Time synchronization method, electronic equipment and storage medium

Abstract

The embodiment of the invention provides a time synchronization method, electronic equipment and a storage medium, and the method comprises the steps: segmenting first air interface data, and carrying out the down-sampling processing, and obtaining a plurality of groups of main synchronization signal sequences with the same symbol length; calculating the relevancy between the multiple groups of main synchronization signal sequences and the first air interface data, and obtaining coarse synchronization position information with the maximum relevancy with the first air interface data; determining to-be-synchronized data in the first air interface data based on the coarse synchronization position information and the data synchronization length; determining actual auxiliary synchronization data and a cell ID from the first auxiliary synchronization data and the second auxiliary synchronization data; performing frequency offset calculation on the actual auxiliary synchronization data and the main synchronization data to obtain frequency offset information; and performing time synchronization according to the frequency offset information and the cell ID. According to the time synchronization method, the electronic equipment and the storage medium provided by the invention, the data volume is reduced, the data can be processed in parallel, the processing speed and the subsequent processing efficiency and accuracy are improved, and the resource consumption is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of time synchronization, and in particular to a time synchronization method, electronic equipment and storage medium. Background Art

[0002] The initial synchronization process for LTE (Long-Term Evolution, 4G wireless communication technology standard) and NR (New Radio) systems involves multiple steps and signals to ensure that the device can detect the cell and achieve time and frequency synchronization.

[0003] Currently, when running 4G physical layer (PHY) programs on domestic chips, there are strict real-time and computing resource requirements. The 4G LTE standard specifies a series of complex signal processing tasks, including channel estimation, demodulation, decoding, etc. These tasks need to be completed within a strict timing window.

[0004] In the prior art, since the 4G LTE standard has very high real-time requirements, when it comes to operations with long cycles and large amounts of data, such as the processing of broadcast signals (BCH, BCCH), there will be problems of resource shortage and timing constraints. Summary of the invention

[0005] In order to solve one of the above-mentioned technical defects, a time synchronization method, an electronic device and a storage medium are provided in an embodiment of the present application. The implementation of the present application significantly improves the synchronization accuracy and efficiency, while reducing the computational complexity and resource consumption.

[0006] According to a first aspect of an embodiment of the present application, a time synchronization method is provided.

[0007] The first air interface data is segmented and down-sampled to obtain multiple groups of primary synchronization signal sequences with the same symbol length, and adjacent primary synchronization signal sequences contain the same symbol;

[0008] Calculating the correlation between each segment of data in the plurality of groups of primary synchronization signal sequences and the first air interface data, and obtaining the coarse synchronization position information with the maximum correlation with the first air interface data;

[0009] Determine the data to be synchronized in the first air interface data based on the coarse synchronization position information and the data synchronization length, where the data to be synchronized includes: primary synchronization data, first auxiliary synchronization data, and second auxiliary synchronization data;

[0010] determining actual auxiliary synchronization data and a cell ID from the first auxiliary synchronization data and the second auxiliary synchronization data;

[0011] Performing frequency deviation calculation on actual auxiliary synchronization data and main synchronization data to obtain frequency deviation information;

[0012] Time synchronization is performed based on the frequency offset information and the cell ID.

[0013] Optionally, determining actual auxiliary synchronization data and a cell ID from the first auxiliary synchronization data and the second auxiliary synchronization data includes:

[0014] Convert the first auxiliary synchronization data and the second auxiliary synchronization data into frequency domain data respectively;

[0015] Performing reverse descrambling calculations on the first auxiliary synchronization data and the second auxiliary synchronization data of the frequency domain data respectively to obtain a reverse descrambling result and a cell ID;

[0016] The larger auxiliary synchronization data in the reverse descrambling result is used as the actual auxiliary synchronization data.

[0017] Optionally, before segmenting the first air interface data and performing downsampling processing, the method includes:

[0018] Receive the central frequency information sent by the upper node;

[0019] The acquired second air interface data is converted into first air interface data corresponding to the frequency of the center frequency information based on the center frequency information.

[0020] Optionally, the symbol length of the primary synchronization signal sequence is smaller than the correlation calculation length;

[0021] Accordingly, before calculating the correlation between each segment of data in the plurality of groups of primary synchronization signal sequences and the first air interface data, the method includes:

[0022] Automatic gain control is performed on the primary synchronization signal sequence so that the symbol length of the primary synchronization signal sequence after gain meets the correlation calculation requirement.

