing result is greater than the preset threshold, query the maximum value of the second processing result in a correlation window; wherein, the correlation window represents that each sequence in the spread spectrum preamble is subjected to the first correlation processing The corresponding sliding window;

Based on the maximum value, the synchronization information of the spread-spectrum preamble signal is determined, and synchronization tracking of the spread-spectrum preamble signal is realized according to the synchronization information.

In a second aspect, an embodiment of the present application provides a signal synchronization device, which includes a receiving unit, a processing unit, an inquiry unit, and a synchronization unit, wherein:

A receiving unit configured to receive a spread-spectrum preamble signal, where the spread-spectrum preamble signal includes N sequences, and N is a positive integer greater than or equal to 1;

A processing unit, configured to perform first correlation processing on each sequence in the spread-spectrum preamble signal with a local signal, and determine N first processing results corresponding to the spread-spectrum preamble signal;

The processing unit is further configured to perform second correlation processing on the two first processing results before and after among the N first processing results and the local signal, and determine a second processing result corresponding to the spread-spectrum preamble signal;

The query unit is configured to query the maximum value of the second processing result in a correlation window if the second processing result is greater than a preset threshold; wherein, the correlation window represents each sequence in the spread spectrum preamble The sliding window corresponding to the first relevant processing;

The synchronization unit is configured to determine synchronization information of the spread-spectrum preamble signal based on the maximum value, and implement synchronization tracking of the spread-spectrum preamble signal according to the synchronization information.

In a third aspect, an embodiment of the present application provides a signal synchronization device, which includes a memory and a processor; wherein,

A memory configured to store a computer program that can run on the processor;

The processor is configured to execute the method as described in the first aspect when running the computer program.

In a fourth aspect, an embodiment of the present application provides a computer storage medium that stores a signal synchronization program that implements the method described in the first aspect when the signal synchronization program is executed by at least one processor.

The signal synchronization method, device, and computer storage medium provided by the embodiments of the present application first receive a spread-spectrum preamble signal. The spread-spectrum preamble signal includes N sequences, where N is a positive integer greater than or equal to 1; Each sequence in the spread-spectrum preamble signal is subjected to the first correlation processing with the local signal to determine the N first processing results corresponding to the spread-spectrum preamble signal; Perform second correlation processing between the processing result and the local signal to determine the second processing result corresponding to the spread-spectrum preamble signal; if the second processing result is greater than the preset threshold, query the maximum value of the second processing result in the correlation window; Finally, based on the maximum value, the synchronization information of the spread-spectrum preamble signal is determined, and the synchronization of the spread-spectrum preamble signal is realized according to the synchronization information; in this way, the received spread-spectrum preamble signal is mutually exchanged with the local signal. Correlation processing, and judgment based on the peak value obtained after cross-correlation processing, so that the synchronization information of the spread spectrum preamble signal can be determined, and the time domain and frequency domain synchronization of the preamble code in the CSS spread spectrum signal can be realized; in addition, this The solution of the application embodiment does not require the receiver to always perform Fast Fourier Transform (FFT) calculations, and can also save power consumption and calculation time, thereby also improving the overall performance of the receiver.

Description of the drawings

FIG. 1 is a schematic diagram of the composition structure of a wireless modem provided by related technical solutions;

2 is a schematic flowchart of a signal synchronization method provided by an embodiment of this application;

3 is a schematic diagram of a simulation signal corresponding to a spread spectrum preamble signal provided by an embodiment of the application;

4 is a schematic diagram of a simulation result of conjugate multiplication of a spread spectrum preamble signal and a local chirp signal provided by an embodiment of the application;

FIG. 5 is a schematic diagram of an FFT result obtained by performing conjugate multiplication of a spread spectrum preamble signal and a local chirp signal according to an embodiment of the application;

FIG. 6 is a schematic diagram of a simulation result of another spread spectrum preamble signal and a local chirp signal performing conjugate multiplication according to an embodiment of this application;

FIG. 7 is a schematic diagram of an FFT result of another spread-spectrum preamble signal and a local chirp signal subjected to conjugate multiplication according to an embodiment of the application;

FIG. 8 is a detailed flowchart of a signal synchronization method provided by an embodiment of this application;

FIG. 9 is a schematic diagram of a simulation result of another spread spectrum preamble signal and a local chirp signal performing conjugate multiplication according to an embodiment of this application;

FIG. 10 is a schematic diagram of another FFT result obtained by performing conjugate multiplication of a spread spectrum preamble signal and a local chirp signal according to an embodiment of this application;

FIG. 11 is a schematic diagram of another FFT result obtained by performing conjugate multiplication of a spread spectrum preamble signal and a local chirp signal according to an embodiment of the application; FIG.

FIG. 12 is a schematic diagram of the composition structure of a signal synchronization device provided by an embodiment of the application;

FIG. 13 is a schematic diagram of a specific hardware structure of a signal synchronization device provided by an embodiment of the application.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It can be understood that the specific embodiments described here are only used to explain the related application, but not to limit the application. In addition, it should be noted that, for ease of description, only the parts related to the relevant application are shown in the drawings.

LoRa can be regarded as the abbreviation of Long Range, which is a kind of Low Power Wide Area Network (LPWAN) communication technology. As a long-distance wireless transmission technology based on spread spectrum technology, LoRa can provide users with a simple means of long-distance, low-power wireless communication. Among them, the biggest feature of LoRa is that it can travel farther than other wireless methods under the same power consumption, realizes the unity of low power consumption and long distance, and can compare the traditional radio frequency communication distance under the same power consumption. Expand 3 to 5 times.

LoRa is a physical layer or wireless modulation used to establish long-distance communication links. Many traditional wireless systems use Frequency-Shift Keying (FSK) modulation as the physical layer, which can effectively meet the needs of low power consumption. LoRa is based on chirp spread spectrum modulation, which not only retains the same low power consumption characteristics as FSK modulation, but also increases the communication distance. Because it can achieve long communication distance and interference robustness, LoRa is the first low-cost implementation for commercial use. With the introduction of LoRa, LoRa technology has changed the traditional compromise between transmission distance and power consumption. , Provides a simple communication system that can realize long-distance, large-capacity, and low-cost. The principle of its radio receiver is shown in Figure 1.

