Downlink synchronization detection method, device and terminal

Abstract

The invention provides a downlink synchronization detection method, a downlink synchronization detection device and a terminal. The method comprises the following steps: performing frequency offset correction on a received downlink signal to obtain a first signal sequence; performing down-sampling data extraction on the first signal sequence to obtain a second signal sequence; performing correlation operation on the PSS sequence and the second signal sequence, and determining a first positioning position of the PSS sequence in the second signal sequence; determining a second positioning position of a signal corresponding to the first positioning position in the first signal sequence; and reading a third signal sequence from the first signal sequence by taking the second positioning position as the center of an acquisition window for performing signal acquisition from the first signal of the acquisition window, performing correlation operation on the third signal sequence and the local PSS sequence, and determining a third positioning position of the PSS sequence in the first signal sequence. By adopting the method, the purpose of reducing hardware resource consumption can be achieved, and the problem that equipment hardware is difficult to implement is avoided.

Description

Technical Field

[0001] The present invention relates to the field of wireless technology, and in particular to a downlink synchronization detection method, device and terminal. Background Art

[0002] In the downlink, when the terminal initially enters the network, it does not know the specific location of the primary synchronization signal (PSS) in the network in the frequency domain, and needs to perform synchronization detection.

[0003] At present, a synchronization detection method related to the local PSS sequence is usually used. When the number of local PSS sequence bits is large, the synchronization detection method of this type consumes a lot of hardware resources and is difficult to implement on the device hardware. For example, when the local PSS sequence is 4096 points, in order to meet the synchronization-related real-time detection, 4096 complex multipliers are required to operate simultaneously, and the corresponding hardware multipliers require 4096*3. This hardware configuration cannot be met by the currently used field programmable gate array (FPGA) and other hardware. Summary of the invention

[0004] The technical solution of the present invention aims to provide a downlink synchronization detection method, device and terminal, which are used to solve the problem that the detection method using the existing technology consumes a lot of hardware resources and is difficult to implement on the device hardware.

[0005] The present invention provides a downlink synchronization detection method, which includes:

[0006] Based on the first preset frequency offset, the received downlink signal is corrected for frequency offset to obtain a corrected first signal sequence;

[0007] Performing downsampling data extraction on the first signal sequence to obtain a second signal sequence;

[0008] Performing a correlation operation on a local primary synchronization signal PSS sequence and the second signal sequence to determine a first positioning position of the PSS sequence in the downlink signal in the second signal sequence;

[0009] Determine a second positioning position of the signal corresponding to the first positioning position in the first signal sequence;

[0010] Taking the second positioning position as the center of the acquisition window for signal acquisition in the first signal sequence, starting from the first signal of the acquisition window, the third signal sequence is read in the first signal sequence, and the read third signal sequence is correlated with the local PSS sequence to determine the third positioning position of the PSS sequence in the downlink signal in the first signal sequence.

[0011] Optionally, the downlink synchronization detection method, wherein the performing a correlation operation on a local primary synchronization signal PSS sequence and the second signal sequence to determine a first positioning position of the PSS sequence in the downlink signal in the second signal sequence, includes:

[0012] Perform sliding correlation on a local primary synchronization signal PSS sequence and the second signal sequence to obtain a correlation energy value of each signal in the second signal sequence corresponding to the local PSS sequence;

[0013] Calculating average energy values ​​of multiple signals in the second signal sequence;

[0014] When the ratio of the correlation energy value to the average energy value is greater than or equal to a first preset threshold, the first positioning position is determined according to the position of the signal corresponding to the correlation energy value in the second signal sequence.

[0015] Optionally, in the downlink synchronization detection method, the step of sliding correlation of a local primary synchronization signal PSS sequence with the second signal sequence includes:

[0016] Perform conjugate multiplication of a signal in the second signal sequence with each signal in the local primary synchronization signal PSS sequence to obtain multiple calculated values;

[0017] The multiple calculated values ​​are summed up to obtain the relevant energy value of the signal corresponding to the local PSS sequence.

[0018] Optionally, the downlink synchronization detection method, wherein sliding correlation is performed on a local primary synchronization signal PSS sequence and the second signal sequence to obtain a correlation energy value of each signal in the second signal sequence corresponding to the local PSS sequence, includes:

[0019] Sequentially in each clock cycle, respectively obtaining a correlation energy value of a signal in the second signal sequence corresponding to the local PSS sequence;

[0020] Wherein, the method further comprises:

[0021] After each clock cycle, comparing the ratio of the obtained correlation energy value to the average energy value with the first preset threshold;

[0022] If within the first preset search time, the ratio of each of the obtained correlation energy values ​​to the average energy value is less than the first preset threshold, the local PSS sequence is updated, and based on the updated local PSS sequence, the step of performing correlation operation on the local main synchronization signal PSS sequence and the second signal sequence is returned to be re-executed until the ratio of one of the obtained correlation energy values ​​to the average energy value is greater than or equal to the first preset threshold.

[0023] Optionally, the downlink synchronization detection method further comprises:

[0024] After updating the local PSS sequence and returning to re-execute the step of performing correlation operation on the local main synchronization signal PSS sequence and the second signal sequence, if after multiple updates of the local PSS sequence, corresponding to each local PSS sequence, the comparison between each obtained correlation energy value and the average energy value is less than the first preset threshold, then the first preset frequency deviation is replaced with the second preset frequency deviation, and returning to re-execute the step of performing frequency deviation correction on the received downlink signal to obtain the corrected first signal sequence, until the ratio of one of the obtained correlation energy values ​​to the average energy value is greater than or equal to the first preset threshold.

[0025] Optionally, the downlink synchronization detection method, wherein starting from the first signal of the acquisition window, reading a third signal sequence in the first signal sequence, performing a correlation operation on the third signal sequence and the local PSS sequence, and determining a third positioning position of the PSS sequence in the downlink signal in the first signal sequence, includes:

[0026] Starting from the first signal of the acquisition window, a correlation operation is performed on the local PSS sequence and the third signal sequence obtained in each calculation cycle by using a parallel processing method or a serial processing method to obtain a correlation energy value of the third signal sequence corresponding to the local PSS sequence; wherein the obtained third signal sequence slides on the first signal sequence toward the tail signal of the acquisition window according to the calculation cycle; and the number of bits of the third signal sequence is the same as the number of bits of the local PSS sequence;

[0027] The signal position corresponding to the maximum correlation energy value among the multiple correlation energy values ​​is determined as the third positioning position.

[0028] Optionally, the downlink synchronization detection method, wherein a serial processing method is adopted to perform a correlation operation on the local PSS sequence and a third signal sequence obtained in each calculation cycle to obtain a correlation energy value of the third signal sequence corresponding to the local PSS sequence, includes:

[0029] Starting from the first signal of the acquisition window, one signal of the first signal sequence is read in each calculation cycle, and N signals are read continuously to obtain a third signal sequence; wherein, the first signal of the next third signal sequence is shifted by one signal after the first signal of the previous third signal sequence, and N signals are read continuously to obtain the next third signal sequence; wherein, the number of bits of the local PSS sequence is N bits; and N is an integer greater than or equal to 1;

[0030] Conjugate and multiply one of the signals of the local PSS sequence with a signal of a corresponding bit of the third signal sequence to obtain a corresponding calculated value;

[0031] A sum is calculated for a plurality of calculated values ​​obtained by correspondingly conjugating and multiplying each signal of the local PSS sequence with the signal of the corresponding bit of the third signal sequence, so as to obtain a correlation energy value of the third signal sequence corresponding to the local PSS sequence.

