Control method for peak search in signal synchronous detection and computer device

Abstract

The invention discloses a control method for peak search in signal synchronous detection and a computer device, the method comprises the following steps: processing a received leader sequence sampling point signal to obtain a synchronous detection metric value, further searching and calibrating feature points in a classified manner, and in different parameter updating modes, according to the position relationship between the feature points and a search window, determining the peak value in the synchronous detection. Effective peak points are obtained, peak counting updating is carried out through the effective peak points, and synchronous judgment is carried out. According to the method, peak value searching is carried out on multiple points at a time in different parameter updating modes, effective peak value points are obtained, and the peak value searching efficiency is improved. The method can be realized on the basis of traditional synchronous detection single-point peak value search, can also be used for simultaneously carrying out peak value search on multiple input points, effectively improves the processing rate of a receiving end of a communication system, and can be suitable for more communication system scenes.

Description

Technical Field

[0001] The present invention relates to wireless communication technology, and in particular to a control method and a computer device for peak value search in signal synchronization detection. Background Art

[0002] In wireless communication systems, due to the openness of the channel, wireless communication is easily affected by various external interferences, so it is necessary to synchronize the received signal in real time. In order to achieve the purpose of signal synchronization detection, communication systems such as OFDM (Orthogonal Frequency Division Multiplexing) systems often use known local preamble sequence signals for modulation, transmission and reception demodulation, which is convenient for signal synchronization detection using signal correlation characteristics to obtain more accurate timing synchronization.

[0003] Traditional signal synchronization detection generally includes two parts: synchronization detection metric calculation and peak search. In practice, the peak search part uses a single sampling point, which is often insufficient to cope with various complex high-speed communication systems. If the replication structure is simply used for parallel processing, the hardware area overhead will be increased. Therefore, it is necessary to fully consider the multi-point processing mode for the existing peak search part to better meet the communication system performance and more application scenarios.

[0004] In the prior art, the efficiency of searching for a single sampling point of a peak using a search window is low. For example, a Chinese patent application document with publication number CN117279087A discloses a method, device, electronic device and storage medium for determining a synchronization position. The method also searches for a peak and determines the synchronization position based on the distance between the peaks. In this method, the mutual correlation value of the local sequence and the received signal is first compared with a preset threshold to obtain the first correlation peak greater than the preset threshold, and the correlation peak is used as a starting point to search for the first peak using the first search window, and then the position of the second search window is determined according to the position of the first peak, and the second peak is searched using the second search window. Only a single point comparison search is performed on one peak each time, and the operating efficiency is low, which is not enough to cope with various complex high-speed communication systems. Summary of the invention

[0005] The purpose of the present invention is to provide a control method and computer device for peak search in signal synchronization detection, so as to solve the problem in the prior art that only a single point comparison search is performed on one peak each time during peak search, resulting in low operating efficiency and limited application scenarios.

[0006] In order to solve the above technical problems, the present invention provides a control method for peak value search in signal synchronization detection, the method comprising: 1) Process the received signal to obtain a synchronization detection metric value; 2) calibrating the obtained synchronous detection metric value with characteristic points, wherein the characteristic points include maximum value points, threshold points and peak points; determining the parameter updating method according to the positional relationship between the characteristic points and the search window and the number of peaks; 3) updating the parameters according to the determined parameter updating method, and counting the effective peak points obtained after the update, wherein the parameters include a first peak value and a second peak value; 4) Use the valid peak point to update the peak count and make a synchronization decision; if the synchronization condition is not met, repeat steps 1)-4) until the peak count value meets the synchronization condition.

[0007] Furthermore, the parameter updating method includes: Method 1: When there is no first peak and second peak, the maximum value point is selected as the first peak candidate point; Method 2: When there is only the first peak, the first peak candidate point and the second peak candidate point are determined according to the positional relationship between the feature point and the first peak search window and the double search window of the first peak; wherein the first peak search window is a window with a width of N / 2 and a starting point of the first peak point, where N is the number of sampling points of a signal symbol; Method three: There is a first peak and a second peak. According to the positional relationship between the feature point and the first peak search window, the twice search window of the first peak, the second peak search window and the twice search window of the second peak, the first peak candidate point and the second peak candidate point are obtained, wherein the second peak search window is a window with the second peak point as the starting point and a width of N / 2.

