CN115051771B - A cell search method, device, equipment and computer storage medium - Google Patents

Abstract

The embodiment of the application discloses a cell searching method, a cell searching device, a cell searching equipment and a computer storage medium, wherein the cell searching 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 is eliminated for the received time domain data; based on a preset first time offset value, performing time offset compensation on a first conversion sequence after discrete conversion of the first correlation sequence 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 after interference cancellation in the received time domain data. By the method, the problem of low cell searching efficiency can be solved.

Description

A cell search method, device, equipment and computer storage medium

Technical Field

The embodiments of the present application relate to, but are not limited to, the field of communication technology, and in particular, to a cell search method, apparatus, device, and computer storage medium.

Background Art

In the communication network system, after the terminal device is turned on, the initial search is first started to search for the serving cell for residence. After the terminal device successfully resides in a serving cell, the neighboring cell search is started. The main purpose of the neighboring cell search is to search for the neighboring cells of the serving cell in preparation for operations such as reselecting the cell or switching the cell. At present, the scheme for cell search needs further study.

Summary of the invention

Embodiments of the present application provide a cell search method, apparatus, device, and computer storage medium.

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

Performing a 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 is eliminated from the received time domain data;

Based on a preset first time offset value, respectively performing time offset compensation on a first transformed sequence after the first correlation sequence is discretely transformed to obtain a first correlation compensation sequence;

Based on the first correlation compensation sequence, the first time offset value and the first SSS frequency domain data, the information of the target cell is determined; the first SSS frequency domain data is the SSS frequency domain data after eliminating interference in the received time domain data.

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

A processing module, configured to perform a 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 is eliminated from the received time domain data;

A compensation module, configured to perform time offset compensation on a first transformed sequence after the first correlation sequence is discretely transformed based on a preset first time offset value, to obtain a first correlation compensation sequence;

A determination module is used to determine 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; the first SSS frequency domain data is the SSS frequency domain data after eliminating interference in the received time domain data.

In a third aspect, an embodiment of the present application provides a device, the device comprising: a processor and a memory,

The memory stores a computer program executable on the processor.

When the processor executes the program, the method according to the first aspect is implemented.

In a fourth aspect, an embodiment of the present application provides a computer storage medium, wherein the computer storage medium stores a computer program, and when the computer program is executed by a processor, the method described in the first aspect is implemented.

In an embodiment of the present application, a cross-correlation operation is performed 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 the interference is eliminated from the received time domain data; here, since the interference is eliminated from the received time domain data, the PSS frequency domain data after the interference is eliminated, that is, the first PSS frequency domain data, is obtained. In this way, the interference is eliminated, and the number of cells detected in the first PSS frequency domain data is reduced, thereby improving the search performance of the cell. Further, based on the preset first time deviation value, the first transformed sequence after the discrete transformation of the first correlation sequence is respectively compensated for the time deviation to obtain a first correlation compensation sequence; in this way, in the frequency domain PSS detection stage, the discrete transformation method is used to compensate the time deviation value of the transformed sequence of the first PSS frequency domain data to obtain the first correlation compensation sequence, that is, the present application uses a discrete transformation method to make a time deviation assumption, which reduces the amount of calculation and implementation complexity, and improves the efficiency of cell search. Finally, the information of the target cell is determined based on the first correlation compensation sequence, the first time deviation value and the first SSS frequency domain data; the first SSS frequency domain data is the SSS frequency domain data after eliminating interference in the received time domain data; in this way, in the process of determining the information of the target cell based on the aforementioned first correlation compensation sequence, the first SSS frequency domain data and the preset first time deviation value, both cell search performance and cell search efficiency are taken into account.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described herein are used to provide further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute improper limitations on the present application.

FIG1 is a schematic diagram of an application scenario of an embodiment of the present application;

FIG2 is a schematic diagram of an implementation flow of an optional cell search method provided in an embodiment of the present application;

FIG3 is a schematic diagram of an implementation flow of an optional cell search method provided in an embodiment of the present application;

FIG4 is a schematic diagram of an implementation flow of an optional cell search method provided in an embodiment of the present application;

FIG5 is a schematic diagram of an implementation flow of an optional cell search method provided in an embodiment of the present application;

FIG6 is a schematic diagram of an implementation flow of an optional cell search method provided in an embodiment of the present application;

FIG7 is a flowchart of an implementation of obtaining a candidate peak value of a PSS by assuming a time offset through FFT according to an embodiment of the present application;

FIG8 is a schematic diagram of an implementation flow of an optional cell search method provided in an embodiment of the present application;

FIG9 is a schematic diagram of an implementation flow of an optional cell search method provided in an embodiment of the present application;

FIG10 is a schematic diagram of an implementation flow of an optional cell search method provided in an embodiment of the present application;

FIG11 is a schematic diagram of an implementation flow of an optional cell search method provided in an embodiment of the present application;

FIG12 is a schematic diagram showing a principle of searching for multiple co-frequency cells by a device provided in an embodiment of the present application;

FIG13 is a schematic diagram of an implementation flow of an optional cell search method provided in an embodiment of the present application;

FIG14 is a schematic diagram of an implementation flow of an optional cell search method provided in an embodiment of the present application;

FIG15 is a schematic diagram of an implementation flow of an optional cell search method provided in an embodiment of the present application;

FIG16 is a schematic diagram of the structure of a cell search device provided in an embodiment of the present application;

FIG. 17 is a schematic structural diagram of a device provided in an embodiment of the present application.

DETAILED DESCRIPTION

The technical solution of the present application will be described in detail below through embodiments and in conjunction with the accompanying drawings. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments.

It should be noted that in the examples of the present application, "first", "second", etc. are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

In addition, the technical solutions described in the embodiments of the present application can be combined arbitrarily without conflict. In the description of the present application, "multiple" means two or more, unless otherwise clearly and specifically defined.

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

As shown in FIG1 , 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 via an air interface. The first device 110 and the second device 120 support multi-service transmission.

It should be understood that the embodiments of the present application are only exemplified by the communication system 100, but the embodiments of the present application are not limited thereto. That is to say, the technical solutions of the embodiments of the present application can be applied to various communication systems, such as: Long Term Evolution (LTE) system, LTE Time Division Duplex (TDD), Universal Mobile Telecommunication System (UMTS), Internet of Things (IoT) system, Narrow Band Internet of Things (NB-IoT) system, enhanced Machine Type Communications (eMTC) system, 5G communication system (also called New Radio (NR) communication system), or future communication systems (such as 6G, 7G communication systems), etc.

In the communication system 100 shown in FIG1 , 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 specific geographic area, and may communicate with the first device 110 located in the coverage area. The second device 120 in the embodiment of the present application may include an access network device and/or a core network device.

FIG1 exemplarily shows a base station and a first device. Optionally, the wireless communication system 100 may include multiple base station devices and each base station may include another number of first devices within its coverage area, which is not limited in the embodiments of the present application.