[0032] Optionally, the downlink synchronization detection method, wherein a parallel processing method is used to perform a correlation operation on the local PSS sequence and a third signal sequence obtained in each calculation cycle to obtain a correlation energy value of the third signal sequence corresponding to the local PSS sequence, includes:

[0033] Starting from the first signal of the acquisition window, S signals of the first signal sequence are read in each calculation cycle to obtain a fourth signal sequence; wherein the first signal of the next fourth signal sequence is shifted by one signal after the first signal of the previous fourth signal sequence, and S signals are read continuously to obtain the next fourth signal sequence; wherein the number of bits of the acquisition window is S bits; S is an integer greater than or equal to 1;

[0034] According to the arrangement order of multiple signals in the local PSS sequence, one signal of the local PSS sequence corresponds to one of the multiple fourth signal sequences read in sequence, and within a calculation cycle of reading the fourth signal sequence, each signal in the read fourth signal sequence is conjugate-multiplied with the corresponding signal in the local PSS sequence to obtain a corresponding calculation value;

[0035] Starting from the first signal of the acquisition window, multiple third signal sequences are acquired in sequence, each of the third signal sequences includes N consecutive signals, and the first signal of the next third signal sequence is shifted by one signal after the first signal of the previous third signal sequence, and according to the arrangement order of multiple signals in the third signal sequence and the arrangement order of multiple signals in the local PSS sequence, one signal of the local PSS sequence corresponds to one signal of the third signal sequence, and the calculated values ​​of conjugate multiplication of each signal of the third signal sequence with the corresponding signal of the local PSS sequence are summed to obtain a correlation energy value of the third signal sequence corresponding to the local PSS sequence.

[0036] Optionally, in the downlink synchronization detection method, before downsampling the first signal sequence to extract data to obtain the second signal sequence, the method further includes:

[0037] Perform sequence expansion on the local PSS sequence, and perform an inverse fast Fourier transform IFFT operation on the local PSS sequence after the expansion sequence, so that the number of time domain points of the local PSS sequence after the operation is the same as the number of time domain points of the received downlink signal;

[0038] According to the number of sampling data points required to be extracted when downsampling data is extracted for the first signal sequence, interpolation processing is performed on the local PSS sequence after the calculation, so that the number of points of the local PSS sequence after the interpolation processing is equal to the number of sampling data points.

[0039] Optionally, in the downlink synchronization detection method, before performing a correlation operation on the local PSS sequence and the third signal sequence in the acquisition window, the method further includes:

[0040] The local PSS sequence is sequence extended, and an IFFT operation is performed on the local PSS sequence after the extended sequence, so that the number of points of the local PSS sequence after the operation in the time domain is the same as the number of points of the OFDM symbol corresponding to the first signal sequence.

[0041] One embodiment of the present invention further provides a downlink synchronization detection device, which includes:

[0042] A correction module, configured to perform frequency deviation correction on a received downlink signal based on a first preset frequency deviation to obtain a corrected first signal sequence;

[0043] A data processing module, used for performing downsampling data extraction on the first signal sequence to obtain a second signal sequence;

[0044] A first operation module, configured to perform a correlation operation on a local primary synchronization signal PSS sequence and the second signal sequence to determine a first positioning position of the PSS sequence in the downlink signal in the second signal sequence;

[0045] a position determination module, configured to determine a second positioning position of the signal corresponding to the first positioning position in the first signal sequence;

[0046] The second operation module is used to take the second positioning position as the center of the acquisition window for performing signal acquisition in the first signal sequence, start from the first signal of the acquisition window, read the third signal sequence in the first signal sequence, perform a correlation operation on the read third signal sequence and the local PSS sequence, and determine the third positioning position of the PSS sequence in the downlink signal in the first signal sequence.

[0047] One embodiment of the present invention further provides a terminal, which includes: a processor, a memory, and a program stored in the memory and executable on the processor, wherein the program implements the downlink synchronization detection method as described in any one of the above items when executed by the processor.

[0048] At least one of the above technical solutions in the specific embodiment of the present invention has the following beneficial effects:

[0049] The downlink synchronization detection method described in the embodiment of the present invention is adopted. After the frequency deviation of the received downlink signal is corrected by presetting the frequency deviation, the second signal sequence is obtained by downsampling data extraction for the corrected first signal sequence, and the local main synchronization signal PSS sequence is used to perform correlation operation with the second signal sequence to determine the first positioning position of the PSS in the downlink signal in the second signal sequence, so as to achieve coarse synchronization positioning with less sampling data; then, according to the second positioning position of the signal corresponding to the first positioning position in the first signal sequence, the second positioning position is used as the center of the acquisition window for signal acquisition, and the third signal sequence obtained according to the acquisition window is correlated with the local PSS sequence to achieve precise synchronization positioning of the PSS sequence in the downlink signal. With this downlink synchronization detection process, all points of the sequence in the downlink signal do not need to participate in the calculation at the same time, so as to achieve the purpose of reducing hardware resource consumption and avoid problems that are difficult to achieve in device hardware. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 A schematic diagram of a flow chart of a downlink synchronization detection method according to an embodiment of the present invention;

[0051] Figure 2 A schematic diagram of a flow chart of one implementation of the method described in an embodiment of the present invention;

[0052] Figure 3It is a schematic diagram of the principle of the serial processing method in the precise synchronization detection process;

[0053] Figure 4 It is a schematic diagram of the principle of the parallel processing method in the precise synchronization detection process;

[0054] Figure 5 A schematic diagram of another implementation of the method according to an embodiment of the present invention;

[0055] Figure 6 It is a structural diagram of a downlink synchronization detection device according to an embodiment of the present invention;

[0056] Figure 7 The figure is a schematic diagram of the principle of one implementation method of summing up multiple calculated values ​​in the method described in the embodiment of the present invention. DETAILED DESCRIPTION

[0057] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0058] The terms "first", "second", etc. in the specification and claims of the present invention are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way are interchangeable where appropriate, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first" and "second" are generally of the same type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0059] In order to solve the problem that the detection method using the existing technology consumes a lot of hardware resources and is difficult to implement on the device hardware, the downlink synchronization detection method provided by the embodiment of the present invention adopts a method of first sampling and extracting the received downlink signal, and performing rapid coarse synchronization positioning based on the signal sequence extracted by the data, to preliminarily locate the positioning position of the main synchronization signal PSS sequence in the downlink signal; then, the signal sequence read by the acquisition window determined based on the positioning position is used to achieve precise synchronization positioning. With this downlink synchronization detection process, it is not necessary for all the points in the sequence of the downlink signal to participate in the calculation at the same time, so as to achieve the purpose of reducing the consumption of hardware resources and avoid the problem that is difficult to implement on the device hardware.

[0060] One embodiment of the present invention provides a downlink synchronization detection method, such as Figure 1 As shown, the method includes:

[0061] S110, performing frequency offset correction on a received downlink signal based on a first preset frequency offset to obtain a corrected first signal sequence;

[0062] S120, performing downsampling data extraction on the first signal sequence to obtain a second signal sequence;

[0063] S130, performing a correlation operation on a local primary synchronization signal PSS sequence and the second signal sequence to determine a first positioning position of the PSS sequence in the downlink signal in the second signal sequence;

[0064] S140, determining a second positioning position of the signal corresponding to the first positioning position in the first signal sequence;

[0065] S150, taking the second positioning position as the center of the acquisition window for signal acquisition in the first signal sequence, starting from the first signal of the acquisition window, reading the third signal sequence in the first signal sequence, performing a correlation operation on the read third signal sequence and the local PSS sequence, and determining the third positioning position of the PSS sequence in the downlink signal in the first signal sequence.

[0066] The downlink synchronization detection method described in the embodiment of the present invention performs frequency deviation correction on the received downlink signal by presetting the frequency deviation, obtains the second signal sequence by downsampling data extraction for the corrected first signal sequence, performs correlation operation with the local primary synchronization signal PSS sequence and the second signal sequence, determines the first positioning position of the PSS in the downlink signal in the second signal sequence, and thus achieves rough synchronization positioning with less sampling data; then, according to the second positioning position of the signal corresponding to the first positioning position in the first signal sequence, the third signal sequence in the acquisition window is correlated with the local PSS sequence with the second positioning position as the center in the acquisition window of signal acquisition, and achieves precise synchronization positioning of the PSS sequence in the downlink signal. With this downlink synchronization detection process, it is not necessary for all points of the sequence in the downlink signal to participate in the calculation at the same time, thereby achieving the purpose of reducing hardware resource consumption and avoiding problems that are difficult to achieve in device hardware.