[0023] Optionally, calculating the correlation between each segment of data in the plurality of groups of primary synchronization signal sequences and the first air interface data to obtain coarse synchronization position information having the greatest correlation with the first air interface data includes:

[0024] Performing conjugate calculations on multiple groups of main synchronization signal sequences respectively to obtain multiple groups of conjugate symmetric signals;

[0025] Perform sliding correlation calculation on the first air interface data through multiple groups of conjugate symmetric signals to obtain multiple groups of correlation value sequences representing the correlation with the first air interface data;

[0026] Normalizing multiple groups of correlation value sequences to calculate the power value of each segment of data in each correlation value sequence;

[0027] The coarse synchronization position information with the greatest correlation with the first air interface data is determined based on the maximum power value.

[0028] Optionally, after normalizing the multiple groups of correlation value sequences to calculate the power value of each segment of data in each correlation value sequence, the method includes:

[0029] Determine in sequence whether the power value of each segment of data is greater than a preset power value;

[0030] If the power value of each segment of data is not greater than the preset power value, reacquire the second air interface data;

[0031] If the power value of at least one segment of data is greater than a preset power value, the coarse synchronization position information with the greatest correlation with the first air interface data is determined based on the maximum power value.

[0032] Optionally, determining the data to be synchronized in the first air interface data based on the coarse synchronization position information and the data synchronization length, the method includes:

[0033] Based on the coarse synchronization position information, the data synchronization length and the symbol position of each data in the current communication protocol, the determined data to be synchronized including the primary synchronization data, the first auxiliary synchronization data and the second auxiliary synchronization data are determined in the first air interface data.

[0034] Optionally, performing frequency deviation calculation on actual auxiliary synchronization data and primary synchronization data to obtain frequency deviation information includes:

[0035] Master synchronization frequency domain data that converts master synchronization data into frequency domain data;

[0036] The frequency offset information of the main synchronization frequency domain data and the actual auxiliary synchronization frequency domain data is calculated, and the actual auxiliary synchronization frequency domain data is the frequency domain data corresponding to the actual auxiliary synchronization data.

[0037] According to a second aspect of an embodiment of the present application, a time synchronization device is provided, including:

[0038] Memory;

[0039] Processor; and

[0040] Computer programs;

[0041] The computer program is stored in the memory and is configured to be executed by the processor to implement the above method.

[0042] According to a third aspect of an embodiment of the present application, a computer-readable storage medium is provided, on which a computer program is stored; the computer program is executed by a processor to implement the above method.

[0043] The time synchronization method, electronic device and storage medium provided in the embodiment of the present application are adopted. The time synchronization method provided in the embodiment obtains multiple groups of main synchronization signal sequences with the same symbol length by segmenting and downsampling the first air interface data, thereby reducing the amount of data while retaining key synchronization information; in addition, the data can be processed in parallel, which improves the processing speed and the efficiency and accuracy of subsequent processing and reduces resource consumption. The rough synchronization position information is determined by correlation calculation, and the preliminary position of the synchronization signal can be found in a shorter time, which improves the accuracy of synchronization and avoids full-range search in the entire data stream, greatly reducing the amount of calculation. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0045] Figure 1 A schematic diagram of the structure of the time synchronization method provided in the embodiment of the present application;

[0046] Figure 2 A schematic diagram of the structure of a time synchronization device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0047] In order to make the technical solutions and advantages in the embodiments of the present application more clearly understood, the exemplary embodiments of the present application are further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than an exhaustive list of all the embodiments. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0048] In existing technologies, although the 4G LTE standard provides an efficient data transmission mechanism, all PHY layer processing on domestic chips must be completed within a specific time window. If the processing time is too long or the amount of data processed is too large, it may cause data packet loss or increased delay, seriously affecting the communication quality.

[0049] In view of the above problems, a time synchronization method is provided in an embodiment of the present application, such as Figure 1 As shown, the method includes:

[0050] 100. Segment the first air interface data and perform downsampling processing to obtain multiple groups of primary synchronization signal sequences with the same symbol length, where adjacent primary synchronization signal sequences contain the same symbol;

[0051] Specifically, air interface data refers to data transmitted through a wireless interface (i.e., air interface) in a wireless communication system. These data include control information, user data, and messages related to other protocols. The frequency of the first air interface data in the embodiment of this specification may be the same as the frequency of the center frequency sent by the upper node.

[0052] Specifically, the first air interface data may be segmented in an equal manner, and adjacent primary synchronization signal sequences after segmentation contain the same symbols. The number of identical symbols contained in adjacent primary synchronization signal sequences is not specifically limited in the embodiments of this specification and may be set as needed.

[0053] After the first air interface data is segmented, downsampling processing may be performed on the segmented data in sequence, and the downsampling ratio may be set as required, such as 128-fold downsampling.