It should be noted that FIG. 1 is only an example of the system to which the present application is applicable. Of course, the method shown in the embodiment of the present application can also be applied to other systems. In addition, the terms "system" and "network" are often used interchangeably in this article. The term "and/or" in this article is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and/or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character "/" in this article generally indicates that the associated objects before and after are in an "or" relationship. It should also be understood that the "indication" mentioned in the embodiment of the present application can be a direct indication, an indirect indication, or an indication of an association relationship. For example, A indicates B, which can mean that A directly indicates B, for example, B can be obtained through A; it can also mean that A indirectly indicates B, for example, A indicates C, B can be obtained through C; it can also mean that A and B have an association relationship. It should also be understood that the "correspondence" mentioned in the embodiment of the present application can mean that there is a direct or indirect correspondence relationship between the two, or it can mean that there is an association relationship between the two, or it can mean that the relationship between indicating and being indicated, configuring and being configured, etc. It should also be understood that the "predefined", "protocol agreed", "predetermined" or "predefined rules" mentioned in the embodiments of the present application can be implemented by pre-saving corresponding codes, tables or other methods that can be used to indicate relevant information in a device (for example, including a first device and a second device), and the present application does not limit its specific implementation method. For example, predefined may refer to a definition in a protocol. It should also be understood that in the embodiments of the present application, the "protocol" may refer to a standard protocol in the field of communications, such as an LTE protocol, an NR protocol, and related protocols used in future communication systems, and the present application does not limit this.

In a communication system, a terminal device needs to achieve time and frequency synchronization with a cell through a cell search phase, and search for a cell ID, so as to achieve communication with a network device. For example, in the cell search phase, a correlation detection is performed on the Primary Synchronization Signal (PSS) sequence based on the received signal data to obtain at least one of the following: time deviation, identity within the group, and timing information, among which the identity within the group is also called NID2 or Then, the secondary synchronization signal (SSS) sequence is detected to obtain the physical layer cell identity group (Physical Layer Cell Identity group), and then the cell information is obtained. The physical cell identity group is also called NID1 or However, in the case of co-frequency cell interference, how to effectively eliminate the data of the interfering cell to complete the target cell search.

The technical solution of cell search based on cell signal interference elimination in the related art is either based on time domain interference elimination. Specifically, after receiving the total time domain data based on the target frequency band, the synchronization signal channel is estimated based on the time domain data of the interfering cell, and the signal of the known interfering cell is reconstructed, and then the interference signal is eliminated from the total received data. Then, the conventional target cell PSS and SSS detection is performed on the signal after interference elimination to obtain the cell information. Or it is based on frequency domain interference elimination. Specifically, based on the known interfering cell signal PSS and SSS position, the data is taken for fast Fourier transform (Fast Fourier Transform, FFT), and the interfering cell signal is reconstructed in the frequency domain, and then the target cell PSS and SSS frequency domain detection is performed on the frequency domain signal after interference elimination to finally obtain the cell information.

It should be noted that although the solution for determining the target cell based on frequency domain interference elimination is simple to implement and has relatively small data and calculation amount compared to the solution for determining the target cell based on time domain interference elimination, both the solution for determining the target cell based on time domain interference elimination and the solution for determining the target cell based on frequency domain interference elimination require reconstruction of the interference signal and have high requirements for time offset processing.

In the related art, when performing PSS detection, the process of processing time offset is that after receiving data other than the interfering cell, different time offset assumptions are made for the PSS frequency domain data in the data, and frequency domain correlation is performed on the PSS frequency domain data with the time offset assumption added to obtain the correlation result after time offset compensation; wherein, the correlation result x ₁ (k) after time offset compensation can be realized by the following formula (1):

Wherein, x ₁ (k) represents the correlation result after time offset compensation, xccor(k) represents the frequency domain correlation result between the first PSS frequency domain data and the local PSS sequence, represents the time deviation value; k represents the point of the PSS sequence, x(k) represents the kth PSS correlation result, N represents the sequence length of the first PSS frequency domain data, and L represents the time deviation value.

Furthermore, the correlation result after time offset compensation needs to be normalized and antenna combined, so the correlation result x ₁ (k) after time offset compensation is accumulated to obtain the accumulated result Y, as shown in the following formula (2):

Wherein, M is the total number of time deviation values.

Finally, based on the square of the accumulated result, the time offset used to compensate the SSS signal is estimated. After that, the SSS signal is compensated for the time offset and frequency domain related processing is performed to determine the information of the target cell. However, in the process of compensating the time offset value of the PSS frequency domain data, if there are multiple time offset values L, such as S, S is an integer greater than or equal to 2, and 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, the method of compensating the time offset value of the PSS frequency domain data in the related art has an operation complexity of S multiplications and N×S square sums. Obviously, this method at least has the problem of large amount of calculation, resulting in low efficiency of cell search.

FIG2 is a schematic diagram of an implementation flow of an optional cell search method provided in an embodiment of the present application. As shown in FIG2 , the method can be applied to a device, which can be a chip or a terminal device. Here, the terminal device is used as the execution subject for description. The method includes:

Step 201: Perform a cross-correlation operation on first PSS frequency domain data and a local PSS sequence to obtain a first correlation sequence.

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

In the embodiment of the present application, the time domain data is the signal data of at least two cells in the same frequency band received within the search range after the terminal device resides in a service cell. It should be noted that after the terminal device resides in a service cell, the service cell is regarded as a known cell and a neighboring cell search is initiated so that the terminal device can prepare for the reselection or switching of the next service cell, i.e., the target cell, during the movement.

Here, due to the limitation of spectrum resources and the requirement of high bandwidth of LTE, the communication system uses the same frequency networking mode to improve the utilization of spectrum resources. For example, in a given coverage area, there are many cells using the same set of frequencies, which are called same-frequency cells. The interference between cells with the same frequency is called same-frequency interference. When searching for cells, it is necessary to eliminate the data of the same-frequency interference cells.

When the signal-to-noise ratio is low and there are multiple co-frequency cells within the search range of the terminal device, the service cell (known cell) where the terminal device resides will interfere with the search for the target cell (neighboring cell) signal, affecting the cell search and causing the search to fail. At this time, it is necessary to reconstruct and eliminate the signal of the known cell to reduce the impact of the interference signal, thereby achieving 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 is eliminated from the received time domain data. Exemplarily, after the terminal device resides in a service cell, the service cell is taken as a known cell, and the PSS frequency domain data of the known cell is reconstructed according to the location and time information of the known cell. Further, the reconstructed PSS frequency domain data of the known cell is eliminated from the mixed PSS frequency domain data after the time domain data is transformed 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 the protocol, and each local PSS sequence corresponds to an intra-group identifier NID2. Optionally, the intra-group identifier NID2 can take values of 0, 1, and 2. It should be noted that the local PSS sequence is essentially formed by cyclic shift of the same sequence, and the local PSS sequence can be pre-acquired and stored in the terminal device.

