CN115051771A

CN115051771A - Cell search method, device, equipment and computer storage medium

Info

Publication number: CN115051771A
Application number: CN202210555535.XA
Authority: CN
Inventors: 方昶
Original assignee: Zeku Technology Beijing Corp Ltd
Current assignee: Zeku Technology Beijing Corp Ltd
Priority date: 2022-05-20
Filing date: 2022-05-20
Publication date: 2022-09-13
Anticipated expiration: 2042-05-20
Also published as: CN115051771B

Abstract

The embodiment of the application discloses a cell search method, a device, equipment and a computer storage medium, wherein the method comprises the following steps: performing cross-correlation operation on the first PSS frequency domain data and the local PSS sequence to obtain a first correlation sequence; the first PSS frequency domain data is the PSS frequency domain data after interference of the received time domain data is eliminated; respectively performing time offset compensation on a first conversion sequence after the first correlation sequence is subjected to discrete conversion based on a preset first time offset value to obtain a first correlation compensation sequence; determining information of a target cell based on the first correlation compensation sequence, the first time offset value and the first SSS frequency domain data; the first SSS frequency-domain data is SSS frequency-domain data from which interference is cancelled in the received time-domain data. By the method, the problem of low cell search efficiency can be solved.

Description

Cell search method, device, equipment and computer storage medium

Technical Field

Embodiments of the present application relate to, but not limited to, the field of communications technologies, and in particular, to a cell search method, apparatus, device, and computer storage medium.

Background

In a communication network system, after a terminal device is powered on, an initial search is first initiated to search for a serving cell for camping. After the terminal device successfully resides in a certain serving cell, the neighbor cell search is started. The main purpose of the neighbor cell search is to search for a neighbor cell of the serving cell in preparation for operations such as cell reselection or cell handover. Currently, schemes for cell search are still under further study.

Disclosure of Invention

The embodiment of the application provides a cell search method, a cell search device, a cell search equipment and a computer storage medium.

In a first aspect, an embodiment of the present application provides a cell search method, including:

performing cross-correlation operation on the first PSS frequency domain data and the local PSS sequence to obtain a first correlation sequence; the first PSS frequency domain data is the PSS frequency domain data after interference of the received time domain data is eliminated;

respectively performing time offset compensation on a first conversion sequence after the first correlation sequence is subjected to discrete conversion based on a preset first time offset value to obtain a first correlation compensation sequence;

determining information of a target cell based on the first correlation compensation sequence, the first time offset value and first SSS frequency domain data; the first SSS frequency domain data is SSS frequency domain data with interference eliminated from received time domain data.

In a second aspect, an embodiment of the present application provides a cell search apparatus, including:

the processing module is used for performing cross-correlation operation on the first PSS frequency domain data and the local PSS sequence to obtain a first correlation sequence; the first PSS frequency domain data is the PSS frequency domain data after interference of the received time domain data is eliminated;

the compensation module is used for respectively carrying out time offset compensation on a first conversion sequence after the first correlation sequence is subjected to discrete conversion based on a preset first time offset value to obtain a first correlation compensation sequence;

a determining module, configured to determine information of a target cell based on the first correlation compensation sequence, the first time offset value, and first SSS frequency-domain data; the first SSS frequency domain data is SSS frequency domain data with interference eliminated from received time domain data.

In a third aspect, an embodiment of the present application provides an apparatus, where the apparatus includes: a processor and a memory, wherein the processor is capable of processing a plurality of data,

the memory stores a computer program operable on the processor,

the processor, when executing the program, implements a method as described in the first aspect.

In a fourth aspect, an embodiment of the present application provides a computer storage medium storing a computer program, which when executed by a processor implements the method of the first aspect.

In the embodiment of the application, cross-correlation operation is carried out on the first PSS frequency domain data and the local PSS sequence to obtain a first correlation sequence; the first PSS frequency domain data is the PSS frequency domain data after interference of the received time domain data is eliminated; here, since interference is eliminated from the received time domain data, the interference-eliminated PSS frequency domain data, that is, the first PSS frequency domain data, is obtained, so that interference is eliminated, and the number of cells detected in the first PSS frequency domain data is reduced, thereby improving the cell search performance. Further, respectively performing time offset compensation on a first conversion sequence after the first correlation sequence is subjected to discrete conversion based on a preset first time offset value to obtain a first correlation compensation sequence; therefore, in the frequency domain PSS detection stage, the time offset value of the transformation sequence of the first PSS frequency domain data is compensated in a discrete transformation mode to obtain a first related compensation sequence, namely, the time offset hypothesis is carried out in a discrete transformation mode, so that the operation amount and the implementation complexity are reduced, and the cell search efficiency is improved. Finally, determining information of the target cell based on the first correlation compensation sequence, the first time offset value and the first SSS frequency domain data; the first SSS frequency domain data is SSS frequency domain data after interference is eliminated from received time domain data; therefore, in the process of determining the information of the target cell based on the first correlation compensation sequence, the first SSS frequency domain data, and the preset first time offset value, the cell search performance and the cell search efficiency are considered at the same time.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application.

FIG. 1 is a schematic diagram of an application scenario of an embodiment of the present application;

fig. 2 is a schematic implementation flowchart of an optional cell search method according to an embodiment of the present application;

fig. 3 is a schematic implementation flow diagram of an alternative cell search method according to an embodiment of the present application;

fig. 4 is a schematic implementation flow diagram of an alternative cell search method according to an embodiment of the present application;

fig. 5 is a schematic implementation flowchart of an optional cell search method according to an embodiment of the present application;

fig. 6 is a schematic implementation flow diagram of an alternative cell search method according to an embodiment of the present application;

fig. 7 is a block diagram of a flow of implementing the method for obtaining a candidate peak of the PSS by assuming time offset through FFT according to an embodiment of the present disclosure;

fig. 8 is a schematic implementation flow diagram of an alternative cell search method according to an embodiment of the present application;

fig. 9 is a schematic implementation flowchart of an optional cell search method according to an embodiment of the present application;

fig. 10 is a schematic implementation flow diagram of an alternative cell search method according to an embodiment of the present application;

fig. 11 is a schematic implementation flow diagram of an alternative cell search method according to an embodiment of the present application;

fig. 12 is a schematic diagram illustrating a principle that a device searches for multiple co-frequency cells according to an embodiment of the present application;

fig. 13 is a schematic implementation flow diagram of an alternative cell search method according to an embodiment of the present application;

fig. 14 is a schematic implementation flow diagram of an alternative cell search method according to an embodiment of the present application;

fig. 15 is a schematic implementation flow diagram of an alternative cell search method according to an embodiment of the present application;

fig. 16 is a schematic structural diagram of a cell search apparatus according to an embodiment of the present application;

fig. 17 is a schematic structural diagram of an apparatus provided in an embodiment of the present application.

Detailed Description

The technical solution of the present application will be specifically described below by way of examples with reference to the accompanying drawings. The following several specific embodiments may be combined with each other, and details of the same or similar concepts or processes may not be repeated in some embodiments.

It should be noted that: in the present examples, "first", "second", etc. are used for distinguishing similar objects and are not necessarily used for describing a particular order or sequence.

The technical means described in the embodiments of the present application may be arbitrarily combined without conflict. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

Fig. 1 is a schematic diagram of an application scenario according to an embodiment of the present application.

As shown in fig. 1, the communication system 100 may include a first device 110 and a second device 120. Here, the first device includes, but is not limited to, a terminal device and a chip, and the second device may be a network device. The second device 120 may communicate with the first device 110 over the air. Multi-service transport is supported between the first device 110 and the second device 120.

It should be understood that the embodiment of the present application is only illustrated as the communication system 100, but the embodiment of the present application is not limited thereto. That is to say, the technical solution of the embodiment of the present application may be applied to various communication systems, for example: long Term Evolution (LTE) System, LTE Time Division Duplex (TDD), Universal Mobile Telecommunications System (UMTS), Internet of Things (Internet of Things, IoT) System, narrowband Band Internet of Things (NB-IoT) System, enhanced Machine-Type communication (eMTC) System, 5G communication System (also called New Radio, NR) communication System), or future communication System (e.g. 6G, 7G communication System), etc.

In the communication system 100 shown in fig. 1, the second device 120 may be an access network device that communicates with the first device 110. The access network device may provide communication coverage for a particular geographic area and may communicate with a first device 110 located within the coverage area. The second device 120 in the embodiments of the present application may include an access network device and/or a core network device.

Fig. 1 exemplarily shows one base station and one first device, and optionally, the wireless communication system 100 may include a plurality of base station devices and may include other numbers of first devices within the coverage area of each base station, which is not limited in this embodiment of the present application.

It should be noted that fig. 1 illustrates a system to which the present application is applied by way of example, and of course, the method shown in the embodiment of the present application may also be applied to other systems. Further, the terms "system" and "network" are often used interchangeably herein. The term "and/or" herein is merely an association describing an associated object, meaning that three relationships may exist, e.g., a and/or B, may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter associated objects are in an "or" relationship. It should also be understood that "indication" mentioned in the embodiments of the present application may be a direct indication, an indirect indication, or an indication of an association relationship. For example, a indicates B, which may mean that a directly indicates B, e.g., B may be obtained by a; it may also mean that a indicates B indirectly, for example, a indicates C, and B may be obtained by C; it can also mean that there is an association between a and B. It should also be understood that "correspond" mentioned in the embodiments of the present application may mean that there is a direct or indirect correspondence between the two, and may also mean that there is an association relationship between the two, and may also be a relationship of indicating and being indicated, configuring and being configured, and the like. It should also be understood that, in the embodiments of the present application, the "predefined", "agreement convention", "predetermined", or "predefined rule" may be implemented by pre-saving corresponding codes, tables, or other manners that may be used to indicate relevant information in the devices (for example, including the first device and the second device), and the present application is not limited to the specific implementation manner thereof. Such as predefined, may refer to what is defined in the protocol. It should also be understood that, in the embodiment of the present application, the "protocol" may refer to a standard protocol in the field of communications, and may include, for example, an LTE protocol, an NR protocol, and a related protocol applied in a future communication system, which is not limited in this application.