[0008] Furthermore, the process of determining the first peak candidate point and the second peak candidate point in the second method includes: When there is a peak point on or within the first peak search window, and there is a maximum point within the double search window of the first peak, the maximum point is selected as the first peak candidate point; When there is no peak point on or within the first peak search window, and there is a threshold point after the first peak search window and within the double search window of the first peak, the maximum value point is selected as the first peak candidate point, and the original first peak point is selected as the second peak candidate point; When there is a threshold point on the double search window of the first peak, and all threshold points within the double search window of the first peak are smaller than the threshold point, the threshold point is selected as the first peak candidate point, and the original first peak point is selected as the second peak candidate point; When the threshold point appears after the double search window of the first peak, the first peak point is discarded and the maximum value point is used as the first peak candidate point; When there is no threshold point for the synchronous detection metric value and the last input synchronous detection metric value is behind the double search window of the first peak value, the first peak value is discarded.

[0009] Furthermore, the process of determining the first peak candidate point and the second peak candidate point in the third method includes: When there are peak points and maximum points within the double search window of the second peak, the maximum point is selected as the first peak candidate point; When there is a peak point on the double search window of the second peak, and all peak points within the double search window of the second peak are smaller than the peak point, the peak point is selected as the first peak candidate point; When there is no peak point on or within the double search window of the second peak, and there are peak points and maximum points outside the double search window of the second peak and on or within the first peak search window, the original second peak is discarded and the maximum point is selected as the first peak candidate point; When there is no peak point on or within the double search window of the second peak and on or within the first peak search window, and there is a threshold point and a maximum point outside the first peak search window, the maximum point is selected as the first peak candidate point, and the original first peak is selected as the second peak candidate point; When there is no threshold point for the synchronous detection metric value and the last input synchronous detection metric value is behind the double search window of the second peak value, the second peak value is discarded.

[0010] Furthermore, the process of determining the effective peak value is: The first peak candidate point is updated to the first peak, and the second peak candidate point is updated to the second peak; After the update, if both the first peak and the second peak exist and the distance between them is equal to N, the latest historical valid peak is updated to the second peak, the second peak is discarded, and the first peak is retained.

[0011] Furthermore, the method for updating the peak count using the effective peak points is as follows: the initial value of the peak count is set to 0, the distance between the first peak point and the latest effective peak point in history is recorded as D1, and the distance between the second peak point and the latest effective peak point in history is recorded as D2; When only the first peak value and the latest historical valid peak value exist, if D1≠N, the peak count is restored to the initial 0 and all historical valid peak values ​​are cleared; if the latest historical valid peak value has been updated, that is, D1=N is satisfied, the value in the peak counter is increased by 1; When there are the latest historical valid peak value, the first peak value and the second peak value, if D2=N is satisfied, the peak count will remain unchanged; if D2≠N, the peak count will be restored to the initial 0 and all historical valid peak values ​​will be cleared.

[0012] Furthermore, the process of determining the synchronization detection metric value is as follows: at least one sampling point signal is input into the received demodulated signal in sequence to obtain a corresponding sampling point sequence, each group of sampling point sequences is cross-correlated with the local preamble sequence to obtain a cross-correlation value corresponding to each group of sampling point sequences, and when performing cross-correlation, cross-correlation is performed with the non-zero point preamble code sampling points in the local preamble sequence; each cross-correlation value is delayed autocorrelated by one symbol period to obtain a corresponding autocorrelation value; each autocorrelation value is modulo-squared to obtain a corresponding signal energy value, and the signal energy value is the synchronization detection metric value, wherein the symbol period is equal to the number of sampling points.

[0013] Furthermore, the process of determining the maximum point is: when there are two points whose synchronization detection metric values ​​are equal and both are greater than the remaining synchronization detection metric values, the point with the largest input order index value is selected as the maximum point, and the input order index value is the order value of sampling the received demodulated signal.

[0014] A computer device comprises a processor, wherein the processor is used to run a computer program to implement the control method for peak value search in signal synchronization detection as described above.