Specifically, in FIG. 1, the transceiver includes a baseband part 200 and a radio frequency part 100. Among them, for the transmitter part of the transceiver, the modulator 150 generates a baseband signal based on the digital data 152 at its input. The I and Q components in the baseband signal are converted into the desired transmission frequency by the radio frequency part 100, and then Amplified by an over-power amplifier (PA) 120 and transmitted through an antenna; that is, by combining the signal provided by the amplifier 154 with a phase-locked loop (PLL) circuit 190 in the mixer 110 The in-phase component and quadrature component of the local carrier are mixed to complete the conversion of the signal from the baseband to the desired frequency, and the PLL circuit 190 is linked to the reference clock 129. Once the signal is received on the other end of the radio link, it is processed by the receiver part of the transceiver, where the receiver part includes a low noise amplifier (LNA) 160, and a low noise amplifier 160 and The power amplifier 120 is isolated by a switch (SW) 102 to achieve a bidirectional management mode; after the low noise amplifier 160 is a down-conversion stage 170 that generates a series of chirped baseband signals, and then the baseband signals pass through a video graphics array (Video Graphics Array). The Graphics Array (VGA) interface is transmitted to the demodulator 180 for processing and provides a reconstructed digital signal 182; here, the function of the demodulator 180 is the inverse transformation of the function of the modulator 150.

Chirp Spread Spectrum (CSS) is a spread spectrum technology used in communication systems. In CSS modulation, if the transmitted radio frequency pulse signal changes linearly in its carrier frequency within one cycle, it is called chirp; here, the chirp signal is also called a chirp signal. Because its frequency changes in a wider frequency band, the frequency band of the signal is also broadened. Specifically, there is a sawtooth wave at the transmitting end to modulate the voltage-controlled oscillator, thereby generating chirp pulses. It is the same as the signal generated by the sweep signal generator. At the receiving end, the chirp is compressed by a matched filter, and the energy is concentrated in a short period of time to output, thereby improving the signal-to-noise ratio and gaining processing gain. The matched filter can use a dispersive delay line, which is a storage and accumulation device, and its mechanism of action is that the delay time for different frequencies is different. If the frequencies at both ends of the pulse are output together after different delays, the matched filter plays a role in pulse compression and energy concentration. The improvement of the output signal-to-noise ratio of the matched filter is a function of the product of the pulse width and the FM deviation. The mathematical expression of a typical CSS signal is as follows,

Among them, f ₀ is the center frequency of the chirp signal, T is the period of the chirp signal, and k is the slope of the chirp signal, which controls the rate of frequency change.

In the current solution, the CSS spread spectrum technology can greatly increase the carrier-to-noise ratio threshold of the receiver's demodulation, and the sensitivity of the receiver's demodulation can be improved again through the Hamming code. However, the premise of receiver demodulation is to discover and identify the transmitter's preamble code and synchronize with it. Since the preamble code is recognized as a fixed format, it cannot be coded or decoded. For example, the preamble code in LoRa technology does not have any modulation information, but the frequency changes linearly from -BW to BW, and the receiver must perform it when receiving any signal It is judged whether it is a valid signal, so the judgment and synchronization of the preamble code have high requirements on power consumption and time. Although the sensitivity of LoRa IoT devices can be above -140dBm through a high spreading factor, and at the same time it has good power consumption performance; but it is difficult to achieve this indicator in actual scene testing. The main reasons are as follows: The performance of is not limited by the signal-to-noise ratio but by the adjacent channel interference of other frequency bands; in addition, the signal that is too weak cannot be identified and synchronized in the preamble code.

The embodiment of the application provides a signal synchronization method. Firstly, a spread-spectrum preamble signal is received. The spread-spectrum preamble signal includes N sequences, where N is a positive integer greater than or equal to 1, and then the spread-spectrum preamble signal Each sequence is subjected to the first correlation processing with the local signal to determine the N first processing results corresponding to the spread spectrum preamble signal; then the two first processing results before and after the N first processing results are compared with the local signal Perform second correlation processing to determine the second processing result corresponding to the spread spectrum preamble signal; if the second processing result is greater than the preset threshold, query the maximum value of the second processing result in the correlation window; finally, based on the maximum value, determine Spread-spectrum preamble signal synchronization information, and realize the synchronization tracking of the spread-spectrum preamble signal according to the synchronization information; in this way, the received spread-spectrum preamble signal and the local signal are subjected to cross-correlation processing, and based on the cross-correlation The peak value obtained after processing is judged, so that the synchronization information of the spread spectrum preamble signal can be determined, and the time domain and frequency domain synchronization of the preamble code in the CSS spread spectrum signal can be realized; in addition, the solution in the embodiment of the application does not require The receiver has been doing FFT calculations, which can also save power consumption and calculation time, which can also improve the overall performance of the receiver.

Hereinafter, each embodiment of the present application will be described in detail with reference to the accompanying drawings.

In an embodiment of the present application, refer to FIG. 2, which shows a schematic flowchart of a signal synchronization method provided in an embodiment of the present application. As shown in Figure 2, the method may include:

S201: Receive a spread-spectrum preamble signal, where the spread-spectrum preamble signal includes N sequences, and N is a positive integer greater than or equal to 1;

It should be noted that in a communication system, a signal can be transmitted through the transmitter and then received by the receiver; and the premise of signal demodulation in the receiver is to find and identify the transmitter’s preamble code and synchronize with it. . Here, the transmitter may be located in the terminal device, and the receiver may be located in the base station, but the embodiment of the present application does not specifically limit it.

Exemplarily, the transmitted signal can be represented by the following formula (2), as shown below,

s(t)=exp(j*2π*f _CSS *t+phi) (2)

Among them, phi represents the initial phase, and the value of phi can generally be 0; f _CSS is the frequency of the modulated signal, and _{the value of f css} can be determined by the spreading factor (SF) and bandwidth (Band Width, BW) , Specifically, f _CSS = 2^SF/BW*t.

In this way, the spread-spectrum preamble signal can use the chirp signal generated as above, and assuming that the period is 0, the signal example obtained by the spread-spectrum preamble signal in MATLAB simulation is shown in FIG. 3. In Figure 3, the horizontal axis represents time (indicated by Time), and the unit is represented by seconds (s); the vertical axis represents frequency (indicated by Frequency), and the unit is represented by hertz (Hz).

