Pss synchronization search method, apparatus and device, and computer readable storage medium

Abstract

The application discloses a PSS synchronization search method and device, equipment and a computer readable storage medium, comprising: acquiring a time domain received signal in a preset PSS receiving time window; performing a sliding correlation operation on the time domain received signal and a locally stored PSS mother code signal; calculating a correlation power value corresponding to each time domain sample according to the sliding correlation result; determining a correlation noise power interval according to a preset signal window interval unilateral length and a preset detection interval unilateral length, calculating a power autocorrelation peak-to-average ratio of each time domain sample based on the correlation power value of each time domain sample in the correlation noise power interval and a correlation noise average value, and acquiring a maximum value in the power autocorrelation peak-to-average ratio, and when the maximum value exceeds a preset threshold, it is determined that a PSS signal is successfully detected. The power autocorrelation peak-to-average ratio of each time domain sample can be compared with the preset threshold, false peaks caused by various interferences can be effectively filtered, false detection can be prevented, and multi-cell PSS signal missed detection can be reduced.

Description

Technical Field

[0001] This application relates to the field of mobile communication technology, and in particular to a PSS synchronization search method, apparatus, device and computer-readable storage medium. Background Technology

[0002] In 5G NR (New Radio) communication systems, initial cell searches are performed during the power-on of NR terminal devices, cell handover, and transition from connected to idle states. NR cell searches rely on the Primary Synchronization Signal (PSS) to complete downlink time-domain synchronization and obtain the intra-cell identifier. With the increased number of PSSs in 5G NR systems, rapid searches for PSS signals from multiple cells are required.

[0003] Existing conventional PSS detection schemes correlate the received signal in the time domain with three local PSS reference sequences, determining the synchronization position and cell ID based on the correlation power peak. Mainstream peak determination methods fall into two categories: global peak detection and fixed ratio discrimination. The global peak detection method uses the maximum correlation power across the entire segment as the effective synchronization peak; the algorithm is simple to implement but lacks interference discrimination logic. The fixed ratio discrimination method determines the signal by comparing the ratio of a single peak value to the average power of the other two peak values ​​with a preset threshold, but it treats coexisting effective PSS signals from neighboring cells as interference noise.

[0004] However, both conventional PSS detection methods are based on correlation processing and peak decision. In wireless environments where multiple NR cells are simultaneously experiencing strong pulse interference, they suffer from serious false detection and false detection defects, and lack synchronization robustness, making them unsuitable for the NR downlink synchronization requirements of diverse networking scenarios. Summary of the Invention

[0005] The main purpose of this application is to provide a PSS synchronization search method, apparatus, device and computer-readable storage medium. The technical problem to be solved is that when multiple NR cells are simultaneously subject to strong pulse interference, traditional peak decision or fixed ratio discrimination is prone to false detection or missed detection, resulting in poor reliability of synchronization point and cell group ID decision.

[0006] To achieve the above objectives, this application provides a PSS synchronous search method, the method comprising: Acquire the time-domain received signal within the preset PSS receiving time window; The time-domain signal is subjected to a sliding correlation operation with the locally stored PSS mother code signal to obtain the sliding correlation result; Calculate the correlation power value corresponding to each time domain sample point based on the sliding correlation results; The relevant noise power range is determined based on the single-sided length of the preset signal window range and the single-sided length of the preset detection range. Based on the mean value of the relevant noise within the noise power range and the relevant power value of each time-domain sample point, the power autocorrelation peak-to-average ratio of each time-domain sample point is calculated. The maximum value of the peak-to-average power autocorrelation ratio of each time-domain sample point is obtained. When the maximum value exceeds a preset threshold, it is determined that the PSS signal has been successfully detected.

[0007] Optionally, determining the relevant noise power range based on the single-sided length of the preset signal window interval and the single-sided length of the preset detection interval includes: Calculate the boundary index value of the signal window interval based on the current time-domain sample point index value and the preset single-side length of the signal window interval; Calculate the boundary index value of the detection interval based on the current time-domain sample point index value and the preset single-sided length of the detection interval; By using a clamping function to correct for out-of-bounds errors in the boundary index values ​​of the signal window interval and the detection interval, the candidate signal interval and the detection interval are obtained. The candidate signal interval is removed from the detection interval, and the remaining time-domain samples are used as the relevant noise power interval.

[0008] Optionally, the signal window interval boundary index value includes a first start index value and a first end index value, and the step of calculating the signal window interval boundary index value based on the current time-domain sample point index value and the preset single-side length of the signal window interval includes: When the current time-domain sample index value is less than the single-sided length of the preset signal window interval, the current time-domain sample is taken as the starting position of the signal candidate interval, and the first termination index value is taken as the termination position of the signal candidate interval. If the sum of the current time-domain sample index value and the single-sided length of the preset detection interval exceeds the upper limit of the index range, the current time-domain sample is taken as the termination position of the signal candidate interval, and the first starting index value is taken as the starting position of the signal candidate interval.