In a communication system, a terminal device needs to acquire time and frequency synchronization with a cell through a cell search stage and search for a cell ID, thereby realizing communication with a network device. For example, correlation detection is performed on a Primary Synchronization Signal (PSS) sequence based on received Signal data in a cell search phase, resulting in at least one of: time offset, Identity with the group, and timing information, among others, wherein the Identity is also referred to as NID2 or NID2

Then, Secondary Synchronization Signal (SSS) sequence detection is performed to obtain a Physical Cell Identity group (Physical Layer Identity group), and further obtain Cell information, where the Physical Cell Identity group is also called NID1 or NID1

However, in the case of co-channel cell interference, how to effectively eliminate the data of the interfering cell completes the target cell search.

In the related art, the technical scheme of cell search based on cell signal interference cancellation is either based on time domain interference cancellation, specifically, after receiving total time domain data based on a target frequency band, a synchronization signal channel is estimated based on the time domain data of an interfering cell, and a signal of a known interfering cell is reconstructed, and then an interference signal is cancelled from the total received data. And then carrying out conventional target cell PSS and SSS detection on the signal subjected to interference cancellation to obtain cell information. Or based on frequency domain interference cancellation, specifically, based on known interfering cell signal PSS and SSS positions, data is taken to perform Fast Fourier Transform (FFT), and interfering cell signals are reconstructed in the frequency domain, and then frequency domain detection is performed on the frequency domain signals subjected to interference cancellation on target cell PSS and SSS, so as to finally obtain cell information.

It should be noted that, although the scheme for determining the target cell based on the frequency domain interference cancellation is simple to implement and relatively small in data and calculation amount compared with the scheme for determining the target cell based on the time domain interference cancellation, no matter the scheme for determining the target cell based on the time domain interference cancellation or the scheme for determining the target cell based on the frequency domain interference cancellation needs to reconstruct the interference signal, and the processing requirement on the time offset is high.

In the related technology, when PSS detection is carried out, the time offset processing process is that after data except for an interference cell is received, different time offset assumptions are carried out on PSS frequency domain data in the data, and the PSS frequency domain data added with the time offset assumptions are subjected to frequency domain correlation to obtain a correlation result after time offset compensation; wherein, the correlation result x after time offset compensation ₁ (k) This can be achieved by the following equation (1):

wherein x is ₁ (k) Represents the correlation result after time offset compensation, xccor (k) represents the frequency domain correlation result of the first PSS frequency domain data and the local PSS sequence,

represents a time offset value; k denotes a PSS sequence several points, x (k) denotes a k-th PSS correlation result, N denotes a sequence length of the first PSS frequency domain data, and L denotes a time offset value.

Further, the correlation result after time offset compensation needs to be normalized and antenna combined, so the correlation result x after time offset compensation is used ₁ (k) Accumulating to obtain an accumulation result Y, as shown in the following formula (2),

wherein M is the total number of the time offset values.

And finally, estimating the time offset for performing time offset compensation on the SSS signals based on the square of the accumulation result, and then performing time offset compensation on the SSS signals and performing frequency domain correlation processing on the SSS signals so as to determine the information of the target cell. However, in the process of time offset compensation for the PSS frequency domain data, if there are a plurality of, for example, S time offsets L, S is an integer greater than or equal to 2, S multiplications are required according to the above formula (1), and N × S square sums are required according to the above formula (2); that is, in the method of compensating the time offset value for the PSS frequency domain data in the related art, the operation complexity is S times of multiplication and N × S times of square sum. Obviously, the method at least has the problem of large calculation amount, which causes low cell search efficiency.

Fig. 2 is a schematic flow chart of an implementation of an optional cell search method provided in an embodiment of the present application, and as shown in fig. 2, the method may be applied to a device, where the device may be a chip or a terminal device, and here, the terminal device is taken as an execution subject for description, and the method includes:

step 201, performing cross-correlation operation on the first PSS frequency domain data and the local PSS sequence to obtain a first correlation sequence.

The first PSS frequency domain data is the PSS frequency domain data after interference of the received time domain data is eliminated.

In the embodiment of the present application, the time domain data is signal data of at least two cells in the same frequency band received within a search range after the terminal device resides in a serving cell. It should be noted that, after residing in a serving cell, the terminal device takes the serving cell as a known cell and starts searching for an adjacent cell, so that the terminal device prepares for reselection or handover of a next serving cell, i.e., a target cell, in a moving process.

Here, due to the limitation of spectrum resources and the requirement of LTE high bandwidth, the communication system uses the same-frequency networking mode to improve the utilization rate of spectrum resources. Illustratively, within a given coverage area, there are many cells that use the same set of frequencies, which are referred to as co-frequency cells. The interference between co-channel cells is called co-channel interference, and when searching for a cell, data of the co-channel interfering cell needs to be eliminated.

Under the condition of low signal-to-noise ratio, when a plurality of co-frequency cells exist in a terminal equipment searching range, a serving cell (known cell) where the terminal equipment resides interferes with the searching of a target cell (adjacent cell) signal, the cell searching is influenced, and the condition of searching failure is caused; at this time, the signal of the known cell needs to be reconstructed and eliminated, and the influence of the interference signal is reduced, so as to achieve the purpose of searching the target cell.

In the embodiment of the present application, the first PSS frequency domain data is the PSS frequency domain data after the interference of the received time domain data is eliminated. Exemplarily, after the terminal device resides in a serving cell, the serving cell is taken as a known cell, the PSS frequency domain data of the known cell is reconstructed according to the position and time information of the known cell, and further, the reconstructed PSS frequency domain data of the known cell is removed from the mixed PSS frequency domain data after the time domain data transformation, so as to obtain the first PSS frequency domain data.

In the embodiment of the present application, the local PSS sequence is a locally generated PSS sequence specified by a protocol, and each local PSS sequence corresponds to one in-group identifier NID 2. Optionally, the in-group identifier NID2 may take values of 0,1, 2. It should be noted that the local PSS sequence is essentially formed by circularly shifting the same sequence, and the local PSS sequence can be obtained in advance and stored in the terminal device.

Here, the cross-correlation operation refers to an operation of analyzing two or more variable elements having correlation, thereby measuring the degree of closeness of correlation between the two variable elements. In an embodiment of the present invention, a cross-correlation operation, i.e., an operation that calculates the degree of closeness between two sequences, is performed on the two sequences.

Optionally, performing cross-correlation operation on the first PSS frequency domain data and the local PSS sequence to obtain a first correlation sequence, which may include: and performing cross-correlation operation between the first PSS frequency domain data and each local PSS sequence in the plurality of local PSS sequences respectively to obtain a first correlation sequence corresponding to each local PSS sequence.

Optionally, performing cross-correlation operation on the first PSS frequency domain data and the local PSS sequence to obtain a first correlation sequence, which may further include: and performing frequency domain conjugate point multiplication on the first PSS frequency domain data and the local PSS sequence to obtain a first correlation sequence.

Step 202, respectively performing time offset compensation on the first transformed sequence after the first correlation sequence is subjected to the discrete transformation based on a preset first time offset value to obtain a first correlation compensation sequence.

In the embodiment of the application, the first time offset value is used for performing time offset compensation on the first transformation sequence, and the first transformation sequence is a sequence of a first correlation sequence after discrete transformation; the first time offset value is a value of a difference between the position signals estimated in advance between the other cells and the known cell for the terminal device.

Optionally, the first time offset value is less than or equal to half of a cyclic prefix in the time domain data. Therefore, the complete first PSS frequency domain data and the complete first SSS frequency domain data can be obtained. It should be noted that, a Cyclic Prefix (CP) is formed by moving a signal at the tail of an Orthogonal Frequency Division Multiplexing (OFDM) symbol to the head, and the purpose of the CP is to ensure that complete information is obtained and to achieve time pre-estimation and Frequency synchronization. Therefore, according to the scheme, the time offset between the target cell and the current serving cell of the terminal device, namely the preset first time offset value, is estimated in advance through the cyclic prefix.

Optionally, the number of the preset first time offset values is related to the network type of the serving cell where the terminal device resides, and the serving cells of different network types correspond to different numbers of the first time offset values.

Optionally, the number of the first time offset values is related to the priority of the network type of the cell in which the terminal device resides; here, the number of the first time offset values is proportional to the priority of the network type of the cell in which the terminal device resides. For example, if the cell in which the terminal device resides is an NR network cell, the number of the first time offset values belongs to a first range, and the first range may be [10,15 ]; if the cell where the terminal device resides is an LTE network cell, the number of the first time offset values belongs to a second range, which may be [7,10], and the priority of the network type of the NR network is higher than the priority of the network type of the LTE network; of course, if the cell in which the terminal device resides may also be another network cell, the present application is not limited specifically.

It should be noted that, because the first correlation compensation sequence is obtained by respectively performing time offset compensation on the first transform sequence based on a preset first time offset value, the first transform sequence is a sequence of the first correlation sequence after discrete transform, and the first correlation sequence is a result of performing cross-correlation operation on the first PSS frequency domain data and each local PSS sequence, for the first time offset value, each first correlation compensation sequence corresponds to a unique local PSS sequence and a unique first time offset value.

Alternatively, the discrete Transform may be a Fourier Transform (FT).

Alternatively, the discrete Transform may be a Fast Fourier Transform (FFT).

Alternatively, the Discrete Transform may be a Discrete Fourier Transform (DFT). Illustratively, the operating principle of the discrete fourier transform is as follows (formula (3):

where x (k) denotes a DFT-transformed sequence, x (N) denotes a transformed sequence, N denotes a DFT-transformed length, N denotes a sequence number of a sequence sample, and k denotes an independent variable of a spectrum.

Optionally, the discrete transform is performed on the first correlation sequence to obtain a first transform sequence, and the discrete transform may be performed by using an FPGA-based fast fourier transform IP core in the terminal device, that is, the FFT IP core of the terminal device based on the FPGA is used to perform fourier transform calculation on the first correlation sequence to obtain the first transform sequence. Therefore, the pre-designed FFT IP core is adopted, the implementation is simple, and meanwhile, the operation efficiency is greatly improved.

In an implementation scenario, taking discrete transform as discrete Fourier transform, after cross-correlation operation is performed on frequency domain data of a first PSS and a local PSS sequence to obtain a first correlation sequence xccor (n), discrete Fourier transform is performed on the first correlation sequence xccor (n) to obtain a first transform sequence X ₂ (k) (ii) a Then, based on the preset first time offset value, the first transformation sequence X is respectively processed ₂ (k) And performing time offset compensation to obtain a first correlation compensation sequence. Here, a first transform sequence X ₂ (k) Can be obtained by the following equation (4):

wherein, X ₂ (k) Denotes the first transformed sequence, xccor (k) denotes the frequency domain correlation result of the first PSS frequency domain data with the local PSS sequence.