It should also be noted that the preamble code can be composed of N repetitive sequences with a length of 2^SF; that is, the spread spectrum preamble signal includes N sequences, and each sequence includes M points; among them, N is a positive integer greater than or equal to 1, and M is a positive integer greater than or equal to 1. In the embodiment of the present application, the value of M may be 2^SF.

Further, in some embodiments, after S201, the method may further include:

Perform sampling processing on the received spread-spectrum preamble signal according to a preset sampling rate, and determine the sampled spread-spectrum preamble signal as the spread-spectrum preamble signal.

It should be noted that the preset sampling rate represents a preset sampling frequency for sampling the received spread spectrum preamble signal. The preset sampling rate is set according to actual conditions. The preset sampling rate in the embodiment of the present application is usually a high sampling rate, and generally can be twice the sampling rate or four times the sampling rate. However, in the embodiments of the present application, There is no specific limitation.

In this way, the received spread-spectrum preamble signal can be sampled according to the preset sampling rate (such as twice the sampling rate), and the sampled spread-spectrum preamble signal can be determined as the spread-spectrum preamble signal, and then follow-up The first correlation processing and the second correlation processing are calculated.

S202: Perform first correlation processing on each sequence in the spread-spectrum preamble signal and a local signal respectively, and determine N first processing results corresponding to the spread-spectrum preamble signal;

It should be noted that the spread spectrum preamble signal is a chirp signal, and the local signal is also a chirp signal. Specifically, the chirp signal is an up chirp signal; among them, as shown in Figure 3, for the spread spectrum preamble signal, the frequency is an up process that gradually rises ^{from 0 to 12×10 4, so it can be called} up chirp signal.

It should also be noted that after obtaining the N sequences of the spread-spectrum preamble signal, each sequence can be subjected to the first correlation processing with the local signal respectively, so that the N first-correlation processing corresponding to the spread-spectrum preamble signal can be determined. process result.

Specifically, in some embodiments, for S202, the first correlation processing is performed on each sequence in the spread-spectrum preamble signal with a local signal, and the N corresponding to the spread-spectrum preamble signal are determined. The first processing result may include:

Conjugate multiplication of each sequence in the spread spectrum preamble signal with a local signal to obtain N product signals;

FFT operation is performed on each of the N product signals separately to obtain N FFT results;

The obtained N FFT results are determined as the N first processing results corresponding to the spread spectrum preamble signal.

It should be noted that the first correlation processing is performed on each sequence in the spread-spectrum preamble signal with the local signal. Specifically, it may mean that each sequence in the spread-spectrum preamble signal is conjugate multiplied with the local signal, respectively. Obtain N product signals; and then perform FFT operations on each of the N product signals separately to obtain N FFT results.

It should also be noted that for N product signals, each product signal can include M points. Specifically, by performing FFT operation on the M points included in each product signal, the corresponding value of each product signal can be obtained. FFT results, so that N FFT results can be obtained, and N first processing results corresponding to the spread spectrum preamble signal are also obtained.

S203: Perform second correlation processing on the two first processing results before and after among the N first processing results and the local signal, and determine a second processing result corresponding to the spread-spectrum preamble signal;

It should be noted that after the N first processing results are obtained, the two first processing results before and after the local signal can be subjected to second correlation processing, so that the second processing result corresponding to the spread spectrum preamble signal can be determined .

Specifically, in some embodiments, for S203, the two first processing results before and after the N first processing results are subjected to second correlation processing with the local signal to determine the spread spectrum The second processing result corresponding to the preamble signal may include:

Performing conjugate multiplication on the front and back two FFT results of the obtained N FFT results with the local signal at the same position, and accumulating the multiplied results to obtain a correlation result;

The obtained correlation result is determined as the second processing result corresponding to the spread spectrum preamble signal.

It should be noted that the second correlation processing is performed on the two first processing results before and after the local signal among the N first processing results. Specifically, it may mean that the two FFT results before and after the obtained N FFT results are The same position is conjugate multiplied with the local signal, and then the multiplied result is accumulated and processed, so that the correlation result can be obtained, and the second processing result corresponding to the spread-spectrum preamble signal is obtained.

S204: If the second processing result is greater than a preset threshold, query the maximum value of the second processing result in a relevant window;

It should be noted that the preset threshold is a predetermined value used to measure whether the received spread-spectrum preamble signal is a useful signal. Wherein, the value of the preset threshold is set according to actual conditions, and the embodiment of the present application does not specifically limit it.

It should also be noted that the correlation window represents a sliding window corresponding to the first correlation processing performed on each sequence in the spread spectrum preamble. That is to say, after each sequence in the spread spectrum preamble signal is conjugate multiplied by the local signal, the sliding window of the FFT operation is performed on the product signal. Here, the length of the sliding window is related to the sequence length; in the embodiment of the present application, the length of the sliding window may be equal to the sequence length, for example, each sequence includes 2^SF points, then the length of the sliding window is also 2^SF points point. In this way, only when the start time and end time corresponding to the sliding window are correct, the second processing result obtained at this time is the maximum value.

In this way, after the second processing result is obtained, the second processing result can be compared with a preset threshold, and according to the comparison result, it can be determined whether the received spread spectrum preamble signal is a useful signal, so as to determine whether it is necessary to execute the The step of querying the maximum value of the second processing result in the relevant window. Therefore, in some embodiments, the method may further include:

Judging whether the second processing result is greater than a preset threshold;

If the second processing result is greater than the preset threshold, determining that the spread-spectrum preamble signal is a useful signal, and continuing to perform the step of querying the maximum value of the second processing result in the relevant window;

If the second processing result is not greater than the preset threshold, it is determined that the spread spectrum preamble signal is a non-useful signal, and the step of querying the maximum value of the second processing result in the relevant window is stopped.

It should be noted that, by comparing the second processing result with the preset threshold, it is determined whether the received spread spectrum preamble signal is a useful signal. Specifically, if the second processing result is greater than the preset threshold, it indicates that the received spread-spectrum preamble signal is a useful signal. At this time, the process shown in FIG. 2 can be continued, that is, the query in the relevant window needs to be continued. The step of the maximum value of the second processing result; if the second processing result is not greater than the preset threshold, it indicates that the received spread spectrum preamble signal is not a useful signal. At this time, there is no need to continue the process shown in Figure 2 , That is, there is no need to perform the step of querying the maximum value of the second processing result in the relevant window.