[0067] In the embodiment of the present invention, the terminal receives the downlink signal transmitted by the base station, and after being processed by the antenna and the radio frequency link, the downlink signal is sampled by the analog-to-digital converter (ADC) to obtain a baseband digital signal, that is, a downlink signal to be processed that can perform downlink synchronization detection.

[0068] In one implementation mode, optionally, after obtaining the downlink signal converted by ADC, frequency offset correction is performed on the downlink signal based on a first preset frequency offset to correct the PSS sequence in the downlink signal to the center frequency band of an orthogonal frequency division multiplexing symbol (OFDM).

[0069] Optionally, the frequency offset of the downlink signal may be corrected by multiplying the first preset frequency offset by the downlink signal.

[0070] In one implementation mode, optionally, the frequency offset of the downlink signal may be corrected using the following formula:

[0071]

[0072] Where x(t) is the downlink signal converted by ADC at time t; y(t) is the first signal sequence after frequency offset correction, f pre is the first preset frequency deviation.

[0073] After the corrected first signal sequence y(t) is obtained in the above manner, the first signal sequence y(t) is subjected to two processes, namely, coarse synchronization processing detection and fine synchronization processing detection, so that the positioning position of the PSS sequence in the first signal sequence y(t) can be determined.

[0074] The process from steps S120 to S130 is a coarse synchronization process detection process, and the process from S140 to S150 is a fine synchronization process detection process.

[0075] Specifically, the purpose of performing coarse synchronization processing on the first signal sequence y(t) is to achieve preliminary positioning of the PSS sequence. Optionally, a sliding correlation operation is performed on a second signal sequence obtained by downsampling the time domain sequence of the local PSS sequence and the first signal sequence y(t), and the correlation energy value of the signal in the second signal sequence corresponding to the local PSS sequence is determined, and the correlation energy value is compared with the average energy value of multiple signals in the second signal sequence. The coarse positioning position of the PSS sequence in the downlink signal is determined according to the comparison result, that is, the first positioning position is obtained.

[0076] In an embodiment of the present invention, in one implementation manner, optionally, in order to enable the local PSS sequence to perform a correlation operation with the second signal sequence, before downsampling the first signal sequence to extract data to obtain the second signal sequence, the method further includes:

[0077] Performing sequence expansion on the local PSS sequence, and performing an inverse fast Fourier transform (IFFT) operation on the local PSS sequence after the expansion sequence, so that the number of time domain points of the local PSS sequence after the operation is the same as the number of time domain points of the received downlink signal;

[0078] According to the number of sampling data points required to be extracted when downsampling data is extracted for the first signal sequence, interpolation processing is performed on the local PSS sequence after the calculation, so that the number of points of the local PSS sequence after the interpolation processing is equal to the number of sampling data points.

[0079] Among them, the number of time domain points of the PSS sequence usually does not match the data length for FFT operation. For example, the length of the PSS sequence is usually 127 points. In order to facilitate FFT operation, it is necessary to expand the local PSS sequence, expand the 127-point local PSS sequence to a 128-point sequence, and then perform IFFT operation on the 128-point local PSS sequence, so that the number of time domain points of the local PSS sequence after the operation is the same as the number of time domain points of the received downlink signal, that is, to obtain a local PSS sequence of a 128-point time domain sequence.

[0080] Optionally, the local PSS sequence may be extended by adding a zero point, for example, a 127-point local PSS sequence may be extended to a 128-point sequence by adding a zero point.

[0081] On the other hand, in order to balance system performance and implementation complexity, it is necessary to perform interpolation processing on the local PSS sequence after the above-mentioned IFFT operation, so that the number of points of the local PSS sequence after the interpolation processing is the same as the number of sampling data points required for downsampling data extraction, so as to simplify the subsequent sliding correlation operation process.

[0082] For example, if the first signal sequence y(t) is downsampled and the length of the second signal sequence obtained is 256 points, the local PSS sequence after the operation needs to be interpolated so that the number of points of the local PSS sequence after the interpolation is 256 points. Optionally, when the local PSS sequence after the operation is 128 points, a two-fold interpolation method can be used, and the interpolation value is zero to obtain a reference sequence of the local PSS sequence for correlation operation.

[0083] It should be noted that, in the embodiment of the present invention, in the process of performing coarse synchronization processing and detection in the above steps S120 to S130, the local primary synchronization signal PSS sequence mentioned is a sequence having the same sequence length as the second signal sequence after the above interpolation processing.

[0084] Combination Figure 2 As shown, the specific implementation process of the rough synchronization processing detection in steps S120 to S130 includes the following steps:

[0085] S121, obtaining a corrected first signal sequence y(t); wherein the first signal sequence y(t) is OFDM data; optionally, the number of points n of the first signal sequence is 4096 points;

[0086] S122, performing low-pass filtering on the first signal sequence y(t) to filter out signals outside the signal bandwidth in the first signal sequence y(t);

[0087] S123, downsample the first signal sequence y(t) after low-pass filtering to obtain a second signal sequence; wherein the second signal sequence obtained after downsampling data extraction has the same sequence length as the sequence after interpolation processing of the local PSS sequence.

[0088] For example, when the local PSS sequence is interpolated to a sequence of 256 points, a first signal sequence y(t) having 4096 points needs to be downsampled by 1 / 16 to obtain a second signal sequence of 256 points.

[0089] S131, performing sliding correlation on a local primary synchronization signal PSS sequence and a second signal sequence to obtain a correlation energy value of each signal in the second signal sequence corresponding to the local PSS sequence;

[0090] In one implementation manner, optionally, in step S131, sliding correlation is performed on a local primary synchronization signal PSS sequence and a second signal sequence, including:

[0091] Perform conjugate multiplication of a signal in the second signal sequence with each signal in the local primary synchronization signal PSS sequence to obtain multiple calculated values;

[0092] The multiple calculated values ​​are summed up to obtain the relevant energy value of the signal corresponding to the local PSS sequence.

[0093] In the embodiment of the present application, optionally, the following formula may be used to perform corresponding conjugate multiplication of the signal in the second signal sequence and the signal in the local primary synchronization signal PSS sequence:

[0094]

[0095] Among them, y(n) is the calculated value after conjugate multiplication, h(i) represents the signal in the local primary synchronization signal PSS sequence; x(ni) represents the signal in the second signal sequence, and N is the number of sequence points of the second signal sequence.

[0096] By adopting the above method, each signal in the second signal sequence is extracted in turn, and the extracted signals are respectively conjugate multiplied with each signal in the local main synchronization signal PSS sequence to obtain multiple calculated values, and the multiple calculated values ​​are summed up, so that the relevant energy value of the extracted signal corresponding to the local PSS sequence can be obtained. By performing calculations for each signal in the second signal sequence, the relevant energy value of each signal in the second signal sequence corresponding to the local PSS sequence can be obtained.

[0097] Here, considering the real-time requirements of the actual application system, it is necessary to complete the calculation of the above-mentioned related energy values ​​within a preset time (such as 1 clock cycle). In order to save hardware implementation resources, optionally, a pipeline structure can be used for implementation. Taking the sequence lengths of the second signal sequence and the local PSS sequence as 256 points respectively as an example, the specific implementation method is: each clock cycle requires the 256-point local PSS sequence to be conjugate multiplied with the continuous 256-point second signal sequence signal to obtain 256 values, and then the 256 points are summed to obtain the related energy value. Taking the system clock and timing conditions into consideration, the 256-point summation is implemented in a four-stage pipeline manner, such as Figure 7 As shown, the obtained multiple calculated values, such as Y(1), Y(2), ..., Y(256), are calculated by four-level summation processing. In each level of summation processing, the calculation result obtained by summing the four calculated values ​​is used for the next level of summation calculation. In this way, through the delay of 4 clocks, each clock outputs a value, the clock rate can be increased as much as possible while meeting the timing requirements, and the relevant energy value can be obtained in real time.

[0098] S132, calculating average energy values ​​of multiple signals in the second signal sequence;

[0099] The average energy value is a reference energy used for synchronous positioning decision.

[0100] Optionally, in this implementation, calculating the average energy values ​​of multiple signals in the second signal sequence includes:

[0101] Calculating the sample energy of each signal in the plurality of signals in the second signal sequence; wherein the sample energy can be obtained by calculating the square sum of the real part and the imaginary part of the signal;

[0102] According to the calculated sample energy of each signal, the average energy value is calculated by sliding window length.