[0015] The beneficial effects of the present invention are as follows: As an improved invention, the present invention first calibrates the characteristic points of the synchronous detection metric value, classifies the parameter update mode, and performs peak search on multiple points at one time according to the positional relationship between the characteristic point and the search window to obtain effective peak points, thereby improving the peak search efficiency. At the same time, the method can be implemented on the traditional synchronous detection single-point peak search, and can also input multiple points for peak search at the same time, effectively improving the processing rate of the receiving end of the communication system, and can be applied to more communication system scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a structural diagram of a synchronous detection accelerated peak search system; Figure 2 is an illustration of the distribution of feature points; Figure 3 This is a diagram illustrating the second distribution method of feature points; Figure 4 This is the third diagram illustrating the distribution of feature points. DETAILED DESCRIPTION

[0017] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings.

[0018] Method Embodiment like Figure 1As shown, the present invention first performs periodic sampling on the demodulated leading sequence signal, and converts the sampling result into a synchronous detection metric value. Since the leading sequence signal is a periodic signal, the periodic signal is periodically sampled, and the obtained sequence is also a periodic sequence. Therefore, when the number of samples is large enough, the sequence formed by the synchronous detection metric value should also be a periodic sequence with a sampling period as a cycle. Subsequently, the threshold point, maximum point and peak point in the synchronous detection metric value are marked, a search window and a double search window are set, and the sampling period is divided by the width of the search window and the double search window. The position of the effective peak point is set and updated by judging the position relationship between the threshold point, the maximum point and the peak point and the search window and the double search window. After multiple rounds of circulation, when the system finds the position of two or more effective peak points, it is judged whether the distance between the effective peak points is equal to the number of symbol sampling points, thereby judging whether the sampled signal is a periodic signal. When the distances between multiple consecutive effective peak points all meet the cycle period of the periodic signal, the sampled signal is a periodic signal, and then it can be judged that the sampled signal comes from the leading sequence signal and currently meets the synchronization requirement.

[0019] The specific steps include: Step 1): Process the received signal to obtain a synchronization detection metric value.

[0020] At least one sampling point signal is sequentially input into the received demodulated preamble sequence signal to obtain a corresponding sampling point sequence, wherein each sampling point sequence is composed of N sampling points, where N represents the number of sampling points in a sampling point signal, and N is a positive integer greater than or equal to 1.

[0021] Subsequently, each set of sampling point sequences is cross-correlated with the local preamble sequence to obtain the cross-correlation value corresponding to each set of sampling point sequences. In the existing cross-correlation calculation, sometimes continuous 0s are inserted into the local preamble sequence in order to achieve a better reception effect. In order to reduce the amount of calculation and control the required hardware area, when the sampling point sequence is cross-correlated with the local preamble sequence, the continuous 0 positions are not calculated, and only the sampling points corresponding to the non-zero value positions in the local preamble code are multiplied and accumulated.

[0022] Subsequently, each mutual correlation value is subjected to delayed autocorrelation of a symbol period T to obtain a corresponding autocorrelation value, where T = N. Then, each autocorrelation value is modulo squared to obtain a corresponding signal energy value, which is the synchronous detection metric value.

[0023] Step 2): Perform feature point calibration on the obtained synchronous detection metric value, and determine the parameter update method according to the position relationship between the feature point and the search window and the number of peaks.

[0024] Specifically, the characteristic points in the synchronous detection metric value include a maximum value point, a threshold value point and a peak value point.

[0025] Compare the synchronous detection metric values ​​in pairs to obtain the maximum synchronous detection metric value, mark the point where the maximum synchronous detection metric value is located as the maximum value point, and record the location of the maximum value point. If there are two points with the same synchronous detection metric values ​​and both are greater than the remaining synchronous detection metric values, select the point with the largest index value in the input sequence as the maximum value point. The index value of the input sequence is the sequence value of the received demodulated signal sampling.

[0026] Each synchronous detection metric value is compared with the threshold value, and the point where the synchronous detection metric value is greater than or equal to the threshold value is marked as the threshold point, and the position of all threshold points is recorded. Among them, the threshold value is preset according to the energy value of the local preamble sequence autocorrelation value. If the synchronous detection metric value does not exceed the threshold value, it means that the point cannot be a peak point.