S205: Determine synchronization information of the spread spectrum preamble signal based on the maximum value, and implement synchronization tracking of the spread spectrum preamble signal according to the synchronization information.

It should be noted that when the second processing result is greater than the preset threshold, the maximum value of the second processing result can be queried at this time; according to the maximum value, the synchronization information of the spread spectrum preamble signal can be determined, thereby realizing the Synchronous tracking of spread-spectrum preamble signals.

In the embodiment of the present application, for the synchronization tracking of spreading code signals, the synchronization tracking includes time synchronization tracking and frequency synchronization tracking. In addition, for time synchronization tracking and frequency synchronization tracking, the two are processed in parallel, and there is no priority.

Specifically, in some embodiments, for frequency synchronization tracking, the determining the synchronization information of the spread spectrum preamble signal based on the maximum value may include:

Determine the time value corresponding to the maximum value according to the maximum value;

Perform a fractional multiple frequency offset estimation according to the time value to obtain an estimated value of the frequency offset;

Perform frequency synchronization tracking on the spread spectrum preamble signal according to the estimated value of the frequency offset.

It should be noted that before performing correlation processing on the received spread-spectrum preamble signal, the spread-spectrum preamble signal needs to be sampled, and the sampling processing is performed at a high sampling rate, usually twice Sampling rate or quadruple sampling rate. In this case, the frequency compensation requires fractional frequency offset estimation.

It should also be noted that for frequency synchronization tracking, if the frequencies of the two are inconsistent, the time value corresponding to the maximum value can be determined according to the maximum value obtained at this time; the fractional frequency offset estimation is performed according to the time value Therefore, the frequency offset estimation value can be obtained; frequency compensation is performed on the spread spectrum preamble signal according to the frequency offset estimation value, and the frequency synchronization tracking of the spread spectrum preamble signal is realized.

Specifically, in some embodiments, for time synchronization tracking, the determining the synchronization information of the spread spectrum preamble signal based on the maximum value includes:

Determine the sequence corresponding to the maximum value according to the maximum value;

Obtaining the start time and end time of the sequence according to the determined sequence;

Perform time synchronization tracking on the spread spectrum preamble signal according to the start time and the end time.

It should be noted that for time synchronization tracking, the sequence corresponding to the maximum value is determined according to the maximum value that is queried; then the start time and end time of the sequence are obtained according to the determined sequence; The start time and end time also realize the time synchronization tracking of the spread spectrum preamble signal.

Exemplarily, assuming that the received spread-spectrum preamble signal is shown in Figure 3, after the received spread-spectrum preamble signal and the local chirp signal are conjugate multiplied, if the two frequencies are completely consistent At this time, the simulation results obtained in the MATLAB simulation under ideal conditions are shown in Figure 4; correspondingly, the FFT results are shown in Figure 5, where the horizontal axis represents the frequency, and the vertical axis represents the component value (ie FFT As can be seen from Figure 5, all signals of the FFT result are direct current (DC) components. At this time, it can be judged that the carrier frequency between the transmitter and the receiver is synchronized; if it is due to the Doppler effect, The frequencies of the two are different. At this time, the simulation results obtained in MATLAB simulation under ideal conditions are shown in Figure 6; correspondingly, the FFT results are shown in Figure 7. As can be seen from Figure 7, there are FFT results. There is a peak. At this time, it can be judged that the carrier frequency between the transmitter and the receiver is not synchronized, and the frequency at which the peak is located is the carrier frequency difference between the two. In view of the situation that the carrier frequency between the transmitter and the receiver is not synchronized, at this time, the signal synchronization method according to the embodiment of the present application can be used to realize the carrier frequency synchronization tracking between the two.

This embodiment provides a signal synchronization method by receiving a spread-spectrum preamble signal. The spread-spectrum preamble signal includes N sequences, where N is a positive integer greater than or equal to 1, and each of the spread-spectrum preamble signals The sequence is first correlated with the local signal to determine the N first processing results corresponding to the spread-spectrum preamble signal; the two first processing results before and after the N first processing results and the local signal are second Correlation processing, determine the second processing result corresponding to the spread spectrum preamble signal; if the second processing result is greater than the preset threshold, query the maximum value of the second processing result in the correlation window; determine the spread spectrum preamble based on the maximum value The synchronization information of the signal and the synchronization tracking of the spread spectrum preamble signal according to the synchronization information; in this way, the received spread spectrum preamble signal and the local signal are subjected to cross-correlation processing, and the results obtained after the cross-correlation processing To determine the synchronization information of the spread-spectrum preamble signal, the time-domain and frequency-domain synchronization of the preamble code in the CSS spread-spectrum signal can be realized; in addition, the solution in the embodiment of the present application does not require the receiver to always do FFT operation can also save power consumption and operation time, which can also improve the overall performance of the receiver.

In another embodiment of the present application, based on the same inventive concept as the foregoing embodiment, refer to FIG. 8, which shows a detailed flowchart of a signal synchronization method provided by an embodiment of the present application. As shown in Figure 8, the detailed process may include:

S801: Receive a spread-spectrum preamble signal, where the spread-spectrum preamble signal includes N sequences, and N is a positive integer greater than or equal to 1;

S802: Perform sampling processing on the received spread-spectrum preamble signal according to a preset sampling rate, and determine the sampled spread-spectrum preamble signal as the spread-spectrum preamble signal;

It should be noted that, after the transmitter transmits the signal, the receiver receives the spread-spectrum preamble signal, and the spread-spectrum preamble signal may be an up chirp signal. Among them, because the preamble code can be composed of N repetitive sequences with a length of 2^SF; that is, the spread spectrum preamble signal includes N sequences, and each sequence includes M points; where N is greater than or A positive integer equal to 1, and M is a positive integer greater than or equal to 1. In the embodiment of the present application, the value of M may be 2^SF.

In this way, the received spread-spectrum preamble signal is sampled according to the preset sampling rate (for example, twice the sampling rate), and the sampled spread-spectrum preamble signal is determined as the spread-spectrum preamble signal, and then the follow-up is performed on it. Related processing calculations.