[0054] By segmenting and downsampling the first air interface data, multiple groups of main synchronization signal sequences with the same symbol length are obtained, which reduces the amount of data while retaining key synchronization information. Adjacent main synchronization signal sequences have overlapping symbols, which can improve the synchronization accuracy because the upper node can find the same symbol in multiple main synchronization data sequences, thereby more accurately determining the starting position of the symbol. At the same time, through the overlapping symbols in multiple main synchronization data sequences, the upper node can reduce the probability of synchronization failure caused by misjudgment of single-segment data.

[0055] Specifically, the primary synchronization signal sequence can be a PSS (Primary Synchronization Signal), which occupies 6 RBs of the system bandwidth, i.e., 72sc, in the frequency domain. In the LTE system, the PSS sequence is generated based on the Zadoff-Chu sequence. The PSS sequence has three different root sequences, corresponding to the three cell IDs in the cell ID group.

[0056] 200. Calculate the correlation between each segment of data in multiple groups of primary synchronization signal sequences and the first air interface data, and obtain coarse synchronization position information with the maximum correlation with the first air interface data;

[0057] Specifically, the correlation is used to characterize the degree of synchronization or matching between two signals in time, that is, whether the two signals can maintain consistent timestamps in time. The higher the correlation, the more consistent the consistent timestamps are.

[0058] Specifically, the coarse synchronization position information is the approximate position information about the signal arrival time obtained through a preliminary synchronization process.

[0059] The symbol length of the primary synchronization signal sequence may be smaller than the correlation calculation length.

[0060] Accordingly, before calculating the correlation between each segment of data in the multiple groups of primary synchronization signal sequences and the first air interface data, the following may be included:

[0061] Automatic gain control is performed on the primary synchronization signal sequence so that the symbol length of the primary synchronization signal sequence after gain meets the correlation calculation requirement.

[0062] In order to improve the accuracy of correlation calculation, the symbol length of the primary synchronization signal sequence can be increased to a required length that meets the correlation calculation through automatic gain control, wherein the automatic gain control parameters can be set as needed.

[0063] In an optional embodiment, the method for determining the coarse synchronization position information may include:

[0064] Conjugate calculations are performed on multiple groups of main synchronization signal sequences respectively to obtain multiple groups of conjugate symmetric signals.

[0065] Specifically, conjugate calculation is performed on each main synchronization signal sequence to obtain a conjugate symmetric signal x i * (k), denoted as:

[0066] x i * (k), k=0,1,…,M-1, i=0,1,2

[0067] Where i is the group number of the conjugate symmetric signal and M is the length of the symbol.

[0068] Perform sliding correlation calculation on the first air interface data through multiple groups of conjugate symmetric signals to obtain multiple groups of correlation value sequences representing the correlation with the first air interface data;

[0069] Specifically, the first air interface data y(n) is combined with multiple groups of conjugate symmetric signals x i * (k) Perform sliding correlation calculation, the relevant calculation formula is:

[0070]

[0071] Among them, r i (m) is the cross-correlation value between y(j) and x(j) at time shift m, m is the time offset, M is the symbol length, and N is the number of samples.

[0072] Normalizing multiple groups of correlation value sequences to calculate the power value of each segment of data in each correlation value sequence;

[0073] Specifically, the correlation value r i(m) Normalized to get the correlation value c i (m) to eliminate the influence of signal amplitude, the normalization and power value calculation formula is:

[0074]

[0075] The coarse synchronization position information with the greatest correlation with the first air interface data is determined based on the maximum power value.

[0076] Specifically, the coarse synchronization position information may include: sequence information z and first position information p, wherein the sequence information z and the first position information p may be determined by the following formula:

[0077]

[0078] The first position information p is the corresponding timing position, the sequence information z is the local sequence number corresponding to the maximum peak value, and the sequence information z corresponds to the physical layer cell ID (NID1), which can be specifically determined by the ZC sequence.

[0079] Through multiple sets of downsampled signals and conjugate calculations, the redundancy of synchronization is increased and the accuracy of synchronization is improved. Sliding correlation calculation and normalization processing ensure the accurate determination of the synchronization point. In addition, downsampling processing can significantly reduce the amount of data, reduce the calculation complexity and processing time. The correlation calculation is simplified through conjugate calculation, further improving the calculation efficiency. At the same time, multi-level verification and determination of the maximum peak reduce the probability of missynchronization, ensuring that the system can still operate stably in complex environments.

[0080] In actual operation, the relevant value c i (m) is often related to the correlation between the multiple groups of conjugate symmetric signals and the first air interface data. In order to avoid the problem of wasting computing resources by performing time synchronization when the multiple groups of conjugate symmetric signals and the first air interface data do not have a strong enough correlation, the correlation value c can be calculated. i (m) after

[0081] Determine in sequence whether the power value of each segment of data is greater than a preset power value;

[0082] If the power value of each segment of data is not greater than the preset power value, reacquire the second air interface data;

[0083] If the power value of at least one segment of data is greater than a preset power value, the coarse synchronization position information with the greatest correlation with the first air interface data is determined based on the maximum power value.