[0009] The detection interval boundary index value includes a second start index value and a second end index value. The calculation of the detection interval boundary index value based on the current time-domain sample point index value and the preset single-sided length of the detection interval includes: When the current time-domain sample point index value is less than the single-sided length of the preset detection interval, the current time-domain sample point is taken as the starting position of the detection interval, and the second termination index value is taken as the ending position of the detection interval. If the sum of the current time-domain sample point index value and the single-sided length of the preset detection interval exceeds the upper limit of the index range, the current time-domain sample point is taken as the end position of the detection interval, and the second starting index value is taken as the start position of the detection interval.

[0010] Optionally, the sliding correlation operation satisfies:

[0011] in, For receiving signals in the time domain, Indicates the first Each time-domain sample point takes a value of _____. N is the length of the signal sequence, and M is the length of the PSS mother code signal. Indicates taking the conjugate. Indicates the PSS mother code signal. ∈{0, 1, 2}.

[0012] Optionally, the mean of the relevant noise is the arithmetic average of the relevant noise power values ​​of each time-domain sample point within the noise power range.

[0013] Optionally, obtaining the maximum value of the peak-to-average power ratio (PAPR) of each time-domain sample includes: By iterating through all time-domain samples corresponding to each group of PSS mother code signals, comparing the peak-to-average power ratio (PAPR) of each time-domain sample, and selecting the maximum PAPR for each group of PSS mother code signals, the following steps are taken: The maximum value of the peak-to-average power ratio (PAPR) is the maximum value of the PAPR of the power autocorrelation of a single PSS mother code signal across all time-domain samples within the entire PSS reception time window.

[0014] Optionally, the method is applicable to multi-cell PSS synchronous search of terminal equipment, user premises equipment, and roadside equipment in dense heterogeneous networking, high-speed mobile Doppler scenarios, and in-band sudden interference environments.

[0015] This application also provides a PSS synchronous search device, including: The signal receiving module is used to acquire the time-domain received signal within a preset PSS receiving time window; The correlation processing module is used to perform sliding correlation operation on the time-domain signal and the locally stored PSS master code signal to obtain the sliding correlation result; The power calculation module is used to calculate the correlation power value corresponding to each time domain sample point based on the sliding correlation result; The peak-to-average power calculation module is used to determine the relevant noise power range based on the single-sided length of the preset signal window interval and the single-sided length of the preset detection interval, and to calculate the power autocorrelation peak-to-average power ratio of each time-domain sample based on the mean of the relevant noise within the noise power range and the relevant power value of each time-domain sample. The decision module is used to obtain the maximum value of the peak-to-average power autocorrelation ratio of each time-domain sample point, and when the maximum value exceeds a preset threshold, it is determined that the PSS signal has been successfully detected.

[0016] This application also provides an electronic device, including a processor and a memory, wherein the memory stores a computer program that, when executed by the processor, implements the method described in the foregoing embodiments.

[0017] This application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the methods described in the foregoing embodiments.

[0018] The beneficial effects of this application are that it can acquire time-domain signals within a preset PSS reception time window, improve the time-domain identification capability of the synchronization peak by using locally stored PSS master code signals for sliding correlation, calculate the correlation power of each time-domain sample based on the sliding correlation results, and divide the correlation noise power interval according to the preset signal window interval and detection interval. By dividing the independent noise power interval, the mean local noise can be estimated. The PSS signal decision is completed using the power autocorrelation peak-to-average power ratio of each time-domain sample. By comparing the power autocorrelation peak-to-average power ratio of each time-domain sample with a preset threshold, a simple and computationally controllable decision rule is realized. This can effectively filter false peaks caused by various interferences, improve the ability to distinguish between real PSS signals and time-domain random noise peaks, prevent false detections, and effectively avoid missed detections in multi-cell PSS signal superposition scenarios, thereby significantly improving the accuracy and robustness of PSS synchronization search. Attached Figure Description

[0019] Figure 1 A flowchart illustrating a PSS synchronous search method provided in this application embodiment; Figure 2 Peak power distribution diagram of a PSS synchronization search method provided in an embodiment of this application; Figure 3 A structural block diagram of a PSS synchronous search device provided in an embodiment of this application; Figure 4 This is a structural block diagram of an electronic device for PSS synchronous search provided in an embodiment of this application.

[0020] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0023] Figure 1 A flowchart of a PSS synchronous search method provided in an embodiment of this application.

[0024] Reference Figure 1 This PSS synchronization search method can be applied to downlink PSS signal synchronization scenarios in NR cell search. The method can be executed by the NR terminal equipment and includes: Step S101: Acquire the time-domain received signal within the preset PSS receiving time window.

[0025] It should be noted that NR is the 3GPP 5G wireless communication access technology system, which specifies a complete downlink synchronization mechanism. NR terminal equipment relies on the master synchronization signal to complete the downlink time domain synchronization of the NR cell search domain.

[0026] In the embodiments of this application, the NR terminal device may be, for example, a smartphone, a client terminal device, an industrial module, etc., which performs robust cell search and synchronization search methods during processes such as power-on, handover, and return from continuous state to idle state.