[0103] Specifically, the sample point energies of the signal in the sliding window are summed, and the total energy after the summation is divided by the number of bits of the signal in the window length to obtain the average energy value.

[0104] Optionally, the sliding window length may be set to be consistent with the sequence length of the second signal sequence Y2(n), wherein the sliding window length is synchronized with the relevant energy position in real time.

[0105] It should be noted that there is no temporal order relationship between the above-mentioned step S131 and step S132, and the two steps can be executed simultaneously.

[0106] After completing the above steps S131 and S132, perform the following step S133:

[0107] S133, respectively obtaining a ratio of each calculated correlation energy value to the average energy value, comparing the calculated ratio with a first preset threshold, and determining whether the ratio of the correlation energy value to the average energy value is greater than or equal to the first preset threshold;

[0108] S134, determining whether there is a correlation energy value whose ratio is greater than or equal to the first preset threshold; if the determination result is yes, executing step S135; if the determination result is no, executing step S136;

[0109] S135, determining a first positioning position according to the position of the signal corresponding to the correlation energy value whose ratio is greater than or equal to the first preset threshold.

[0110] Optionally, when there is one signal corresponding to the correlated energy value corresponding to the ratio being greater than or equal to the first preset threshold, the position of the signal corresponding to the correlated energy value in the second signal sequence is the first positioning position; when there are multiple signals corresponding to the correlated energy values ​​corresponding to the ratio being greater than or equal to the first preset threshold, the first positioning position is determined based on the peak value of the correlated energy value, that is, the signal starting point corresponding to the peak value is the determined first positioning position.

[0111] In the embodiment of the present invention, optionally, performing sliding correlation on a local primary synchronization signal PSS sequence and the second signal sequence to obtain a correlation energy value of each signal in the second signal sequence corresponding to the local PSS sequence includes:

[0112] Sequentially in each clock cycle, respectively obtaining a correlation energy value of a signal in the second signal sequence corresponding to the local PSS sequence;

[0113] Wherein, the method further comprises:

[0114] After each clock cycle, comparing the ratio of the obtained correlation energy value to the average energy value with the first preset threshold;

[0115] If within the first preset search time, the ratio of each of the obtained correlation energy values ​​to the average energy value is less than the first preset threshold, the local PSS sequence is updated, and based on the updated local PSS sequence, the step of performing correlation operation on the local main synchronization signal PSS sequence and the second signal sequence is returned to be re-executed until the ratio of one of the obtained correlation energy values ​​to the average energy value is greater than or equal to the first preset threshold.

[0116] Based on the above, in step S136, it is determined that when the duration of the sliding correlation operation reaches the first preset search duration, the ratio of the correlation energy value to the average energy value is still not detected to be greater than or equal to the first preset threshold, then it is determined that the current local PSS sequence is not the sequence used by the upper layer, and the local PSS sequence needs to be updated, and the process of re-executing the coarse synchronization detection is returned until each local PSS sequence is updated and a ratio of the correlation energy value to the average energy value is obtained to be greater than or equal to the first preset threshold.

[0117] Therefore, after step S136, the following steps are continued:

[0118] S137, updating and regenerating the local PSS sequence;

[0119] S138, performing IFFT operation on the generated local PSS sequence, so that the number of time domain points of the local PSS sequence after the operation is the same as the number of time domain points of the received downlink signal; and, according to the number of sampling data points required to be extracted when downsampling data is extracted on the first signal sequence, interpolation processing is performed on the local PSS sequence after the operation, so that the number of points of the local PSS sequence after the interpolation processing is equal to the number of sampling data points.

[0120] Afterwards, return to execute step S131.

[0121] In the embodiment of the present invention, optionally, the first preset search duration may be agreed upon by a protocol.

[0122] In another embodiment, optionally, the method further comprises:

[0123] After updating the local PSS sequence and returning to re-execute the step of performing correlation operation on the local main synchronization signal PSS sequence and the second signal sequence, if after multiple updates of the local PSS sequence, corresponding to each local PSS sequence, the comparison between each obtained correlation energy value and the average energy value is less than the first preset threshold, then the first preset frequency deviation is replaced with the second preset frequency deviation, and returning to re-execute the step of performing frequency deviation correction on the received downlink signal to obtain the corrected first signal sequence, until the ratio of one of the obtained correlation energy values ​​to the average energy value is greater than or equal to the first preset threshold.

[0124] Based on the above implementation process, when the first preset search time is reached and the relevant energy value that meets the first preset threshold is still not detected, it indicates that the local main synchronization sequence is not the sequence used by the upper layer, and the main synchronization sequence needs to be updated and the search needs to be restarted until all local main synchronization sequences are searched. When all main synchronization sequences do not meet this condition, it is necessary to readjust the value of the first preset frequency deviation, and then return to the above process of step S110 and re-execute the synchronization detection process until coarse synchronization is achieved.

[0125] After completing the rough synchronization detection process of steps S120 to S130 and obtaining the first positioning position, continue to execute steps S140 to S150 to perform fine synchronization detection to obtain a more accurate synchronization position and improve subsequent system performance.

[0126] For example, in a time division duplex (TDD) communication mode that requires precise time synchronization, the effect of improving the TDD time control accuracy can be achieved.

[0127] Specifically, the process of performing precise synchronization detection first needs to obtain the time domain sequence of the local PSS sequence, and then determine the second positioning position as the center of the acquisition window for signal acquisition in the first signal sequence, determine the first signal of the acquisition window according to the pre-set window length S of the acquisition window, and start from the first signal of the acquisition window. Read the third signal sequence in the first signal sequence, perform a correlation operation on the read third signal sequence and the local PSS sequence, determine the correlation energy value, and determine the synchronization position of the precise synchronization according to the signal position corresponding to the maximum value in the correlation energy value.

[0128] Optionally, in step S140, when determining the second positioning position of the signal corresponding to the first positioning position in the first signal sequence, the position (second positioning position) of each corresponding signal in the first signal sequence can be determined based on the relationship between the position of each signal in the second signal sequence (first positioning position) extracted when downsampling data is extracted and the position of the signal in the first signal sequence.

[0129] Optionally, before performing a correlation operation on the read third signal sequence and the local PSS sequence in step S150, the method further includes:

[0130] Sequence extension is performed on the local PSS sequence, and an IFFT operation is performed on the local PSS sequence after the extension, so that the number of points of the local PSS sequence after the operation in the time domain is the same as the number of points of the OFDM symbol corresponding to the first signal sequence.

[0131] In the fine synchronization process, since the original first signal sequence is a signal that has not been downsampled, the local PSS sequence also needs to conform to the number of OFDM symbol points corresponding to the original signal. For example, when the first signal sequence after frequency offset correction is a 4096-point OFDM symbol, a 4096-point iFFT operation is also required when the local PSS sequence is transformed into a time domain sequence. The calculation method is to directly add zeros to the front and back ends of the 127-point value of the local PSS sequence frequency domain to expand it to 240 points, and then place the 240-point data at the center of the iFFT and expand it to 4096 points. The expanded value is zero, and then the 4096-point data is iFFT-operated to obtain the 4096-point time domain symbol of the local PSS sequence.

[0132] It should be noted that, in the embodiment of the present invention, in steps S140 to S150, the local PSS sequence mentioned is a signal sequence after time domain sequence symbol extension. In the embodiment of the present invention, in step S150, starting from the first signal of the acquisition window, a third signal sequence is read in the first signal sequence, and a correlation operation is performed on the third signal sequence and the local PSS sequence to determine the third positioning position of the PSS sequence in the downlink signal in the first signal sequence, including:

[0133] Starting from the first signal of the acquisition window, a correlation operation is performed on the local PSS sequence and the third signal sequence obtained in each calculation cycle by using a parallel processing method or a serial processing method to obtain a correlation energy value of the third signal sequence corresponding to the local PSS sequence; wherein the obtained third signal sequence slides on the first signal sequence toward the tail signal of the first signal sequence according to the calculation cycle; and the number of bits of the third signal sequence is the same as the number of bits of the local PSS sequence;

[0134] The signal position corresponding to the maximum correlation energy value among the multiple correlation energy values ​​is determined as the third positioning position.