Step 203, determining information of the target cell based on the first correlation compensation sequence, the first time offset value and the first SSS frequency domain data.

The first SSS frequency domain data is the SSS frequency domain data from which interference is cancelled in the received time domain data.

In the embodiment of the present application, determining the information of the target Cell at least includes determining a Physical Cell Identifier (PCI) and a frame synchronization position of the target Cell.

In this embodiment, the first SSS frequency domain data is the SSS frequency domain data after interference is eliminated from the received time domain data. Exemplarily, after the terminal device resides in a serving cell, the serving cell is taken as a known cell, and the SSS frequency domain data of the known cell is reconstructed according to the location and time information of the known cell; further, the reconstructed SSS frequency domain data of the known cell is eliminated from the mixed SSS frequency domain data after the time domain data transformation, and the first SSS frequency domain data is obtained.

Here, there is a fixed positional relationship of the primary and secondary synchronization signals corresponding to the communication mode between the PSS and the SSS, and the terminal device may determine the frequency domain position of the first SSS frequency domain data from the frequency domain position of the first PSS frequency domain data and the positional relationship of the primary and secondary synchronization signals. The communication mode includes a TDD mode and a Frequency Division Duplex (FDD) mode. Further, the fixed position relationship of the primary and secondary synchronization signals includes, but is not limited to: in the FDD mode, the difference between the primary synchronization signal and the secondary synchronization signal is an OFDM symbol; in the TDD mode, the primary synchronization signal and the secondary synchronization signal differ by three OFDM symbols.

In the embodiment of the application, under the condition that the first correlation compensation sequence is obtained by respectively performing time offset compensation on the first transform sequence after the first correlation sequence is subjected to the discrete transform based on the preset first time offset value, the information of the target cell is determined based on the first correlation compensation sequence, the preset plurality of first time offset values and the first SSS frequency domain data.

In the embodiment of the application, cross-correlation operation is carried out on the first PSS frequency domain data and the local PSS sequence to obtain a first correlation sequence; the first PSS frequency domain data is the PSS frequency domain data after interference of the received time domain data is eliminated; here, since interference is eliminated from the received time domain data, the interference-eliminated PSS frequency domain data, that is, the first PSS frequency domain data, is obtained, so that interference is eliminated, and the number of cells detected in the first PSS frequency domain data is reduced, thereby improving the cell search performance. Further, respectively performing time offset compensation on a first conversion sequence after the first correlation sequence is subjected to discrete conversion based on a preset first time offset value to obtain a first correlation compensation sequence; therefore, in the frequency domain PSS detection stage, the time offset value compensation is carried out on the transformation sequence of the first PSS frequency domain data in a discrete transformation mode to obtain a first relevant compensation sequence, namely, the time offset hypothesis is carried out in a discrete transformation mode, so that the operation amount and the implementation complexity are reduced, and the cell search efficiency is improved. Finally, determining information of the target cell based on the first correlation compensation sequence, the first time offset value and the first SSS frequency domain data; the first SSS frequency domain data is SSS frequency domain data after interference is eliminated from received time domain data; therefore, in the process of determining the information of the target cell based on the first correlation compensation sequence, the first SSS frequency domain data, and the preset first time offset value, the cell search performance and the cell search efficiency are considered at the same time.

Fig. 3 is a schematic flow chart of an implementation of an optional cell search method provided in an embodiment of the present application, and as shown in fig. 3, the method may be applied to a device, where the device may be a chip or a terminal device, and here, the terminal device is taken as an execution subject for description, and the method includes:

step 301, performing cross-correlation operation on the first PSS frequency domain data and the local PSS sequence to obtain a first correlation sequence.

Step 302, performing discrete transformation on the first correlation sequence to obtain a first transformation sequence.

Step 303, determining a first correlation compensation sequence corresponding to the first time offset value from the first transform sequence, so as to complete time offset compensation.

Here, since there are a plurality of local PSS sequences, there are also a plurality of first transform sequences that perform discrete transform on the first correlation sequence, and each correlation compensation sequence corresponding to the offset first time offset value is determined from each transform sequence, and a plurality of correlation compensation sequences are obtained, thereby completing the time offset compensation. Therefore, each sampling point in the first conversion sequence after discrete conversion deviates the first time offset value to obtain the first relevant compensation sequence, and further, the discrete value of the corresponding position when each sampling point deviates the first time offset value can be quickly obtained in the first compensation sequence, so that the time length for detecting the synchronous signal can be reduced, the target cell can be quickly searched, and the cell search efficiency is further improved.

Here, taking the example of discrete Fourier transform, the first transform sequence X is obtained ₂ (k) Then, from each first transform sequence X ₂ (k) Determining a first correlation compensation sequence corresponding to the time offset value L to obtain a plurality of first correlation compensation sequences so as to complete time offset compensation.

Y1＝X ₂ (k-L)

Where Y1 represents a plurality of first correlation compensation sequences and L represents a first time offset value.

Step 304, determining a second time offset value based on the first time offset value and the first correlation compensation sequence.

In this embodiment of the application, the second time offset value may be used to perform time offset compensation on a second correlation sequence obtained by performing cross-correlation operation on the first SSS frequency domain data and the local SSS sequence; of course, the second time offset value may also be used to perform time offset compensation on the second correlation sequence subjected to fourier transform, and the application is not limited in this respect.

And 305, performing time offset compensation on a second correlation sequence obtained by performing cross-correlation operation on the first SSS frequency domain data and the local SSS sequence based on a second time offset value to obtain a second correlation compensation sequence.

The first SSS frequency domain data is the SSS frequency domain data after interference is eliminated from the received time domain data.

In this embodiment of the present application, a local SSS sequence is a locally generated SSS sequence specified by a protocol, and each local SSS sequence corresponds to a group number identifier NID 1. Optionally, in the LTE network, the number of the group number identifiers NID1 is 168 in total, that is, NID1 may take a value of 0 to 167; in the NR network, there are 336 group number identifiers NID1, that is, NID1 may be set to 0 to 335, and of course, in other networks, the total number of group identifier NID1 may be set to other values, which is not limited in this application. Here, the local SSS sequence may be obtained in advance and stored in the terminal device.

Optionally, based on the second time offset value, performing time offset compensation on the second correlation sequence obtained by performing cross-correlation operation on the first SSS frequency domain data and the local SSS sequence to obtain a second correlation compensation sequence, which may include: performing cross-correlation operation on the first SSS frequency domain data and the local SSS sequence to obtain a second correlation sequence; and performing time offset compensation on the second correlation sequence based on the second time offset value to obtain a second correlation compensation sequence.

Optionally, based on the second time offset value, performing time offset compensation on the second correlation sequence obtained by performing cross-correlation operation on the first SSS frequency domain data and the local SSS sequence to obtain a second correlation compensation sequence, which may include: performing cross-correlation operation on the first SSS frequency domain data and a local SSS sequence to obtain a second correlation sequence; performing discrete transformation on the second correlation sequence to obtain a second transformation sequence; and performing time offset compensation on the second transformation sequence based on the second time offset value to obtain a second correlation compensation sequence.

Optionally, performing cross-correlation operation on the first SSS frequency domain data and the local SSS sequence to obtain a second correlation sequence, which may further include: and carrying out frequency domain conjugate point multiplication on the first SSS frequency domain data and the local SSS sequence to obtain a second correlation sequence.

And step 306, determining the information of the target cell based on the first correlation compensation sequence and the second correlation compensation sequence.

In the embodiment of the application, a first correlation sequence of the PSS is processed through discrete transformation to obtain a first transformation sequence, and then time offset compensation is carried out on the first transformation sequence based on a first time offset value to obtain a first correlation compensation sequence; and compensating the second conversion sequence of the SSS through the second time offset to obtain a second relevant compensation sequence, so that the discrete transformation is effectively utilized to perform time offset compensation assumption on the first conversion sequence of the PSS, and the sequence is obtained by compensating the second conversion sequence of the SSS based on the obtained numerical value of the corresponding position of each first time offset in the first relevant compensation sequence and the second time offset, the information of the target cell is determined, the data computation amount and the realization complexity are greatly reduced, the search time is reduced, and the search efficiency of the cell is improved.

In some embodiments, in the case that the time offset compensation is performed on the first transformed sequence based on the preset first time offset value to obtain the first correlation compensation sequence, step 304 determines the second time offset value based on the first time offset value and the first correlation compensation sequence, as further described in conjunction with fig. 4,

step 401, a first candidate peak is determined based on the first time offset value and the first correlation compensation sequence.

In the embodiment of the present application, the first candidate peak corresponds to a first time offset value and a local PSS sequence, and the first candidate peak may be a peak satisfying a peak condition from the first correlation compensation sequence; the first candidate peak is used for estimating a time offset value of a sequence obtained based on SSS frequency domain data for time offset compensation.

Step 402, performing a remainder operation on the first candidate peak and the length of the first PSS frequency domain data to obtain a second time offset value.

In the embodiment of the present application, the length of the first PSS frequency domain data is the number of points for performing discrete transform.

Here, when the first candidate peak is determined based on the first time offset value and the first correlation sequence, the first candidate peak and the length of the first PSS frequency domain data are subjected to a remainder operation to obtain a second time offset value. Wherein the second time offset value can be realized by the following formula (5):

Y3＝mod(Y2，N) (5)

where Y3 denotes the second time offset value, Y2 denotes the first candidate peak value, N denotes the length of the frequency domain data of the first PSS, and mod denotes a complementary function.

Optionally, performing a remainder operation on the length of the first candidate peak and the first PSS frequency domain data to obtain a second time offset value, which may include: the first candidate peak includes: and performing remainder operation on each first candidate peak value and the length of the first PSS frequency domain data to obtain at least one second time offset value.

As can be seen from the above, when the first candidate peak corresponding to the first correlation compensation sequence is determined, the first candidate peak and the PSS frequency domain data are subjected to a remainder operation, so that not only the time offset compensation value of the sequence obtained based on the first SSS frequency domain data can be obtained, but also the position of the first SSS frequency domain data can be determined based on the position of the first candidate peak. In this manner, SSS data locations may be quickly located to improve search efficiency.