[0027] The NR terminal device may include an RF front-end module, a baseband processing module, and a control processing module. The RF front-end module receives the synchronization signal block transmitted downlink from the gNB base station (next-generation base station) on the target NR band, downconverts the RF signal to a baseband signal, performs I / Q sampling via an ADC, and outputs a complex-form time-domain sampled sequence as the time-domain received signal. The baseband processing module internally includes a synchronization detection unit, an OFDM demodulation unit, and a demodulation reference signal processing unit. The synchronization detection unit pre-stores three NR standard-defined PSS master code sequences and performs sliding correlation, correlation power calculation, and peak detection on the baseband time-domain received signal. The control module receives the PSS detection results and synchronization point information output from the baseband and drives subsequent cell search, synchronization, and access control processes.

[0028] During the initial cell search phase of the NR system, before the NR terminal equipment has established a connection with any NR cell, the RF front-end module performs low-noise amplification, down-conversion, and filtering on the downlink RF signal, and samples it through an ADC. The baseband processing module extracts a baseband time-domain sampling sequence of corresponding length from the preset PSS receiving time window in the time-domain signal sequence output by the ADC. Then, according to the preset search frequency point and SSB scanning strategy, it periodically opens the PSS receiving time window on the candidate frequency band. Within each preset PSS receiving time window, a data sequence of length N can be extracted from the time-domain sampling signal sequence continuously acquired by the RF front-end module. As a time-domain received signal. This time-domain received signal may contain PSS, noise, interference, or neighboring cell signals, wherein, k Represents the first in the time-domain received signal k Each time-domain sample point, sample point index k The value range is (0, N-1), where N is the length of the time-domain signal sequence.

[0029] Step S102: Perform a sliding correlation operation on the time-domain received signal and the locally stored PSS master code signal to obtain the sliding correlation result.

[0030] It should be noted that the PSS master code signal is a reference pseudo-random sequence pre-stored locally by the NR terminal equipment according to the 3GPP TS 38.211 protocol. It is usually represented by a complex sequence in the time domain and is also the core reference sequence for the terminal equipment to perform initial cell search and downlink synchronization detection. It can be pre-stored in the local non-volatile memory of the NR terminal equipment and used to generate the corresponding time-domain PSS master code signal by processing the frequency domain PSS sequence through IFFT and cyclic prefix according to the NR system sampling rate and OFDM parameters.

[0031] In the embodiments of this application, the synchronization detection unit inside the baseband processing module extracts three pre-stored PSS mother code signals, and performs conjugate sliding correlation operations on the time-domain received signal to be detected and each PSS mother code signal point by point. Using the autocorrelation characteristics of the PSS mother code signals, three sets of time-shifted correlation output sequences are obtained as sliding correlation results.

[0032] Specifically, in a 5G NR system, the primary synchronization signal (PSS) is used to carry the intra-cell identifier of the NR cell group. These correspond to three sets of locally stored PSS master code signals. Where n = 0, 1, ..., M-1, and .

[0033] The synchronization detection unit can perform correlation operations point-by-point on the sequence of the time-domain received signal and the local PSS mother code signal at different alignment positions (k') using the following formula to obtain the correlation results at each position (k').

[0034] in, For receiving signals in the time domain, Indicates the starting index of the sliding relationship, i.e., the first... Each time-domain sample point takes a value of _____. , This indicates the locally stored PSS master code signal. ∈{0, 1, 2}, N The length of the received signal sequence, M The length of the PSS mother code signal. This represents the conjugate operation for complex numbers.

[0035] Specifically, the synchronization detection unit can slide a starting point on the time-domain received signal sequence. k' At position =0, the locally stored PSS mother code signal is shifted. At each position, a sliding correlation operation is performed between the time-domain received signal and the local PSS mother code signal to obtain the correlation result; when ( k' ) Just aligned with the actual starting point of the PSS signal and When choosing the right one, A significant peak will appear. In order to eliminate the complex phase impression and characterize the correlation strength, the magnitude of the moving correlation result is squared. | 2 Calculate the relevant power at the corresponding position; used to determine the local PSS parameters and the position of the synchronization frame header.

[0036] Therefore, it can be seen that traditional PSS detection algorithms all use three PSS mother code signals as the calculation basis. However, the global peak detection method and the fixed ratio discrimination method are affected by interference and the superposition of signals from multiple neighboring cells, and cannot accurately identify the PSS mother code signal matching results. Based on the standard PSS mother code signal as the basic calculation object, this paper realizes single NR cell anti-interference detection and multi-neighbor cell multi-sequence parallel retrieval, thereby improving the detection range and accuracy of PSS synchronization.

[0037] Step S103: Calculate the correlation power value corresponding to each time domain sample point based on the sliding correlation results.

[0038] In the embodiments of this application, after the NR terminal device completes the conjugate sliding correlation operation between the received signal and the three sets of PSS mother code signals, it obtains the time-domain samples of each set of mother codes. k' The relevant output results at the specified point. The modulus-square operation can be performed on the complex correlation results corresponding to each time-domain sample point using the following formula to calculate the correlation power value corresponding to each time-domain sample point, thereby transforming the sliding correlation result into a non-negative correlation power index:

[0039] in, For the corresponding position ( k' The relevant power is obtained by calculating the power of each relevant output sequence.