S803: Perform conjugate multiplication of each sequence in the spread spectrum preamble signal with a local chirp signal to obtain N product signals;

S804: Perform an FFT operation on each product signal of the N product signals to obtain N FFT results;

It should be noted that, after obtaining the N sequences of the spread spectrum preamble signal, each sequence in the spread spectrum preamble signal is subjected to the first correlation processing with the local chirp signal. Specifically, it may refer to the first correlation process of the spread spectrum preamble signal. Each sequence in the signal is conjugate multiplied with the local chirp signal to obtain N product signals; then, each of the N product signals is subjected to FFT operation separately to obtain N FFT results.

Specifically, each sequence in the spread spectrum preamble signal is conjugate multiplied with the local chirp signal to obtain N product signals; the corresponding codes are as follows:

for i = 0: N-1

decoder(i+1:i+2^SF)=preamble(i+1:i+2^SF).*conj(local);

end

Specifically, the FFT operation is performed on each of the N product signals to obtain N FFT results; the corresponding codes are as follows:

for k = 0: N-1

DECODER(k)=FFT(decoder(k+1:k+2^SF));

end

Among them, preamble(i+1:i+2^SF) represents the i-th sequence in the received spread spectrum preamble signal, conj(local) represents the local chirp signal, decoder(i+1:i+2^ SF) represents the product signal corresponding to the i-th sequence, and DECODER(k) represents the FFT result corresponding to the k-th product signal; since the value of k is 0 to N-1, N FFT results can be obtained in this way.

S805: Perform conjugate multiplication on the front and back two FFT results of the obtained N FFT results with the local chirp signal at the same position, and perform accumulation processing on the multiplied results to obtain a correlation result;

It should be noted that after the N FFT results are obtained, the second correlation processing is performed on the two FFT results before and after the N FFT results and the local chirp signal. Specifically, it can refer to the first correlation of the obtained N FFT results. The two FFT results before and after are conjugate multiplied with the local signal at the same position, and then the multiplied results are accumulated and processed, so that the correlation result can be obtained.

Specifically, assuming N=4, if the sequence of 2^SF points selects the correct start time and end time, the calculation results of the 4 FFTs are accumulated at this time, and the peak value is the largest among the correlation results obtained. , That is, the correlation result is the maximum value; however, if the sequence of 2^SF points selects the wrong start time and end time, that is, the initial and end time of the selected 2^SF are inconsistent with the sequence, at this time The calculation results of the 4 FFTs are accumulated, and two peaks can be obtained, and the two peaks are smaller than the peak under the correct situation.

S806: If the correlation result is greater than the preset threshold, query the maximum value of the correlation result in the correlation window;

S807: Determine synchronization information of the spread spectrum preamble signal based on the maximum value, and implement time synchronization tracking and frequency synchronization tracking of the spread spectrum preamble signal according to the synchronization information.

It should be noted that the preset threshold is a predetermined value used to measure whether the received spread-spectrum preamble signal is a useful signal. Wherein, the value of the preset threshold is set according to actual conditions, and the embodiment of the present application does not specifically limit it. In this way, after the correlation result is obtained, the correlation result can be compared with the preset threshold, and according to the comparison result, it can be determined whether the received spread spectrum preamble signal is a useful signal, so as to determine whether S806 needs to be executed, that is, whether it is needed. The step of querying the maximum value of the correlation result in the correlation window.

It should also be noted that when the correlation result is greater than the preset threshold, the search continues for a period of time, and the maximum value of the correlation result can be queried in the correlation window; according to the maximum value, the spread spectrum preamble signal can be determined Synchronous information, thus realizing the synchronous tracking of the spread spectrum preamble signal.

Specifically, because before performing correlation processing on the received spread-spectrum preamble signal, the spread-spectrum preamble signal needs to be sampled, and the sampling processing is performed at a high sampling rate, usually twice the sampling rate. Or quadruple sampling rate. In this case, the frequency compensation requires fractional frequency offset estimation. That is to say, for frequency synchronization tracking, if the frequencies of the two are inconsistent, the time value corresponding to the maximum value can be determined according to the maximum value obtained at this time; the fractional frequency offset is estimated according to the time value, thereby The frequency offset estimation value can be obtained; frequency compensation is performed on the spread spectrum preamble signal according to the frequency offset estimation value, and the frequency synchronization tracking of the spread spectrum preamble signal is realized.

In addition, for time synchronization tracking, the sequence corresponding to the maximum value is determined according to the maximum value found; then the start time and end time of the sequence are obtained according to the determined sequence; thus according to the start time And the end time, the spread spectrum preamble signal can be time synchronized tracking. That is to say, when the correlation result is the maximum value, the sequence of 2^SF points at this time selects the correct start time and end time, thereby realizing the time synchronization tracking of the spread spectrum preamble signal.

It can be seen that synchronous tracking requires a large amount of calculations, and requires the receiver to perform FFT calculations all the time. Especially across the two preamble code characters before and after; due to the discontinuity of the phase, the result of conjugate multiplication with the local chirp signal at this time is the separated ends, that is, the spectrum of the peak obtained after the FFT operation will be If there is interference, the peak value will be reduced, which will interfere with the normal judgment. As shown in FIG. 9, it shows a schematic diagram of the simulation result of a spread spectrum preamble signal related to the two preamble code characters before and after the spread spectrum provided by the embodiment of the application; correspondingly, the FFT result is shown in FIG. It can be seen that the peak value has been reduced.

In the embodiment of this application, since the character length of the local chirp signal and the received chirp signal are the same, the difference is only on the carrier frequency; therefore, the two can be cross-correlation processing, and then the result can be obtained through cross-correlation processing. The peak value is judged to obtain the start time and end time of each character, so as to achieve time synchronization. At this time, it is also possible to quickly determine the relevant window of the FFT operation required by the corresponding 2^SF.

Further, when the spread spectrum preamble signal includes multiple preamble code characters, at this time, according to the signal synchronization method of the embodiment of the present application, after the local chirp signal and the received chirp signal are cross-correlated, the result is The FFT result is shown in Figure 11. It can be seen from Figure 11 that for multiple preamble code characters, there are multiple corresponding peaks.