[0084] Specifically, the preset power value may be a preset threshold value for determining whether the power of the data segment is high enough. Subsequent calculations are performed only when the power value of the data segment is greater than the preset power value. Similarly, when the power values ​​of each data segment are not greater than the preset power value, the second air interface data may be reacquired.

[0085] By judging whether the power value of each segment of data is greater than a preset power value and determining the coarse synchronization position information based on the maximum power value, the synchronization accuracy and reliability of the wireless communication system can be significantly improved.

[0086] 300. Determine data to be synchronized in the first air interface data based on the coarse synchronization position information and the data synchronization length. The data to be synchronized includes: primary synchronization data, first auxiliary synchronization data, and second auxiliary synchronization data.

[0087] Specifically, the coarse synchronization position information is used to determine the starting position of the data to be synchronized, and the data synchronization length is used to determine the ending position of the data to be synchronized. The data to be synchronized includes at least: main synchronization data, first auxiliary synchronization data and second auxiliary synchronization data. Among them, the first auxiliary synchronization data and the second auxiliary synchronization data are both actual auxiliary synchronization data to be verified.

[0088] In an optional embodiment, a method for determining the data to be synchronized may include:

[0089] Based on the coarse synchronization position information, the data synchronization length and the symbol position of each data in the current communication protocol, the determined data to be synchronized including the primary synchronization data, the first auxiliary synchronization data and the second auxiliary synchronization data are determined in the first air interface data.

[0090] Specifically, both the first auxiliary synchronization data and the second auxiliary synchronization data may be SecondarySynchronization Signal (auxiliary synchronization signal), and more specifically, the first auxiliary synchronization data may be TDD-SSS, which is sent in the 1st and 6th subframes in a 10ms frame. The first auxiliary synchronization data may be FDD-SSS, which is sent in the 1st subframe in each 10ms frame. The two have different time slots, and accordingly, the positions of the first air interface data are different, and the specific position can be determined according to the communication protocol.

[0091] 400, determining actual auxiliary synchronization data and a cell ID from the first auxiliary synchronization data and the second auxiliary synchronization data;

[0092] Specifically, the actual auxiliary synchronization data is the first auxiliary synchronization data or the second auxiliary synchronization data, and the actual auxiliary synchronization data is used for time synchronization calculation to calculate the frequency deviation information. It can be understood that in LTE and NR communications, the first auxiliary synchronization data or the second auxiliary synchronization data can be used for time synchronization. The first auxiliary synchronization data and the second auxiliary synchronization data have different positions in the first air interface data, and the same cell is often configured with a communication standard. In actual applications, the actual auxiliary synchronization data representing the cell standard can be determined by the first auxiliary synchronization data and the second auxiliary synchronization data, wherein the cell ID can be determined by the ZC sequence, and the cell ID can include NID1 (cell ID within the cell ID group) and NID2 (cell ID group).

[0093] Specifically, the method for determining the actual auxiliary synchronization data and the cell ID may include:

[0094] Convert the first auxiliary synchronization data and the second auxiliary synchronization data into frequency domain data respectively;

[0095] Specifically, the PSS frequency domain signal is used for frequency offset estimation, and the SSS frequency domain signal is used for SSS detection. During the frequency domain data conversion process, the main synchronization data may also be converted.

[0096] For example, the main synchronization data (pss_filter_out), the first auxiliary synchronization data (sss_tddfilter_out), and the second auxiliary synchronization data (sss_fdd_filter_out) can be used as inputs in turn, and the PSS, SSS-TDD, and SSS-FDD time domain symbols (frequency domain data) with a symbol length of 2192 are extracted according to the position of the fine synchronization estimation PSS_POS_Second. The CP (cyclic prefix) of the time domain symbols of PSS, FDD-SSS, and TDD-SSS is removed, and a 2048-point FFT is performed to obtain the frequency domain data. Take 31 REs ([994:10241026:1056]) before and after the center frequency point (excluding the DC position) and splice them into frequency domain data with a length of 62.

[0097] Performing reverse descrambling calculation on the first auxiliary synchronization data and the second auxiliary synchronization data of the frequency domain data respectively;

[0098] The larger auxiliary synchronization data in the reverse descrambling result is used as the actual auxiliary synchronization data.