[0040] By traversing all time-domain samples within the entire PSS reception time window, the power of all samples can be calculated sequentially, ultimately generating full-time-domain power distribution sequences that correspond one-to-one with the three sets of PSS master code signals. This power sequence intuitively reflects the degree of matching between the received signal and the corresponding PSS master code at different time-domain locations. A higher power value indicates a greater probability of a valid PSS synchronization peak occurring at that location, providing fundamental data for subsequent noise interval division, peak-to-average power ratio calculation, and signal decision.

[0041] Specifically, the synchronous detection unit performs a modulo-conjugate multiplication on the complex correlation results corresponding to each time-domain sample point to obtain... The relevant power value is stored in the power buffer. At the starting position of the sliding motion ( k' Aligned with the starting position of the actual PSS signal sequence and When the match is correct, the relevant output sequences at that position will coherently superimpose, resulting in a significant power peak. This is because the relevant power sequences ( ) becomes larger, therefore p A sharp power peak will appear. At the starting position of the sliding motion ( k' When the correlation output sequence at that position is not aligned with the starting position of the true PSS signal sequence or the signal sequence is mismatched, the correlation power sequence ( (become smaller)p Near the bottom of the noise level. Because... Since it is a complex number, frequency offset or channel phase rotation will change. The phase, but Unaffected, thus eliminating the influence of complex phase, the decision index is unified as a non-negative scalar, which facilitates subsequent calculation of noise mean, peak-to-average ratio and comparison with preset threshold.

[0042] Therefore, this step fully preserves the power characteristics across the entire time domain without losing power information at any point. The generated power sequence can completely present the peak values ​​corresponding to multiple PSS signals and the power distribution of interference noise, laying a data foundation for subsequent differentiation between real signal peaks and interference pseudo-peaks, and detecting multiple coexisting PSS signals. This allows for more reliable PSS correlation peak detection and threshold decision, improving detection accuracy.

[0043] Step S104: Determine the relevant noise power range based on the single-sided length of the preset signal window range and the single-sided length of the preset detection range. Calculate the power autocorrelation peak-to-average power ratio of each time-domain sample point based on the mean value of the relevant noise within the relevant noise power range and the relevant power value of each time-domain sample point.

[0044] In the embodiments of this application, the baseband processing module defines a signal window interval and a detection interval for each candidate sample point on the relevant power sequence according to the preset signal window length and detection interval length, and obtains a noise power interval; the average correlation power of the sample points within the noise power interval is calculated to obtain the average correlation noise power; the correlation power at each candidate sample point within the signal window interval is divided by the average noise power to obtain the corresponding power autocorrelation peak-to-average power ratio.

[0045] Specifically, the baseband processing module can calculate relevant configuration parameters in intervals. and , Indicates the length of one side of a possible signal window interval. This represents the length of one side of the detection interval, and > The current position of the time domain sample point ( k Centered on '), with The detection interval is constructed for a single-sided length as [ k '- L w , k '+ L w ], and remove items with a length of 2 from the detection interval. L n The signal window interval is used to obtain the remaining sample point index set as the correlated noise interval.

[0046] and The sampling length can be set to a fixed value based on system bandwidth and multipath spread, for example: You can take 4 to 8 sampling points. 32 to 64 sampling points can be selected; there is no limitation here. The endpoints of the detection interval can be pre-constructed as follows: and At this point, the set of integer indices for the detection interval is i. dx w ( k' )={i| d n ≤i≤ d w ,i∈Z}.

[0047] Therefore, by determining an effective correlation noise range, we can avoid including time-domain samples near the true correlation peak in the noise statistics.

[0048] Step S104 includes: Sub-step S1: Calculate the boundary index value of the signal window interval based on the current time-domain sample point index value and the preset single-side length of the signal window interval; Sub-step S2: Calculate the boundary index value of the detection interval based on the current time-domain sample point index value and the preset single-sided length of the detection interval; Sub-step S3: Perform boundary correction on the signal window interval boundary index value and the detection interval boundary index value through a clamping function to obtain the signal candidate interval and the detection interval; Sub-step S4: Remove the candidate signal interval from the detection interval and use the remaining time-domain samples as the relevant noise power interval.

[0049] Optionally, the signal window interval boundary index value includes a first start index value and a first end index value. The signal window interval boundary index value is calculated based on the current time-domain sample point index value and the preset single-side length of the signal window interval, including: When the length of the temporal sample index interval is less than the length of the single-sided detection interval, the current temporal sample is determined to be in the starting edge region; If the sum of the length of the time-domain sample index interval and the length of the single-sided detection interval exceeds the upper limit of the index range, it is determined that the current time-domain sample is in the end edge region. The preset signal window interval and detection interval are truncated or wrapped around to obtain the relevant noise interval.