Here, the cross-correlation operation refers to an operation for analyzing two or more variable elements with correlation, thereby measuring the degree of correlation between the two variable factors. In an embodiment of the present invention, a cross-correlation operation is performed on two sequences, that is, an operation for calculating the degree of correlation between the two sequences.

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

Optionally, performing a cross-correlation operation on the first PSS frequency domain data and the local PSS sequence to obtain a first correlation sequence may also include: performing a 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: Based on a preset first time offset value, time offset compensation is performed on a first transformed sequence after discrete transformation of a first correlation sequence to obtain a first correlation compensation sequence.

In an embodiment of the present application, the first time deviation value is used to perform time deviation compensation on the first transformation sequence, and the first transformation sequence is a sequence after the first related sequence has been discretely transformed; the first time deviation value is the difference between the position signals of other cells estimated in advance and the known cells for the terminal device.

Optionally, the first time offset value is less than or equal to half of the cyclic prefix in the time domain data. In this way, it is guaranteed that the complete first PSS frequency domain data and the complete first SSS frequency domain data can be obtained. It should be noted that the cyclic prefix (CP) is formed by moving the signal at the tail of the orthogonal frequency division multiplexing (OFDM) symbol to the head. The purpose of the cyclic prefix is to ensure that complete information is obtained. At the same time, the cyclic prefix can realize time estimation and frequency synchronization. Therefore, this scheme uses the cyclic prefix to pre-estimate the time offset between the target cell and the current service cell of the terminal device, that is, the preset first time offset value.

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

Optionally, the number of first time deviation values is related to the priority of the network standard of the cell where the terminal device resides; here, the number of first time deviation values is proportional to the priority of the network standard of the cell where the terminal device resides. Exemplarily, if the cell where the terminal device resides is an NR network cell, the number of first time deviation 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 first time deviation values belongs to a second range, and the second range may be [7, 10], and the priority of the network standard of the NR network is higher than the priority of the network standard of the LTE network; of course, if the cell where the terminal device resides may also be other network cells, this application does not impose specific restrictions on this.

It should be noted that since the first correlation compensation sequence is obtained by performing time offset compensation on the first transformation sequence based on the preset first time offset value, the first transformation sequence is a sequence after the first correlation sequence has been discretely transformed, and the first correlation sequence is the result of cross-correlation operation between the first PSS frequency domain data and each local PSS sequence. Therefore, 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.

Optionally, the discrete transform may be a Fourier transform (FT).

Optionally, the discrete transform may also be a Fast Fourier Transform (FFT).

Optionally, the discrete transform may also be a discrete Fourier transform (DFT). Exemplarily, the operation principle of the discrete Fourier transform is as follows:

Among them, X(k) represents the sequence after DFT transformation, x(n) is the transformed sequence, N represents the length of DFT transformation, n represents the sequence sample number, and k is the independent variable of the spectrum.

Optionally, the first transformation sequence is obtained by performing discrete transformation on the first correlation sequence, which can be completed by using an FPGA-based fast Fourier transform IP core in the terminal device, that is, the first transformation sequence is obtained by using an FPGA-based fast Fourier transform FFT IP core of the terminal device to complete the Fourier transform calculation of the first correlation sequence. In this way, the pre-designed FFT IP core is used, which is simple to implement and greatly improves the computing efficiency.

In one implementation scenario, taking discrete Fourier transform as an example, after cross-correlation operation is performed on the first PSS frequency domain data and the 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 transformation sequence X ₂ (k); then, based on a preset first time offset value, time offset compensation is performed on the first transformation sequence X ₂ (k) to obtain a first correlation compensation sequence. Here, the first transformation sequence X ₂ (k) can be obtained by the following formula (4):

Wherein, X ₂ (k) represents the first transformed sequence, and xccor(k) represents the frequency domain correlation result of the first PSS frequency domain data and the local PSS sequence.

Step 203: Determine the target cell information 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 after interference is eliminated in the received time domain data.

In the embodiment of the present application, determining the information of the target cell at least includes determining the physical cell identifier (PCI) and frame synchronization position of the target cell.

In the embodiment of the present application, the first SSS frequency domain data is the SSS frequency domain data after the interference is eliminated from the received time domain data. Exemplarily, after the terminal device resides in a service cell, the service 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 is transformed to obtain the first SSS frequency domain data.

Here, there is a fixed position relationship between the PSS and the SSS of the primary and secondary synchronization signals corresponding to the communication mode, and the terminal device can determine the frequency domain position of the first SSS frequency domain data through the frequency domain position of the first PSS frequency domain data and the position relationship of the primary and secondary synchronization signals. Among them, the communication modes include TDD mode and frequency division duplex FDD mode. Furthermore, the fixed position relationship of the primary and secondary synchronization signals includes but is not limited to: in FDD mode, the primary synchronization signal and the secondary synchronization signal differ by one OFDM symbol; in TDD mode, the primary synchronization signal and the secondary synchronization signal differ by three OFDM symbols.

In an embodiment of the present application, based on a preset first time offset value, time offset compensation is performed on the first transformed sequence after discrete transformation of the first correlation sequence to obtain a first correlation compensation sequence, and the information of the target cell is determined based on the first correlation compensation sequence, the preset multiple first time offset values and the first SSS frequency domain data.

In an embodiment of the present application, a cross-correlation operation is performed 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 the interference is eliminated from the received time domain data; here, since the interference is eliminated from the received time domain data, the PSS frequency domain data after the interference is eliminated, that is, the first PSS frequency domain data, is obtained. In this way, the interference is eliminated, and the number of cells detected in the first PSS frequency domain data is reduced, thereby improving the search performance of the cell. Further, based on the preset first time deviation value, the first transformed sequence after the discrete transformation of the first correlation sequence is respectively compensated for the time deviation to obtain a first correlation compensation sequence; in this way, in the frequency domain PSS detection stage, the discrete transformation method is used to compensate the time deviation value of the transformed sequence of the first PSS frequency domain data to obtain the first correlation compensation sequence, that is, the present application uses a discrete transformation method to make a time deviation assumption, which reduces the amount of calculation and implementation complexity, and improves the efficiency of cell search. Finally, the information of the target cell is determined based on the first correlation compensation sequence, the first time deviation value and the first SSS frequency domain data; the first SSS frequency domain data is the SSS frequency domain data after eliminating interference in the received time domain data; in this way, in the process of determining the information of the target cell based on the aforementioned first correlation compensation sequence, the first SSS frequency domain data and the preset first time deviation value, both cell search performance and cell search efficiency are taken into account.

FIG3 is a schematic diagram of an implementation flow of an optional cell search method provided in an embodiment of the present application. As shown in FIG3 , the method can be applied to a device, which can be a chip or a terminal device. Here, the terminal device is used as the execution subject for description. The method includes:

Step 301: Perform a cross-correlation operation on first PSS frequency domain data and a local PSS sequence to obtain a first correlation sequence.