[0027] If there is a first peak, each synchronous detection metric value is compared with the first peak value, the points where the synchronous detection metric values ​​are greater than or equal to the first peak value are marked as peak points, and the positions of all peak points are recorded.

[0028] The maximum value point, the threshold point and the peak point may be the point where the same synchronous detection metric value is located.

[0029] The position of the point where the synchronous detection metric value is located is the distance between the point and the first peak point or the second peak point, that is, the number of sampling points between the point and the first peak point or the second peak point. If there is no first peak and second peak, the position of the point where the synchronous detection metric value is located is represented by the index value of the input order.

[0030] Step 3): Update the parameters according to the determined parameter update method, and count the effective peak points obtained after the update.

[0031] Specifically, the parameters include a first peak and a second peak. According to the number of peaks, the parameter update modes are divided into three categories: mode 1: the first peak and the second peak do not exist, mode 2: only the first peak mode exists, and mode 3: the first peak and the second peak mode exist. When the first peak exists, the first peak search window and the double search window of the first peak are set, and the first peak search window and the double search window of the first peak both use the first peak point as the starting point. When the second peak exists, the second peak search window and the double search window of the second peak are set, and the second peak search window and the double search window of the second peak both use the second peak point as the starting point. The width of the first peak search window and the second peak search window is N / 2, and the width of the double search window of the first peak and the double search window of the second peak is N. According to the autocorrelation characteristics of the local leading sequence, only the peak points that appear within the N / 2 window length can be used as the first peak update point. The first peak can be used to find the position where the first periodic signal begins to appear. Other redundant peak points may be caused by signal interference.

[0032] Then, for different modes, according to the positional relationship between the feature points and the search window, the corresponding mode is selected to obtain the effective peak point.

[0033] Method 1: For the mode without the first peak value and the second peak value, if there is a threshold point, the maximum value point is also the threshold point. Therefore, the maximum value point is selected as the first peak candidate point.

[0034] Method 2: For a mode with only the first peak value, the positional relationship between the feature point and the search window includes: E1: When there are a peak point and a maximum point, and the positions of the peak point and the maximum point are both on or within the first peak search window, and the maximum point is detected in the first peak search window, the maximum point is selected as the first peak candidate point.

[0035] E2: When there is a peak point on or within the first peak search window, and there is a maximum value point between the first peak search window and the double search window of the first peak, and the double search window of the first peak detects the maximum value point, the maximum value point is selected as the first peak candidate point.

[0036] E3: If all peak points are not within the first peak search window, and there are threshold points and maximum points between the first peak search window and the double search window of the first peak, then the maximum point is selected as the first peak candidate point, and the original first peak point is selected as the second peak candidate point. The maximum point is the valid peak point.

[0037] E4: If there is a threshold point on the double search window of the first peak, and the threshold point before the double search window of the first peak does not exist or is smaller than the threshold point on the double search window of the first peak, then the threshold point on the double search window of the first peak is the point where the maximum value observable on the first peak search window and the double search window of the first peak is located. The threshold point is selected as the first peak candidate point, and the original first peak point is selected as the second peak candidate point.

[0038] E5: If no threshold point appears on or within the double search window of the first peak, and a threshold point and a maximum point appear outside the double search window of the first peak. Since the leading sequence signal should be a periodic signal, and the first peak and the current maximum value are not in the same period, it proves that the first peak initially selected does not belong to the leading sequence signal, so the first peak point should be discarded, and the maximum point detected outside the double search window of the first peak is used as the first peak candidate point.

[0039] E6: If the collected synchronization detection degree values ​​are all smaller than the threshold value and the first peak value, and the last input synchronization detection degree point is outside the double search window of the first peak value, it proves that the signal corresponding to the synchronization detection degree value and the first peak value do not belong to the leading sequence signal, so the first peak point is discarded.

[0040] Method 3: When there are the first peak and the second peak, the positional relationship between the feature point and the search window includes: F1: If there are a peak point and a maximum point within the double search window of the second peak, the maximum point is selected as the candidate point for the first peak.

[0041] F2: When there is a peak point on the double search window of the second peak, and the peak points within the double search window of the second peak do not exist or are all smaller than the peak point on the double search window of the second peak, the peak point on the double search window of the second peak is selected as the first peak candidate point.

