CN111294084B

CN111294084B - PSS detection method and device, storage medium and terminal

Info

Publication number: CN111294084B
Application number: CN201910116625.7A
Authority: CN
Inventors: 薛丰廷
Original assignee: Spreadtrum Communications Shanghai Co Ltd
Current assignee: Spreadtrum Communications Shanghai Co Ltd
Priority date: 2019-02-13
Filing date: 2019-02-13
Publication date: 2022-04-26
Anticipated expiration: 2039-02-13
Also published as: CN111294084A

Abstract

A PSS detection method and device, a storage medium and a terminal are provided, and the method comprises the following steps: acquiring air interface data, wherein the air interface data comprises a PSS sequence received in a preset cell search period; carrying out segmentation processing on the air interface data to obtain N segments of PSS sequences to be processed; respectively carrying out correlation processing on the N segments of PSS sequences to be processed and a preset number of local PSS sequences to obtain corresponding correlation results; for each local PSS sequence, splicing the respective corresponding correlation results of the N segments of PSS sequences to be processed to obtain the correlation results of the local PSS sequences and the air interface data; and determining the ID in the cell group according to the local PSS sequence corresponding to the correlation result with the maximum correlation peak in the correlation results of the preset number of local PSS sequences and the air interface data. The scheme provided by the invention can improve the data processing efficiency of the UE when the UE performs initial cell access, and simultaneously save the storage space of the UE.

Description

PSS detection method and device, storage medium and terminal

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a PSS detection method and apparatus, a storage medium, and a terminal.

Background

In a New Radio (NR, may also be referred to as a New air interface) scenario, initial synchronization is a first step of accessing a mobile terminal (also may be referred to as a User Equipment (UE)) of a Fifth-Generation mobile communications technology (5G, for short) to a 5G base station. According to the latest protocol of the third Generation Partnership Project (3rd Generation Partnership Project, 3GPP), a UE performing initial access needs to search and receive a Synchronization Signal Block (SS Block, i.e., SSB) to complete access to an initial cell.

In general, the period of the SSB is 20 milliseconds (ms), and the effective window length of the SSB is 5 ms. However, the initially accessed UE does not know the specific location of the SSB, so it needs to search for 20ms time domain data.

On the other hand, since the crystal oscillator of the UE and the base station may have a relatively large frequency offset, the large frequency offset needs to be corrected during initial access, which results in a large amount of data to be processed during initial access by the UE.

Based on the above two points, in a 5G communication scenario, the amount of data that needs to be processed when the UE performs initial access is relatively large. The simplest method at present is to receive all 20ms of data and then correlate it with a locally stored sequence. The correlation here needs to be done for each possible frequency offset in addition to the correlation for all sequences of cell Identities (IDs). This results in a slow data processing speed of the conventional 5G UE during initial access, which affects the cell search speed of the UE.

Disclosure of Invention

The technical problem solved by the invention is how to improve the data processing efficiency when the UE performs initial cell access.

In order to solve the above technical problem, an embodiment of the present invention provides a PSS detection method, including: acquiring air interface data, wherein the air interface data comprises a PSS sequence received in a preset cell search period; carrying out segmentation processing on the air interface data to obtain N segments of PSS sequences to be processed; respectively carrying out correlation processing on the N segments of PSS sequences to be processed and a preset number of local PSS sequences to obtain corresponding correlation results; for each local PSS sequence, splicing the respective corresponding correlation results of the N segments of PSS sequences to be processed to obtain the correlation results of the local PSS sequences and the air interface data; and determining the ID in the cell group according to the local PSS sequence corresponding to the correlation result with the maximum correlation peak in the correlation results of the preset number of local PSS sequences and the air interface data.

Optionally, the segmenting the air interface data to obtain N segments of PSS sequences to be processed includes: dividing the air interface data into N sections of data, wherein the length of each section of data is a first preset length; and for each segment of data, filling the length of the data to a second preset length to obtain the PSS sequence to be processed, wherein the second preset length is larger than the first preset length.

Optionally, the performing, by the N segments of PSS sequences to be processed, correlation processing on a preset number of local PSS sequences, respectively to obtain corresponding correlation results includes: and multiplexing the same FFT module to carry out correlation processing on the PSS sequence to be processed and the local PSS sequence section by section for each local PSS sequence so as to obtain the correlation result.

Optionally, the multiplexing the same FFT module to perform correlation processing on the PSS sequence to be processed and the local PSS sequence segment by segment, so as to obtain the correlation result includes: and when the FFT module outputs the correlation result between the previous segment of the PSS sequence to be processed in the N segments of the PSS sequences to be processed and the local PSS sequence, inputting the next segment of the PSS sequence to be processed in the N segments of the PSS sequences to be processed into the FFT module until the correlation result between the last segment of the PSS sequence to be processed in the N segments of the PSS sequences to be processed and the local PSS sequence is obtained.

Optionally, the number of the FFT modules is the same as the preset number of the local PSS sequences, and the FFT modules correspond to the local PSS sequences one to one.

Optionally, the N segments of PSS sequences to be processed are stored in a preset memory in an overlapping manner.

Optionally, the piecing together the correlation results corresponding to the N segments of PSS sequences to be processed to obtain the correlation result between the local PSS sequence and the air interface data includes: for each segment of PSS sequence to be processed, discarding the data with the first third preset length of the corresponding correlation result to obtain the corresponding processed correlation result; and splicing the processed correlation results corresponding to the N segments of PSS sequences to be processed respectively to obtain the correlation result of the local PSS sequence and the air interface data.