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

Step 302: Perform discrete transformation on the first correlation sequence to obtain a first transformed sequence.

Step 303: Determine a first correlation compensation sequence corresponding to the offset of the first time offset value from the first transformation sequence to complete the time offset compensation.

Here, since there are multiple local PSS sequences, there are also multiple first transformation sequences for discretely transforming the first correlation sequence. From each transformation sequence, each correlation compensation sequence corresponding to the offset first time offset value is determined, and then multiple correlation compensation sequences are obtained, thereby completing the time offset compensation. In this way, each sampling point in the first transformation sequence after discrete transformation is offset by the first time offset value to obtain the first correlation compensation sequence. Further, the discrete value of the corresponding position when each sampling point is offset by the first time offset value can be quickly obtained in the first compensation sequence, thereby reducing the time length for detecting the synchronization signal, so as to quickly search for the target cell and further improve the cell search efficiency.

Here, taking discrete Fourier transform as an example, after obtaining the first transform sequence X ₂ (k), a first correlation compensation sequence corresponding to the offset of the first time offset value L is determined from each first transform sequence X ₂ (k), and multiple first correlation compensation sequences are obtained to complete time offset compensation.

Y1＝X ₂ (kL)

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

Step 304: Determine a second timing offset value based on the first timing offset value and the first correlation compensation sequence.

In an embodiment of the present application, the second time offset value can be used to perform time offset compensation on a second correlation sequence after cross-correlation operation is performed on the first SSS frequency domain data and the local SSS sequence; of course, the second time offset value can also be used to perform time offset compensation on a second correlation sequence after Fourier transformation, and the present application does not impose any specific restrictions on this.

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

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

In an embodiment of the present application, the local SSS sequence is a locally generated SSS sequence specified by the protocol, and each local SSS sequence corresponds to a group number identifier NID1. Optionally, in an LTE network, there are a total of 168 group number identifiers NID1, that is, NID1 can take a value of 0-167; in an NR network, there are a total of 336 group number identifiers NID1, that is, NID1 can take a value of 0-335. Of course, in other networks, the total number of intra-group identifiers NID1 can be other values, and this application does not make specific restrictions on this. Here, the local SSS sequence can be pre-acquired and stored in the terminal device.

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

Optionally, based on the second time deviation value, time deviation compensation is performed on the second correlation sequence obtained after the first SSS frequency domain data and the local SSS sequence are cross-correlated to obtain a second correlation compensated sequence, which may include: performing a cross-correlation operation on the first SSS frequency domain data and the local SSS sequence to obtain a second correlation sequence; performing a discrete transformation on the second correlation sequence to obtain a second transformed sequence; and based on the second time deviation value, performing time deviation compensation on the second transformed sequence to obtain a second correlation compensated sequence.

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

Step 306: Determine information of the target cell based on the first correlation compensation sequence and the second correlation compensation sequence.

In an embodiment of the present application, the first correlated sequence of the PSS is processed by discrete transformation to obtain a first transformed sequence, and then the first transformed sequence is compensated for the time offset based on the first time offset value to obtain a first correlated compensated sequence; the second transformed sequence of the SSS is compensated by the second time offset value to obtain a second correlated compensated sequence. In this way, the discrete transformation is effectively used to perform a time offset compensation hypothesis on the first transformed sequence of the PSS, and the sequence is obtained by compensating the second transformed sequence of the SSS by the second time offset value based on obtaining the numerical value of the corresponding position of each first time offset value in the first correlated compensation sequence, and the second time offset value is used to compensate for the second transformed sequence of the SSS to obtain the information of the target cell, which greatly reduces the amount of data calculation and implementation complexity, thereby reducing the search time and improving the cell search efficiency.

In some embodiments, when 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, the process of determining the second time offset value based on the first time offset value and the first correlation compensation sequence in step 304 is further described in conjunction with FIG. 4.

Step 401: Determine a first candidate peak based on a first time offset value and a first correlation compensation sequence.

In an embodiment of the present application, the first candidate peak corresponds to a first time deviation value and a local PSS sequence, and the first candidate peak may be a peak that satisfies the peak condition from the first related compensation sequence; the first candidate peak is used to estimate the time deviation value for time deviation compensation of a sequence obtained based on SSS frequency domain data.

Step 402: Perform a modulo operation on the first candidate peak value 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 discrete transformation.

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

Y3＝mod(Y2，N) (5)

Among them, Y3 represents the second time deviation value, Y2 represents the first candidate peak value, N represents the length of the first PSS frequency domain data, and mod represents a remainder function.

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

As can be seen from the above, when determining the first candidate peak corresponding to the first correlation compensation sequence, by performing a modulo operation on the first candidate peak and the PSS frequency domain data, not only can the time offset compensation value of the sequence obtained based on the first SSS frequency domain data 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 way, the SSS data position can be quickly located to improve the search efficiency.

In some embodiments, when 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, the process of determining the first candidate peak based on the first time offset value and the first correlation compensation sequence in step 401 is further described in conjunction with FIG. 5.

Step 501, the first time offset value includes: W first time offset values, each first time offset value corresponds to N1 first sub-correlation compensation sequences, the first correlation compensation sequence includes N1 first sub-correlation compensation sequences corresponding to the W first time offset values, and for each first time offset value, based on the N1 first sub-correlation compensation sequences, N1 first peaks are determined.

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 timing offset values, N1 first peaks are determined based on the first correlation compensation sequence including N1 first sub-correlation compensation sequences corresponding to the W first timing offset values.

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

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

In an embodiment of the present application, the first preset peak threshold may be a pre-set peak value, or the first preset peak threshold may be a peak value dynamically adjusted according to the current scene, and the present application does not impose any specific restrictions on this.

In an embodiment of the present application, for W first time offset values, U first candidate peaks greater than or equal to the first preset peak threshold are determined from W×N1 first peaks, so that SSS related detection is performed based on the first candidate peaks to determine the information of the target cell.

From the above, it can be seen that when there are multiple first time deviation values, in the first correlation compensation sequence obtained after discrete transformation, each first time deviation value will correspond to multiple first sub-correlation compensation sequences in the first correlation compensation sequence, and each first sub-correlation compensation sequence will have a peak, so each first time deviation value will correspond to multiple peaks. From all the peaks corresponding to all the first time deviation values, the peak that meets the conditions is screened out as the first candidate peak. In this way, not only the position of the first SSS frequency domain data is determined based on the position of the first candidate peak, but also the time deviation compensation value of the sequence obtained based on the first SSS frequency domain data can be obtained, so as to detect the SSS related data after time deviation compensation and determine the information of the target cell.

In some embodiments, when the time offset compensation is performed on the first transformed sequence based on the preset W first time offset values 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 peaks based on the N1 first sub-correlation compensation sequences for each first time offset value in step 501 is further described in conjunction with FIG. 6.