[0099] Specifically, since the PSS of the two half frames in a frame are exactly the same, PSS synchronization can only determine 5msiming; while SSS is a different signal in the half frame, as long as one SSS is detected, the current subframe index can be determined to achieve 10ms timing downlink synchronization. In addition, the detection of the SSS sequence can be performed in both the time domain and the frequency domain. Since correlation detection in the time domain requires correlation detection of the 2048 values ​​of the entire OFDM symbol, the calculation complexity is large and it is easily affected by the timing estimation error; while the frequency domain detection only needs to extract 62 points of the SSS receiving sequence to perform correlation, the calculation amount is small, and the timing synchronization error has little effect on the correlation peak in the frequency domain, so the SSS sequence is detected in the frequency domain.

[0100] Based on the generation rules of the SSS sequence, NID1, system subframe number (0ms / 5ms) and cell standard LTE-FDD / LTE-TDD can be determined by reverse descrambling. The extracted frequency domain FDD-SSS and TDD-SSS signals are reversely descrambled to obtain {m_tdd, m0_tdd, m1_tdd} and {m_fdd, m0_fdd, m1_fdd), and the cell standard is further determined by comparing m_tdd and m_fdd, and the current subframe index is determined by comparing the corresponding m0 and m1, and NID1 is calculated.

[0101] Specifically, the reverse descrambling of the second auxiliary synchronization data FDD-SSS is taken as an example for explanation, and the specific algorithm flow is described as follows:

[0102] SSS frequency domain signal reverse descrambling:

[0103] ①FDD-SSS signal is sent on 62 subcarriers, which can be divided into odd and even subcarriers. First, the FDD-SSS signal is divided into d(2n) and d(2n+1) according to the odd and even subcarriers, where n=0, 1.., 30. Two local descrambling sequences s0 and s1 are generated according to NID1 (cell ID in the cell ID group) and NID2 (cell ID group); based on NID2, the sequence m(n) is cyclically shifted to generate c0(n) and c1(n) sequences;

[0104] ②Use c0(n) dual sequence d(2n) to descramble and obtain the descrambled dual sequence

[0105]

[0106] ③ Use the local descrambling sequence s(n) and the descrambling even sequence Perform a circular cross-correlation operation to find the peak value, which is the estimated value of m0_fdd:

[0107]

[0108] Wherein, k is the time shift amount, and k = 0, 1... 30.

[0109] ④ Cyclically shift the local descrambling sequence z(n) based on m0_fdd to obtain For odd sequence descrambling:

[0110]

[0111] ⑤ Use c1(n) and Descramble the sequence d(2n + 1) to obtain the descrambled odd sequence

[0112]

[0113] ⑥ Perform a cyclic cross-correlation operation between the local descrambling sequence s(n) and the descrambled odd sequence to find the peak value, and this peak value is the estimated value of m1_fdd:

[0114]

[0115] Wherein, k is the time shift amount, and k = 0, 1…, 30.

[0116] ⑦ Average m0_fdd and m1_fdd to obtain the base sequence m_fdd;

[0117] m_fdd = (m0_fdd + m1_fdd) / 2

[0118] Similarly, m_tdd, m0_tdd, and m1_tdd can be obtained.

[0119] Cell mode judgment

[0120] Judge the cell mode by comparing m_tdd and m_fdd. Specifically:

[0121] ① If m_tdd > mfdd, the cell is LTE-TDD; meanwhile, m0 = m0_tdd and m1 = m1_tdd;

[0122] ② Otherwise, the cell is LTE-FDD; meanwhile, m0 = m0_fdd and m1 = m1_fdd.

[0123] Subframe index judgment

[0124] Regardless of whether the system is ITE-FDD or LTE-TDD, the subframe index positions of the SSS are only two: 0 and 5. Judge the subframe index by comparing m0 and m1. Specifically:

[0125] ① If m0 < m1, the subframe index is 0, and at the same time, the estimated value of m0 Estimated value of

[0126]

[0127] Otherwise, the subframe index is 5, and

[0128] By converting the auxiliary synchronization data into frequency domain data, frequency domain processing can be performed more accurately to improve the synchronization accuracy. Through reverse descrambling, the original auxiliary synchronization data can be restored to ensure the correctness of the data, while reducing synchronization failures caused by single detection misjudgment. In addition, reverse descrambling can eliminate the interference caused by descrambling, improve the clarity of the signal, and complete symbol timing and carrier frequency synchronization in a short time, improving the response speed of the system.

[0129] 500, frequency deviation calculation is performed on actual auxiliary synchronization data and main synchronization data to obtain frequency deviation information.

[0130] Specifically, the frequency offset information represents the frequency offset between LTE and NR. The frequency offset information can be estimated by calculating the phase difference between the actual auxiliary synchronization data and the primary synchronization data.