In some embodiments, in the case that the time offset compensation is performed on the first transformed sequence based on the preset first time offset value to obtain the first correlation compensated sequence, step 401 is further illustrated with reference to fig. 5 for determining the first candidate peak based on the first time offset value and the first correlation compensated sequence,

step 501, the first time offset value includes: w first offset values, each corresponding to N1 first sub-correlation compensation sequences, the first correlation compensation sequences including N1 first sub-correlation compensation sequences corresponding to the W first offset values, respectively, and N1 first peak values are determined based on the N1 first sub-correlation compensation sequences for each first offset value.

Wherein W is an integer greater than or equal to 1, and N1 is an integer greater than or equal to 1.

Here, N1 is the total number of all local PSS sequences.

In the embodiment of the present application, for each of the W first offset values, N1 first peak values are determined based on that the first correlation compensation sequence includes N1 first sub correlation compensation sequences corresponding to the W first offset values, respectively.

Step 502, for the W first time offset values, U first candidate peaks larger than or equal to a first preset peak threshold are determined from the W × N1 first peaks.

Wherein U is an integer of 1 or more and W × N1 or less.

In this embodiment of the present application, the first preset peak threshold may be a preset peak value, and the first preset peak threshold may also be a peak value dynamically adjusted according to the current scene, which is not specifically limited in this application.

In the embodiment of the present application, for W first time offset values, U first candidate peaks that are greater than or equal to a first preset peak threshold value are determined from W × N1 first peaks, so as to perform SSS correlation detection according to the first candidate peaks, so as to determine information of a target cell.

As can be seen from the above, when there are a plurality of first time offset values, each first time offset value in the first correlation compensation sequence obtained through discrete transformation corresponds to a plurality of first sub-correlation compensation sequences in the first correlation compensation sequence, and each first sub-correlation compensation sequence has a peak value, so each first time offset value corresponds to a plurality of peak values, and a peak value meeting the condition is selected as a first candidate peak value from all peak values corresponding to all first time offset values, so that not only the position of the first SSS frequency domain data is determined based on the position of the first candidate peak value, but also the time offset compensation value of the sequence obtained based on the first SSS frequency domain data can be obtained, so as to detect the SSS correlation data after time offset compensation and determine the information of the target cell.

In some embodiments, in a case that the time offset compensation is performed on the first transform sequence based on the preset W first time offset values, so as to obtain a first correlation compensation sequence including N1 first sub correlation compensation sequences corresponding to the W first time offset values, the process of determining N1 first peak values based on N1 first sub correlation compensation sequences in step 501 for each first time offset value is further described with reference to fig. 6,

step 601, for each first time offset value, based on N1 first sub-correlation compensation sequences, obtaining energy distribution information corresponding to each first sub-correlation compensation sequence.

In the embodiment of the present application, the energy distribution information includes, but is not limited to, a plurality of discrete values corresponding to each of the first sub-correlation compensation sequences. In some embodiments, for each first time offset value, based on N1 first sub-correlation compensation sequences, normalization processing may be performed on a plurality of discrete values corresponding to each first sub-correlation compensation sequence to obtain energy distribution information, and of course, in other embodiments of the present application, energy distribution information may also be obtained in other manners, which is not limited in this application.

Step 602, determining a first peak value corresponding to each first sub-correlation compensation sequence based on the energy distribution information corresponding to each first sub-correlation compensation sequence, thereby obtaining N1 first peak values corresponding to N1 first sub-correlation compensation sequences.

In the embodiment of the present application, first, for each first time offset value L, based on N1 first sub-correlation compensation sequences, each first sub-correlation compensation sequence, that is, X, is obtained ₂ (k-L) since the value range of k is [0, N-1 ]]When k takes all the values, a plurality of discrete values are obtained, and further energy distribution information corresponding to each first sub-correlation compensation sequence is obtained; it is composed ofAnd secondly, determining the maximum peak value as a first peak value from the energy distribution information corresponding to each first sub-correlation compensation sequence, thereby obtaining N1 first peak values corresponding to N1 first sub-correlation compensation sequences, further screening out candidate peak values from N1 first peak values, determining the information of the target cell, and improving the search efficiency of the target cell.

In some embodiments, for each first time offset value, based on the N1 first sub-correlation compensation sequences, normalizing the plurality of discrete values corresponding to each first sub-correlation compensation sequence to obtain the energy distribution information may be implemented by:

and for each first time offset value, based on the N1 first sub-correlation compensation sequences, performing normalization processing on a plurality of discrete values corresponding to each first sub-correlation compensation sequence to obtain a plurality of normalization values corresponding to each first sub-correlation compensation sequence.

The energy distribution information comprises a plurality of normalization values corresponding to each first sub-correlation compensation sequence.

In the embodiment of the present application, first, for each first time offset value L, based on N1 first sub-correlation compensation sequences, each first sub-correlation compensation sequence, that is, X, is obtained ₂ (k-L) since the value range of k is [0, N-1 ]]Therefore, when k takes different values, it will correspond to a discrete value, and when k takes all values, it will get multiple discrete values. Secondly, the squares of all the discrete numerical values are obtained and summed to obtain the square sum, the square sum is further subjected to root opening twice to obtain the PSS energy, each numerical value in the plurality of discrete numerical values is squared, the squared discrete numerical value is divided by the PSS energy to obtain a plurality of normalization values corresponding to each first sub-correlation compensation sequence, and then energy distribution information corresponding to each first sub-correlation compensation sequence is obtained. Specifically, the plurality of normalization values corresponding to each first sub-correlation compensation sequence can be obtained by the following equation (6):

Y4＝|Y1| ² /S＝|X ₂ (k-L)| ² /S (6)

wherein Y4 represents a plurality of normalized values corresponding to each of the first sub-correlation compensation sequences, Y1 represents the first sub-correlation compensation sequences, and S represents the PSS energy.

Further, the terminal device determines the first peak value with the largest value from the plurality of normalized values corresponding to each first sub-correlation compensation sequence, so as to obtain N1 first peak values corresponding to N1 first sub-correlation compensation sequences. Therefore, a plurality of normalization values are obtained through a normalization processing mode, peak values can be quickly obtained from the normalization values, so that N1 first peak values are obtained, candidate peak values are further screened out from the N1 first peak values, information of the target cell is further determined, and searching efficiency of the target cell is improved.

In an implementation-capable application scenario, referring to fig. 7, fig. 7 is a schematic flow chart illustrating that a time offset is assumed through an FFT to obtain a first candidate peak according to an embodiment of the present application. After the first PSS frequency domain data is obtained, performing frequency domain correlation descrambling, namely cross-correlation operation, on the first PSS frequency domain data, and performing Fast Fourier Transform (FFT) time offset hypothesis on the first PSS frequency domain data subjected to frequency domain correlation descrambling according to a preset first time offset value to obtain a first correlation compensation sequence; in addition, calculating the PSS energy of the first PSS frequency domain data, performing normalization processing based on the calculated PSS energy and the first correlation compensation sequence, wherein the normalization processing is also called antenna combination normalization processing, and determining a candidate peak value corresponding to the first correlation compensation sequence based on the normalized first correlation compensation sequence so as to determine the information of the target cell according to the candidate peak value, thereby improving the search efficiency of the target cell.

In some embodiments, in the case of determining the second time offset value, step 305 performs time offset compensation on the second correlation sequence obtained by performing cross-correlation operation on the first SSS frequency-domain data and the local SSS sequence based on the second time offset value, and the process of obtaining the second correlation compensation sequence is further described with reference to fig. 8,

and 801, performing cross-correlation operation on the first SSS frequency domain data and the local SSS sequence to obtain a second correlation sequence.

And 802, performing discrete transformation on the second correlation sequence to obtain a second transformation sequence.

And step 803, determining a second correlation compensation sequence corresponding to the second time offset value from the second transformation sequence so as to complete time offset compensation.

In the embodiment of the application, the local SSS sequences comprise a plurality of local SSS sequences, and cross-correlation operation is performed on the first SSS frequency domain data and each local SSS sequence in the plurality of local SSS sequences to obtain a plurality of second correlation sequences; based on the plurality of second correlation sequences, performing discrete transformation on each second correlation sequence to obtain a plurality of second transformation sequences; and determining a second correlation compensation sequence corresponding to the second time offset value in each second transformation sequence based on the plurality of second transformation sequences to obtain a plurality of second correlation compensation sequences, thereby completing the time offset compensation. Therefore, each sampling point in the second conversion sequence after discrete conversion is shifted by the second time offset value to obtain a second relevant compensation sequence, and further, the discrete value of the corresponding position of each sampling point when the sampling point is shifted by the second time offset value can be quickly obtained in the second compensation sequence, so that the time length for detecting the synchronous signal can be reduced, the target cell can be quickly detected, and the cell search efficiency is further improved.

In some embodiments, the process of determining the information of the target cell based on the first correlation compensation sequence and the second correlation compensation sequence in step 306 is further illustrated in conjunction with fig. 9 in the case of obtaining the first correlation compensation sequence and the second correlation compensation sequence,

and step 901, determining a second candidate peak value based on the second time offset value and the second correlation compensation sequence.

Wherein the second candidate peak corresponds to a second time offset value and a local SSS sequence.

In the embodiment of the present application, the second candidate peak corresponds to a second time offset value and a local SSS sequence, that is, the group number id NID1 corresponding to the second candidate peak is determined, and the second candidate peak is associated with the existence of the first candidate peak.

Step 902, determining information of the target cell based on the first candidate peak and the second candidate peak corresponding to the first correlation compensation sequence.

Wherein the first candidate peak corresponds to a first time offset value and a local PSS sequence.

In the embodiment of the present application, the first candidate peak corresponds to a first time offset value and a local PSS sequence, that is, the in-group identification NID2 corresponding to the first candidate peak is determined.

In the embodiment of the present application, based on the group number identification NID1 corresponding to the second candidate peak and the in-group identification NID2 corresponding to the first candidate peak corresponding to the second candidate peak, the physical cell identification PCI of the target cell is determined, and then the information of the target cell is obtained.

Here, determining the physical cell identity PCI of the target cell may be obtained by the following equation (7):

PCI＝3×NID1+NID2 (7)

wherein, PCI represents the physical cell identifier of the target cell, and NID1 represents the group number identifier corresponding to the second candidate peak; NID2 represents a corresponding in-group identification of a first candidate peak corresponding to a second candidate peak.

Therefore, under the condition that the first candidate peak value corresponding to the PSS data and the second candidate peak value corresponding to the SSS data are determined, the information of the target cell is determined based on the position of the second candidate peak value and the position of the first candidate peak value corresponding to the obtained second candidate peak value, so that it is ensured that the terminal device can be quickly reselected or switched to the target cell in the moving process.