Step 601: For each first time offset value, based on N1 first sub-correlation compensation sequences, obtain 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 first sub-correlation compensation sequence. In some embodiments, for each first time offset value, based on N1 first sub-correlation compensation sequences, a plurality of discrete values corresponding to each first sub-correlation compensation sequence may be normalized to obtain energy distribution information. Of course, in other embodiments of the present application, the energy distribution information may also be obtained by other means, and the present application does not make any specific limitation on this.

Step 602: Determine a first peak value corresponding to each first sub-correlation compensation sequence based on 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, firstly, for each first time offset value L, based on N1 first sub-correlation compensation sequences, each first sub-correlation compensation sequence, i.e., _X2 (kL), is obtained. Since the value range of k is [0, N-1], a discrete value will correspond to different values of k. When k takes all values, multiple discrete values are obtained, and then energy distribution information corresponding to each first sub-correlation compensation sequence is obtained; secondly, the maximum peak is determined as the first peak from the energy distribution information corresponding to each first sub-correlation compensation sequence, so as to obtain N1 first peaks corresponding to the N1 first sub-correlation compensation sequences, and then the candidate peaks are screened out from the N1 first peaks, the information of the target cell is determined, and the search efficiency of the target cell is improved.

In some embodiments, for each first time offset value, based on N1 first sub-correlation compensation sequences, a plurality of discrete values corresponding to each first sub-correlation compensation sequence are normalized to obtain energy distribution information, which can be achieved by the following process:

For each first timing offset value, based on the N1 first sub-correlation compensation sequences, a plurality of discrete values corresponding to each first sub-correlation compensation sequence are normalized to obtain a plurality of normalized values corresponding to each first sub-correlation compensation sequence.

The energy distribution information includes a plurality of normalized 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, i.e., X ₂ (kL), is obtained. Since the value range of k is [0, N-1], a discrete value will correspond to different values of k. When k takes all values, multiple discrete values are obtained. Secondly, the squares of all discrete values are obtained and summed to obtain the square sum, and then the square sum is processed to obtain the PSS energy. Each value of the multiple discrete values is squared, and each squared discrete value is divided by the PSS energy to obtain multiple normalized values corresponding to each first sub-correlation compensation sequence, and then the energy distribution information corresponding to each first sub-correlation compensation sequence is obtained. Specifically, the multiple normalized values corresponding to each first sub-correlation compensation sequence can be obtained by the following formula (6):

Y4＝|Y1| ² /S＝|X ₂ (kL)| ² /S (6)

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

Furthermore, the terminal device determines the first peak value with the largest value from the multiple normalized values corresponding to each first sub-correlated compensation sequence, thereby obtaining N1 first peak values corresponding to the N1 first sub-correlated compensation sequences. In this way, multiple normalized values are obtained through normalization processing, and peak values can be quickly obtained from the multiple normalized values, thereby obtaining N1 first peak values, and then candidate peak values are screened out from the N1 first peak values, thereby determining the information of the target cell, and improving the search efficiency of the target cell.

In an achievable application scenario, as shown in FIG. 7, FIG. 7 shows a flow chart of an embodiment of the present application for obtaining a first candidate peak value by assuming a time offset through FFT. After obtaining the first PSS frequency domain data, the first PSS frequency domain data is subjected to frequency domain correlation descrambling, i.e., cross-correlation operation, and according to the preset first time offset value, the first PSS frequency domain data after frequency domain correlation descrambling is subjected to a fast Fourier transform FFT time offset assumption to obtain a first correlation compensation sequence; in addition, the PSS energy of the first PSS frequency domain data is calculated, and normalization processing is performed based on the calculated PSS energy and the first correlation compensation sequence, where the normalization processing is also called antenna merging normalization processing, and based on the normalized first correlation compensation sequence, the candidate peak value corresponding to the first correlation compensation sequence is determined, so as to determine the information of the target cell based on the candidate peak value, thereby improving the search efficiency of the target cell.

In some embodiments, when the second time offset value is determined, step 305 performs time offset compensation on a second correlation sequence after cross-correlation operation is performed on the first SSS frequency domain data and the local SSS sequence based on the second time offset value. The process of obtaining the second correlation compensation sequence is further described in conjunction with FIG. 8.

Step 801: Perform a cross-correlation operation on first SSS frequency domain data and a local SSS sequence to obtain a second correlation sequence.

Step 802: Perform discrete transformation on the second correlation sequence to obtain a second transformed sequence.

Step 803: Determine a second correlation compensation sequence corresponding to the second time offset value from the second transformation sequence to complete the time offset compensation.

In the embodiment of the present application, the local SSS sequence includes multiple local SSS sequences, and a cross-correlation operation is performed on the first SSS frequency domain data and each local SSS sequence in the multiple local SSS sequences to obtain multiple second correlation sequences; based on the multiple second correlation sequences, each second correlation sequence is discretely transformed to obtain multiple second transformation sequences; based on the multiple second transformation sequences, from each second transformation sequence, the second correlation compensation sequence corresponding to the offset of the second time deviation value is determined to obtain multiple second correlation compensation sequences, thereby completing the time deviation compensation. In this way, each sampling point in the second transformation sequence after the discrete transformation is offset by the second time deviation value to obtain the second correlation compensation sequence. Further, the discrete value of the corresponding position when each sampling point is offset by the second time deviation value can be quickly obtained in the second compensation sequence, thereby reducing the time length for detecting the synchronization signal, so as to quickly detect the target cell and further improve the cell search efficiency.

In some embodiments, when the first correlation compensation sequence and the second correlation compensation sequence are obtained, 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 described in conjunction with FIG. 9.

Step 901: Determine a second candidate peak based on a second time offset value and a second correlation compensation sequence.

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 identifier NID1 corresponding to the second candidate peak is determined, and the second candidate peak is associated with the first candidate peak.

Step 902: Determine information of a target cell based on a first candidate peak value and a second candidate peak value corresponding to a first correlation compensation sequence.

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 intra-group identifier NID2 corresponding to the first candidate peak is determined.

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

Here, the physical cell identifier PCI of the target cell can be obtained by the following formula (7):

PCI＝3×NID1+NID2 (7)

Among them, PCI represents the physical cell identifier of the target cell, NID1 represents the group number identifier corresponding to the second candidate peak; NID2 represents the corresponding intra-group identifier of the first candidate peak corresponding to the second candidate peak.

From the above, it can be seen that when the first candidate peak corresponding to the PSS data and the second candidate peak corresponding to the SSS data are determined, the information of the target cell is determined based on the position of the second candidate peak and the position of the first candidate peak corresponding to the second candidate peak. In this way, the terminal device can quickly reselect or switch to the target cell during the movement.

In some embodiments, when the second time offset value and the second correlation compensation sequence are obtained, the process of determining the second candidate peak value based on the second time offset value and the second correlation compensation sequence in step 901 is further described in conjunction with FIG. 10.

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

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 P second time offset values, determine Q second candidate peaks that are greater than or equal to a second preset peak threshold from P×N2 second peaks.