[0135] In one implementation manner, optionally, a serial processing method is used to perform a correlation operation on the local PSS sequence and a third signal sequence obtained in each calculation cycle to obtain a correlation energy value of the third signal sequence corresponding to the local PSS sequence, including:

[0136] Starting from the first signal of the acquisition window, one signal of the first signal sequence is read in each calculation cycle, and N signals are read continuously to obtain a third signal sequence; wherein, the first signal of the next third signal sequence is shifted by one signal after the first signal of the previous third signal sequence, and N signals are read continuously to obtain the next third signal sequence; wherein, the number of bits of the local PSS sequence is N bits; and N is an integer greater than or equal to 1;

[0137] Conjugate and multiply one of the signals of the local PSS sequence with a signal of a corresponding bit of the third signal sequence to obtain a corresponding calculated value;

[0138] A sum is calculated for a plurality of calculated values ​​obtained by correspondingly conjugating and multiplying each signal of the local PSS sequence with the signal of the corresponding bit of the third signal sequence, so as to obtain a correlation energy value of the third signal sequence corresponding to the local PSS sequence.

[0139] In an embodiment of the present invention, the window length S of the acquisition window can be preset, that is, the number of signal bits in the acquisition window is S. In one implementation mode, optionally, according to the second positioning position of the signal corresponding to the first positioning position in the first signal sequence and the window length S of the acquisition window, the signal is selected to the left with the second positioning position as the center, the first signal of the acquisition window is determined, and starting from the first signal of the acquisition window, the signal is read in sequence in the first signal sequence, and the read signal is also the third signal sequence, which is correlated with the local PSS sequence.

[0140] In one implementation mode, when performing serial processing, one data is read in one calculation cycle, and optionally, one calculation cycle can be one clock cycle. Specifically, the local PSS sequence is represented as W(N), where N represents the number of time domain points of the local PSS sequence. In the embodiment of the present invention, optionally, N is 4096 points. Figure 3 As shown, starting from the first signal of the acquisition window (the first signal), one signal is read in one clock cycle in the first signal sequence until N signals are read out continuously to form the first third signal sequence Y; then, starting from the second signal of the acquisition window, one signal is read in one clock cycle in the first signal sequence until N signals are read out continuously to form the second third signal sequence Y; this principle is recursively applied until, starting from the Sth signal of the acquisition window, N signals are read out continuously in the first signal sequence to form the Sth third signal sequence.

[0141] A correlation operation is performed on each determined third signal sequence and the local PSS sequence to obtain a correlation energy value of the third signal sequence corresponding to the local PSS sequence.

[0142] With this implementation, N*S clock cycles are required to perform a correlation operation on the read third signal sequence and the local PSS sequence to determine the third positioning position of the PSS sequence in the downlink signal in the first signal sequence.

[0143] Specifically, one of the signals of the local PSS sequence W(N) is conjugate multiplied with the signal of the corresponding bit of the third signal sequence Y to obtain a corresponding calculated value. Based on this principle, multiple calculated values ​​obtained by correspondingly conjugate multiplying each signal of the local PSS sequence with the signal of the corresponding bit of the third signal sequence are summed to obtain the relevant energy value of the third signal sequence corresponding to the local PSS sequence.

[0144] For example, combining Figure 3 As shown, starting from the first signal (first signal) of the acquisition window, between clock cycles t1 and tN, a signal is read in each clock cycle of the first signal sequence Y, until N signals are read out continuously, forming the first third signal sequence Y(1) to Y(N). At the same time, in clock cycle t1, the first signal W(1) of the local PSS sequence W(N) is conjugated and multiplied with the first signal Y(1) of the third signal sequence Y to obtain a corresponding calculated value; at time t2, the second signal W(2) of the local PSS sequence W(N) is conjugated and multiplied with the second signal Y(2) of the third signal sequence Y(S) to obtain a corresponding calculated value, and in turn, in each clock cycle, a calculated value of a signal of the local PSS sequence W(N) corresponding to a signal of the third signal sequence Y(S) is obtained, and each calculated value obtained is summed to obtain a correlation energy value of the third signal sequence Y(S) corresponding to the local PSS sequence W(N).

[0145] According to this rule, the correlation energy value of the next third signal sequence Y corresponding to the local PSS sequence W(N) is calculated, and by comparing the correlation energy values ​​of each third signal sequence Y corresponding to the local PSS sequence W(N), the position of the third signal sequence corresponding to the maximum value among the multiple correlation energy values ​​is determined as the third positioning position.

[0146] Optionally, in the embodiment of the present invention, S is 4096. By using this calculation method, the hardware resources required to be consumed can be greatly reduced.

[0147] In the embodiment of the present invention, another implementation manner, optionally, adopts a parallel processing method to perform a correlation operation on the local PSS sequence and a third signal sequence obtained in each calculation cycle to obtain a correlation energy value of the third signal sequence corresponding to the local PSS sequence, including:

[0148] Starting from the first signal of the acquisition window, S signals of the first signal sequence are read in each calculation cycle to obtain a fourth signal sequence; wherein the first signal of the next fourth signal sequence is shifted by one signal after the first signal of the previous fourth signal sequence, and S signals are read continuously to obtain the next fourth signal sequence; wherein the number of bits of the acquisition window is S bits; S is an integer greater than or equal to 1;

[0149] According to the arrangement order of multiple signals in the local PSS sequence, one signal of the local PSS sequence corresponds to one of the multiple fourth signal sequences read in sequence, and within a calculation cycle of reading the fourth signal sequence, each signal in the read fourth signal sequence is conjugate-multiplied with the corresponding signal in the local PSS sequence to obtain a corresponding calculation value;

[0150] Starting from the first signal of the acquisition window, multiple third signal sequences are acquired in sequence, each of the third signal sequences includes N consecutive signals, and the first signal of the next third signal sequence is shifted by one signal after the first signal of the previous third signal sequence, and according to the arrangement order of multiple signals in the third signal sequence and the arrangement order of multiple signals in the local PSS sequence, one signal of the local PSS sequence corresponds to one signal of the third signal sequence, and the calculated values ​​of conjugate multiplication of each signal of the third signal sequence with the corresponding signal of the local PSS sequence are summed to obtain a correlation energy value of the third signal sequence corresponding to the local PSS sequence.

[0151] Optionally, one calculation cycle may be one clock cycle.

[0152] Assume that the local PSS sequence is represented as W(N) for example, in the parallel processing mode, Figure 4As shown, corresponding to multiple signals in the first signal sequence, starting from the first signal Y(1) of the acquisition window, S signals of the first signal sequence are read in each calculation cycle to obtain a fourth signal sequence; for example, the first fourth signal sequence obtained in the first calculation cycle t1 includes signals Y(1), Y(2), ..., Y(S), and the second fourth signal sequence obtained in the second calculation cycle t2 includes signals Y(2), Y(3), ..., Y(S+1). According to this rule, the first signal of the next fourth signal sequence moves one signal after the first signal of the previous fourth signal sequence, and S signals are read continuously to obtain the next fourth signal sequence, until the Nth fourth signal sequence is obtained in the Nth calculation cycle.

[0153] According to the arrangement order of multiple signals in the local PSS sequence W(N) and the arrangement order of multiple fourth signal sequences obtained, one signal in the local PSS sequence W(N) corresponds to a fourth signal sequence, for example, W(1) corresponds to the first fourth signal sequence, W(2) corresponds to the second fourth signal sequence,..., W(N) corresponds to the Nth fourth signal sequence, and each signal in the fourth signal sequence is conjugate multiplied with the corresponding signal in the local PSS sequence to obtain the corresponding calculated value. For example, each of the signals Y(1), Y(2), ..., Y(S) in the first fourth signal sequence is conjugate multiplied with the corresponding signal in the local PSS sequence (the first signal W(1)) to obtain S calculated values; similarly, each of the signals Y(2), Y(3), ..., Y(S+1) in the second fourth signal sequence is conjugate multiplied with the corresponding signal in the local PSS sequence (the second signal W(2)) to obtain S calculated values. Based on this principle, multiple calculated values ​​can be obtained by conjugate multiplying each fourth signal sequence with the corresponding signal in the local PSS sequence.