In some embodiments, where a second time offset value and a second correlation compensation sequence are obtained, step 901 further illustrates the process of determining a second candidate peak based on the second time offset value and the second correlation compensation sequence, as described in conjunction with fig. 10,

step 1001, the second time offset value includes: p second time offset values, each corresponding to N2 second sub-correlation compensation sequences, each second correlation compensation sequence including N2 second sub-correlation compensation sequences corresponding to P second time offset values, and for each second time offset value, N2 second peaks are determined based on the N2 second sub-correlation compensation sequences.

Wherein, P is an integer greater than or equal to 1 and less than or equal to W; n2 is an integer greater than or equal to 1.

Here, N2 is the total number of all local SSS sequences.

Step 1002, for the P second time offset values, Q second candidate peaks larger than or equal to a second preset peak threshold are determined from the P × N2 second peaks.

Wherein Q is an integer of 1 or more and P × N2 or less.

In this embodiment of the application, the second preset peak threshold may be a preset peak value, or the second preset peak threshold may be a peak value dynamically adjusted according to the current scene, for example, the second preset peak threshold is dynamically set to obtain the largest candidate peak, and this is not limited in this application. It should be noted that, the first preset peak threshold and the second preset peak threshold may be the same, or the first preset peak threshold and the second preset peak threshold may also be different, and the application is not limited specifically.

In this embodiment, first, for each of the P second time offset values, N2 second peak values are determined based on N2 second sub-correlation compensation sequences corresponding to the second correlation compensation sequences respectively including the P second time offset values. Secondly, for the P second time offset values, Q second candidate peaks greater than or equal to a second preset peak threshold value are determined from the P × N2 second peaks, so as to determine information of the target cell according to the second candidate peaks.

As can be seen from the above, when there are a plurality of second time offset values, each second time offset value corresponds to a plurality of second sub-correlation compensation sequences in the second correlation compensation sequence obtained through discrete transformation, and each second sub-correlation compensation sequence has a peak value, so each second time offset value corresponds to a plurality of peak values, and a peak value meeting a condition is selected as a second candidate peak value from all peak values corresponding to all second time offset values, so that information of a target cell can be determined based on a position of the second candidate peak value and a position of a first candidate peak value corresponding to the obtained second candidate peak value, and thus it is ensured that the terminal device can quickly reselect or switch to the target cell during moving.

Fig. 11 is a schematic flow chart of an implementation of an optional cell search method provided in an embodiment of the present application, and as shown in fig. 11, the method may be applied to a device, where the device may be a chip or a terminal device, and here, the terminal device is taken as an execution subject for description, and the method includes:

step 1101, performing data transformation on the received time domain data of the plurality of cells to obtain second PSS frequency domain data and second SSS frequency domain data.

In the embodiment of the present application, the time domain data is formed by adding Noise to signals of multiple co-frequency cells, and the Noise may be, for example, Additive White Gaussian Noise (AWGN). Referring to fig. 12, fig. 12 is a schematic diagram illustrating a principle that a device searches for a plurality of co-frequency cells; when a plurality of cells with the same frequency exist in the searching range of the terminal equipment, the received time domain data is formed by adding noise to a plurality of cell signals.

Optionally, performing data transformation on the received time domain data of multiple cells may include: and performing frequency domain transformation on the received time domain data of the plurality of cells.

Optionally, the data transformation of the received time domain data of the multiple cells may include: and performing fast Fourier transform on the received time domain data of the plurality of cells.

Here, after receiving the time domain data of the multiple co-frequency cells, the terminal performs fast fourier transform on the time domain data to obtain frequency domain data, where the frequency domain data includes second PSS frequency domain data and second SSS frequency domain data.

It should be noted that the received signal data can be modeled in the frequency domain space, i.e., Y ═ Σ _i H _i ×D _i + N; where Y denotes signal data received via a channel, and H _i Representing the channel frequency response of the ith channel, D _i Indicating the signal data transmitted on the ith channel. The received signal data is composed of multiple cell signals and noise, interference cell elimination mainly refers to elimination in the same frequency band, and the signal position difference does not exceed circulationThe basic principle of the interfering cell signals in the prefix range is to estimate and reconstruct each cell signal at the UE receiving end, then sequentially subtract these interferences from the received signals, and finally perform cell detection on the obtained signals to obtain the information of the target cell.

Step 1102, eliminating the PSS frequency domain data reconstructed by the same-frequency known cell in the second PSS frequency domain data to obtain first PSS frequency domain data; and eliminating the SSS frequency domain data reconstructed by the known cell with the same frequency in the second SSS frequency domain data to obtain first SSS frequency domain data.

In this embodiment of the present application, the known cell may be a serving cell where the terminal device currently resides, and the known cell may also be a neighboring cell of the serving cell where the terminal device resides, and of course, the known cell may also be information of a first target cell determined after performing one or more cell detections, where the known cell may also be referred to as an interfering cell, and the known cell may also be any cell except the first target cell, which is not limited in this application.

In the embodiment of the present application, there may be one known cell, or there may be a plurality of known cells; under the condition that a plurality of cells are known, eliminating PSS frequency domain data reconstructed by a plurality of known cells with the same frequency in the second PSS frequency domain data to obtain first PSS frequency domain data; and eliminating the SSS frequency domain data reconstructed by a plurality of known cells with the same frequency in the second SSS frequency domain data to obtain first SSS frequency domain data.

In the embodiment of the application, under the condition that received time domain data of a plurality of cells are subjected to data transformation to obtain second PSS frequency domain data and second SSS frequency domain data, PSS frequency domain data reconstructed by a known cell and reconstructed SSS frequency domain data with the same frequency are obtained, and the PSS frequency domain data reconstructed by the known cell is eliminated from the second PSS frequency domain data to obtain first PSS frequency domain data; and eliminating the SSS frequency domain data reconstructed by the known cell from the second SSS frequency domain data to obtain first SSS frequency domain data.

In some embodiments, step 1102 eliminates PSS frequency domain data reconstructed for a known cell of the same frequency from the second PSS frequency domain data to obtain first PSS frequency domain data; and eliminating the SSS frequency-domain data reconstructed for the known cell of the same frequency from the second SSS frequency-domain data to obtain the first SSS frequency-domain data, as further described with reference to fig. 13,

and step 1301, performing least square parameter estimation on the second SSS frequency domain data to obtain a first channel frequency response of the known cell.

In this embodiment of the present application, the first channel frequency response of the known cell may be directly obtained after performing Least Square Method (LS) parameter estimation on the second SSS frequency domain data, and certainly, the first channel frequency response of the known cell may be directly obtained after performing LS parameter estimation on the second PSS frequency domain data, which is not limited in this application.

In other embodiments of the present application, the first channel frequency response of the known cell may also be obtained by performing LS parameter estimation on the second SSS frequency domain data to obtain a second channel frequency response, and performing filtering processing on the second channel frequency response; of course, the first channel frequency response of the known cell may also be obtained by performing LS parameter estimation on the second PSS frequency domain data to obtain the second channel frequency response, and performing filtering processing on the second channel frequency response. In this regard, the present application is not particularly limited.

Here, taking an example that the LS parameter estimation is performed on the second SSS frequency domain data to obtain the first channel frequency response of the known cell, the first channel frequency response is obtained by performing a dot division operation on the second SSS frequency domain data and the local SSS sequence corresponding to the known cell.

In some embodiments, step 1301 derives the first channel frequency response of the known cell based on least squares parameter estimation of the second SSS frequency domain data, as further illustrated in conjunction with figure 14,

and 1401, performing least square parameter estimation on the second SSS frequency domain data to obtain a second channel frequency response of the known cell.

And 1402, filtering the second channel frequency response by using the minimum mean square error to obtain the first channel frequency response.

In the embodiment of the application, under the condition that the second channel frequency response of a known cell is obtained by performing least Square method parameter estimation on the second SSS frequency domain data, the second channel frequency response is filtered through Minimum Mean Square Error (MMSE), so as to obtain the first channel frequency response. Therefore, the accuracy of the channel frequency response is improved by performing the filtering operation on the channel frequency response, so that the accuracy of the frequency reconstruction data of the known cell based on the first channel frequency response is improved.

Step 1302, reconstructing the local PSS sequence of the known cell according to the first channel frequency response to obtain the PSS frequency domain reconstruction data of the known cell.

And step 1303, eliminating the PSS frequency domain reconstruction data in the second PSS frequency domain data to obtain the first PSS frequency domain data.

And 1304, reconstructing the local SSS sequence of the known cell through the first channel frequency response to obtain SSS frequency domain reconstruction data of the known cell.

And step 1305, eliminating the SSS frequency domain reconstruction data in the second SSS frequency domain data to obtain the first SSS frequency domain data.

In the embodiment of the application, firstly, terminal equipment receives time domain data and performs fast Fourier transform on the received time domain data to obtain second PSS frequency domain data and second SSS frequency domain data; and secondly, determining a current cell where the terminal equipment resides as a known cell based on the second PSS frequency domain data and the second SSS frequency domain data, and then determining a local PSS sequence and a local SSS sequence corresponding to the known cell according to the position and time information of the known cell. Then, performing dot division operation on the second SSS frequency domain data and a local SSS sequence corresponding to the known cell, namely performing channel estimation on the known cell to obtain a first channel frequency response of the known cell; further, reconstructing a local PSS sequence of the known cell through the first channel frequency response to obtain PSS frequency domain reconstruction data of the known cell, and reconstructing a local SSS sequence of the known cell through the first channel frequency response to obtain SSS frequency domain reconstruction data of the known cell; and finally, eliminating PSS frequency domain reconstruction data of a known cell in the second PSS frequency domain data to obtain first PSS frequency domain data, and eliminating SSS frequency domain reconstruction data of the known cell in the second SSS frequency domain data to obtain first SSS frequency domain data. Therefore, by eliminating the frequency domain data of the known cell, such as the current cell where the terminal equipment is located or the target cell, and detecting the frequency domain data of other cells except the known cell, the complexity of the PSS interference elimination is effectively reduced, the efficiency of the PSS interference elimination is improved, and convenience is provided for the reselection and the switching of the terminal equipment.

It should be noted that, in the neighbor cell search process, it is assumed that there is no frequency offset between the neighbor cell and the serving cell, and therefore, the frequency domain estimated value of the PSS channel and the frequency domain estimated value of the SSS channel can be regarded as being equal. Thus, the calculation amount of the PSS channel estimation can be saved, and the performance has no influence.