[0042] F3: When there is no peak point within or on the double search window of the second peak, and there are peak points and maximum points outside the double search window of the second peak, on or before the first peak search window, that is, the next peak does not appear within a cycle after the second peak is emitted, but the next peak appears in the cycle after the first peak, it proves that the second peak does not belong to the leading sequence signal, and the first peak may belong to the leading sequence signal. Therefore, the original second peak point is discarded and the maximum point is selected as the first peak candidate point.

[0043] F4: If the threshold point and the maximum point only appear outside the first peak search window, the maximum point is selected as the first peak candidate point, and the original first peak point is used as the second peak candidate point.

[0044] F5: If the collected synchronization detection metric values ​​are all smaller than the threshold value and the first peak value, and the last input synchronization detection metric point is outside the double search window of the second peak value, it proves that the signal corresponding to the synchronization detection metric and the second peak value do not belong to the leading sequence signal, so the second peak value is discarded.

[0045] Subsequently, the valid peak is confirmed. Specifically, the peak candidate points obtained above are updated, that is, the first peak candidate point is updated to a new first peak, and the corresponding search window and double search window position of the first peak are updated, and the second peak candidate point is updated to a new second peak, and the corresponding search window and double search window position of the second peak are updated. After the update, if both the first peak and the second peak exist, and the distance between the two is equal to N, then the latest historical valid peak is updated to the second peak, and the second peak is discarded, and only the first peak is retained.

[0046] Step 4): Use the valid peak point to update the peak count and make a synchronization decision; if the synchronization condition is not met, repeat steps 1)-4) until the peak count value meets the synchronization condition.

[0047] Specifically, the preset peak count is 0. When only the first peak exists or only the first peak and the second peak exist, the peak count is not updated, and steps 1) to 4) are executed again.

[0048] When the distance between the first peak and the second peak is N, that is, only the first peak and the latest historical valid peak exist, the distance between the first peak and the latest historical valid peak is recorded as D1. If D1≠N at this time, that is, the latest historical valid peak point has not been updated in this round, and the distance between the first peak and the latest historical valid peak point does not satisfy the periodic cycle, it proves that the interval between the first peak point and the latest historical valid peak point does not constitute a periodic cycle of the leading sequence signal. At this time, the peak count is restored to the initial 0 and all historical valid peaks are cleared; if the latest historical valid peak has been updated in this round of peak search, it means that a new valid peak has been found, satisfying D1=N, and the value in the peak counter is increased by 1; then a synchronization judgment is made. If the value in the peak counter is equal to the expected peak value, the synchronization ends and the synchronization result is output. Otherwise, the above steps are repeated.

[0049] When the distance between the first peak and the second peak is not N, that is, when there are the latest historical valid peak, the first peak and the second peak, the distance between the second peak and the latest historical valid peak is D2. If D2=N, it indicates that the current peak search is still in progress, the peak count will remain unchanged, and the above steps will be repeated; if D2≠N, it indicates that the historical valid peak and the current first peak cannot be repeated periodically. At this time, the peak count will be restored to the initial 0, all historical valid peaks will be cleared, and the above steps will be repeated.

[0050] In order to explain the present invention more intuitively, this embodiment uses 4 sampling point inputs to illustrate the present invention, and the initial value of the peak count is set to 0. The corresponding specific control process is as follows: Step 1): First, input the sampling point to calculate the synchronous detection metric value. Generally, the following method can be adopted: with the input of 4 sampling point signals, 4 groups of N latest sampling points are taken in turn to form the sampling point sequences A0, A1, A2, A3, where N is the number of sampling points of a symbol; the 4 groups of sampling point sequences A0, A1, A2, A3 are cross-correlated with the local sequence to obtain the cross-correlation values ​​B0, B1, B2, B3, where for each group of sampling point sequences, only the sampling points at the non-zero position are required to be multiplied, accumulated and correlated. Subsequently, the 4 cross-correlation values ​​B0, B1, B2, B3 are respectively autocorrelated with a delay of one symbol period N to obtain the autocorrelation values ​​D0, D1, D2, D3. The autocorrelation values ​​D0, D1, D2, D3 are squared modulo to obtain the signal energy value, that is, the synchronous detection metric values ​​G0, G1, G2, G3.