[0050] Optionally, the detection interval boundary index value includes a second start index value and a second end index value. The step of calculating the detection interval boundary index value based on the current time-domain sample point index value and the preset single-sided length of the detection interval includes: When the current time-domain sample point index value is less than the single-sided length of the preset detection interval, the current time-domain sample point is taken as the starting position of the detection interval, and the second termination index value is taken as the ending position of the detection interval. If the sum of the current time-domain sample point index value and the single-sided length of the preset detection interval exceeds the upper limit of the index range, the current time-domain sample point is taken as the end position of the detection interval, and the second starting index value is taken as the start position of the detection interval.

[0051] Specifically, the signal window interval boundary index value and the detection interval boundary index value can be corrected for out-of-bounds errors using a clamping function to obtain the signal candidate interval and the detection interval.

[0052] Clamping functions can be used To each d n and d w Implement boundary restrictions to ensure that the boundary falls within the valid index range [0, NM] of the receiving window.

[0053] when At that time, at the current sliding position ( k ') is the starting position of the signal, and the signal window interval i is defined. dx n and detection interval i dx w And complete the out-of-bounds truncation process: , .

[0054] exist At that time, at the current sliding position ( k The position ') represents the signal termination position, obtained after completing the wraparound value acquisition process. The signal window interval value is... The detection interval takes values ​​of .

[0055] Optionally, if there is sufficient sampling space before and after the time-domain sample point index interval, the current time-domain sample point is determined to be a centrally symmetric sample; the current time-domain sample point position can be used as the center. L w Within the detection interval constructed with the radius as the reference, samples centered on the current time-domain sample point are removed. L n The signal window interval with radius is used as the remaining time-domain sample set as the correlation noise power interval.

[0056] Specifically, the signal window interval takes the value of The detection interval takes the value of .

[0057] Then, the arithmetic mean of the correlation noise power values ​​for each time-domain sample point is calculated using the following formula:

[0058] in, and Indicates by parameters and The range of values ​​for the defined time-domain sample point index interval.

[0059] Then, based on the mean value of the correlated noise within the noise power range and the correlated power value of each time-domain sample point, the power autocorrelation peak-to-average ratio of each time-domain sample point is calculated.

[0060] Specifically, the power correlation peak-to-average power ratio (PAPR) of each time-domain sample point can be calculated using the following formula:

[0061] in, For position ( k The relevant peak power of ') includes signal power and interference power; This represents the average power of the correlated noise in the adjacent domain, excluding the signal interval. The correlation peak-to-average power ratio (SINR) indicates the strength of the signal relative to the noise. When the correlation peak power is much higher than the noise mean, the true PSS signal sequence can be identified.

[0062] Therefore, it can be seen that when the detection area exceeds the boundary, the index set can be truncated or reconstructed to ensure the validity of the index set. Thus, by calculating the autocorrelation peak-to-average ratio at each position, signal synchronization and the detectability of the PSS signal sequence can be achieved.

[0063] Step S105: Obtain the maximum value of the peak-to-average power autocorrelation ratio of each time-domain sample point. When the maximum value exceeds a preset threshold, it is determined that the PSS signal has been successfully detected.

[0064] It should be noted that a preset threshold can be set. , representing the threshold of the autocorrelation peak-to-average power ratio, is used to determine the threshold of the final PSS signal sequence detection result. This preset threshold can be adjusted in range based on the false detection rate and false negative rate required by the system. It can be selected as the standard threshold based on different application scenarios (e.g., indoor, outdoor, multipath, or frequency offset) to achieve the best overall performance across all scenarios. The preset threshold can be adjusted for applicability based on the standard threshold.

[0065] In the embodiments of this application, after calculating the noise mean and the peak-to-average power autocorrelation ratio (PAPR) of each time-domain sample, the baseband processing module can search for the maximum value of the PAPR of all time-domain samples within the entire PSS receiving time window for each PSS master code signal, extract the maximum value of the PAPR corresponding to that PSS master code signal, and compare the maximum value of the PAPR with a preset threshold stored internally by the system. When the maximum value of the PAPR exceeds the preset threshold, the baseband processing module generates a PSS signal detection success indication and a synchronization point location (corresponding time-domain sample index), and reports the result to the control processing module. The control processing module receives the detection result and uses it for control decisions in subsequent SSS detection, PBCH demodulation, and cell search and access procedures.

[0066] The maximum peak-to-average power ratio (PAPR) can be calculated using the following formula across all time-domain samples for the nth PSS mother code. In other words, across all... and( k The maximum value of the peak-to-average power autocorrelation ratio (PAPR) at each time-domain sample point is obtained by solving the above method.

[0067] When identified When it is determined that a PSS signal has been successfully detected within the current PSS reception time window, the output is... The corresponding effective PSS signal sequence, This is the start point of the frame header of the PSS signal sequence.

[0068] When identified If no valid PSS signal is detected within the current reception time window, the system can proceed to the next frame or the next PSS reception time window to continue detection.

[0069] Optionally, this method is applicable to multi-cell PSS synchronous search of terminal equipment, user premises equipment, and roadside equipment in dense heterogeneous networking, high-speed mobile Doppler scenarios, and in-band sudden interference environments.