Wherein, Q is an integer greater than or equal to 1 and less than or equal to P×N2.

In the embodiment of the present 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, such as a second preset peak threshold dynamically set to obtain the largest candidate peak value, and the present application does not impose any specific restrictions on this. 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 be different, and the present application does not impose any specific restrictions on this.

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

From the above, it can be seen that when there are multiple second time deviation values, in the second related compensation sequence obtained after discrete transformation, each second time deviation value will correspond to multiple second sub-related compensation sequences in the second related compensation sequence, and each second sub-related compensation sequence will have a peak, so each second time deviation value will correspond to multiple peaks. From all the peaks corresponding to all the second time deviation values, the peaks that meet the conditions are screened out as the second candidate peaks. In this way, the information of the target cell can be determined based on the position of the second candidate peak and the position of the first candidate peak corresponding to the second candidate peak. In this way, it is ensured that the terminal device can quickly reselect or switch to the target cell during the movement.

FIG11 is a schematic diagram of an implementation flow of an optional cell search method provided in an embodiment of the present application. As shown in FIG11 , the method can be applied to a device, which can be a chip or a terminal device. Here, the terminal device is used as the execution subject for description. The method includes:

Step 1101: Perform data transformation on the received time domain data of multiple 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 composed of the signals of multiple co-frequency cells plus noise. For example, the noise can be additive white Gaussian noise (AWGN). Referring to Figure 12, Figure 12 shows a schematic diagram of the principle of the device searching for multiple co-frequency cells; when there are multiple co-frequency cells within the search range of the terminal device, the received time domain data is composed of multiple cell signals plus noise.

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

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

Here, after receiving the time domain data of multiple co-frequency cells, the terminal performs fast Fourier transform on the time domain data to obtain frequency domain data, wherein 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, that is, Y = ∑ _i H _i × D _i + N; where Y represents the signal data received through the channel, H _i represents the channel frequency response of the i-th channel, and D _i represents the signal data sent on the i-th channel. The received signal data is composed of multiple cell signals plus noise. Interference cell elimination mainly refers to eliminating interference cell signals in the same frequency band and whose signal positions do not differ by more than the cyclic prefix range. The basic principle is to estimate and reconstruct each cell signal at the UE receiving end, and then subtract these interferences from the received signal in turn. The final signal is used for cell detection to obtain the information of the target cell.

Step 1102: Eliminate the PSS frequency domain data reconstructed for the known cell with the same frequency in the second PSS frequency domain data to obtain the first PSS frequency domain data; and eliminate the SSS frequency domain data reconstructed for the known cell with the same frequency in the second SSS frequency domain data to obtain the first SSS frequency domain data.

In an embodiment of the present application, the known cell may be a service cell in which the terminal device is currently located. The known cell may also be a neighboring cell of the service cell in which the terminal device is located. Of course, the known cell may also be information of the first target cell determined after one or more cell detections. Here, the known cell may also be called an interference cell. The known cell may also be any cell except the first target cell. The present application does not impose any specific restrictions on this.

In an embodiment of the present application, there may be one known cell or multiple known cells; in the case of multiple known cells, the PSS frequency domain data reconstructed for multiple known cells of the same frequency in the second PSS frequency domain data is eliminated to obtain the first PSS frequency domain data; and the SSS frequency domain data reconstructed for multiple known cells of the same frequency in the second SSS frequency domain data is eliminated to obtain the first SSS frequency domain data.

In an embodiment of the present application, when data transformation is performed on the time domain data of multiple cells received to obtain second PSS frequency domain data and second SSS frequency domain data, PSS frequency domain data and reconstructed SSS frequency domain data of a known cell 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 the SSS frequency domain data reconstructed by the known cell is eliminated from the second SSS frequency domain data to obtain first SSS frequency domain data.

In some embodiments, step 1102 eliminates the PSS frequency domain data reconstructed for the known cell with the same frequency in the second PSS frequency domain data to obtain the first PSS frequency domain data; and eliminates the SSS frequency domain data reconstructed for the known cell with the same frequency in the second SSS frequency domain data to obtain the first SSS frequency domain data. Further explanation is given in conjunction with FIG. 13.

Step 1301: Perform least squares parameter estimation on the second SSS frequency domain data to obtain a first channel frequency response of a known cell.

In an embodiment of the present application, the first channel frequency response of the known cell can be directly obtained after performing the least squares method (LS) parameter estimation on the second SSS frequency domain data. Of course, the first channel frequency response of the known cell can be directly obtained after performing the LS parameter estimation on the second PSS frequency domain data. This application does not make any specific restrictions on this.

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 the second channel frequency response, and filtering 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 filtering the second channel frequency response. This application does not make any specific restrictions on this.

Here, taking the first channel frequency response of a known cell obtained after LS parameter estimation of the second SSS frequency domain data as an example, the second SSS frequency domain data is divided by a local SSS sequence corresponding to the known cell to obtain the first channel frequency response.

In some embodiments, step 1301 is based on performing least squares parameter estimation on the second SSS frequency domain data to obtain the first channel frequency response of the known cell. This is further described in conjunction with FIG. 14.

Step 1401: Perform least squares parameter estimation on the second SSS frequency domain data to obtain a second channel frequency response of a known cell.

Step 1402: Filter the second channel frequency response using minimum mean square error to obtain a first channel frequency response.

In the embodiment of the present application, when the second SSS frequency domain data is subjected to least squares parameter estimation to obtain the second channel frequency response of the known cell, the second channel frequency response is filtered by minimum mean square error (MMSE) to obtain the first channel frequency response. In this way, by filtering the channel frequency response, the accuracy of the channel frequency response is improved, thereby improving the accuracy of the frequency reconstruction data of the known cell based on the first channel frequency response.

Step 1302: reconstruct the local PSS sequence of the known cell through the first channel frequency response to obtain PSS frequency domain reconstructed data of the known cell.

Step 1303: Eliminate the PSS frequency domain reconstructed data in the second PSS frequency domain data to obtain the first PSS frequency domain data.

Step 1304: reconstruct the local SSS sequence of the known cell through the first channel frequency response to obtain SSS frequency domain reconstructed data of the known cell.

Step 1305: Eliminate the SSS frequency domain reconstructed data in the second SSS frequency domain data to obtain the first SSS frequency domain data.