[0131] Specifically, the method for determining the frequency deviation information may include:

[0132] Master synchronization frequency domain data that converts master synchronization data into frequency domain data;

[0133] The frequency offset information of the main synchronization frequency domain data and the actual auxiliary synchronization frequency domain data is calculated, and the actual auxiliary synchronization frequency domain data is the frequency domain data corresponding to the actual auxiliary synchronization data.

[0134] In the specific implementation process, the actual auxiliary synchronization frequency domain data can be multiplied by time domain multiplication.

[0135] η*(o) is used to perform frequency shifting, thereby obtaining the second actual auxiliary synchronization frequency domain data

[0136]

[0137] Assume the frequency shift range is: [-b:Δ:b];

[0138]

[0139] Among them, η*(o) is the original time domain signal, is the frequency offset to be removed, b is the maximum value of the attempted frequency offset, and Δ is the attempted step size; f s is the sampling rate of the ADC.

[0140] Specifically, the second actual auxiliary synchronization frequency domain data Perform related operations with the main synchronization data a, which can be processed by the relevant formula, the related value sequence θ e The calculation formula of (s) is:

[0141]

[0142] For the correlation value sequence θ e (s) is normalized to calculate each θ e (s) power value;

[0143] Specifically, for θ e (s) can be normalized by the following formula:

[0144]

[0145] Among them, λ e (s) is θ e (s) power value.

[0146] Based on θ e The maximum power value in (s) is used to obtain the frequency offset information and the second position information with the greatest correlation with the time domain signal.

[0147] Specifically, the maximum peak position ξ and the frequency deviation information κ are selected.

[0148]

[0149] The embodiments of this specification can improve synchronization accuracy, reduce misjudgment, improve anti-interference capability, simplify synchronization algorithms, and support fast synchronization by calculating frequency deviation information of primary synchronization frequency domain data and actual auxiliary synchronization frequency domain data.

[0150] 600, performing time synchronization according to the frequency offset information and the cell ID;

[0151] Specifically, the frequency offset information and the cell ID may be transmitted to an upper node connected thereto, so that the upper node performs time synchronization based on the frequency offset information and the cell ID.

[0152] The time synchronization method provided in this embodiment obtains multiple groups of main synchronization signal sequences with the same symbol length by segmenting and downsampling the first air interface data, thereby reducing the amount of data while retaining key synchronization information; in addition, data can be processed in parallel, which improves the processing speed and the efficiency and accuracy of subsequent processing and reduces resource consumption. The rough synchronization position information is determined by correlation calculation, and the preliminary position of the synchronization signal can be found in a shorter time, which improves the accuracy of synchronization and avoids full-range search in the entire data stream, greatly reducing the amount of calculation.

[0153] In the above embodiment, in one embodiment of the present specification, before segmenting the first air interface data and performing downsampling processing, the method may include:

[0154] Receive the central frequency information sent by the upper node;

[0155] Specifically, the upper node may be Operation Administration and Maintenance. The center frequency refers to the center frequency of the signal spectrum, that is, the middle frequency of the signal bandwidth. It should be noted that in a communication system, the center frequency usually refers to the carrier frequency. The center frequency is used to determine the position of the signal in the frequency domain.

[0156] The acquired second air interface data is converted into first air interface data corresponding to the frequency of the center frequency information based on the center frequency information.

[0157] Specifically, the second air interface data refers to original data received from a wireless interface, and the data is usually received at an initial center frequency point or an uncalibrated center frequency point.

[0158] For example, the frequency of the second air interface data transmitted through the wireless interface (ie, air interface) is 128 GHz, and the center frequency is 2.6 GHz. In actual use, the second air interface data with a frequency of 128 GHz can be modulated into the first air interface data with a frequency of 2.6 GHz.

[0159] The implementation of the embodiments of this specification can improve spectrum utilization and improve the transmission efficiency of the system. It is understandable that there can be multiple wireless interfaces, and correspondingly, different wireless interfaces can be configured with different central frequencies. Through reasonable frequency planning and central frequency setting, interference between adjacent cells can be reduced and the reliability of the system can be improved.

[0160] The time synchronization method, electronic device and storage medium provided in the embodiment of the present application are adopted. The time synchronization method provided in the embodiment obtains multiple groups of main synchronization signal sequences with the same symbol length by segmenting and downsampling the first air interface data, thereby reducing the amount of data while retaining key synchronization information; in addition, the data can be processed in parallel, which improves the processing speed and the efficiency and accuracy of subsequent processing and reduces resource consumption. The rough synchronization position information is determined by correlation calculation, and the preliminary position of the synchronization signal can be found in a shorter time, which improves the accuracy of synchronization and avoids full-range search in the entire data stream, greatly reducing the amount of calculation.