Step 1103, performing cross-correlation operation on the first PSS frequency domain data and the local PSS sequence to obtain a first correlation sequence.

And 1104, respectively performing time offset compensation on the first transformed sequence after the first correlation sequence is subjected to the discrete transformation based on a preset first time offset value to obtain a first correlation compensation sequence.

Step 1105, determining information of the target cell based on the first correlation compensation sequence, the first time offset value and the first SSS frequency domain data.

According to the method, the position of the known cell is determined, the frequency domain data reconstructed by the known cell is eliminated from the frequency domain data transformed by the time domain data received in total, the frequency domain data after interference elimination is obtained, and PSS detection and SSS detection are carried out on the frequency domain data after interference elimination.

In some embodiments, after determining the information of the target cell based on the first correlation compensation sequence, the first time offset value and the first SSS frequency domain data in step 1105, the following steps may be further performed:

step 1106, in a case that the first PSS frequency domain data is the PSS frequency domain data after the interference of the known cell is eliminated for the received time domain data, taking the target cell as the known cell, updating the first PSS frequency domain data and the first SSS frequency domain data, and determining information of the next target cell based on the updated first PSS frequency domain data and the updated first SSS frequency domain data until a preset stop condition is reached.

In the embodiment of the application, the preset stop condition may be a number of rounds that can be circulated according to the capability information of the terminal device; the preset stop condition may also be that PSS frequency domain data and/or SSS data are not detected at the terminal device.

In the embodiment of the application, when first PSS frequency domain data is PSS frequency domain data obtained by eliminating interference of a known cell for received time domain data and first SSS frequency domain data is SSS frequency domain data obtained by eliminating interference of the known cell for the received time domain data, a terminal device first determines information of a target cell based on the first PSS frequency domain data and the first SSS frequency domain data; and secondly, taking the target cell as a known cell, updating the first PSS frequency domain data and the first SSS frequency domain data, and determining the information of the next target cell based on the updated first PSS frequency domain data and the updated first SSS frequency domain data until a preset stop condition is reached.

Here, the target cell is taken as a known cell, the first PSS frequency domain data and the first SSS frequency domain data are updated, and the information of the next target cell is determined based on the updated first PSS frequency domain data and the updated first SSS frequency domain data until a preset stop condition is reached, which may be implemented by the following processes:

determining a local PSS sequence and a local SSS sequence corresponding to a target cell (known cell) according to the position and time information of the target cell; then, performing dot division operation on the first SSS frequency domain data and a local SSS sequence corresponding to the target cell, namely performing channel estimation on the target cell to obtain a third channel frequency response of the target cell; further, reconstructing the local PSS sequence of the target cell through a third channel frequency response to obtain PSS frequency domain reconstruction data of the target cell, and reconstructing the local SSS sequence of the target cell through the third channel frequency response to obtain SSS frequency domain reconstruction data of the target cell; and finally, removing the PSS frequency domain reconstruction data of the target cell in the first PSS frequency domain data to obtain third PSS frequency domain data (namely, updating the first PSS frequency domain data), and removing the SSS frequency domain reconstruction data of the target cell in the first SSS frequency domain data to obtain third SSS frequency domain data (namely, updating the first SSS frequency domain data). Further, performing cross-correlation operation on the third PSS frequency domain data and a local PSS sequence corresponding to the target cell to obtain a third correlation sequence; respectively performing time offset compensation on a third conversion sequence after discrete conversion on the third correlation sequence based on a preset third time offset value to obtain a third correlation compensation sequence; and determining the information of the next target cell based on the third correlation compensation sequence, the third time offset value and the third SSS frequency domain data, and repeating the steps until the preset cycle number is reached or the PSS frequency domain data and/or the SSS data are detected unsuccessfully, stopping searching the next target cell, and thus obtaining the information of a plurality of target cells through multiple detections.

As can be seen from the above, each time the information of one target cell is determined, the target cell may be used as a known cell, PSS frequency domain data reconstructed by the known cell is removed from the first PSS frequency domain data to obtain third PSS frequency domain data, and SSS frequency domain data reconstructed by the known cell is removed from the first SSS frequency domain data to obtain third SSS frequency domain data; further, PSS detection is carried out on third PSS frequency domain data after interference elimination, and SSS detection is carried out on third SSS frequency domain data after interference elimination; obtaining the information of the next target cell, and analogizing until the detection times reach the preset cycle times or the detection of PSS frequency domain data and/or SSS data fails, stopping searching the information of the target cell, thus eliminating the interference of the same-frequency cells, avoiding the interference of the known cells, searching a plurality of same-frequency cells, improving the accuracy of searching the same-frequency cells and improving the detection performance of the same-frequency cells; meanwhile, the terminal equipment is ensured to be capable of reselecting or switching to the target cell quickly in the moving process.

Fig. 15 is a schematic flow chart of an implementation of an optional cell search method provided in an embodiment of the present application, and as shown in fig. 15, the method may be applied to a device, where the device may be a chip or a terminal device, and here, the terminal device is taken as an execution subject for description, and the method includes:

step 1501, receiving time domain data of a plurality of cells.

Step 1502, performing fast fourier transform on the time domain data to obtain second PSS frequency domain data and second SSS frequency domain data of the multiple cells.

In an embodiment of the present application, the second PSS frequency domain data includes PSS frequency domain data and noise data of a plurality of cells. The second SSS frequency domain data includes SSS frequency domain data and noise data for the plurality of cells.

And step 1503, acquiring a local SSS sequence of the known cell.

Wherein the plurality of cells includes known cells.

In this embodiment of the present application, the known cell may be one or multiple cells, where the known cell may be a serving cell where the terminal device currently resides, or the known cell may also be a neighboring cell of the serving cell where the terminal device resides, or of course, the known cell may also be information of a first target cell determined after performing one or more cell searches, or the known cell may also be any cell for which information of the cell has been determined through other approaches.

Step 1504, based on the local SSS sequence of the known cell, performing LS parameter estimation on the second SSS frequency domain data to obtain a second channel frequency response H of the known cell.

In the embodiment of the present application, the terminal device performs LS parameter estimation on the second SSS frequency domain data based on the local SSS sequence of the known cell to obtain the second channel frequency response H of the known cell, which may be understood as performing a dot division operation on the second SSS frequency domain data and the local SSS sequence of the known cell to obtain the second channel frequency response H of the known cell.

Step 1505, filter the second channel frequency response with the minimum mean square error to obtain the first channel frequency response H' of the known cell.

And 1506, reconstructing the local PSS sequence of the known cell through the first channel frequency response to obtain PSS frequency domain reconstruction data of the known cell, and reconstructing the local SSS sequence of the known cell through the first channel frequency response to obtain SSS frequency domain reconstruction data of the known cell.

Step 1507, the second PSS frequency domain data is updated based on the PSS frequency domain reconstruction data of the known cell, and the second SSS frequency domain data is updated based on the SSS frequency domain reconstruction data of the known cell.

In the embodiment of the application, the PSS frequency domain reconstruction data of the known cell in the second PSS frequency domain data is eliminated, so that the second PSS frequency domain data is updated; and eliminating SSS frequency domain reconstruction data of the known cell in the second SSS frequency domain data, thereby realizing the update of the second SSS frequency domain data.

Step 1508, judging whether other known cells exist, if so, returning to step 1503; if not, go to step 1509.

In this embodiment, if there are multiple known cells, if it is determined that there are other known cells, step 1503 to step 1508 may be continuously performed repeatedly, so as to eliminate the signal of the next known cell until all the signals of the known cells are completely eliminated.

It should be noted that, when the PSS frequency domain reconstruction data of all known cells have been eliminated from the second PSS frequency domain data, the obtained updated second PSS frequency domain data is the first PSS frequency domain data. Similarly, when the SSS frequency-domain reconstruction data of all known cells have been eliminated from the second SSS frequency-domain data, the obtained updated second SSS frequency-domain data is the first SSS frequency-domain data.

Step 1509, obtain a preset first time offset value.

Step 1510, based on the first time offset value, perform correlation compensation and detection on the updated second PSS frequency domain data, thereby obtaining a second time offset value for performing correlation compensation on the updated second SSS frequency domain data.

And 1511, performing correlation compensation and detection on the updated second SSS frequency domain data based on the second time offset value.

Step 1512, determine information of the target cell.

1513, judging whether the preset stop condition is reached, if not, taking the target cell as a known cell, and returning to step 1503 to determine the information of the next target cell; if yes, the search is ended.

Therefore, the frequency domain data of the known cell is eliminated in the received data, so that the second PSS frequency domain data and the second SSS frequency domain data with the interference of the known cell eliminated are obtained, and the number of the cells detected in the second PSS frequency domain data is reduced, so that the cell search performance is improved; further, in a frequency domain PSS detection stage, time offset compensation is performed on a transform sequence of the updated second PSS frequency domain data (i.e., the first PSS frequency domain data) in a discrete transform manner to obtain a related compensation sequence, and then information of the target cell is determined based on the related compensation sequence, the updated second SSS frequency domain data (the first SSS frequency domain data), and a preset first time offset value; further, when the preset stop condition is not reached, the target cell is used as a known cell, the second PSS frequency domain data and the second SSS frequency domain data are continuously updated, and information of a next target cell is determined based on the updated second PSS frequency domain data and the updated second SSS frequency domain data until the preset stop condition is reached. Therefore, the calculation amount and the realization complexity are greatly reduced, the cell search efficiency is improved, and the cell search performance and the cell search efficiency are considered in a double mode in the process of determining the information of the target cell.

Based on the foregoing embodiments, an embodiment of the present application provides a cell search apparatus, where the apparatus includes units and modules included in the units, and the cell search apparatus may be implemented by a processor in a terminal device; of course, it may be implemented by a specific logic circuit.

Fig. 16 is a schematic structural diagram of a cell search apparatus according to an embodiment of the present application, and as shown in fig. 16, the cell search apparatus 1600 includes:

the processing module 1601 is configured to perform cross-correlation operation on the first PSS frequency domain data and the local PSS sequence to obtain a first correlation sequence; the first PSS frequency domain data is the PSS frequency domain data after interference of the received time domain data is eliminated;

a compensation module 1602, configured to perform time offset compensation on a first transform sequence after discrete transform of the first correlation sequence based on a preset first time offset value, respectively, to obtain a first correlation compensation sequence;

a determining module 1603, configured to determine information of the target cell based on the first correlation compensation sequence, the first time offset value, and the first SSS frequency-domain data; the first SSS frequency-domain data is SSS frequency-domain data from which interference is cancelled in the received time-domain data.