[0070] The method in this embodiment can be executed by digital signal processing (DSP), FPGA, ASIC or general-purpose processor, or it can be executed by loading a software program into memory.

[0071] Therefore, it can be seen that the sliding correlation between the locally stored PSS mother code sequence and the time-domain received signal can be used to enhance the main peak energy of the PSS signal and suppress mismatch components. By constructing a noise power interval near each time-domain sample point to be detected and using the local noise power mean as a normalization benchmark to calculate the autocorrelation peak-to-average power ratio, the ability to distinguish random noise peaks is effectively improved. The decision is made by comparing the maximum autocorrelation peak-to-average power ratio with a preset threshold, which has low computational complexity and is easy to implement in low-power or embedded hardware. Compared with the scheme based solely on absolute correlation power, it can solve the defects of missed detection and false detection of traditional algorithms in the context of multi-channel neighboring PSS signals or sudden pulse interference, thereby maintaining higher detection robustness and stability.

[0072] Figure 2 This application provides a schematic diagram of the detection process of a PSS synchronous search method in an embodiment.

[0073] like Figure 2 As shown in the figure, the horizontal axis (t) represents the index of the time-domain sampling point, and the vertical axis (power) represents the normalized output power value. The figures also show the values ​​within the group, with N-ID2 indicating... The output power curves and corresponding signal window and detection intervals for different values ​​are shown. The normalized power distribution of the three candidate PSS signal sequences is: N-ID2=0 indicates... The solid power curve, N-ID2=1 indicates The long dashed curve and N-ID2=2 represent The short dashed curve.

[0074] Compared to the fixed ratio discrimination method, the correlation power of the real PSS signal in any cell is more accurate in calculations. Sinr The denominator is significantly increased by the high power of other real PSS signals, resulting in a higher calculated value. Sinr The value is too low, possibly below the detection threshold, which may result in the missed detection of all PSS signals.

[0075] In the embodiments of this application, an NR terminal device is used as an example. "This cell" refers to the serving cell, and "neighboring cells" refers to adjacent coverage cells. When the time-domain signal received by the NR terminal within a preset PSS reception time window includes both the PSS signals of the current cell and neighboring cells, the received time-domain signal can be... By performing a sliding correlation with the locally stored PSS master code signal, the corresponding PSS signal can be obtained. The power value varies with the sliding position ( kThe waveform distribution of the changes in the horizontal axis (t) in the figure. The three curve trajectories all show obvious main peaks at the center position, indicating that at the correct alignment position, the correlation output between the time domain signal and the corresponding PSS mother code signal is the maximum, and the two sides of the curve show ringing or side lobes that gradually decay.

[0076] Among them, k Around 1000, two significant power-related peaks appear, corresponding to... and The "peak power", and The overall correlation power is low and flat. Several vertical dashed lines mark different intervals on both sides of the main power peak. The narrow interval containing the main peak is marked as the "detection interval", which is used to select the power peak point within the detection interval, calculate the correlation power corresponding to the power peak point and use it as the "signal power". Outside the detection interval, a certain range is designated as the "noise interval", which is used to statistically analyze the correlation noise power of time-domain samples near the peak.

[0077] For example, during the initial cell search phase, the NR terminal device extracts a time-domain sampling sequence of length N within a preset PSS reception time window. NR terminal equipment is designed for each ,Will Sequence of the locally stored PSS mother code signal Perform a sliding correlation to obtain the sliding correlation results at each sample point position (k'). For example, it can be calculated using the following formula:

[0078] The definitions of various parameters are the same as in the aforementioned embodiments, and will not be repeated here.

[0079] Furthermore, the autocorrelation power value of each time-domain sample is calculated: .

[0080] at this time, and The presence of significant peak power within the same time window indicates that the NR terminal equipment simultaneously receives PSS signals from at least two cells; while No comparable peak was formed.

[0081] For each sliding position ( k Set the detection interval length parameter. With signal window interval length parameter .by( k Construct a detection interval centered on ') , Indicates by parameters and The defined range of sample point index values; the signal window interval index value. The detection interval index takes the value of The signal window range that may contain relevant peaks is removed from the detection range, and the remaining part is used as the noise power range. Figure 2 (Marked as "Noise Range"), at this point, the power of each time-domain sample point within the noise power range can be analyzed. Calculate the arithmetic mean to obtain the average noise power. The processor in an NR terminal device can calculate the power autocorrelation peak-to-average power ratio (PAPR).

[0082] It can be done in all of the following formulas and all ( k Find the maximum value on '). and corresponding k max ,

[0083] Furthermore, in When the PSS signal is detected, the output is determined to be... As the detected PSS parameter, and output k max As the starting position of the synchronization frame header. If no valid PSS signal is detected within the current reception time window, it is determined that no valid PSS signal was detected.