[0154] On this basis, starting from the first signal of the acquisition window, the signals in the first signal sequence are re-sequenced to obtain multiple third signal sequences in sequence, each third signal sequence includes N consecutive signals, and the first signal of the next third signal sequence is shifted by one signal after the first signal of the previous third signal sequence, to obtain multiple third signal sequences, wherein the division rule of the third signal sequence is the same as the division rule of the third signal sequence in the serial processing method, that is, starting from the first signal of the acquisition window, the first third signal sequence formed includes signals Y(1) to Y(N), and the second third signal sequence includes signals Y(2) to Y(N+1), and according to this rule, multiple third signal sequences are formed.

[0155] According to the arrangement order of the multiple signals in the third signal sequence and the arrangement order of the multiple signals in the local PSS sequence, a signal in each third signal sequence corresponds to a signal in the local PSS sequence. In this way, the calculated values ​​of conjugate multiplication of each signal in the third signal sequence and the corresponding signal of the local PSS sequence are summed to obtain a correlation energy value of the third signal sequence corresponding to the local PSS sequence.

[0156] Using the above method, the multiple calculation values ​​obtained from the first calculation period t1 to the Nth calculation period tN can be used to obtain the correlation energy value of each third signal sequence corresponding to the local PSS sequence, and the multiple correlation energy values ​​obtained are compared to determine the position of the third signal sequence corresponding to the maximum value among the multiple correlation energy values ​​as the third positioning position.

[0157] According to the above principle, a parallel processing method is adopted to obtain the relevant energy value of each signal in the third signal sequence corresponding to the local PSS sequence, which requires N clock cycles. Compared with the serial processing method, the calculation time is shorter and the synchronous positioning effect can be achieved quickly.

[0158] According to the above, in the embodiment of the present invention, combined Figure 5 As shown, the complete process of downlink synchronization detection includes the following steps:

[0159] S501, based on a first preset frequency offset, performing frequency offset correction on a received downlink signal to obtain a corrected first signal sequence;

[0160] S502, cache the first signal sequence; while executing step S502, step S503 may be executed;

[0161] S503, perform a coarse synchronization detection process, that is, combine Figure 1 , executing steps S120 to S130 to determine a first positioning position of a PSS sequence in the downlink signal in the second signal sequence;

[0162] S504, determining a second positioning position of a PSS sequence in the downlink signal in the second signal sequence;

[0163] S505, reading the first signal sequence cached in step S502, taking the second positioning position as the center of the acquisition window, and determining a third signal sequence within the acquisition window in the first signal sequence;

[0164] While executing step S504 and step S505, step S506 may also be executed:

[0165] S506, obtaining a local primary synchronization signal PSS sequence in a coarse synchronization detection process;

[0166] S507, extending and zero-padding the local primary synchronization signal PSS sequence and performing IFFT operation to obtain a local primary synchronization signal PSS sequence for a fine synchronization detection process;

[0167] S508, updating the third signal sequence within the acquisition window;

[0168] S509, calculating the correlation energy value by using a parallel processing method or a serial processing method according to the third signal sequence of step S508 and the local primary synchronization signal PSS sequence obtained in step S507;

[0169] S510, obtaining correlation energy values ​​of a plurality of third signal sequences corresponding to a local PSS sequence; when the number of bits of the acquisition window is S, obtaining S correlation energy values;

[0170] S511, determining the maximum value among the S related energy values;

[0171] S512: Determine the position of the third signal sequence corresponding to the maximum value among the S correlation energy values ​​as the third positioning position.

[0172] By adopting the downlink synchronization detection method described in the embodiment of the present invention, it is not necessary for all points in the sequence of the downlink signal to participate in the calculation at the same time, thereby achieving the purpose of reducing hardware resource consumption and avoiding problems that are difficult to implement on device hardware.

[0173] One embodiment of the present invention further provides a downlink synchronization detection device, such as Figure 6 As shown, including:

[0174] The correction module 610 is used to perform frequency offset correction on the received downlink signal based on the first preset frequency offset to obtain a corrected first signal sequence;

[0175] The data processing module 620 is used to perform downsampling data extraction on the first signal sequence to obtain a second signal sequence;

[0176] A first operation module 630 is used to perform a correlation operation on a local primary synchronization signal PSS sequence and the second signal sequence to determine a first positioning position of the PSS sequence in the downlink signal in the second signal sequence;

[0177] A position determination module 640, configured to determine a second positioning position of the signal corresponding to the first positioning position in the first signal sequence;

[0178] The second operation module 650 is used to take the second positioning position as the center of the acquisition window for performing signal acquisition in the first signal sequence, start from the first signal of the acquisition window, read the third signal sequence in the first signal sequence, perform a correlation operation on the read third signal sequence and the local PSS sequence, and determine the third positioning position of the PSS sequence in the downlink signal in the first signal sequence.

[0179] By using the device described in the embodiment of the present invention, after the frequency deviation of the received downlink signal is corrected by presetting the frequency deviation, the second signal sequence is obtained by downsampling the corrected first signal sequence, and the local main synchronization signal PSS sequence is used to perform correlation operation with the second signal sequence to determine the first positioning position of the PSS in the downlink signal in the second signal sequence, so as to achieve coarse synchronization positioning with less sampling data; then, according to the second positioning position of the signal corresponding to the first positioning position in the first signal sequence, the third signal sequence obtained according to the acquisition window is correlated with the local PSS sequence with the second positioning position as the center of the acquisition window of signal acquisition, so as to achieve precise synchronization positioning of the PSS sequence in the downlink signal. By using this downlink synchronization detection process, it is not necessary for all points of the sequence in the downlink signal to participate in the calculation at the same time, so as to achieve the purpose of reducing hardware resource consumption and avoid problems that are difficult to achieve in device hardware.

[0180] Optionally, in the downlink synchronization detection device, the first operation module 630 performs a correlation operation on a local primary synchronization signal PSS sequence and the second signal sequence to determine a first positioning position of the PSS sequence in the downlink signal in the second signal sequence, including:

[0181] Perform sliding correlation on a local primary synchronization signal PSS sequence and the second signal sequence to obtain a correlation energy value of each signal in the second signal sequence corresponding to the local PSS sequence;

[0182] Calculating average energy values ​​of multiple signals in the second signal sequence;

[0183] When the ratio of the correlation energy value to the average energy value is greater than or equal to a first preset threshold, the first positioning position is determined according to the position of the signal corresponding to the correlation energy value in the second signal sequence.

[0184] Optionally, in the downlink synchronization detection device, the first operation module 630 performs sliding correlation on a local primary synchronization signal PSS sequence and the second signal sequence, including:

[0185] Perform conjugate multiplication of a signal in the second signal sequence with each signal in the local primary synchronization signal PSS sequence to obtain multiple calculated values;

[0186] The multiple calculated values ​​are summed up to obtain the relevant energy value of the signal corresponding to the local PSS sequence.

[0187] Optionally, in the downlink synchronization detection device, the first operation module 630 performs sliding correlation on a local primary synchronization signal PSS sequence and the second signal sequence to obtain a correlation energy value of each signal in the second signal sequence corresponding to the local PSS sequence, including:

[0188] Sequentially in each clock cycle, respectively obtaining a correlation energy value of a signal in the second signal sequence corresponding to the local PSS sequence;

[0189] The first operation module 630 is further used for:

[0190] After each clock cycle, comparing the ratio of the obtained correlation energy value to the average energy value with the first preset threshold;

[0191] If within the first preset search time, the ratio of each of the obtained correlation energy values ​​to the average energy value is less than the first preset threshold, the local PSS sequence is updated, and based on the updated local PSS sequence, the step of performing correlation operation on the local main synchronization signal PSS sequence and the second signal sequence is returned to be re-executed until the ratio of one of the obtained correlation energy values ​​to the average energy value is greater than or equal to the first preset threshold.