Optionally, the determining, by the local PSS sequences corresponding to the correlation result with the largest correlation peak in the correlation results of the preset number of local PSS sequences and the air interface data, the ID in the cell group includes: for each local PSS sequence, combining the correlation results of the air interface data received by each antenna and the local PSS sequence to obtain the average correlation result of the local PSS sequence and the air interface data received by each antenna; and determining the ID in the cell group according to the local PSS sequence corresponding to the average correlation result with the maximum correlation peak in the average correlation results.

Optionally, the performing, by the N segments of PSS sequences to be processed, correlation processing on a preset number of local PSS sequences, respectively to obtain corresponding correlation results includes: and for each local PSS sequence, performing correlation processing on the N sections of PSS sequences to be processed and at least one frequency offset shift result of the local PSS sequence to obtain a corresponding correlation result.

In order to solve the above technical problem, an embodiment of the present invention further provides a PSS detection apparatus, including: an obtaining module, configured to obtain air interface data, where the air interface data includes a PSS sequence received in a preset cell search period; the segmentation module is used for carrying out segmentation processing on the air interface data to obtain N segments of PSS sequences to be processed; the correlation processing module is used for performing correlation processing on the N segments of PSS sequences to be processed and a preset number of local PSS sequences respectively to obtain corresponding correlation results; a splicing module, which splices the respective corresponding correlation results of the N segments of PSS sequences to be processed for each local PSS sequence to obtain the correlation results of the local PSS sequence and the air interface data; and the determining module is used for determining the ID in the cell group according to the local PSS sequence corresponding to the correlation result with the maximum correlation peak in the correlation results of the preset number of local PSS sequences and the air interface data.

To solve the above technical problem, an embodiment of the present invention further provides a storage medium having stored thereon computer instructions, where the computer instructions execute the steps of the above method when executed.

In order to solve the above technical problem, an embodiment of the present invention further provides a terminal, including a memory and a processor, where the memory stores computer instructions capable of being executed on the processor, and the processor executes the computer instructions to perform the steps of the method.

Compared with the prior art, the technical scheme of the embodiment of the invention has the following beneficial effects:

the embodiment of the invention provides a PSS detection method, which comprises the following steps: acquiring air interface data, wherein the air interface data comprises a PSS sequence received in a preset cell search period; carrying out segmentation processing on the air interface data to obtain N segments of PSS sequences to be processed; respectively carrying out correlation processing on the N segments of PSS sequences to be processed and a preset number of local PSS sequences to obtain corresponding correlation results; for each local PSS sequence, splicing the respective corresponding correlation results of the N segments of PSS sequences to be processed to obtain the correlation results of the local PSS sequences and the air interface data; and determining the ID in the cell group according to the local PSS sequence corresponding to the correlation result with the maximum correlation peak in the correlation results of the preset number of local PSS sequences and the air interface data. By the scheme provided by the embodiment, the data processing efficiency of the UE during initial cell access can be effectively improved, and meanwhile, the storage space of the UE is saved. Specifically, the acquired air interface data is segmented, and the PSS detection is performed on the N segmented PSS sequences to be processed in an overlapped correlation and parallel pipelining manner, so that the data processing efficiency is improved, the purpose of rapidly searching the cell is achieved, and meanwhile, the storage space of the UE can be saved.

Further, the performing correlation processing on the N segments of PSS sequences to be processed and a preset number of local PSS sequences respectively to obtain corresponding correlation results includes: and multiplexing the same FFT module to carry out correlation processing on the PSS sequence to be processed and the local PSS sequence section by section for each local PSS sequence so as to obtain the correlation result. Therefore, by multiplexing the same FFT module, the structure complexity of the internal functional module of the UE can be reduced, and the related processing operation of parallel pipelining can be realized, so that the overall data processing efficiency is improved. In particular, since the FFT operation performed inside the FFT module and the IFFT operation of the corresponding branch are not overlapped in time, it is possible to multiplex the same FFT module.

Drawings

FIG. 1 is a flow chart of existing PSS detection;

FIG. 2 is a flow chart of a PSS detection method according to an embodiment of the present invention;

FIG. 3 is a flowchart of one embodiment of step S102 of FIG. 2;

FIG. 4 is a block diagram of the PSS detection method of FIG. 2 implemented on an FPGA;

FIG. 5 is a schematic diagram of the pipeline processing of the FFT module of FIG. 4;

fig. 6 is a schematic diagram of a correlation result between the local PSS sequence and the air interface data in the PSS detection process shown in fig. 2;

FIG. 7 is a flowchart of one embodiment of step S105 of FIG. 2;

FIG. 8 is a schematic structural diagram of a PSS detection apparatus according to an embodiment of the present invention.

Detailed Description

As mentioned in the background, there are many problems in the initial access process of the existing 5G UE, which results in a slow cell search speed of the existing UE.

Specifically, the SSB signals that the UE needs to search for and receive when making initial access include: a Primary Synchronization Signal (PSS), a Secondary Synchronization Signal (SSS), and a Broadcast channel signal (PBCH).