[0051] Step 2): Secondly, perform feature point search and determine the parameter update method based on the positional relationship between the feature point and the search window and the number of peaks.

[0052] Compare the synchronous detection metric values ​​in pairs, mark the point where the maximum value is located as the maximum value point, denoted as m; compare the synchronous detection metric value with the threshold value, mark the point greater than or equal to the threshold value as the threshold point, denoted as t. When the first peak value exists, compare the synchronous detection metric value with the first peak value, and mark the point greater than or equal to the first peak value as the peak point, denoted as p. Set the first peak search window w11 and the double search window w12 of the first peak according to the first peak point p1, and set the second peak search window w21 and the second peak double search window w22 according to the second peak point p2. The width of the first peak search window w11 and the second peak search window w21 is N / 2, and the width of the double search window w12 of the first peak and the double search window w22 of the second peak is N.

[0053] To further explain, when a point is marked as t / m, it means that it satisfies both the threshold point and the maximum point, and the same applies to other points; when a point is a peak point, it must be a threshold point, but not necessarily the other way around. Therefore, the peak point may be marked as t / p, t / p / m, the threshold point may be marked as t, t / m, t / p, t / p / m, and the maximum point may be marked as m, t / m, t / p / m.

[0054] Step 3): Update the parameters according to the determined parameter update method, and count the effective peak points obtained after the update.

[0055] Mode 1: When there is no first peak and second peak, the parameter update mode 1 is satisfied, and there is a point marked as t / m, such as Figure 2 As shown, the method 1 in the parameter update mode is satisfied, and the point, i.e., the maximum value point, is selected as the first peak candidate point, and the arrow line at this position is bold to indicate selection.

[0056] When only the first peak exists, the second parameter update mode is satisfied, and there are 6 position relationships, such as Figure 3 shown.

[0057] E1: If there is a point marked as t / p / m on or within w11, select the maximum value point as the first peak candidate point, such as Figure 3 As shown in ①; E2: If there is a t / p point with a position equal to or within w11, and there is a t / p / m point with a position between w11 and w12, select the maximum value point as the candidate point for p1, such as Figure 3 As shown in ②; E3: If the positions of the t / p points are not equal to w11 or within w11, and there are points t, t / p, t / p / m, t / m outside w11 but within w12, select the maximum value point as the first peak point, and the original first peak point as the candidate point p2, such as Figure 3 As shown in ③; E4: If there are points t, t / p, t / p / m: located on w12, and the t and t / p points within w12 are smaller than the threshold point or there is no threshold point, select the threshold point as the first peak candidate point, and the original first peak point as the second peak candidate point, such as Figure 3 As shown in ④; E5: If the fourth condition above is not met, and there are points t, t / p, t / p / m, t / m outside w12, the maximum value point is used as the candidate point of p1, and the original first peak point is discarded, such as Figure 3 As shown in ⑤; E6: If there is only a maximum value point marked as m, and the last input synchronization detection metric point is outside w12, the first peak point is discarded, such as Figure 3 As shown in ⑥.

[0058] When there are the first peak and the second peak, the third parameter update mode is satisfied, and there are 5 position relationships, such as Figure 4 shown.

[0059] F1: If there are points t / p and t / p / m located within w22, select the maximum value point as the first peak candidate point, such as Figure 4 As shown in ①; F2: If there are points t / p, t / p / m, and their positions are on w22, and the t / p points within w22 are all smaller than the peak point or do not exist, then select the peak point as the first peak candidate point, such as Figure 4 As shown in ②; F3: If F2 is not satisfied, and there is a t / p / m point outside w22 but within w11, the maximum value point is selected as the first peak candidate point, and the original second peak point is discarded, such as Figure 4 As shown in ③; F4: If F3 is not satisfied and the positions of t / m, t / p, t / p / m are outside w11, the maximum value point is selected as the first peak candidate point, and the original first peak point is selected as the second peak candidate point, such as Figure 4 As shown in ④; F5: If there is only a maximum value point marked as m, and the last input synchronization detection metric point is after w22, the second peak point is discarded, such as Figure 4 As shown in ⑤.