[0161] In addition to time synchronization, in satellite communication systems, symbol synchronization is also required. For example, symbol synchronization is performed on the above-mentioned main synchronization signal. The synchronization process is as follows:

[0162] Acquire a main synchronization signal, and process the main synchronization signal in sections to obtain a plurality of sub-signals to be processed;

[0163] For each target sub-signal in the multiple sub-signals to be processed, a conjugate product operation is performed on a first sampling value and a second sampling value corresponding to a current sampling point in the target sub-signal to obtain a clock error value of the target sub-signal, wherein the second sampling value represents a difference between sampling values ​​of two adjacent sampling points of the current sampling point;

[0164] Performing error correction on the clock error value, and determining a sampling clock deviation of the target sub-signal based on the corrected clock error value;

[0165] An interpolation filtering operation is performed on the target sub-signal based on the sampling clock deviation to obtain a target signal after symbol synchronization processing is performed on each of the sub-signals to be processed.

[0166] In an optional embodiment of the present application, the segmented processing of the main synchronization signal to obtain a plurality of sub-signals to be processed includes:

[0167] Acquire the total data length of the primary synchronization signal;

[0168] The main synchronization signal is processed in segments with equal data lengths according to a preset data length to obtain a plurality of initial sub-signals to be processed;

[0169] If it is determined based on the total data length that the data length of the last initial sub-signal to be processed is less than the preset data length, data padding is performed on the last initial sub-signal to be processed so that the data length of the last initial sub-signal to be processed after data padding is equal to the preset data length, thereby obtaining the multiple sub-signals to be processed; or, if it is determined based on the total data length that the data length of the last initial sub-signal to be processed is equal to the preset data length, the multiple initial sub-signals to be processed are determined as the multiple sub-signals to be processed.

[0170] In an optional embodiment of the present application, the main synchronization signal is a signal of a superframe structure, and the superframe structure is composed of a head protection symbol, a tail protection symbol, a superframe start SOSF, a superframe format indicator SFFI, a superframe header SFH, a physical layer frame PLF and a pilot.

[0171] In an optional embodiment of the present application, the error correction of the clock error value includes:

[0172] Obtaining a roll-off factor and a signal-to-noise ratio of a raised cosine roll-off RRC filter, and determining a compensation factor for the clock error value based on the roll-off factor and the signal-to-noise ratio;

[0173] Normalizing the clock error value of the target sub-signal;

[0174] The normalized clock error value is corrected based on the compensation factor to obtain the corrected clock error value of the target sub-signal.

[0175] In an optional embodiment of the present application, determining the sampling clock deviation of the target sub-signal based on the corrected clock error value includes:

[0176] Determining a preset fitting order, and determining a fitting factor of each fitting order in the preset fitting order;

[0177] According to the fitting factors of the respective fitting orders, a polynomial fitting function of the preset fitting order is constructed for the corrected clock error value to obtain a sampling clock deviation of the target sub-signal;

[0178] The interpolation filtering operation is performed on the target sub-signal based on the sampling clock deviation to obtain the target signal after the symbol synchronization processing is performed on each of the sub-signals to be processed, including:

[0179] Performing data padding before the start sampling point and after the end sampling point in the target sub-signal to obtain the target sub-signal after data padding;

[0180] Determine a second interpolation coefficient according to the target sub-signal after the data filling and a pre-configured first interpolation coefficient; the first interpolation coefficient is a matrix vector of the preset fitting order;

[0181] An interpolation filtering operation is performed on the sampling clock deviation of the target sub-signal based on the second interpolation coefficient to obtain a target signal after symbol synchronization processing is performed on each of the sub-signals to be processed.

[0182] In an optional embodiment of the present application, the above method further includes:

[0183] Determine at least two pilot data sequences of the target sub-signal based on a current sampling point at which a pilot signal in the target sub-signal is located and at least one adjacent sampling point of the current sampling point;

[0184] performing correlation calculations on the at least two pilot data sequences and the local pilot data sequence respectively, to obtain a cross-correlation value between the at least two pilot data sequences of the target sub-signal and the local pilot data sequence;

[0185] The correlation power value of the target sub-signal is determined according to the mutual correlation value between the at least two pilot data sequences and the local pilot data sequence.

[0186] In an optional embodiment of the present application, the primary synchronization signal is a digital signal with a symbol rate of 2 times.

[0187] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods or computer program products. Therefore, the present application can adopt the form of complete hardware embodiments, complete software embodiments, or embodiments in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code. The scheme in the embodiments of the present application can be implemented in various computer languages, for example, C language, VHDL language, Verilog language, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0188] The present application is described with reference to the flowcharts and / or block diagrams of the methods and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of the processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0189] These computer program instructions may also be stored in a computer readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0190] These computer program instructions can also be loaded into a computer or other programmable data processing device, such as Figure 2 As shown, a series of operation steps are executed on a computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1The steps for the functions specified in one or more boxes.