In some embodiments, the processing module 1601 is further configured to perform discrete transform on the first correlation sequence to obtain a first transform sequence; the compensation module 1602 is further configured to determine a first correlation compensation sequence corresponding to the first time offset value from the first transform sequence, so as to complete time offset compensation.

In some embodiments, the determining module 1603 is further configured to determine a second time offset value based on the first time offset value and the first correlation compensation sequence; the processing module 1601 is further configured to perform time offset compensation on a second correlation sequence obtained by performing cross-correlation operation on the first SSS frequency domain data and the local SSS sequence based on a second time offset value, to obtain a second correlation compensation sequence; the determining module 1603 is further configured to determine information of the target cell based on the first correlation compensation sequence and the second correlation compensation sequence.

In some embodiments, the determining module 1603 is further configured to determine a first candidate peak based on the first time offset value and the first correlation compensation sequence; the processing module 1601 is further configured to perform a remainder operation on the first candidate peak and the length of the first PSS frequency domain data, so as to obtain a second time offset value.

In some embodiments, the first time offset value comprises: w first time offset values, W being an integer greater than or equal to 1; each first time offset value corresponds to N1 first sub-correlation compensation sequences, each first correlation compensation sequence includes N1 first sub-correlation compensation sequences corresponding to W first time offset values, N1 is an integer greater than or equal to 1; a determining module 1603, further configured to determine, for each first time offset value, N1 first peaks based on N1 first sub-correlation compensation sequences; determining U first candidate peaks which are larger than or equal to a first preset peak threshold value from W multiplied by N1 first peaks for W first time offset values; u is an integer greater than or equal to 1 and less than or equal to W × N1.

In some embodiments, the cell search apparatus further includes an obtaining module 1604, where the obtaining module 1604 is configured to obtain, for each first time offset value, energy distribution information corresponding to each first sub-correlation compensation sequence based on the N1 first sub-correlation compensation sequences; the determining module 1603 is further configured to determine a first peak value corresponding to each first sub-correlation compensation sequence based on the energy distribution information corresponding to each first sub-correlation compensation sequence, so as to obtain N1 first peak values corresponding to N1 first sub-correlation compensation sequences.

In some embodiments, the processing module 1601 is further configured to perform a remainder operation on each first candidate peak and the length of the first PSS frequency domain data to obtain at least one second time offset value.

In some embodiments, the processing module 1601 is further configured to perform cross-correlation operation on the first SSS frequency domain data and the local SSS sequence to obtain a second correlation sequence; performing discrete transformation on the second correlation sequence to obtain a second transformation sequence; the compensation module 1602 is further configured to determine a second associated compensation sequence corresponding to the second time offset value from the second transformed sequence, so as to complete time offset compensation.

In some embodiments, the obtaining module 1604 is further configured to obtain a first candidate peak corresponding to the first correlation compensation sequence; wherein, the first candidate peak value corresponds to a first time offset value and a local PSS sequence; a determining module 1603, further configured to determine a second candidate peak value based on the second time offset value and the second correlation compensation sequence; wherein the second candidate peak corresponds to a second time offset value and a local SSS sequence; information of the target cell is determined based on the first candidate peak and the second candidate peak.

In some embodiments, the second time offset value comprises: p second time offset values, wherein P is an integer which is greater than or equal to 1 and less than or equal to W; each second time offset value corresponds to N2 second sub-correlation compensation sequences, each second correlation compensation sequence includes N2 second sub-correlation compensation sequences corresponding to P second time offset values, N2 is an integer greater than or equal to 1; a determining module 1603, further configured to determine, for each second time offset value, N2 second peak values based on N2 second sub-correlation compensation sequences; determining Q second candidate peaks greater than or equal to a second preset peak threshold from the P × N2 second peaks for the P second time offset values; q is an integer greater than or equal to 1 and less than or equal to P × N2.

In some embodiments, the processing module 1601 is further configured to perform data transformation on the received time domain data of the multiple cells to obtain second PSS frequency domain data and second SSS frequency domain data; eliminating the PSS frequency domain data reconstructed aiming at the known cells with the same frequency in the second PSS frequency domain data to obtain first PSS frequency domain data; and eliminating the SSS frequency domain data reconstructed by the known cells with the same frequency in the second SSS frequency domain data to obtain first SSS frequency domain data.

In some embodiments, the processing module 1601 is further configured to obtain a first channel frequency response of the known cell based on performing least square parameter estimation on the second SSS frequency-domain data; reconstructing a local PSS sequence of the known cell through the first channel frequency response to obtain PSS frequency domain reconstruction data of the known cell; and eliminating the PSS frequency domain reconstruction data in the second PSS frequency domain data to obtain the first PSS frequency domain data.

In some embodiments, the processing module 1601 is further configured to reconstruct the local SSS sequence of the known cell through the first channel frequency response, to obtain SSS frequency domain reconstruction data of the known cell; and eliminating SSS frequency domain reconstruction data in the second SSS frequency domain data to obtain first SSS frequency domain data.

In some embodiments, the processing module 1601 is further configured to perform least squares parameter estimation on the second SSS frequency-domain data to obtain a second channel frequency response of the known cell; and filtering the second channel frequency response by adopting the minimum mean square error to obtain the first channel frequency response.

In some embodiments, the first PSS frequency domain data is PSS frequency domain data obtained by eliminating interference of a known cell for the received time domain data, and the processing module 1601 is further configured to take the target cell as the known cell, update the first PSS frequency domain data and the first SSS frequency domain data, and determine the next target cell information based on the updated first PSS frequency domain data and the updated first SSS frequency domain data until a preset stop condition is reached.

The above description of the apparatus embodiments, similar to the above description of the method embodiments, has similar beneficial effects as the method embodiments. For technical details not disclosed in the embodiments of the apparatus of the present application, reference is made to the description of the embodiments of the method of the present application for understanding.

It should be noted that, in the embodiment of the present application, if the cell search method is implemented in the form of a software functional module and sold or used as a standalone product, the cell search method may also be stored in a computer storage medium. Based on such understanding, the technical solutions of the embodiments of the present application or portions thereof that contribute to the related art may be embodied in the form of a software product, where the computer software product is stored in a storage medium and includes several instructions for enabling a terminal device to execute all or part of the methods described in the embodiments of the present application.

Fig. 17 is a schematic configuration diagram of an apparatus of the embodiment of the present application. The apparatus 1700 shown in figure 17 comprises a processor 1701 and a memory 1702,

the memory 1702 stores a computer program operable on the processor 1701,

the processor 1701, when executing the computer program, implements the steps of the cell search method of any of the above embodiments.

The device in the embodiment of the present application may be a terminal device or a chip. The Terminal equipment may be referred to herein as a Terminal (Terminal), User Equipment (UE), Mobile Station (MS), Mobile Terminal (MT), etc. The electronic device herein may include one or a combination of at least two of the following: internet of Things (IoT) devices, satellite terminals, Wireless Local Loop (WLL) stations, Personal Digital Assistant (PDA), handheld devices with Wireless communication capabilities, computing devices or other processing devices connected to Wireless modems, servers, cell phones (mobile phones), tablet computers (Pad), computers with Wireless transceiving capabilities, palm computers, desktop computers, Personal Digital assistants, portable media players, smart speakers, navigation devices, smart watches, smart glasses, wearable devices such as smart necklaces, pedometers, Digital TVs, Virtual Reality (VR) terminal devices, Augmented Reality (AR) terminal devices, Wireless terminals in industrial control (industrial control), Wireless terminals in unmanned driving (self), Wireless terminals in remote surgical (remote medical) terminals, A wireless terminal in a smart grid (smart grid), a wireless terminal in transportation safety (transportation safety), a wireless terminal in a smart city (smart city), a wireless terminal in a smart home (smart home), and a vehicle, a vehicle-mounted device, a vehicle-mounted module, a wireless modem (modem), a handheld device (hand), a Customer Premises Equipment (CPE), a smart appliance, and the like in a vehicle networking system.

The processor 1701 in the apparatus 1700 may be a chip, such as an integrated circuit chip, having signal processing capabilities. In implementation, the steps of the above method embodiments may be performed by integrated logic circuits of hardware in a processor or instructions in the form of software.

The Processor 1701 may also be a general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic, discrete hardware components. The various methods, steps, and logic blocks disclosed in the embodiments of the present application may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in connection with the embodiments of the present application may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor.

Embodiments of the present application may also provide a computer storage medium storing one or more programs, which are executable by one or more processors to implement the steps of the cell search method according to any of the above embodiments.

Here, it should be noted that: the above description of the embodiments of the storage medium and the terminal device is similar to the description of the embodiments of the method described above, and has similar advantageous effects to the embodiments of the method. For technical details not disclosed in the embodiments of the storage medium and the terminal device of the present application, please refer to the description of the embodiments of the method of the present application for understanding.

The computer storage media/memory may include an integration of one or more of the following: memories such as Read Only Memory (ROM), Programmable Read Only Memory (PROM), Erasable Programmable Read Only Memory (EPROM), Electrically Erasable Programmable Read Only Memory (EEPROM), magnetic Random Access Memory (FRAM), Flash Memory (Flash Memory), magnetic surface Memory, optical Disc, and optical Disc (CD-ROM); but may also be various terminals such as mobile phones, computers, tablet devices, personal digital assistants, etc., that include one or any combination of the above-mentioned memories.

It should be appreciated that reference throughout this specification to "one embodiment" or "an embodiment of the present application" or "a previous embodiment" or "some implementations" or "some embodiments" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" or "an embodiment of the present application" or "the preceding embodiments" or "some embodiments" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. It should be understood that, in the various embodiments of the present application, the sequence numbers of the above-mentioned processes do not mean the execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application. The above-mentioned serial numbers of the embodiments of the present application are merely for description and do not represent the merits of the embodiments.

In a case where no specific description is given, the terminal device may execute any step in the embodiment of the present application, where the processor of the terminal device may execute the step. The embodiment of the present application does not limit the sequence of the steps executed by the terminal device unless otherwise specified. In addition, the data may be processed in the same way or in different ways in different embodiments. It should be further noted that any step in the embodiments of the present application may be executed by the terminal device independently, that is, when the terminal device executes any step in the embodiments, it may not depend on the execution of other steps.