[0060] Update the first peak point to the first peak candidate point, and update the starting points of the corresponding search window and the double search window to the new first peak point. At this time, the corresponding w11 and w12 will be updated to the distance from the new first peak point; Update the second peak point to the second peak candidate point, and update the corresponding search window and the starting point of the double search window to the new second peak point. At this time, the corresponding w21 and w22 will be updated to the distance from the new second peak point. If after the update, there is a first peak and a second peak, and the distance between the two is N, then update the second peak to the latest historical valid peak, discard the second peak, and only keep the first peak.

[0061] Step 4): Use the valid peak points to update the peak count and make a synchronization decision.

[0062] First, if there are only the latest historical valid peak point and the first peak point, the distance between the two is expressed as D1; ​​first, when D1 is not equal to N, the peak count is restored to the initial 0, and all historical valid peaks are cleared; when the latest historical peak has been updated in this round of peak search, the peak counter is increased by 1. Secondly, if there is the latest historical valid peak point, the first peak point and the second peak point, the distance between the second peak and the latest historical valid peak point is recorded as D2. When D2 is equal to N, the peak counter remains unchanged. When D2 is not equal to N, the peak count is restored to the initial 0, and all historical valid peaks are cleared; finally, a synchronization decision is made. If the peak counter is equal to the expected number of peaks, the synchronization ends and the synchronization result is output. Otherwise, steps 1)-4) are repeated.

[0063] Computer device embodiment A computer device includes a processor, the processor is used to run a computer program, the computer program can be divided into a synchronous detection metric value calculation module, a feature point search module, a type mode calculation module, a parameter update module, a synchronous determination module and an output module, and the synchronous determination module is connected to the synchronous detection metric value calculation module. The synchronous detection metric value calculation module is mainly used in step 1) to sample the received demodulated leading sequence signal, pre-process each group of sampling point sequences respectively, and obtain the corresponding synchronous detection metric value. The feature point search module is mainly used in step 2) to calibrate the feature points in the synchronous detection metric value respectively. The type mode calculation module is mainly used in step 2) to classify the parameter update mode and obtain the effective peak point according to the positional relationship between the feature point and the search window. The parameter update module is mainly used in step 3) to select the parameter update method under the corresponding parameter update mode to update the parameters. The synchronous determination module is mainly used in step 4) to calculate and update the peak count according to the distance between the first peak point, the second peak point and the point where the latest historical effective peak is located. The synchronous determination module is mainly used in step 4) to determine whether the value in the peak counter is equal to the expected peak value. The output module is mainly used to output the synchronization result. The specific implementation process has been described in detail in the method embodiment, and will not be repeated here.

Claims

1. A control method for peak search in signal synchronization detection, characterized in that: The method includes: 1) Process the received signal to obtain a synchronization detection metric value; 2) calibrating the obtained synchronous detection metric value with characteristic points, wherein the characteristic points include maximum value points, threshold points and peak points; determining the parameter updating method according to the positional relationship between the characteristic points and the search window and the number of peaks; 3) updating the parameters according to the determined parameter updating method, and counting the effective peak points obtained after the update, wherein the parameters include a first peak value and a second peak value; 4) Use the valid peak point to update the peak count and make a synchronization decision; if the synchronization condition is not met, repeat steps 1)-4) until the peak count value meets the synchronization condition.

2. The control method for peak search in signal synchronization detection according to claim 1, characterized in that: The parameter updating methods include: Method 1: When there is no first peak and second peak, the maximum value point is selected as the first peak candidate point; Method 2: When there is only the first peak, the first peak candidate point and the second peak candidate point are determined according to the positional relationship between the feature point and the first peak search window and the double search window of the first peak; wherein the first peak search window is a window with a width of N / 2 and a starting point of the first peak point, where N is the number of sampling points of a signal symbol; Method three: There is a first peak and a second peak. According to the positional relationship between the feature point and the first peak search window, the twice search window of the first peak, the second peak search window and the twice search window of the second peak, the first peak candidate point and the second peak candidate point are obtained, wherein the second peak search window is a window with the second peak point as the starting point and a width of N / 2.