In a 5G communication scenario, the existing detection algorithm of a more general synchronization signal can be divided into two major steps: PSS detection and SSS detection. And more particularly to PSS blind detection (coarse frequency offset attempt), timing coarse synchronization, SSS blind detection, and timing fine synchronization.

Wherein, the relevant processing procedure for the PSS signal comprises the following steps: respectively associated with 3 local PSS sequences and a plurality of local PSS sequences with a frequency offset.

Whereas in a 5G communication scenario, the default cell search period for initial cell search is 20ms (corresponding to the period of an SSB set), the sampling rate of an Analog-to-Digital Converter (ADC) is typically 122.88 mega (M). In order to reduce the amount of data calculation, the prior art usually performs 16 times down-sampling on the sampled data. Even so, for 20ms data at 30 kilohertz (KHz) subcarrier spacing, there is a total of 153600 points of data that need to be correlated.

The existing PSS detection process determines the coarse timing by means of time-domain cross-correlation, and a coarse frequency offset attempt is required before determining the coarse timing. When the subcarrier spacing is 30khz, the trial range of coarse frequency offset is [ -30khz, +30khz ], and the spacing (step) is 7.5khz, in other words, a total of 9 frequency offset attempts (including the case without frequency offset) are required.

Referring to fig. 1, according to the existing protocol, the air interface data (153600 points in total) sampled within 20ms needs to be cross-correlated (referred to as correlation processing) with a local PSS sequence (referred to as local PSS), wherein three 4096-point frequency domain PSS sequences are cached locally by the UE in advance. Then, for different frequency offsets, the three local PSS sequences need to be shifted and then cross-correlated with the air interface data of 153600 points, and the results after cross-correlation are antenna-combined and 20 ms-combined. Therefore, the PSS detection result can be obtained, and the ID(s) in the cell group can be determined (

Value).

As can be seen from the above, according to the scheme in the prior art, the sampled 153600 point air interface data needs to be completely processed by 9 × 3 times of correlation processing, which is undoubtedly a great test for the data processing capability of the internal functional module of the UE, and while the structural complexity of the functional module is improved, the whole data processing time is prolonged, which affects the cell search speed of the UE.

In order to improve the cell search efficiency when 5G UE initially synchronizes, an embodiment of the present invention provides a PSS detection method, including: acquiring air interface data, wherein the air interface data comprises a PSS sequence received in a preset cell search period; carrying out segmentation processing on the air interface data to obtain N segments of PSS sequences to be processed; respectively carrying out correlation processing on the N segments of PSS sequences to be processed and a preset number of local PSS sequences to obtain corresponding correlation results; for each local PSS sequence, splicing the respective corresponding correlation results of the N segments of PSS sequences to be processed to obtain the correlation results of the local PSS sequences and the air interface data; and determining the ID in the cell group according to the local PSS sequence corresponding to the correlation result with the maximum correlation peak in the correlation results of the preset number of local PSS sequences and the air interface data.

By the scheme provided by the embodiment, the data processing efficiency of the UE during initial cell access can be effectively improved, and meanwhile, the storage space of the UE is saved. Specifically, the acquired air interface data is segmented, and the PSS detection is performed on the N segmented PSS sequences to be processed in an overlapped correlation and parallel pipelining manner, so that the data processing efficiency is improved, the purpose of rapidly searching the cell is achieved, and meanwhile, the storage space of the UE can be saved.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

FIG. 2 is a flow chart of a PSS detection method according to an embodiment of the present invention. The scheme of the embodiment can be applied to an initial synchronization scene of 5G UE, such as a cell search scene when the UE is powered on. Further, by adopting the scheme of this embodiment, the data calculation amount for performing correlation processing on the received air interface data and the local PSS sequence in the PSS detection flow shown in fig. 1 can be greatly reduced, and the storage space of the UE is saved.

Specifically, referring to fig. 1, the PSS detection method according to this embodiment may include the following steps:

step S101, obtaining air interface data, wherein the air interface data comprises a PSS sequence received in a preset cell search period;

step S102, carrying out segmentation processing on the air interface data to obtain N segments of PSS sequences to be processed;

step S103, the N segments of PSS sequences to be processed are respectively correlated with a preset number of local PSS sequences to obtain corresponding correlation results;

step S104, for each local PSS sequence, piecing up the respective corresponding correlation results of the N segments of PSS sequences to be processed to obtain the correlation results of the local PSS sequences and the air interface data;

and step S105, determining the ID in the cell group according to the local PSS sequences corresponding to the correlation result with the maximum correlation peak in the correlation results of the preset number of local PSS sequences and the air interface data.

More specifically, the air interface data includes data searched through an interface between the UE and the base station in the preset cell search period. Wherein the data may be a time domain PSS sequence. For the acquisition method of the air interface data, reference may be made to related procedures in the prior art, for example, after data reception and 16-fold down-sampling processing are performed on 30khz subcarrier intervals at a sampling rate of 122.88M within a preset cell search period of 20ms, a time domain PSS sequence of 153600 points may be obtained.

Further, the data over the air interface may include a PSS sequence received through multiple antennas, where for each antenna, the time-domain PSS sequence received through the antennas may have 153600 points.

Preferably, the preset cell search period may be 20ms to correspond to the period of the SSB specified by the existing protocol.