[0192] Optionally, in the downlink synchronization detection device, the first operation module 630 is further configured to:

[0193] After updating the local PSS sequence and returning to re-execute the step of performing correlation operation on the local main synchronization signal PSS sequence and the second signal sequence, if after multiple updates of the local PSS sequence, corresponding to each local PSS sequence, the comparison between each obtained correlation energy value and the average energy value is less than the first preset threshold, then the first preset frequency deviation is replaced with the second preset frequency deviation, and returning to re-execute the step of performing frequency deviation correction on the received downlink signal to obtain the corrected first signal sequence, until the ratio of one of the obtained correlation energy values ​​to the average energy value is greater than or equal to the first preset threshold.

[0194] Optionally, in the downlink synchronization detection device, the second operation module 650 starts from the first signal of the acquisition window, reads a third signal sequence in the first signal sequence, performs a correlation operation on the third signal sequence and the local PSS sequence, and determines a third positioning position of the PSS sequence in the downlink signal in the first signal sequence, including:

[0195] Starting from the first signal of the acquisition window, a correlation operation is performed on the local PSS sequence and the third signal sequence obtained in each calculation cycle by using a parallel processing method or a serial processing method to obtain a correlation energy value of the third signal sequence corresponding to the local PSS sequence; wherein the obtained third signal sequence slides on the first signal sequence toward the tail signal of the acquisition window according to the calculation cycle; and the number of bits of the third signal sequence is the same as the number of bits of the local PSS sequence;

[0196] The signal position corresponding to the maximum correlation energy value among the multiple correlation energy values ​​is determined as the third positioning position.

[0197] Optionally, in the downlink synchronization detection device, the second operation module 650 adopts a serial processing method to perform a correlation operation on the local PSS sequence and a third signal sequence obtained in each calculation cycle to obtain a correlation energy value of the third signal sequence corresponding to the local PSS sequence, including:

[0198] Starting from the first signal of the acquisition window, one signal of the first signal sequence is read in each calculation cycle, and N signals are read continuously to obtain a third signal sequence; wherein, the first signal of the next third signal sequence is shifted by one signal after the first signal of the previous third signal sequence, and N signals are read continuously to obtain the next third signal sequence; wherein, the number of bits of the local PSS sequence is N bits; and N is an integer greater than or equal to 1;

[0199] Conjugate and multiply one of the signals of the local PSS sequence with a signal of a corresponding bit of the third signal sequence to obtain a corresponding calculated value;

[0200] A sum is calculated for a plurality of calculated values ​​obtained by correspondingly conjugating and multiplying each signal of the local PSS sequence with the signal of the corresponding bit of the third signal sequence, so as to obtain a correlation energy value of the third signal sequence corresponding to the local PSS sequence.

[0201] Optionally, in the downlink synchronization detection device, the second operation module 650 adopts a parallel processing method to perform a correlation operation on the local PSS sequence and a third signal sequence obtained in each calculation cycle to obtain a correlation energy value of the third signal sequence corresponding to the local PSS sequence, including:

[0202] Starting from the first signal of the acquisition window, S signals of the first signal sequence are read in each calculation cycle to obtain a fourth signal sequence; wherein the first signal of the next fourth signal sequence is shifted by one signal after the first signal of the previous fourth signal sequence, and S signals are read continuously to obtain the next fourth signal sequence; wherein the number of bits of the acquisition window is S bits; S is an integer greater than or equal to 1;

[0203] According to the arrangement order of multiple signals in the local PSS sequence, one signal of the local PSS sequence corresponds to one of the multiple fourth signal sequences read in sequence, and within a calculation cycle of reading the fourth signal sequence, each signal in the read fourth signal sequence is conjugate-multiplied with the corresponding signal in the local PSS sequence to obtain a corresponding calculation value;

[0204] Starting from the first signal of the acquisition window, multiple third signal sequences are acquired in sequence, each of the third signal sequences includes N consecutive signals, and the first signal of the next third signal sequence is shifted by one signal after the first signal of the previous third signal sequence, and according to the arrangement order of multiple signals in the third signal sequence and the arrangement order of multiple signals in the local PSS sequence, one signal of the local PSS sequence corresponds to one signal of the third signal sequence, and the calculated values ​​of conjugate multiplication of each signal of the third signal sequence with the corresponding signal of the local PSS sequence are summed to obtain a correlation energy value of the third signal sequence corresponding to the local PSS sequence.

[0205] Optionally, in the downlink synchronization detection device, before downsampling the first signal sequence to extract data to obtain the second signal sequence, the second operation module 650 is further used to:

[0206] Perform sequence expansion on the local PSS sequence, and perform an inverse fast Fourier transform IFFT operation on the local PSS sequence after the expansion sequence, so that the number of time domain points of the local PSS sequence after the operation is the same as the number of time domain points of the received downlink signal;

[0207] According to the number of sampling data points required to be extracted when downsampling data is extracted for the first signal sequence, interpolation processing is performed on the local PSS sequence after the calculation, so that the number of points of the local PSS sequence after the interpolation processing is equal to the number of sampling data points.

[0208] Optionally, in the downlink synchronization detection device, before performing a correlation operation on the local PSS sequence and the third signal sequence in the acquisition window, the second operation module 650 is further used to:

[0209] The local PSS sequence is sequence extended, and an IFFT operation is performed on the local PSS sequence after the extended sequence, so that the number of points of the local PSS sequence after the operation in the time domain is the same as the number of points of the OFDM symbol corresponding to the first signal sequence.

[0210] One embodiment of the present application further provides a terminal, which includes a processor, a memory, and a program stored in the memory and executable on the processor, wherein the program, when executed by the processor, implements the downlink synchronization detection method as described in any one of the above items.

[0211] The specific implementation of the downlink synchronization detection method executed by the program running on the processor of the terminal can refer to the detailed description of the downlink synchronization detection method when it is applied to the terminal, and will not be repeated here.

[0212] In addition, a specific embodiment of the present application further provides a readable storage medium on which a computer program is stored, wherein when the program is executed by a processor, the steps in the downlink synchronization detection method as described in any one of the above items are implemented.

[0213] Specifically, the readable storage medium is applied to the above-mentioned terminal. When applied to the terminal, the execution steps in the corresponding downlink synchronization detection method are described in detail above and will not be repeated here.

[0214] Another embodiment of the present invention further provides a computer program product, which includes computer instructions, and when the computer instructions are executed by a processor, the steps in any of the downlink synchronization detection methods described above are implemented.

[0215] Optionally, the embodiments of the present application may take 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.) containing computer-usable program codes.

[0216] The computer program product described in the embodiment of the present invention includes computer instructions that implement the various processes of the method embodiment shown above when executed by a processor, and can achieve the same technical effect. To avoid repetition, they are not described here.

[0217] In the several embodiments provided in the present application, it should be understood that the disclosed methods and devices can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0218] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may be physically included separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of hardware plus software functional units.

[0219] The above-mentioned integrated unit implemented in the form of a software functional unit can be stored in a computer-readable storage medium. The above-mentioned software functional unit is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform some steps of the sending and receiving methods described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory, referred to as ROM), random access memory (Random Access Memory, referred to as RAM), disk or optical disk and other media that can store program codes.

[0220] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary personnel in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A downlink synchronization detection method, characterized in that: include: Based on the first preset frequency offset, the received downlink signal is corrected for frequency offset to obtain a corrected first signal sequence; Performing downsampling data extraction on the first signal sequence to obtain a second signal sequence; Performing a correlation operation on a local primary synchronization signal PSS sequence and the second signal sequence to determine a first positioning position of the PSS sequence in the downlink signal in the second signal sequence; Determine a second positioning position of the signal corresponding to the first positioning position in the first signal sequence; Taking the second positioning position as the center of the acquisition window for signal acquisition in the first signal sequence, starting from the first signal of the acquisition window, the third signal sequence is read in the first signal sequence, and the read third signal sequence is correlated with the local PSS sequence to determine the third positioning position of the PSS sequence in the downlink signal in the first signal sequence.