Through the foregoing embodiments, the specific implementation of the foregoing embodiments is described in detail. It can be seen that through the technical solutions of the foregoing embodiments, cross-correlation processing of the local chirp signal and the received chirp signal can quickly determine The start time and end time of each character, and the difference of carrier frequency can be judged for frequency compensation, so that the synchronization information of the spread spectrum preamble signal can be determined, and the time domain of the preamble code in the CSS spread spectrum signal can be realized. Synchronize with the frequency domain; in addition, in the early stage of CSS, it can save a lot of power consumption and computing time. The receiver does not need to perform FFT operations all the time. In this way, the sliding window with the largest peak value in the FFT is selected based on the results of the FFT before and after, and the signal synchronization method It is quickly determined that the corresponding M points require a sliding window for FFT operation, which can also improve the overall performance of the receiver.

In another embodiment of the present application, based on the same inventive concept as the foregoing embodiment, refer to FIG. 12, which shows an example of the composition structure of a signal synchronization device 120 provided by an embodiment of the present application. The signal synchronization device 120 may include : Receiving unit 1201, processing unit 1202, query unit 1203, and synchronization unit 1204, where:

The receiving unit 1201 is configured to receive a spread-spectrum preamble signal, where the spread-spectrum preamble signal includes N sequences, and N is a positive integer greater than or equal to 1;

The processing unit 1202 is configured to perform first correlation processing on each sequence in the spread-spectrum preamble signal and a local signal respectively, and determine N first processing results corresponding to the spread-spectrum preamble signal;

The processing unit 1202 is further configured to perform second correlation processing on the two first processing results before and after the N first processing results and the local signal, and determine a second processing result corresponding to the spread spectrum preamble signal ；

The query unit 1203 is configured to query the maximum value of the second processing result in a correlation window if the second processing result is greater than a preset threshold; wherein, the correlation window represents each of the spread spectrum preambles The sliding window corresponding to the sequence of performing the first correlation processing;

The synchronization unit 1204 is configured to determine synchronization information of the spread-spectrum preamble signal based on the maximum value, and implement synchronization tracking of the spread-spectrum preamble signal according to the synchronization information.

In the above solution, referring to FIG. 12, the signal synchronization device 120 may further include a determining unit 1205 and an estimation unit 1206, where:

The determining unit 1205 is configured to determine a time value corresponding to the maximum value according to the maximum value;

The estimation unit 1206 is configured to perform a fractional frequency offset estimation according to the time value to obtain an estimated value of the frequency offset;

The synchronization unit 1204 is specifically configured to perform frequency synchronization tracking on the spread spectrum preamble signal according to the frequency offset estimation value.

In the above solution, the determining unit 1205 is further configured to determine a sequence corresponding to the maximum value according to the maximum value; and obtain the start time and end time of the sequence according to the determined sequence;

The synchronization unit 1204 is specifically configured to perform time synchronization tracking on the spread spectrum preamble signal according to the start time and the end time.

In the above solution, referring to FIG. 12, the signal synchronization device 120 may further include a sampling unit 1207 configured to sample the received spread spectrum preamble signal according to a preset sampling rate, and determine the sampled spread spectrum preamble signal Is the spread spectrum preamble signal.

In the above solution, the processing unit 1202 is specifically configured to perform conjugate multiplication on each sequence in the spread spectrum preamble signal with a local signal to obtain N product signals; and perform conjugate multiplication on each of the N product signals; Fast Fourier transform FFT operations are performed on the two product signals respectively to obtain N FFT results; and the obtained N FFT results are determined as the N first processing results corresponding to the spread spectrum preamble signal.

In the above solution, the processing unit 1202 is specifically configured to perform conjugate multiplication with the local signal at the same position on the front and back two FFT results among the obtained N FFT results, and accumulate the multiplied results Processing to obtain a correlation result; and determining the obtained correlation result as the second processing result corresponding to the spread spectrum preamble signal.

In the above solution, referring to FIG. 12, the signal synchronization device 120 may further include a determining unit 1208 configured to determine whether the second processing result is greater than a preset threshold;

The determining unit 1205 is further configured to determine that the spread-spectrum preamble signal is not a useful signal if the second processing result is not greater than a preset threshold, and stop performing the query of the second processing result in the relevant window Maximum step.

It is understandable that, in this embodiment, a "unit" may be a part of a circuit, a part of a processor, a part of a program or software, etc., of course, it may also be a module, or it may also be non-modular. Moreover, the various components in this embodiment may be integrated into one processing unit, or each unit may exist alone physically, or two or more units may be integrated into one unit. The above-mentioned integrated unit can be realized in the form of hardware or software function module.

If the integrated unit is implemented in the form of a software function module and is not sold or used as an independent product, it can be stored in a computer readable storage medium. Based on this understanding, the technical solution of this embodiment is essentially or It is said that the part that contributes to the existing technology or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions to enable a computer device (which can A personal computer, server, or network device, etc.) or a processor (processor) executes all or part of the steps of the method described in this embodiment. The aforementioned storage media include: U disk, mobile hard disk, read only memory (Read Only Memory, ROM), random access memory (Random Access Memory, RAM), magnetic disk or optical disk and other media that can store program codes.

Therefore, this embodiment provides a computer storage medium that stores a signal synchronization program that implements the method described in any one of the foregoing embodiments when the signal synchronization program is executed by at least one processor.

Based on the composition of the above-mentioned signal synchronization device 120 and the computer storage medium, refer to FIG. 13, which shows an example of the specific hardware structure of the signal synchronization device 120 provided by the embodiment of the present application, which may include: a communication interface 1301, a memory 1302, and a processor 1303 ; The various components are coupled together through the bus system 1304. It can be understood that the bus system 1304 is used to implement connection and communication between these components. In addition to the data bus, the bus system 1304 also includes a power bus, a control bus, and a status signal bus. However, for clarity of description, various buses are marked as the bus system 1304 in FIG. 13. Among them, the communication interface 1301 is configured to receive and send signals in the process of sending and receiving information with other external network elements;

The memory 1302 is configured to store a computer program that can run on the processor 1303;

The processor 1303 is configured to execute: when running the computer program:

Receiving a spread-spectrum preamble signal, where the spread-spectrum preamble signal includes N sequences, where N is a positive integer greater than or equal to 1;

Perform first correlation processing on each sequence in the spread-spectrum preamble signal and a local signal respectively, and determine N first processing results corresponding to the spread-spectrum preamble signal;

Performing second correlation processing on two first processing results before and after the N first processing results and the local signal to determine a second processing result corresponding to the spread-spectrum preamble signal;

If the second processing result is greater than the preset threshold, query the maximum value of the second processing result in a correlation window; wherein, the correlation window represents that each sequence in the spread spectrum preamble is subjected to the first correlation processing The corresponding sliding window;

Based on the maximum value, the synchronization information of the spread-spectrum preamble signal is determined, and synchronization tracking of the spread-spectrum preamble signal is realized according to the synchronization information.