In the step S102, by performing segmentation processing on the empty data, the data processing efficiency can be improved by overlapping correlation when performing correlation processing subsequently. Because the length of the PSS sequence which needs to be correlated each time is greatly reduced, the data calculation amount during the correlation process each time is greatly reduced, on one hand, the reduction of the structural complexity of the internal functional module of the UE becomes possible, on the other hand, the storage space of the UE is also saved, because the UE can only store the segment of the PSS sequence to be processed which needs to be correlated currently each time.

Preferably, the value of N may range from 30 to 50. For example, the N may be 40.

In one embodiment, referring to fig. 3, the step S102 may include the steps of:

step S1021, the air interface data is divided into N sections of data, wherein the length of each section of data is a first preset length;

step S1022, for each segment of data, filling the length of the data to a second preset length to obtain the PSS sequence to be processed, where the second preset length is greater than the first preset length.

Taking N as an example of 40, in the step S1021, the time domain PSS sequence of 153600 points may be divided into 40 pieces of data with equal length, where each piece of data has a length of 153600/40-3840 points. That is, the first preset length is a data length of 3840 bits.

Further, in order to facilitate performing Fast Fourier Transform (FFT) during the subsequent correlation processing, in step S1022, each segment of data may be padded to a time-domain PSS sequence of 4096 points by zero padding. That is, the second preset length is a data length of 4096 bits.

In the scheme of this embodiment, the number of segments of a segment is determined comprehensively according to the number of sampling points and FFT. Specifically, considering a slot (slot) concept introduced by the NR system, when a subcarrier interval is 30KHz, a corresponding slot is 0.5 ms. Combining the sampling rate of NR as 122.88M, in order to reduce the amount of data computation and satisfy the performance requirement, 16 times of down-sampling processing is performed, so the data in the NR scene is 122.88 × 10^6/16 × 0.5 × 10^ (-3) ═ 3840 points. The FFT butterfly is typically 128/256/512 … to the power of 2, which is the fastest, so 4096 points are selected for operation in the embodiment described.

According to the specification of the existing protocol, the preset number may be 3, in other words, the UE may locally store three local PSS sequences, and the three local PSS sequences are in one-to-one correspondence with the three cell group IDs.

Further, for each local PSS sequence, the local PSS sequence may include a time-domain PSS sequence and a corresponding frequency-domain PSS sequence, wherein the length of the time-domain PSS sequence may be 127 bits and the length of the frequency-domain PSS sequence may be 4096 bits. Specifically, the frequency domain PSS sequence may be obtained by zero padding the tail of the conjugate reverse-order time domain PSS sequence to 4096 points and then performing FFT. In one embodiment, the step S103 may include the steps of: and multiplexing the same FFT module to carry out correlation processing on the PSS sequence to be processed and the local PSS sequence section by section for each local PSS sequence so as to obtain the correlation result. Therefore, by multiplexing the same FFT module, the structure complexity of the internal functional module of the UE can be reduced, and the related processing operation of parallel pipelining can be realized, so that the overall data processing efficiency is improved. In particular, since the FFT operation performed inside the FFT module and the IFFT operation of the corresponding branch are not overlapped in time, it is possible to multiplex the same FFT module.

Specifically, when the FFT module outputs a correlation result between a previous segment of the PSS sequence to be processed in the N segments of the PSS sequences to be processed and the local PSS sequence, a subsequent segment of the PSS sequence to be processed in the N segments of the PSS sequences to be processed is input to the FFT module until a correlation result between a last segment of the PSS sequence to be processed in the N segments of the PSS sequences to be processed and the local PSS sequence is obtained.

For example, referring to fig. 4 and 5, assuming that the null data rx0 is obtained through the antenna 1 (not shown), after the step S102 is performed, 40 segments of PSS sequences to be processed (denoted as seg0 to seg39) with 4096 points can be obtained.

Taking the example of processing the PSS sequence to be processed (denoted as seg0) of the first 4096 points therein, referring to fig. 4 and 5, the data of the segment may be first input to the FFT operation sub-module 411 to perform FFT operation on the PSS sequence to be processed seg0 of the first 4096 points, thereby converting it from time domain data to frequency domain data. Specifically, referring to fig. 5, a square FFT (seg0) indicates that the to-be-processed PSS sequence seg0 of the first 4096 points is input to the FFT computation sub-module 411 at this time, and a square FFT _ out (seg0) indicates that the FFT computation sub-module 411 outputs an FFT computation result for the to-be-processed PSS sequence seg0 of the first 4096 points at this time.

Further, the first segment of to-be-processed PSS sequence seg0 of 4096 points after FFT operation is streamed to the storage sub-module 412, and is transmitted to the relevant operation sub-module 413 through the storage sub-module 412.

Further, the correlation operation sub-module 413 performs correlation operation on the received first segment 4096-point to-be-processed PSS sequence seg0 subjected to FFT operation and three local PSS sequences which are all 4096 points and are locally pre-cached by the UE, so as to obtain correlation results between the first segment 4096-point to-be-processed PSS sequence seg0 and each local PSS sequence, and output the correlation results.

Further, the three correlation results output by the correlation operation sub-module 413 are respectively transferred to corresponding IFFT (Inverse Fast Fourier Transform) operation sub-modules 414 (respectively denoted as IFFT operation sub-modules 414-1, IFFT operation sub-modules 414-2, and IFFT operation sub-modules 414-3), where the IFFT operation sub-module 414-1 corresponds to a local PSS sequence with an intra-cell group ID of 0, the IFFT operation sub-module 414-2 corresponds to a local PSS sequence with an intra-cell group ID of 1, and the IFFT operation sub-module 414-3 corresponds to a local PSS sequence with an intra-cell group ID of 2.