[0084] Therefore, in this embodiment, a significant main peak can be generated at the correct synchronization position of the PSS signal correlation output. Two noise intervals are configured near the peak power of the main peak, and normalization can be performed using the peak power and the noise mean, so that the peak power of the two real PSS signals corresponds to... Sinr Both can be significantly increased, which can effectively suppress noise fluctuations and sidelobe effects, improve the robustness and decision reliability of PSS signal detection; at the same time, for local spikes not caused by PSS, the mean value of the surrounding noise often rises synchronously, making it difficult for the peak-to-average power ratio to exceed the preset threshold, thereby reducing the probability of false detection.

[0085] Figure 3 This is a structural block diagram of a PSS synchronous search device provided in an embodiment of this application.

[0086] Reference Figure 3The PSS synchronization search device 300 can be applied to NR terminal equipment in NR cell search scenarios. The PSS synchronization search device 300 can be integrated into the baseband processing unit of the NR terminal equipment, drive test equipment, or base station receiver. The PSS synchronization search device 300 includes: a signal receiving module 301, a correlation processing module 302, a power calculation module 303, a peak-to-average power calculation module 304, and a decision module 305.

[0087] In this embodiment, the signal receiving module 301 is used to acquire the time-domain received signal within a preset PSS receiving time window. Where (k) is the sampling point index; the time-domain received signal includes the target cell PSS, neighboring cell PSS, noise and / or interference signals. The correlation processing module 302 performs a sliding correlation operation between the time-domain signal and the locally stored PSS master code signal to obtain the sliding correlation result, wherein... This represents the locally stored PSS master code signal. The power calculation module 303 calculates the correlation power value corresponding to each time-domain sample point based on the sliding correlation result. The peak-to-average power calculation module 304 determines the correlation noise power range for each time-domain sample point based on the single-sided length of the preset signal window interval and the single-sided length of the preset detection interval. Based on the correlation noise mean within the noise power range and the correlation power value of each time-domain sample point, it calculates the power autocorrelation peak-to-average power ratio (PAPR) for each time-domain sample point. The decision module 305 obtains the maximum value among the PPRs of the power autocorrelation of each time-domain sample point. When the maximum value exceeds a preset threshold, it determines that the PSS signal has been successfully detected.

[0088] Specifically, the signal receiving module 301 receives the time-domain signal within the PSS reception time window and calls the local three-channel PSS master code signal; the correlation processing module 302 performs bit-by-bit conjugate sliding correlation between the received time-domain signal and the three local PSS master code signals, and outputs the correlation results of the full time-domain position, realizing full coverage traversal retrieval of the local area and multiple neighboring cells PSS signals in the full time-domain range; the power calculation module 303 calculates the instantaneous power of the correlation results of each time-domain position and generates a full-point power distribution sequence; the peak-to-average value calculation module 304 splits the candidate peak interval and the independent noise statistical interval based on the preset interval parameters, removes the area where the peak is located, and calculates the noise average power using the interval sampling value without signal interference, calculates the autocorrelation peak-to-average ratio based on the peak power and the noise mean, and extracts the peak value; the false spikes formed by sudden pulse interference are isolated by the independent partition noise estimation method, and the interference noise is distinguished from the real multi-cell PSS effective peak value; the decision module 305 compares the maximum peak-to-average ratio with the preset threshold, and if it exceeds the threshold, the corresponding PSS sequence is determined to be valid, and the synchronization frame header position and cell group ID are locked. Therefore, by combining partitioned noise statistics with peak-to-average ratio (PAR) decision, we can not only filter out interference spikes to avoid false detections, but also independently identify multiple effective synchronization signals from the local and neighboring regions in an environment where multiple PSS signals coexist, thereby improving the multi-target PSS retrieval range and synchronization detection accuracy.

[0089] In the embodiments of this application, the time-domain received signal can be acquired within a preset PSS receiving time window. Sliding correlation is performed using locally stored PSS master code signals to improve the time-domain identification capability of the synchronization peak. Based on the sliding correlation results, the correlation power of each time-domain sample point is calculated, and the correlation noise power interval is divided according to the preset signal window interval and detection interval to achieve local noise estimation and reduce the decision error caused by global noise estimation bias. Utilizing the power autocorrelation peak-to-average power ratio (PAPR) of each time-domain sample point, a decision rule comparing the maximum power PAPR of each time-domain sample point with a preset threshold is implemented. This is simple and computationally controllable, facilitating implementation in the DSP or FPGA of the NR terminal device. It improves the ability to distinguish between real signal peaks and random noise peaks while maintaining robustness and low computational cost; thereby improving the stability of the frame header start position and reducing false alarm and false detection rates.

[0090] Figure 4 This is a structural block diagram of an electronic device for PSS synchronous search provided in an embodiment of this application.

[0091] Reference Figure 4 The electronic device 400 for PSS synchronous search based on noise interval mean estimation includes: a processor 401, a memory 402, and a computer program 4021 stored in the memory and executable on the processor. When executed, the processor implements the object node maintenance method based on robot motion compensation of the aforementioned embodiment.

[0092] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the methods described in the foregoing embodiments.