It can be understood that the memory 1302 in the embodiment of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memory. Among them, the non-volatile memory can be read-only memory (Read-Only Memory, ROM), programmable read-only memory (Programmable ROM, PROM), erasable programmable read-only memory (Erasable PROM, EPROM), and electrically available Erase programmable read-only memory (Electrically EPROM, EEPROM) or flash memory. The volatile memory may be random access memory (Random Access Memory, RAM), which is used as an external cache. By way of exemplary but not restrictive description, many forms of RAM are available, such as static random access memory (Static RAM, SRAM), dynamic random access memory (Dynamic RAM, DRAM), synchronous dynamic random access memory (Synchronous DRAM, SDRAM), Double Data Rate Synchronous Dynamic Random Access Memory (Double Data Rate SDRAM, DDRSDRAM), Enhanced Synchronous Dynamic Random Access Memory (Enhanced SDRAM, ESDRAM), Synchronous Link Dynamic Random Access Memory (Synchlink DRAM, SLDRAM) And Direct Rambus RAM (DRRAM). The memory 1302 of the system and method described in this application is intended to include, but is not limited to, these and any other suitable types of memory.

The processor 1303 may be an integrated circuit chip with signal processing capabilities. In the implementation process, the steps of the foregoing method can be completed by an integrated logic circuit of hardware in the processor 1303 or instructions in the form of software. The aforementioned processor 1303 may be a general-purpose processor, a digital signal processor (Digital Signal Processor, DSP), an application specific integrated circuit (ASIC), a field programmable gate array (Field Programmable Gate Array, FPGA) or other Programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps, and logical block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor or the like. The steps of the method disclosed in the embodiments of the present application can be directly embodied as being executed and completed by a hardware decoding processor, or executed and completed by a combination of hardware and software modules in the decoding processor. The software module can be located in a mature storage medium in the field, such as random access memory, flash memory, read-only memory, programmable read-only memory, or electrically erasable programmable memory, registers. The storage medium is located in the memory 1302, and the processor 1303 reads the information in the memory 1302, and completes the steps of the foregoing method in combination with its hardware.

It can be understood that the embodiments described in this application can be implemented by hardware, software, firmware, middleware, microcode, or a combination thereof. For hardware implementation, the processing unit can be implemented in one or more application specific integrated circuits (ASIC), digital signal processor (Digital Signal Processing, DSP), digital signal processing equipment (DSP Device, DSPD), programmable Logic device (Programmable Logic Device, PLD), Field-Programmable Gate Array (Field-Programmable Gate Array, FPGA), general-purpose processors, controllers, microcontrollers, microprocessors, and others for performing the functions described in this application Electronic unit or its combination.

For software implementation, the technology described in this application can be implemented through modules (for example, procedures, functions, etc.) that perform the functions described in this application. The software codes can be stored in the memory and executed by the processor. The memory can be implemented in the processor or external to the processor.

Optionally, as another embodiment, the processor 1303 is further configured to execute the method described in any one of the foregoing embodiments when the computer program is running.

It should be noted that in this application, the terms "including", "including" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements , But also includes other elements that are not explicitly listed, or elements inherent to the process, method, article, or device. If there are no more restrictions, the element defined by the sentence "including a..." does not exclude the existence of other identical elements in the process, method, article, or device that includes the element.

The serial numbers of the foregoing embodiments of the present application are only for description, and do not represent the advantages and disadvantages of the embodiments.

The methods disclosed in the several method embodiments provided in this application can be combined arbitrarily without conflict to obtain new method embodiments.

The features disclosed in the several product embodiments provided in this application can be combined arbitrarily without conflict to obtain new product embodiments.

The features disclosed in the several method or device embodiments provided in this application can be combined arbitrarily without conflict to obtain a new method embodiment or device embodiment.

The above are only specific implementations of this application, but the protection scope of this application is not limited to this. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed in this application. Should be covered within the scope of protection of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Industrial applicability

In the embodiment of this application, the spread spectrum preamble signal is first received. The spread spectrum preamble signal includes N sequences, where N is a positive integer greater than or equal to 1. Then, each sequence in the spread spectrum preamble signal is connected to the local Perform first correlation processing on the signal to determine N first processing results corresponding to the spread-spectrum preamble signal; then perform second correlation processing on the two first processing results before and after the N first processing results and the local signal, Determine the second processing result corresponding to the spread-spectrum preamble signal; if the second processing result is greater than the preset threshold, query the maximum value of the second processing result in the correlation window; finally, based on the maximum value, determine the value of the spread-spectrum preamble signal Synchronization information, and realize synchronization tracking of spread spectrum preamble signal according to said synchronization information; in this way, by cross-correlating the received spread spectrum preamble signal with the local signal, and according to the peak value obtained after cross-correlation processing Through the judgment, the synchronization information of the spread spectrum preamble signal can be determined, and the time domain and frequency domain synchronization of the preamble code in the CSS spread spectrum signal can be realized; in addition, the solution in the embodiment of the present application does not require the receiver to always perform fast Four The calculation of the FFT (Fast Fourier Transform) can also save power consumption and calculation time, which can also improve the overall performance of the receiver.