Specifically referring to fig. 5, a checkered IFFT (seg0) corresponding to the IFFT operation sub-module 414-1 indicates that at this moment, the correlation result between the to-be-processed PSS sequence seg0 of the first 4096 points subjected to the FFT operation and the local PSS sequence with the intra-cell group ID of 0 is input to the IFFT operation sub-module 414-1; a square lattice IFFT (seg0) corresponding to the IFFT operation submodule 414-2 indicates that at this moment, the correlation result between the to-be-processed PSS sequence seg0 of the first section 4096 points subjected to FFT operation and the local PSS sequence with the ID in the cell group being 1 is input to the IFFT operation submodule 414-2; the square lattice IFFT (seg0) corresponding to the IFFT operation sub-module 414-3 indicates that at this moment, the correlation result between the to-be-processed PSS sequence seg0 of the first section 4096 points subjected to the FFT operation and the local PSS sequence with the intra-cell group ID of 2 is input to the IFFT operation sub-module 414-3.

Further, with continued reference to fig. 5, a square IFFT _ out (seg0) corresponding to the IFFT operation sub-module 414-1 indicates that at this moment, the IFFT operation sub-module 414-1 outputs an IFFT operation result on the correlation result between the to-be-processed PSS sequence seg0 of 4096 points subjected to the FFT operation and the local PSS sequence corresponding to the cell group ID 0; the square IFFT _ out (seg0) corresponding to the IFFT operation sub-module 414-2 indicates that at this moment, the IFFT operation sub-module 414-2 outputs an IFFT operation result of a correlation result between the to-be-processed PSS sequence seg0 of the first section 4096 points subjected to the FFT operation and the local PSS sequence corresponding to the cell group with the ID of 1; the square IFFT _ out (seg0) corresponding to the IFFT operation sub-module 414-3 indicates that at this moment, the IFFT operation sub-module 414-3 outputs an IFFT operation result on the correlation result between the to-be-processed PSS sequence seg0 of the first section 4096 points subjected to the FFT operation and the local PSS sequence corresponding to the cell group with the ID of 2.

The square FFT (seg1) indicates that at this moment a second segment of 4096 points of the to-be-processed PSS sequence seg1 may be input to the FFT operator submodule 411. Here, the squares FFT (seg1) and the squares IFFT (seg0) overlap in the time domain, and thus, the pipeline processing of FFT and IFFT can be realized.

Further, for each IFFT operation sub-module 414, IFFT operation is performed on the received correlation result to obtain a time domain correlation result as a correlation result between the to-be-processed PSS sequence seg0 of the first segment 4096 points and a corresponding local PSS sequence of 4096 points.

Since the PSS sequence to be processed is buffered in the storage sub-module 412 after being processed by FFT operation segment by segment and in a streaming manner, the amount of data to be buffered in the storage sub-module 412 is only 4096 points at a time, which is equivalent to storing 153600 points of the PSS sequence which originally needs to be stored once in a batch manner in an overlapping manner. When the next to-be-processed PSS sequence of 4096 points reaches the storage sub-module 412, since the previous to-be-processed PSS sequence of 4096 points has already completed the correlation processing and IFFT operation, the storage sub-module 412 may directly cover the originally stored to-be-processed PSS sequence of 4096 points with the newly received to-be-processed PSS sequence of 4096 points, so as to achieve the effect of saving the storage space.

It should be noted that, in fig. 4, the FFT operation sub-module 411 and the IFFT operation sub-module 414 are denoted as two independent functional modules according to functions, and in practical applications, the IFFT can be formed by using FFT, so as to conveniently multiplex the same FFT module in a Field Programmable Gate Array (FPGA for short) to save design resources. In fig. 5, a blank square indicates that the FFT module is in an idle state at the current time, where the idle state refers to the FFT operation sub-module 411 being in an idle state and also refers to the IFFT operation sub-module 414 being in an idle state. Therefore, since the IFFT sub-modules 414 are in one-to-one correspondence with the local PSS sequences, when the FFT operation and the IFFT operation are implemented by multiplexing the same FFT module, the number of the FFT modules may be the same as the preset number of the local PSS sequences, and the FFT modules are in one-to-one correspondence with the local PSS sequences.

In one embodiment, for performing the frequency offset attempt, the step S103 may include the steps of: and for each local PSS sequence, performing correlation processing on the N sections of PSS sequences to be processed and at least one frequency offset shift result of the local PSS sequence to obtain a corresponding correlation result.

Specifically, for each local PSS sequence, the local PSS sequence may be shifted 8 times within a range of ± 30KHz according to a preset interval (e.g., 7.5KHz) to perform a total of 9 frequency offset attempts including no frequency offset, where the shifted local PSS sequence needs to be correlated with the N segments of PSS sequences to be processed each time to obtain a corresponding correlation result.

Further, the N PSS sequences to be processed may be stored in a preset memory in an overlapping manner. For example, the preset memory may be the storage submodule 412 shown in fig. 4, and the storage submodule 412 may be a cache (cache) of the UE.