[0093] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0094] Those skilled in the art will understand that embodiments of this application can be provided as methods, apparatus, or computer program products. Therefore, embodiments of this application can take the form of entirely hardware embodiments, entirely software embodiments, or embodiments combining software and hardware aspects. Furthermore, embodiments of this application can take the form of computer program products implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0095] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0096] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A PSS synchronous search method, characterized in that, include: Acquire the time-domain received signal within the preset PSS receiving time window; The time-domain received signal is subjected to a sliding correlation operation with the locally stored PSS master code signal to obtain the sliding correlation result; Calculate the correlation power value corresponding to each time domain sample point based on the sliding correlation results; The relevant noise power range is determined based on the single-sided length of the preset signal window range and the single-sided length of the preset detection range. Based on the mean value of the relevant noise within the noise power range and the relevant power value of each time-domain sample point, the power autocorrelation peak-to-average ratio of each time-domain sample point is calculated. The maximum value of the power autocorrelation peak-to-average power ratio (PAPR) of each time-domain sample point is obtained. When the maximum value of the PPR exceeds a preset threshold, it is determined that the PSS signal has been successfully detected.

2. The method according to claim 1, characterized in that, The step of determining the relevant noise power range based on the single-sided length of the preset signal window interval and the single-sided length of the preset detection interval includes: Calculate the boundary index value of the signal window interval based on the current time-domain sample point index value and the preset single-side length of the signal window interval; Calculate the boundary index value of the detection interval based on the current time-domain sample point index value and the preset single-sided length of the detection interval; By using a clamping function to correct for out-of-bounds errors in the boundary index values ​​of the signal window interval and the detection interval, the candidate signal interval and the detection interval are obtained. The candidate signal interval is removed from the detection interval, and the remaining time-domain samples are used as the relevant noise power interval.

3. The method according to claim 2, characterized in that, The signal window interval boundary index value includes a first start index value and a first end index value. The step of calculating the signal window interval boundary index value based on the current time-domain sample point index value and the preset single-side length of the signal window interval includes: When the current time-domain sample index value is less than the single-sided length of the preset signal window interval, the current time-domain sample is taken as the starting position of the signal candidate interval, and the first termination index value is taken as the termination position of the signal candidate interval. If the sum of the current time-domain sample index value and the single-sided length of the preset detection interval exceeds the upper limit of the index range, the current time-domain sample is taken as the termination position of the signal candidate interval, and the first starting index value is taken as the starting position of the signal candidate interval.

4. The method according to claim 2, characterized in that, The detection interval boundary index value includes a second start index value and a second end index value. The calculation of the detection interval boundary index value based on the current time-domain sample point index value and the preset single-sided length of the detection interval includes: When the current time-domain sample point index value is less than the single-sided length of the preset detection interval, the current time-domain sample point is taken as the starting position of the detection interval, and the second termination index value is taken as the ending position of the detection interval. If the sum of the current time-domain sample point index value and the single-sided length of the preset detection interval exceeds the upper limit of the index range, the current time-domain sample point is taken as the termination position of the detection interval, and the second starting index value is taken as the starting position of the detection interval.

5. The method according to claim 1, characterized in that, The sliding correlation operation satisfies: in, For receiving signals in the time domain, Indicates the first Each time-domain sample point takes a value of _____. N is the length of the signal sequence, and M is the length of the PSS mother code signal. Indicates taking the conjugate. This represents three sets of PSS mother code signals. ∈{0, 1, 2}.

6. The method according to claim 1, characterized in that, The mean of the relevant noise is the arithmetic average of the relevant noise power values ​​of each time-domain sample point within the noise power range.

7. The method according to claim 1, characterized in that, The step of obtaining the maximum value of the peak-to-average power autocorrelation ratio of each time-domain sample point includes: By iterating through all time-domain samples corresponding to each group of PSS mother code signals, comparing the peak-to-average power ratio (PAPR) of each time-domain sample, and selecting the maximum PAPR for each group of PSS mother code signals, the following steps are taken: The maximum value of the peak-to-average power ratio (PAPR) is the maximum value of the PAPR of the power autocorrelation of a single PSS master code signal at all time-domain samples within a preset PSS reception time window.

8. A PSS synchronous search device, characterized in that, include: The signal receiving module is used to acquire the time-domain received signal within a preset PSS receiving time window; The correlation processing module is used to perform sliding correlation operation on the time-domain received signal and the locally stored PSS master code signal to obtain the sliding correlation result; The power calculation module is used to calculate the correlation power value corresponding to each time domain sample point based on the sliding correlation result; The peak-to-average power calculation module is used to determine the relevant noise power range based on the single-sided length of the preset signal window interval and the single-sided length of the preset detection interval, and to calculate the power autocorrelation peak-to-average power ratio of each time-domain sample based on the mean of the relevant noise within the noise power range and the relevant power value of each time-domain sample. The decision module is used to obtain the maximum value of the peak-to-average power autocorrelation ratio of each time-domain sample point, and when the maximum value of the peak-to-average power autocorrelation ratio exceeds a preset threshold, it is determined that the PSS signal has been successfully detected.

9. An electronic device comprising a processor and a memory, characterized in that, The memory stores a computer program that, when executed by the processor, implements the method as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method described in any one of claims 1 to 7.

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