Claims (16)

1. A signal synchronization method, the method includes:

   Receiving a spread-spectrum preamble signal, where the spread-spectrum preamble signal includes N sequences, where N is a positive integer greater than or equal to 1;

   Perform first correlation processing on each sequence in the spread-spectrum preamble signal and a local signal respectively, and determine N first processing results corresponding to the spread-spectrum preamble signal;

   Performing second correlation processing on two first processing results before and after the N first processing results and the local signal to determine a second processing result corresponding to the spread-spectrum preamble signal;

   If the second processing result is greater than the preset threshold, query the maximum value of the second processing result in a correlation window; wherein, the correlation window represents that each sequence in the spread spectrum preamble is subjected to the first correlation processing The corresponding sliding window;

   Based on the maximum value, the synchronization information of the spread-spectrum preamble signal is determined, and synchronization tracking of the spread-spectrum preamble signal is realized according to the synchronization information.
2. The method according to claim 1, wherein the determining the synchronization information of the spread spectrum preamble signal based on the maximum value comprises:

   Determine the time value corresponding to the maximum value according to the maximum value;

   Perform a fractional multiple frequency offset estimation according to the time value to obtain an estimated value of the frequency offset;

   Perform frequency synchronization tracking on the spread spectrum preamble signal according to the estimated value of the frequency offset.
3. The method according to claim 1, wherein the determining the synchronization information of the spread spectrum preamble signal based on the maximum value comprises:

   Determine the sequence corresponding to the maximum value according to the maximum value;

   Obtaining the start time and end time of the sequence according to the determined sequence;

   Perform time synchronization tracking on the spread spectrum preamble signal according to the start time and the end time.
4. The method according to claim 1, wherein, after the receiving the spread spectrum preamble signal, the method further comprises:

   Perform sampling processing on the received spread-spectrum preamble signal according to a preset sampling rate, and determine the sampled spread-spectrum preamble signal as the spread-spectrum preamble signal.
5. The method according to claim 1, wherein the first correlation processing is performed on each sequence in the spread-spectrum preamble signal and a local signal to determine the N first processings corresponding to the spread-spectrum preamble signal The results include:

   Conjugate multiplication of each sequence in the spread spectrum preamble signal with a local signal to obtain N product signals;

   Perform Fast Fourier Transform FFT operation on each of the N product signals, respectively, to obtain N FFT results;

   The obtained N FFT results are determined as the N first processing results corresponding to the spread spectrum preamble signal.
6. 5. The method according to claim 5, wherein the second correlation processing is performed on the two first processing results before and after the N first processing results and the local signal to determine the spread spectrum preamble signal The corresponding second processing result includes:

   Performing conjugate multiplication on the front and back two FFT results of the obtained N FFT results with the local signal at the same position, and accumulating the multiplied results to obtain a correlation result;

   The obtained correlation result is determined as the second processing result corresponding to the spread spectrum preamble signal.
7. The method according to any one of claims 1 to 6, wherein, before the second processing result is greater than a preset threshold, the method further comprises:

   Judging whether the second processing result is greater than a preset threshold;

   If the second processing result is not greater than the preset threshold, it is determined that the spread spectrum preamble signal is a non-useful signal, and the step of querying the maximum value of the second processing result in the relevant window is stopped.
8. A signal synchronization device. The signal synchronization device includes a receiving unit, a processing unit, an inquiry unit, and a synchronization unit, wherein:

   The receiving unit is configured to receive a spread-spectrum preamble signal, where the spread-spectrum preamble signal includes N sequences, and N is a positive integer greater than or equal to 1;

   The processing unit is configured to perform first correlation processing on each sequence in the spread-spectrum preamble signal and a local signal respectively, and determine N first processing results corresponding to the spread-spectrum preamble signal;

   The processing unit is further configured to perform second correlation processing on the two first processing results before and after the N first processing results and the local signal, and determine the second processing corresponding to the spread spectrum preamble signal result;

   The query unit is configured to query the maximum value of the second processing result in a correlation window if the second processing result is greater than a preset threshold; wherein, the correlation window represents each of the spread spectrum preambles Sliding windows corresponding to the first correlation processing for each sequence;

   The synchronization unit is configured to determine synchronization information of the spread-spectrum preamble signal based on the maximum value, and implement synchronization tracking of the spread-spectrum preamble signal according to the synchronization information.
9. The signal synchronization device according to claim 8, wherein the signal synchronization device further comprises a determination unit and an estimation unit, wherein,

   The determining unit is configured to determine a time value corresponding to the maximum value according to the maximum value;

   The estimation unit is configured to perform a fractional multiple frequency offset estimation according to the time value to obtain an estimated value of the frequency offset;

   The synchronization unit is specifically configured to perform frequency synchronization tracking on the spread spectrum preamble signal according to the frequency offset estimation value.
10. The signal synchronization device according to claim 8, wherein the determining unit is further configured to determine a sequence corresponding to the maximum value according to the maximum value; and obtain the start of the sequence according to the determined sequence Time and end time;

    The synchronization unit is specifically configured to perform time synchronization tracking on the spread spectrum preamble signal according to the start time and the end time.
11. The signal synchronization device according to claim 8, wherein the signal synchronization device further comprises a sampling unit configured to perform sampling processing on the received spread spectrum preamble signal according to a preset sampling rate, and the sampled spread spectrum preamble signal The code signal is determined to be the spread spectrum preamble signal.
12. The signal synchronization device according to claim 8, wherein the processing unit is specifically configured to perform conjugate multiplication on each sequence in the spread spectrum preamble signal with a local signal to obtain N product signals; and Perform fast Fourier transform FFT operations on each of the N product signals respectively to obtain N FFT results; and determine the obtained N FFT results as the N corresponding to the spread spectrum preamble signal The first processing result.
13. The signal synchronization device according to claim 12, wherein the processing unit is specifically configured to perform conjugate multiplication on the local signal at the same position on the two FFT results before and after the obtained N FFT results, The multiplication result is accumulated and processed to obtain a correlation result; and the obtained correlation result is determined as the second processing result corresponding to the spread spectrum preamble signal.
14. The signal synchronization device according to any one of claims 8 to 13, wherein the signal synchronization device further comprises a judging unit configured to judge whether the second processing result is greater than a preset threshold;

    The determining unit is further configured to determine that the spread spectrum preamble signal is not a useful signal if the second processing result is not greater than a preset threshold, and stop performing the query of the second processing result in the relevant window The steps of the maximum value.
15. A signal synchronization device, the signal synchronization device includes a memory and a processor; wherein,

    The memory is configured to store a computer program that can run on the processor;

    The processor is configured to execute the method according to any one of claims 1 to 7 when running the computer program.
16. A computer storage medium, wherein the computer storage medium stores a signal synchronization program, and when the signal synchronization program is executed by at least one processor, the method according to any one of claims 1 to 7 is implemented.

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