2. The downlink synchronization detection method according to claim 1, characterized in that: The performing a correlation operation on the local primary synchronization signal PSS sequence and the second signal sequence to determine a first positioning position of the PSS sequence in the downlink signal in the second signal sequence includes: Perform sliding correlation on a local primary synchronization signal PSS sequence and the second signal sequence to obtain a correlation energy value of each signal in the second signal sequence corresponding to the local PSS sequence; Calculating average energy values ​​of multiple signals in the second signal sequence; When the ratio of the correlation energy value to the average energy value is greater than or equal to a first preset threshold, the first positioning position is determined according to the position of the signal corresponding to the correlation energy value in the second signal sequence.

3. The downlink synchronization detection method according to claim 2, characterized in that: The sliding correlation of the local primary synchronization signal PSS sequence with the second signal sequence includes: Perform conjugate multiplication of a signal in the second signal sequence with each signal in the local primary synchronization signal PSS sequence to obtain multiple calculated values; The multiple calculated values ​​are summed up to obtain the relevant energy value of the signal corresponding to the local PSS sequence.

4. The downlink synchronization detection method according to claim 2, characterized in that: The method of slidingly correlating a local primary synchronization signal PSS sequence with the second signal sequence to obtain a correlation energy value of each signal in the second signal sequence corresponding to the local PSS sequence includes: Sequentially in each clock cycle, respectively obtaining a correlation energy value of a signal in the second signal sequence corresponding to the local PSS sequence; Wherein, the method further comprises: After each clock cycle, comparing the ratio of the obtained correlation energy value to the average energy value with the first preset threshold; If within the first preset search time, the ratio of each of the obtained correlation energy values ​​to the average energy value is less than the first preset threshold, the local PSS sequence is updated, and based on the updated local PSS sequence, the step of performing correlation operation on the local main synchronization signal PSS sequence and the second signal sequence is returned to be re-executed until the ratio of one of the obtained correlation energy values ​​to the average energy value is greater than or equal to the first preset threshold.

5. The downlink synchronization detection method according to claim 4, characterized in that: The method further comprises: After updating the local PSS sequence and returning to re-execute the step of performing correlation operation on the local main synchronization signal PSS sequence and the second signal sequence, if after multiple updates of the local PSS sequence, corresponding to each local PSS sequence, the comparison between each obtained correlation energy value and the average energy value is less than the first preset threshold, then the first preset frequency deviation is replaced with the second preset frequency deviation, and returning to re-execute the step of performing frequency deviation correction on the received downlink signal to obtain the corrected first signal sequence, until the ratio of one of the obtained correlation energy values ​​to the average energy value is greater than or equal to the first preset threshold.

6. The downlink synchronization detection method according to claim 1, characterized in that: Starting from the first signal of the acquisition window, reading a third signal sequence in the first signal sequence, performing a correlation operation on the third signal sequence and the local PSS sequence, and determining a third positioning position of the PSS sequence in the downlink signal in the first signal sequence, including: Starting from the first signal of the acquisition window, a correlation operation is performed on the local PSS sequence and the third signal sequence obtained in each calculation cycle by using a parallel processing method or a serial processing method to obtain a correlation energy value of the third signal sequence corresponding to the local PSS sequence; wherein the obtained third signal sequence slides on the first signal sequence toward the tail signal of the acquisition window according to the calculation cycle; and the number of bits of the third signal sequence is the same as the number of bits of the local PSS sequence; The signal position corresponding to the maximum correlation energy value among the multiple correlation energy values ​​is determined as the third positioning position.

7. The downlink synchronization detection method according to claim 6, characterized in that: In a serial processing manner, a correlation operation is performed on the local PSS sequence and a third signal sequence obtained in each calculation cycle to obtain a correlation energy value of the third signal sequence corresponding to the local PSS sequence, including: Starting from the first signal of the acquisition window, one signal of the first signal sequence is read in each calculation cycle, and N signals are read continuously to obtain a third signal sequence; wherein, the first signal of the next third signal sequence is shifted by one signal after the first signal of the previous third signal sequence, and N signals are read continuously to obtain the next third signal sequence; wherein, the number of bits of the local PSS sequence is N bits; and N is an integer greater than or equal to 1; Conjugate and multiply one of the signals of the local PSS sequence with a signal of a corresponding bit of the third signal sequence to obtain a corresponding calculated value; A sum is calculated for a plurality of calculated values ​​obtained by correspondingly conjugating and multiplying each signal of the local PSS sequence with the signal of the corresponding bit of the third signal sequence, so as to obtain a correlation energy value of the third signal sequence corresponding to the local PSS sequence.

8. The downlink synchronization detection method according to claim 6, characterized in that: In a parallel processing manner, a correlation operation is performed on the local PSS sequence and a third signal sequence obtained in each calculation cycle to obtain a correlation energy value of the third signal sequence corresponding to the local PSS sequence, including: Starting from the first signal of the acquisition window, S signals of the first signal sequence are read in each calculation cycle to obtain a fourth signal sequence; wherein the first signal of the next fourth signal sequence is shifted by one signal after the first signal of the previous fourth signal sequence, and S signals are read continuously to obtain the next fourth signal sequence; wherein the number of bits of the acquisition window is S bits; S is an integer greater than or equal to 1; According to the arrangement order of multiple signals in the local PSS sequence, one signal of the local PSS sequence corresponds to one of the multiple fourth signal sequences read in sequence, and within a calculation cycle of reading the fourth signal sequence, each signal in the read fourth signal sequence is conjugate-multiplied with the corresponding signal in the local PSS sequence to obtain a corresponding calculation value; Starting from the first signal of the acquisition window, multiple third signal sequences are acquired in sequence, each of the third signal sequences includes N consecutive signals, and the first signal of the next third signal sequence is shifted by one signal after the first signal of the previous third signal sequence, and according to the arrangement order of multiple signals in the third signal sequence and the arrangement order of multiple signals in the local PSS sequence, one signal of the local PSS sequence corresponds to one signal of the third signal sequence, and the calculated values ​​of conjugate multiplication of each signal of the third signal sequence with the corresponding signal of the local PSS sequence are summed to obtain a correlation energy value of the third signal sequence corresponding to the local PSS sequence.

9. The downlink synchronization detection method according to claim 1, characterized in that: Before performing downsampling data extraction on the first signal sequence to obtain a second signal sequence, the method further includes: Performing sequence expansion on the local PSS sequence, and performing an inverse fast Fourier transform IFFT operation on the local PSS sequence after the expansion sequence, so that the number of time domain points of the local PSS sequence after the operation is the same as the number of time domain points of the received downlink signal; According to the number of sampling data points required to be extracted when downsampling data is extracted for the first signal sequence, interpolation processing is performed on the local PSS sequence after the calculation, so that the number of points of the local PSS sequence after the interpolation processing is equal to the number of sampling data points.

10. The downlink synchronization detection method according to claim 1, characterized in that: Before performing a correlation operation on the local PSS sequence and the third signal sequence within the acquisition window, the method further includes: The local PSS sequence is sequence extended, and an IFFT operation is performed on the local PSS sequence after the extended sequence, so that the number of points of the local PSS sequence after the operation in the time domain is the same as the number of points of the OFDM symbol corresponding to the first signal sequence.

11. A downlink synchronization detection device, characterized in that: include: A correction module, configured to perform frequency deviation correction on a received downlink signal based on a first preset frequency deviation to obtain a corrected first signal sequence; A data processing module, used for performing downsampling data extraction on the first signal sequence to obtain a second signal sequence; A first operation module, configured to perform a correlation operation on a local primary synchronization signal PSS sequence and the second signal sequence to determine a first positioning position of the PSS sequence in the downlink signal in the second signal sequence; a position determination module, configured to determine a second positioning position of the signal corresponding to the first positioning position in the first signal sequence; The second operation module is used to take the second positioning position as the center of the acquisition window for performing signal acquisition in the first signal sequence, start from the first signal of the acquisition window, read the third signal sequence in the first signal sequence, perform a correlation operation on the read third signal sequence and the local PSS sequence, and determine the third positioning position of the PSS sequence in the downlink signal in the first signal sequence.

12. A terminal, characterized in that: include: A processor, a memory, and a program stored in the memory and executable on the processor, wherein the program, when executed by the processor, implements the downlink synchronization detection method according to any one of claims 1 to 10.

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