3. The control method for peak search in signal synchronization detection according to claim 2, characterized in that: The process of determining the first peak candidate point and the second peak candidate point in the second method includes: When there is a peak point on or within the first peak search window, and there is a maximum point within the double search window of the first peak, the maximum point is selected as the first peak candidate point; When there is no peak point on or within the first peak search window, and there is a threshold point after the first peak search window and within the double search window of the first peak, the maximum value point is selected as the first peak candidate point, and the original first peak point is selected as the second peak candidate point; When there is a threshold point on the double search window of the first peak, and all threshold points within the double search window of the first peak are smaller than the threshold point, the threshold point is selected as the first peak candidate point, and the original first peak point is selected as the second peak candidate point; When the threshold point appears after the double search window of the first peak, the first peak point is discarded and the maximum value point is used as the first peak candidate point; When there is no threshold point for the synchronous detection metric value and the last input synchronous detection metric value is behind the double search window of the first peak value, the first peak value is discarded.

4. The control method for peak search in signal synchronization detection according to claim 2, characterized in that: The process of determining the first peak candidate point and the second peak candidate point in the third method includes: When there are peak points and maximum points within the double search window of the second peak, the maximum point is selected as the first peak candidate point; When there is a peak point on the double search window of the second peak, and all peak points within the double search window of the second peak are smaller than the peak point, the peak point is selected as the first peak candidate point; When there is no peak point on or within the double search window of the second peak, and there are peak points and maximum points outside the double search window of the second peak and on or within the first peak search window, the original second peak is discarded and the maximum point is selected as the first peak candidate point; When there are no peak points on and within the double search window of the second peak and on and within the first peak search window, and there are threshold points and maximum points outside the first peak search window, the maximum point is selected as the first peak candidate point, and the original first peak point is selected as the second peak candidate point; When there is no threshold point for the synchronous detection metric value and the last input synchronous detection metric value is behind the double search window of the second peak value, the second peak value is discarded.

5. The control method for peak search in signal synchronization detection according to claim 2, characterized in that: The process of determining the effective peak value is: The first peak candidate point is updated to the first peak, and the second peak candidate point is updated to the second peak; After the update, if both the first peak and the second peak exist and the distance between them is equal to N, the latest historical valid peak is updated to the second peak, and the second peak is discarded, and the first peak is retained.

6. The control method for peak search in signal synchronization detection according to claim 1, characterized in that: The method for updating the peak count using the effective peak points is as follows: the initial value of the peak count is set to 0, the distance between the first peak point and the latest effective peak point in history is recorded as D1, and the distance between the second peak point and the latest effective peak point in history is recorded as D2; When only the first peak value and the latest historical valid peak value exist, if D1≠N, the peak count is restored to the initial 0 and all historical valid peak values ​​are cleared; if the latest historical valid peak value has been updated, that is, D1=N is satisfied, the value in the peak counter is increased by 1; When there are the latest historical valid peak value, the first peak value, and the second peak value, if D2=N is satisfied, the peak count will remain unchanged; If D2≠N, the peak count is restored to the initial 0 and all historical valid peak values ​​are cleared.

7. The control method for peak search in signal synchronization detection according to claim 1, characterized in that: The process of determining the synchronous detection metric value is as follows: at least one sampling point signal is sequentially input into the received demodulated signal to obtain a corresponding sampling point sequence, each group of sampling point sequences is cross-correlated with the local preamble sequence to obtain a cross-correlation value corresponding to each group of sampling point sequences, and when cross-correlating, cross-correlating with a non-zero preamble code sampling point in the local preamble sequence; Perform delayed autocorrelation of one symbol period on each mutual correlation value to obtain the corresponding autocorrelation value; perform modulus square on each autocorrelation value to obtain the corresponding signal energy value, which is the synchronous detection metric value, wherein the symbol period is equal to the number of sampling points.

8. The control method for peak search in signal synchronization detection according to claim 1, characterized in that: The process of determining the maximum point is: when there are two points whose synchronous detection metric values ​​are equal and both are greater than the remaining synchronous detection metric values, the point with the largest input sequence index value is selected as the maximum point, and the input sequence index value is the sequence value of sampling the received demodulated signal.

9. A computer device, characterized in that: The device comprises a processor, and the processor is used to run a computer program to implement the control method for peak value search in signal synchronization detection as described in any one of claims 1 to 8.

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