In one embodiment, the step S104 may include the steps of: for each segment of PSS sequence to be processed, discarding the data with the first third preset length of the corresponding correlation result to obtain the corresponding processed correlation result; and splicing the processed correlation results corresponding to the N segments of PSS sequences to be processed respectively to obtain the correlation result of the local PSS sequence and the air interface data.

Preferably, the third preset length may be equal to a difference between the second preset length and the first preset length, so that the data length of the correlation result between the local PSS sequence and the air interface data obtained through final splicing is consistent with the data length of the initially received air interface data, which is 153600 points.

For example, referring to fig. 6, taking the IFFT operation result (denoted as data 1 in fig. 6) of the correlation result between the FFT-operated first segment 4096 points to-be-processed PSS sequence seg0 output by the IFFT operation sub-module 414-1 shown in fig. 4 and 5 and the local PSS sequence with the intra-cell group ID of 0, the length of the data 1 is also 4096 points. Specifically, in the step S104, the first 256 bits of data 1 are discarded, and the remaining 3840 points of data are used as the correlation result #1 of the first segment 4096 points of the to-be-processed PSS sequence seg0 with the local PSS sequence corresponding to the cell group ID of 0.

By performing the piecing on the PSS sequence seg1 to be processed at the second section of 4096 points to the PSS sequence seg39 to be processed at the fortieth section of 4096 points in this way, the correlation results #1- #40 between the local PSS sequence and the air interface data shown in fig. 6 can be obtained.

In an embodiment, referring to fig. 7, the over-the-air data may include a PSS sequence received through multiple antennas, and the step S105 may include the following steps:

step S1051, for each local PSS sequence, combining the correlation results of the air interface data received by each antenna and the local PSS sequence to obtain the average correlation result of the local PSS sequence and the air interface data received by each antenna;

step S1052, determining the intra-cell group ID according to the local PSS sequence corresponding to the average correlation result with the largest correlation peak in the average correlation results.

For example, in conjunction with fig. 4 and 5, the rx0 and rx1 data can be first obtained from the external memory and then divided into two branches rx0 and rx1 for processing. Wherein, rx0 and rx1 are respectively air interface data of 153600 points acquired through different antennas.

For the rx0 branch, the air interface data of 153600 points is first divided into 40 pieces of data with equal length, and the length of each piece of data is 3840. Each piece of data is then zero padded to the to-be-processed PSS sequence of 4960 points. The air interface data fixed-point C8S8 indicates that the complex number has 8 bits, and the fractional bit part has 8 bits.

Next, based on the FFT operation sub-module 411, FFT operation is performed on the PSS sequence to be processed at the first stage of 4960 points. The PSS sequences to be processed, which are segmented each time, are buffered by the storage sub-module 412 and output to the correlation sub-module 413.

Next, the result of the FFT is multiplied by the local frequency domain PSS sequence in parallel in 3-way based on the correlation operation sub-module 413. Preferably, the multiplication may be followed by saturation processing and truncation to protect the data.

Since the local PSS sequences share 9 frequency offset values for correlation, 9 × 3 times of correlation operations are performed on each segment of the PSS sequences to be processed in the correlation operation sub-module 413.

The correlation results of the 3 branches are respectively output to the corresponding IFFT operation sub-module 414-1, IFFT operation sub-module 414-2, and IFFT operation sub-module 414-3 to perform IFFT operation on each correlation result. The IFFT operation result of the correlation result is also divided into 3 branches and output to the antenna combining module 419.

The rx1 and rx0 have the same processing mode, and the correlation results of 9 frequency offsets between the PSS sequence to be processed (obtained by rx1 segmentation) of each segment of 3 branches and the three local PSS sequences can be obtained through the processing of the corresponding FFT operation sub-module 415, storage sub-module 416, correlation operation sub-module 417 and IFFT operation sub-modules 418-1 to 418-3.

Further, the correlation results of the data of the two antennas after the IFFT operation are combined based on the antenna combination module 419. For example, for the same local PSS sequence, the correlation result obtained by the rx0 branch and the correlation result obtained by the rx1 branch may be summed and averaged to obtain an average correlation result between the local PSS sequence and the air interface data received through the two antennas. Thus, the antenna combining module 419 will finally output the average correlation results of the three local PSS sequences and the air interface data received through the two antennas in parallel.

The fixed point of the data signal power after the two antennas are combined is r15u9, and the real part is 15 bits, and the unsigned fractional part is 9 bits.

Further, to protect the data, the saturation truncation processing may be performed on the average correlation result output by the antenna combining module 419 based on the saturation truncation processing module 420. For example, data having an excessively large value in the average correlation result is mapped to a preset maximum value.

Further, based on the PSS peak selection module 421, the peak sorting of the correlation peaks is performed on the correlation results corresponding to the respective 3 types of local PSS sequences subjected to saturation truncation, and the local PSS sequence with the strongest peak is selected from the correlation results, where the intra-cell ID corresponding to the local PSS sequence with the strongest peak is the intra-group cell ID of the air interface data.

Referring to fig. 4 and 5, the FFT computation submodule 411 and the IFFT computation submodules 414-1 to 414-3 of the corresponding branches do not overlap in time, so that the same FFT module can be multiplexed. Thus, 6 FFT modules are required for both antennas.

On the other hand, rx0 and rx1 can be pipelined simultaneously in parallel, which saves much time.