In an embodiment of the present application, first, the terminal device receives time domain data, and performs a fast Fourier transform on the received time domain data to obtain second PSS frequency domain data and second SSS frequency domain data; secondly, based on the second PSS frequency domain data and the second SSS frequency domain data, after determining that the current cell where the terminal device resides is a known cell, the local PSS sequence and the local SSS sequence corresponding to the known cell are determined according to the location and time information of the known cell. Then, the second SSS frequency domain data is divided by the local SSS sequence corresponding to the known cell, that is, the channel estimation is performed on the known cell, so as to obtain the first channel frequency response of the known cell; further, the local PSS sequence of the known cell is reconstructed through the first channel frequency response to obtain the PSS frequency domain reconstruction data of the known cell, and the local SSS sequence of the known cell is reconstructed through the first channel frequency response to obtain the SSS frequency domain reconstruction data of the known cell; finally, the PSS frequency domain reconstruction data of the known cell in the second PSS frequency domain data is eliminated to obtain the first PSS frequency domain data, and the SSS frequency domain reconstruction data of the known cell in the second SSS frequency domain data is eliminated to obtain the first SSS frequency domain data. In this way, by eliminating the frequency domain data of known cells such as the current cell where the terminal device is located or the target cell, the frequency domain data of other cells except the known cells are detected, which effectively reduces the complexity of PSS interference elimination and improves the efficiency of PSS interference elimination, thereby facilitating the reselection and switching of the terminal device.

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, so the frequency domain estimation value of the PSS channel can be regarded as equal to the frequency domain estimation value of the SSS channel. In this way, the calculation amount of the PSS channel estimation can be saved, and the performance is not affected.

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

Step 1104: Based on a preset first time offset value, time offset compensation is performed on a first transformed sequence after the first correlation sequence is discretely transformed to obtain a first correlation compensated sequence.

Step 1105: 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.

From the above, it can be seen that the location of the known cell is determined, and the frequency domain data reconstructed by the known cell is eliminated from the frequency domain data after the total received time domain data is transformed to obtain the frequency domain data after interference elimination. PSS detection and SSS detection are performed on the frequency domain data after interference elimination. In this way, the interference of the same-frequency cell is eliminated, and the cell is no longer affected by the interference of the known cell, so as to detect the cell with the same frequency as the known cell and with weaker power than the known cell, thereby improving the accuracy of the search for the same-frequency cell and the detection performance of the same-frequency cell.

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 also be performed:

Step 1106. When the first PSS frequency domain data is PSS frequency domain data after the interference of known cells is eliminated from the received time domain data, take the target cell as a known cell, update the first PSS frequency domain data and the first SSS frequency domain data, and determine 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 the preset stop condition is reached.

In an embodiment of the present application, the preset stop condition may be the number of cycles that can be set according to the capability information of the terminal device; the preset stop condition may also be that the terminal device cannot detect PSS frequency domain data and/or SSS data.

In an embodiment of the present application, when the first PSS frequency domain data is PSS frequency domain data after the interference of known cells is eliminated from the received time domain data, and the first SSS frequency domain data is SSS frequency domain data after the interference of known cells is eliminated from the received time domain data, the terminal device first determines the information of the target cell based on the first PSS frequency domain data and the first SSS frequency domain data; secondly, takes the target cell as a known cell, updates the first PSS frequency domain data and the first SSS frequency domain data, and determines 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 the 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 the preset stop condition is reached, which can be achieved by the following process:

According to the position and time information of the target cell (known cell), the local PSS sequence and the local SSS sequence corresponding to the target cell are determined; then, a dot division operation is performed on the first SSS frequency domain data and the local SSS sequence corresponding to the target cell, that is, channel estimation is performed on the target cell to obtain a third channel frequency response of the target cell; further, the local PSS sequence of the target cell is reconstructed through the third channel frequency response to obtain PSS frequency domain reconstruction data of the target cell, and the local SSS sequence of the target cell is reconstructed through the third channel frequency response to obtain SSS frequency domain reconstruction data of the target cell; finally, the PSS frequency domain reconstruction data of the target cell in the first PSS frequency domain data is eliminated to obtain third PSS frequency domain data (that is, the first PSS frequency domain data is updated), and the SSS frequency domain reconstruction data of the target cell in the first SSS frequency domain data is eliminated to obtain third SSS frequency domain data (that is, the first SSS frequency domain data is updated). Furthermore, a cross-correlation operation is performed on the third PSS frequency domain data and the local PSS sequence corresponding to the target cell to obtain a third correlation sequence; based on a preset third time offset value, time offset compensation is performed on the third transformed sequence after discrete transformation of the third correlation sequence to obtain a third correlation compensation sequence; based on the third correlation compensation sequence, the third time offset value and the third SSS frequency domain data, the information of the next target cell is determined, and so on, until the preset number of cycles is reached, or the detection of the PSS frequency domain data and/or SSS data fails, the search for the next target cell is stopped. In this way, information of multiple target cells can be obtained through multiple detections.

From the above, it can be seen that each time the information of a target cell is determined, the target cell can be taken as a known cell, and the PSS frequency domain data reconstructed by the known cell can be eliminated from the first PSS frequency domain data to obtain the third PSS frequency domain data, and the SSS frequency domain data reconstructed by the known cell can be eliminated from the first SSS frequency domain data to obtain the third SSS frequency domain data; further, PSS detection is performed on the third PSS frequency domain data after the interference is eliminated, and SSS detection is performed on the third SSS frequency domain data after the interference is eliminated; the next target cell information is obtained, and so on, until the number of detections reaches the preset number of cycles, or the detection of the PSS frequency domain data and/or SSS data fails, then the search for the target cell information is stopped, in this way, the interference of the same-frequency cells is eliminated, and the interference of the known cells is no longer affected, so that multiple same-frequency cells can be searched, which improves the accuracy of the search for the same-frequency cells, and also improves the detection performance of the same-frequency cells; at the same time, it also ensures that the terminal device can quickly reselect or switch to the target cell during the movement.

FIG15 is a schematic diagram of an implementation flow of an optional cell search method provided in an embodiment of the present application. As shown in FIG15 , the method can be applied to a device, which can be a chip or a terminal device. Here, the terminal device is used as the execution subject for description. The method includes:

Step 1501: Receive time domain data of multiple cells.

Step 1502: Perform fast Fourier transform on the time domain data to obtain second PSS frequency domain data and second SSS frequency domain data of multiple cells.

In the embodiment of the present application, the second PSS frequency domain data includes PSS frequency domain data and noise data of multiple cells. The second SSS frequency domain data includes SSS frequency domain data and noise data of multiple cells.

Step 1503: Obtain the local SSS sequence of the known cell.

The multiple cells include known cells.

In the embodiment of the present application, the known cell may be one or more. The known cell may be the service cell where the terminal device is currently located. The known cell may also be a neighboring cell of the service cell where the terminal device is located. Of course, the known cell may also be the information of the target cell determined after one or more cell searches. The known cell may also be any cell whose cell information has been determined through other means.

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

In an 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. It can be understood that the second SSS frequency domain data is divided by the local SSS sequence of the known cell to obtain the second channel frequency response H of the known cell.

Step 1505: Use minimum mean square error to filter the second channel frequency response to obtain the first channel frequency response H′ of the known cell.

Step 1506: reconstruct 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; 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.

Step 1507: based on the PSS frequency domain reconstruction data of the known cell, update the second PSS frequency domain data; based on the SSS frequency domain reconstruction data of the known cell, update the second SSS frequency domain data.