In the several embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other ways. The above-described device embodiments are merely illustrative, for example, the division of the unit is only a logical functional division, and there may be other division ways in actual implementation, such as: multiple units or components may be combined, or may be integrated into another system, or some features may be omitted, or not implemented. In addition, the coupling, direct coupling or communication connection between the components shown or discussed may be through some interfaces, and the indirect coupling or communication connection between the devices or units may be electrical, mechanical or other forms.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units; can be located in one place or distributed on a plurality of network units; some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, all functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may be separately regarded as one unit, or two or more units may be integrated into one unit; the integrated unit can be realized in a form of hardware, or in a form of hardware plus a software functional unit.

The methods disclosed in the several method embodiments provided in the present application may be combined arbitrarily without conflict to obtain new method embodiments.

Features disclosed in several of the product embodiments provided in the present application may be combined in any combination to yield new product embodiments without conflict.

The features disclosed in the several method or apparatus embodiments provided in the present application may be combined arbitrarily, without conflict, to arrive at new method embodiments or apparatus embodiments.

Those of ordinary skill in the art will understand that: all or part of the steps for realizing the method embodiments can be completed by hardware related to program instructions, the program can be stored in a computer storage medium, and the program executes the steps comprising the method embodiments when executed; and the aforementioned storage medium includes: various media that can store program codes, such as a removable Memory device, a Read Only Memory (ROM), a magnetic disk, or an optical disk.

Alternatively, the integrated units described above in this application may be stored in a computer storage medium if they are implemented in the form of software functional modules and sold or used as separate products. Based on such understanding, the technical solutions of the embodiments of the present application may be essentially implemented or portions thereof contributing to the related art may be embodied in the form of a software product stored in a storage medium, and including several instructions for enabling a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the methods described in the embodiments of the present application. And the aforementioned storage medium includes: a removable storage device, a ROM, a magnetic or optical disk, or other various media that can store program code.

In the embodiments of the present application, the descriptions of the same steps and the same contents in different embodiments may be mutually referred to. In the embodiment of the present application, the term "and" does not affect the order of the steps, for example, the terminal device executes a and executes B, where the terminal device may execute a first and then execute B, or the terminal device executes B first and then executes a, or the terminal device executes B while executing a.

As used in the examples of this application and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It should be noted that, in the embodiments related to the present application, all the steps may be executed or some of the steps may be executed, as long as a complete technical solution can be formed.

The above description is only for the embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A method of cell search, comprising:

performing cross-correlation operation on the frequency domain data of the first primary synchronization signal PSS and the local PSS sequence to obtain a first correlation sequence; the first PSS frequency domain data is the PSS frequency domain data after interference of the received time domain data is eliminated;

determining information of a target cell based on the first correlation compensation sequence, the first time offset value and first Secondary Synchronization Signal (SSS) frequency domain data; the first SSS frequency domain data is SSS frequency domain data with interference eliminated from received time domain data.

2. The method according to claim 1, wherein the performing time offset compensation on the first transform sequence after fourier transform on the first correlation sequence based on a preset first time offset value to obtain a first correlation compensation sequence comprises:

performing discrete transformation on the first correlation sequence to obtain a first transformation sequence;

and determining the first correlation compensation sequence corresponding to the first time offset value in the first transformation sequence so as to complete the time offset compensation.

3. The method of claim 1 or 2, wherein the determining information of the target cell based on the first correlation compensation sequence, the first time offset value and first SSS frequency domain data comprises:

determining a second time offset value based on the first time offset value and the first correlation compensation sequence;

performing time offset compensation on a second correlation sequence obtained after performing cross-correlation operation on the first SSS frequency domain data and a local SSS sequence based on the second time offset value to obtain a second correlation compensation sequence;

determining information of the target cell based on the first correlation compensation sequence and the second correlation compensation sequence.

4. The method of claim 3, wherein determining a second time offset value based on the first time offset value and the first correlation compensation sequence comprises:

determining a first candidate peak based on the first time offset value and the first correlation compensation sequence;

and performing remainder operation on the first candidate peak value and the length of the first PSS frequency domain data to obtain the second time offset value.

5. The method of claim 4, wherein the first time offset value comprises: w first time offset values, W being an integer greater than or equal to 1; each first time offset value corresponds to N1 first sub-correlation compensation sequences, the first correlation compensation sequences include N1 first sub-correlation compensation sequences corresponding to W first time offset values, N1 is an integer greater than or equal to 1;

determining a first candidate peak based on the first time offset value and the first correlation compensation sequence, comprising:

determining N1 first peaks based on the N1 first sub-correlation compensation sequences for the each first time offset value;

determining, for the W first time offset values, U first candidate peaks from among W × N1 first peaks, which are greater than or equal to a first preset peak threshold; u is an integer greater than or equal to 1 and less than or equal to W × N1.

6. The method of claim 5, wherein the determining N1 first peaks for the each first time offset value based on the N1 first sub-correlation compensation sequences comprises:

for each first time offset value, acquiring energy distribution information corresponding to each first sub-correlation compensation sequence based on the N1 first sub-correlation compensation sequences;

and determining a first peak value corresponding to each first sub-correlation compensation sequence based on the energy distribution information corresponding to each first sub-correlation compensation sequence, so as to obtain N1 first peak values corresponding to N1 first sub-correlation compensation sequences.

7. The method of claim 5 or 6, wherein the subtracting the length of the first PSS frequency domain data from the first candidate peak to obtain the second time offset value comprises:

and performing remainder operation on each first candidate peak value and the length of the first PSS frequency domain data to obtain at least one second time offset value.

8. The method according to any one of claims 3 to 7, wherein the performing time offset compensation on the second correlation sequence obtained by performing cross-correlation operation on the first SSS frequency-domain data and a local SSS sequence based on the second time offset value to obtain a second correlation compensation sequence comprises:

performing cross-correlation operation on the first SSS frequency domain data and the local SSS sequence to obtain a second correlation sequence;

performing discrete transformation on the second correlation sequence to obtain a second transformation sequence;

and determining the second relevant compensation sequence corresponding to the second time offset value in the second transformation sequence so as to complete the time offset compensation.

9. The method according to any of claims 4 to 7, wherein the determining the information of the target cell based on the first correlation compensation sequence and the second correlation compensation sequence comprises:

determining a second candidate peak based on the second time offset value and the second correlation compensation sequence; wherein the second candidate peak corresponds to a second time offset value and a local SSS sequence;

determining information of the target cell based on the first candidate peak and the second candidate peak corresponding to the first correlation compensation sequence; the first candidate peak corresponds to a first time offset value and a local PSS sequence.

10. The method of claim 9, wherein the second time offset value comprises: p second time offset values, wherein P is an integer which is greater than or equal to 1 and less than or equal to W; each second time offset value corresponds to N2 second sub-correlation compensation sequences, the second correlation compensation sequences include N2 second sub-correlation compensation sequences corresponding to P second time offset values, N2 is an integer greater than or equal to 1;

determining a second candidate peak based on the second time offset value and the second correlation compensation sequence, including:

determining N2 second peaks based on the N2 second sub-correlation compensation sequences for the each second time offset value;

determining, for the P second time offset values, Q second candidate peaks from among P × N2 second peaks, which are greater than or equal to a second preset peak threshold; q is an integer greater than or equal to 1 and less than or equal to P × N2.

11. The method of any of claims 1 to 10, wherein before performing the cross-correlation of the first PSS frequency-domain data with the local PSS sequence to obtain the first correlation sequence, the method comprises:

performing data transformation on the received time domain data of the plurality of cells to obtain second PSS frequency domain data and second SSS frequency domain data;

eliminating the PSS frequency domain data reconstructed aiming at the known cells with the same frequency in the second PSS frequency domain data to obtain the first PSS frequency domain data; and eliminating SSS frequency domain data reconstructed by the known cell with the same frequency in the second SSS frequency domain data to obtain the first SSS frequency domain data.

12. The method of claim 11, wherein the eliminating of the PSS frequency domain data reconstructed for the co-frequency known cell from the second PSS frequency domain data to obtain the first PSS frequency domain data comprises:

performing least square parameter estimation on the second SSS frequency domain data to obtain a first channel frequency response of the known cell;

reconstructing the local PSS sequence of the known cell through the first channel frequency response to obtain PSS frequency domain reconstruction data of the known cell;

and eliminating the PSS frequency domain reconstruction data in the second PSS frequency domain data to obtain the first PSS frequency domain data.

13. The method of claim 12, wherein the eliminating of the SSS frequency-domain data reconstructed for a known cell of a same frequency from the second SSS frequency-domain data to obtain the first SSS frequency-domain data comprises:

reconstructing a local SSS sequence of the known cell through the first channel frequency response to obtain SSS frequency domain reconstruction data of the known cell;

and eliminating the SSS frequency domain reconstruction data in the second SSS frequency domain data to obtain the first SSS frequency domain data.

14. The method of claim 12, wherein obtaining the first channel frequency response of the known cell based on least squares parameter estimation of the second SSS frequency-domain data comprises:

performing least square parameter estimation on the second SSS frequency domain data to obtain a second channel frequency response of the known cell;

and filtering the second channel frequency response by adopting the minimum mean square error to obtain the first channel frequency response.

15. The method of any of claims 1 to 14, wherein the first PSS frequency domain data is PSS frequency domain data obtained by eliminating interference of a known cell from received time domain data, and wherein after determining the information of the target cell, the method further comprises:

and taking the target cell as a known cell, updating the first PSS frequency domain data and the first SSS frequency domain data, and determining the information of the next target cell based on the updated first PSS frequency domain data and the updated first SSS frequency domain data until a preset stop condition is reached.

16. A cell search apparatus, comprising:

the processing module is used for performing cross-correlation operation on the frequency domain data of the first primary synchronization signal PSS and the local PSS sequence to obtain a first correlation sequence; the first PSS frequency domain data is the PSS frequency domain data after interference of the received time domain data is eliminated;

a determining module, configured to determine information of a target cell based on the first correlation compensation sequence, the first time offset value, and first secondary synchronization signal SSS frequency-domain data; the first SSS frequency domain data is SSS frequency domain data with interference eliminated from received time domain data.

17. An apparatus, characterized in that the apparatus comprises: a processor and a memory, wherein the processor is capable of processing a plurality of data,

the memory stores a computer program operable on the processor,

the processor, when executing the computer program, implements the method of any of claims 1 to 15.

18. A computer-readable storage medium storing a computer program for causing a computer to perform the method of any one of claims 1 to 15.