Therefore, by adopting the scheme of the embodiment, the data processing efficiency of the UE during initial cell access can be effectively improved, and the storage space of the UE is saved. Specifically, the acquired air interface data is segmented, and the PSS detection is performed on the N segmented PSS sequences to be processed in an overlapped correlation and parallel pipelining manner, so that the data processing efficiency is improved, the purpose of rapidly searching the cell is achieved, meanwhile, the storage space of the UE can be saved, and the resource overhead is greatly reduced.

FIG. 8 is a schematic structural diagram of a PSS detection apparatus according to an embodiment of the present invention. Those skilled in the art understand that the PSS detecting device 8 of the present embodiment may be used to implement the method solutions described in the embodiments shown in fig. 2 to 7.

Specifically, in the present embodiment, the PSS detecting apparatus 8 may include: an obtaining module 81, configured to obtain air interface data, where the air interface data includes a PSS sequence received in a preset cell search period; a segmentation module 82, configured to perform segmentation processing on the air interface data to obtain N segments of PSS sequences to be processed; a correlation processing module 83, configured to perform correlation processing on the N segments of to-be-processed PSS sequences and a preset number of local PSS sequences, respectively, to obtain corresponding correlation results; a splicing module 84, for each local PSS sequence, splicing the respective corresponding correlation results of the N segments of PSS sequences to be processed to obtain the correlation result of the local PSS sequence and the air interface data; and a determining module 85, configured to determine an ID in the cell group according to the local PSS sequence corresponding to the correlation result with the largest correlation peak in the correlation results of the preset number of local PSS sequences and the air interface data.

In one embodiment, the segmentation module 82 may include: a division submodule 821, configured to divide the air interface data into N segments of data, where the length of each segment of data is a first preset length; and a padding sub-module 822 for padding the length of each segment of data to a second preset length to obtain the PSS sequence to be processed, wherein the second preset length is greater than the first preset length.

In one embodiment, the correlation processing module 83 may include: and a multiplexing sub-module 831, for each local PSS sequence, multiplexing the same FFT module to perform correlation processing on the PSS sequence to be processed and the local PSS sequence segment by segment to obtain the correlation result.

Further, the multiplexing submodule 831 may include: the pipeline processing unit 8311, when the FFT module outputs the correlation result between the previous segment of the PSS sequence to be processed in the N segments of the PSS sequences to be processed and the local PSS sequence, inputs the next segment of the PSS sequence to be processed in the N segments of the PSS sequences to be processed to the FFT module until the correlation result between the last segment of the PSS sequence to be processed in the N segments of the PSS sequences to be processed and the local PSS sequence is obtained.

Further, the number of the FFT modules may be the same as the preset number of the local PSS sequences, and the FFT modules may correspond to the local PSS sequences one to one.

In one embodiment, the N to-be-processed PSS sequences may be stored in a preset memory in an overlapping manner.

In one embodiment, the hashing module 84 may include: the discarding sub-module 841 discards, for each segment of the PSS sequence to be processed, data of a first third preset length of the corresponding correlation result to obtain a corresponding processed correlation result; the splicing sub-module 842 is configured to splice the processed correlation results corresponding to the N segments of PSS sequences to be processed, so as to obtain the correlation result between the local PSS sequence and the air interface data.

In an embodiment, the air interface data may include a PSS sequence received through multiple antennas, and the determining module 85 may include: an antenna merging sub-module 851, configured to, for each local PSS sequence, merge the correlation results between the air interface data received via each antenna and the local PSS sequence to obtain an average correlation result between the local PSS sequence and the air interface data received via each antenna; and a peak value selecting submodule 852, configured to determine the intra-cell group ID according to the local PSS sequence corresponding to the average correlation result with the largest correlation peak in the average correlation results.

In one embodiment, the correlation processing module 83 may include: for each local PSS sequence, the correlation processing sub-module 832 performs correlation processing on the N segments of PSS sequences to be processed and at least one frequency offset shift result of the local PSS sequence, respectively, to obtain a corresponding correlation result.

For more details of the operating principle and the operating mode of the PSS detecting device 8, reference may be made to the above description in fig. 2 to 7, which are not repeated herein.

Further, the embodiment of the present invention further discloses a storage medium, on which computer instructions are stored, and when the computer instructions are executed, the method technical solutions described in the embodiments shown in fig. 2 to fig. 7 are executed. Preferably, the storage medium may include a computer-readable storage medium such as a non-volatile (non-volatile) memory or a non-transitory (non-transient) memory. The storage medium may include ROM, RAM, magnetic or optical disks, etc.

Further, an embodiment of the present invention further discloses a terminal, which includes a memory and a processor, where the memory stores a computer instruction capable of running on the processor, and the processor executes the method technical solution described in the embodiments shown in fig. 2 to 7 when running the computer instruction. Preferably, the terminal may be a User Equipment (UE). The UE may be a 5G UE.

Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A PSS detection method, comprising:

acquiring air interface data, wherein the air interface data comprises a PSS sequence received in a preset cell search period;

carrying out segmentation processing on the air interface data to obtain N segments of PSS sequences to be processed;

respectively carrying out correlation processing on the N segments of PSS sequences to be processed and a preset number of local PSS sequences to obtain corresponding correlation results;

for each local PSS sequence, splicing the respective corresponding correlation results of the N segments of PSS sequences to be processed to obtain the correlation results of the local PSS sequences and the air interface data;

determining an ID in the cell group according to the local PSS sequences corresponding to the correlation result with the maximum correlation peak in the correlation results of the air interface data and the local PSS sequences with the preset number;

wherein, the performing the correlation processing on the N segments of PSS sequences to be processed and the preset number of local PSS sequences respectively to obtain the corresponding correlation results includes:

for each local PSS sequence, multiplexing the same FFT module to carry out correlation processing on the PSS sequence to be processed and the local PSS sequence section by section so as to obtain a correlation result;

the step of performing segmentation processing on the air interface data to obtain N segments of PSS sequences to be processed comprises:

dividing the air interface data into N sections of data, wherein the length of each section of data is a first preset length;

for each segment of data, performing zero padding at the tail of the data, and padding the length of the data to a second preset length to obtain the PSS sequence to be processed, wherein the second preset length is greater than the first preset length;

the piecing together the correlation results corresponding to the N segments of the PSS sequences to be processed to obtain the correlation results between the local PSS sequences and the air interface data includes:

for each segment of the PSS sequence to be processed, discarding data of a first third preset length of a corresponding correlation result to obtain a corresponding processed correlation result, wherein the third preset length is equal to a difference value between the second preset length and the first preset length;

and splicing the processed correlation results corresponding to the N segments of PSS sequences to be processed respectively to obtain the correlation result of the local PSS sequence and the air interface data.

2. The PSS detection method of claim 1, wherein the multiplexing the same FFT module to perform correlation processing on the PSS sequence to be processed and the local PSS sequence segment by segment to obtain the correlation result comprises:

and when the FFT module outputs the correlation result between the previous segment of the PSS sequence to be processed in the N segments of the PSS sequences to be processed and the local PSS sequence, inputting the next segment of the PSS sequence to be processed in the N segments of the PSS sequences to be processed into the FFT module until the correlation result between the last segment of the PSS sequence to be processed in the N segments of the PSS sequences to be processed and the local PSS sequence is obtained.

3. The PSS detection method of claim 1, wherein the number of FFT modules is the same as the preset number of local PSS sequences, and wherein the FFT modules are in one-to-one correspondence with the local PSS sequences.

4. The PSS detection method of claim 1, wherein the N to-be-processed PSS sequences are stored in a predetermined memory in an overlapping manner.

5. The PSS detection method of claim 1, wherein the air interface data comprises PSS sequences received via multiple antennas, and determining the intra-cell ID according to the local PSS sequence corresponding to the maximum correlation result of the correlation peak in the correlation results of the preset number of local PSS sequences and the air interface data comprises:

for each local PSS sequence, combining the correlation results of the air interface data received by each antenna and the local PSS sequence to obtain the average correlation result of the local PSS sequence and the air interface data received by each antenna;

and determining the ID in the cell group according to the local PSS sequence corresponding to the average correlation result with the maximum correlation peak in the average correlation results.

6. The PSS detection method of claim 1, wherein the correlating the N PSS sequences to be processed with a preset number of local PSS sequences respectively to obtain corresponding correlation results comprises:

and for each local PSS sequence, performing correlation processing on the N sections of PSS sequences to be processed and at least one frequency offset shift result of the local PSS sequence to obtain a corresponding correlation result.

7. A PSS detection apparatus, comprising:

an obtaining module, configured to obtain air interface data, where the air interface data includes a PSS sequence received in a preset cell search period;

the segmentation module is used for carrying out segmentation processing on the air interface data to obtain N segments of PSS sequences to be processed;

the correlation processing module is used for performing correlation processing on the N segments of PSS sequences to be processed and a preset number of local PSS sequences respectively to obtain corresponding correlation results;

a splicing module, which splices the respective corresponding correlation results of the N segments of PSS sequences to be processed for each local PSS sequence to obtain the correlation results of the local PSS sequence and the air interface data;

a determining module, configured to determine an intra-cell group ID according to the local PSS sequence corresponding to the correlation result with the largest correlation peak in the correlation results of the preset number of local PSS sequences and the air interface data;

wherein the correlation processing module comprises: multiplexing sub-modules, for each local PSS sequence, multiplexing the same FFT module to perform correlation processing on the PSS sequence to be processed and the local PSS sequence section by section to obtain the correlation result;

the segmentation module comprises: the division submodule is used for dividing the air interface data into N sections of data, wherein the length of each section of data is a first preset length; the filling submodule is used for carrying out zero filling on the tail part of each section of data and filling the length of the data to a second preset length to obtain the PSS sequence to be processed, wherein the second preset length is larger than the first preset length;

the piecing together module includes: the discarding submodule discards data of a first preset length of the corresponding correlation result for each segment of the PSS sequence to be processed to obtain the corresponding processed correlation result, wherein the third preset length is equal to a difference value between the second preset length and the first preset length; and the splicing sub-module is used for splicing the processed correlation results corresponding to the N segments of PSS sequences to be processed respectively to obtain the correlation result of the local PSS sequence and the air interface data.

8. A storage medium having stored thereon computer instructions, wherein said computer instructions when executed perform the steps of the method of any of claims 1 to 6.

9. A terminal comprising a memory and a processor, the memory having stored thereon computer instructions executable on the processor, wherein the processor, when executing the computer instructions, performs the steps of the method of any one of claims 1 to 6.