[0191] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0192] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0193] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0194] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0195] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A time synchronization method, characterized in that: include: Segmenting the first air interface data and performing downsampling processing to obtain multiple groups of primary synchronization signal sequences with the same symbol length, wherein adjacent primary synchronization signal sequences contain the same symbol; Calculating the correlation between each segment of data in the multiple groups of primary synchronization signal sequences and the first air interface data, and obtaining coarse synchronization position information with the greatest correlation with the first air interface data; Determine the data to be synchronized in the first air interface data based on the coarse synchronization position information and the data synchronization length, the data to be synchronized comprising: primary synchronization data, first auxiliary synchronization data and second auxiliary synchronization data; determining actual auxiliary synchronization data and a cell ID from the first auxiliary synchronization data and the second auxiliary synchronization data; Performing frequency deviation calculation on the actual auxiliary synchronization data and the main synchronization data to obtain frequency deviation information; Time synchronization is performed according to the frequency offset information and the cell ID.

2. The time synchronization method according to claim 1, characterized in that: The determining the actual auxiliary synchronization data and the cell ID from the first auxiliary synchronization data and the second auxiliary synchronization data comprises: Respectively converting the first auxiliary synchronization data and the second auxiliary synchronization data into frequency domain data; Performing reverse descrambling calculations on the first auxiliary synchronization data and the second auxiliary synchronization data of the frequency domain data respectively to obtain a reverse descrambling result and a cell ID; The larger auxiliary synchronization data in the reverse descrambling result is used as the actual auxiliary synchronization data.

3. The time synchronization method according to claim 1, characterized in that: Before segmenting the first air interface data and performing downsampling processing, the method includes: Receive the central frequency information sent by the upper node; Based on the center frequency information, the acquired second air interface data is converted into first air interface data corresponding to the frequency of the center frequency information.

4. The time synchronization method according to claim 1, characterized in that: The symbol length of the primary synchronization signal sequence is less than the correlation calculation length; Accordingly, before calculating the correlation between each segment of data in the multiple groups of primary synchronization signal sequences and the first air interface data, the method includes: Automatic gain control is performed on the primary synchronization signal sequence so that the symbol length of the primary synchronization signal sequence after gain meets the correlation calculation requirement.

5. The time synchronization method according to claim 3, characterized in that: The calculating the correlation between each segment of data in the multiple groups of primary synchronization signal sequences and the first air interface data to obtain the coarse synchronization position information with the maximum correlation with the first air interface data includes: Performing conjugate calculations on the multiple groups of primary synchronization signal sequences respectively to obtain multiple groups of conjugate symmetric signals; Perform sliding correlation calculation on the first air interface data by using multiple groups of the conjugate symmetric signals to obtain multiple groups of correlation value sequences representing correlation with the first air interface data; Normalizing the plurality of correlation value sequences to calculate the power value of each segment of data in each correlation value sequence; The coarse synchronization position information having the greatest correlation with the first air interface data is determined based on the maximum power value.

6. The time synchronization method according to claim 5, characterized in that: After normalizing the plurality of correlation value sequences to calculate the power value of each segment of data in each correlation value sequence, the method comprises: Determine in sequence whether the power value of each segment of data is greater than a preset power value; If the power value of each segment of data is not greater than the preset power value, reacquiring the second air interface data; If the power value of at least one segment of data is greater than a preset power value, the coarse synchronization position information with the greatest correlation with the first air interface data is determined based on the maximum power value.

7. The time synchronization method according to claim 5, characterized in that: The method of determining the data to be synchronized in the first air interface data based on the coarse synchronization position information and the data synchronization length includes: Based on the coarse synchronization position information, the data synchronization length and the symbol position of each data in the current communication protocol, the determined data to be synchronized including the primary synchronization data, the first auxiliary synchronization data and the second auxiliary synchronization data are determined in the first air interface data.

8. The time synchronization method according to claim 2, characterized in that: The performing frequency deviation calculation on the actual auxiliary synchronization data and the primary synchronization data to obtain frequency deviation information includes: The master synchronization data is converted into master synchronization frequency domain data of frequency domain data; The frequency offset information of the primary synchronization frequency domain data and the actual auxiliary synchronization frequency domain data is calculated, and the actual auxiliary synchronization frequency domain data is the frequency domain data corresponding to the actual auxiliary synchronization data.

9. An electronic device, characterized in that: include: Memory; processor; as well as Computer programs; The computer program is stored in the memory and is configured to be executed by the processor to implement the method according to any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that: A computer program is stored thereon; the computer program is executed by a processor to implement the method according to any one of claims 1 to 8.

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