In an embodiment of the present application, the PSS frequency domain reconstruction data of the known cells in the second PSS frequency domain data is eliminated, thereby realizing the update of the second PSS frequency domain data; and the SSS frequency domain reconstruction data of the known cells in the second SSS frequency domain data is eliminated, thereby realizing the update of the second SSS frequency domain data.

Step 1508, determine whether there are other known cells, if so, return to step 1503; if not, execute step 1509.

In the embodiment of the present application, if there are multiple known cells, when it is determined that there are other known cells, steps 1503 to 1508 can be repeatedly executed to eliminate the signal of the next known cell until the signals of all known cells are eliminated.

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

Step 1509: Obtain a preset first time deviation value.

Step 1510: Based on the first time offset value, correlation compensation is performed on the updated second PSS frequency domain data and then detected, thereby obtaining a second time offset value for correlation compensation of the updated second SSS frequency domain data.

Step 1511: Based on the second time offset value, correlation compensation is performed on the updated second SSS frequency domain data and then detected.

Step 1512: Determine the target cell information.

Step 1513: determine whether the preset stop condition is met. If not, take the target cell as a known cell and return to step 1503 to determine the information of the next target cell; if yes, the search ends.

In an embodiment of the present application, the preset stop condition may be the number of cycles that can be set according to the capability information of the terminal device; the preset stop condition may also be that the terminal device cannot detect PSS frequency domain data and/or SSS data.

From the above, it can be seen that since the frequency domain data of the known cell is eliminated in the received data, the second PSS frequency domain data and the second SSS frequency domain data are obtained after the interference of the known cell is eliminated, and the number of cells detected in the second PSS frequency domain data is reduced, thereby improving the cell search performance; further, in the frequency domain PSS detection stage, the time deviation value of the transformed sequence of the updated second PSS frequency domain data (that is, the first PSS frequency domain data) is compensated by discrete transformation to obtain a related compensation sequence, and then based on the related compensation sequence, the updated second SSS frequency domain data (first SSS frequency domain data) and the preset first time deviation value, the information of the target cell is determined; further, when the preset stop condition is not met, the target cell is treated as a known cell, and the second PSS frequency domain data and the second SSS frequency domain data are continued to be updated, and the information of the 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 met. In this way, the amount of calculation and the implementation complexity are greatly reduced, the efficiency of the cell search is improved, and then in the process of determining the information of the target cell, both the cell search performance and the cell search efficiency are taken into consideration.

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

FIG. 16 is a schematic diagram of the composition structure of a cell search device provided in an embodiment of the present application. As shown in FIG. 16 , the cell search device 1600 includes:

The processing module 1601 is used to perform a 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 the interference of the received time domain data is eliminated;

The compensation module 1602 is used to perform time offset compensation on the first transformed sequence after the first correlation sequence is discretely transformed based on a preset first time offset value to obtain a first correlation compensation sequence;

The determination module 1603 is used to determine 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; the first SSS frequency domain data is the SSS frequency domain data after the interference is eliminated in the received time domain data.

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

In some embodiments, the determination module 1603 is also used to determine the second time deviation value based on the first time deviation value and the first correlation compensation sequence; the processing module 1601 is also used to perform time deviation compensation on the second correlation sequence after the first SSS frequency domain data is cross-correlated with the local SSS sequence based on the second time deviation value to obtain a second correlation compensation sequence; the determination module 1603 is also used to determine the information of the target cell based on the first correlation compensation sequence and the second correlation compensation sequence.

In some embodiments, the determination module 1603 is further used to determine a first candidate peak based on the first time deviation value and the first related compensation sequence; the processing module 1601 is further used to perform a modulo operation on the first candidate peak and the length of the first PSS frequency domain data to obtain a second time deviation value.

In some embodiments, the first time deviation value includes: W first time deviation values, W is an integer greater than or equal to 1; each first time deviation value corresponds to N1 first sub-correlation compensation sequences, and the first correlation compensation sequence includes N1 first sub-correlation compensation sequences corresponding to the W first time deviation values, respectively, and N1 is an integer greater than or equal to 1; the determination module 1603 is also used to determine N1 first peaks for each first time deviation value based on the N1 first sub-correlation compensation sequences; for the W first time deviation values, determine U first candidate peaks greater than or equal to the first preset peak threshold from the W×N1 first peaks; U is an integer greater than or equal to 1 and less than or equal to W×N1.

In some embodiments, the cell search device also includes an acquisition module 1604, which is used to obtain energy distribution information corresponding to each first sub-correlation compensation sequence based on N1 first sub-correlation compensation sequences for each first time deviation value; the determination module 1603 is also used to determine the 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 the N1 first sub-correlation compensation sequences.

In some embodiments, the processing module 1601 is further configured to perform a modulo 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.

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

In some embodiments, the acquisition module 1604 is also used to obtain a first candidate peak corresponding to a first related compensation sequence; wherein the first candidate peak corresponds to a first time deviation value and a local PSS sequence; the determination module 1603 is also used to determine a second candidate peak based on a second time deviation value and a second related compensation sequence; wherein the second candidate peak corresponds to a second time deviation value and a local SSS sequence; based on the first candidate peak and the second candidate peak, determine the information of the target cell.

In some embodiments, the second time deviation value includes: P second time deviation values, P is an integer greater than or equal to 1 and less than or equal to W; each second time deviation value corresponds to N2 second sub-correlation compensation sequences, and the second correlation compensation sequence includes N2 second sub-correlation compensation sequences corresponding to the P second time deviation values, respectively, and N2 is an integer greater than or equal to 1; the determination module 1603 is also used to determine N2 second peaks based on the N2 second sub-correlation compensation sequences for each second time deviation value; for the P second time deviation values, determine Q second candidate peaks greater than or equal to the second preset peak threshold from the P×N2 second peaks; 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 also used to perform data transformation on the time domain data of multiple cells received to obtain second PSS frequency domain data and second SSS frequency domain data; eliminate the PSS frequency domain data reconstructed for the known cells with the same frequency in the second PSS frequency domain data to obtain first PSS frequency domain data; and eliminate the SSS frequency domain data reconstructed for 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 also used to obtain a first channel frequency response of a known cell based on least squares parameter estimation of the second SSS frequency domain data; reconstruct 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; eliminate 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 also used 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; eliminate the SSS frequency domain reconstruction data in the second SSS frequency domain data to obtain the first SSS frequency domain data.

In some embodiments, the processing module 1601 is further used 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 filter the second channel frequency response using minimum mean square error to obtain a first channel frequency response.

In some embodiments, the first PSS frequency domain data is the PSS frequency domain data after eliminating the interference of known cells from the received time domain data. The processing module 1601 is also used to take the target cell as a 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 description of the above device embodiment is similar to the description of the above method embodiment, and has similar beneficial effects as the method embodiment. For technical details not disclosed in the device embodiment of the present application, please refer to the description of the method embodiment of the present application for understanding.

It should be noted that in the embodiments of the present application, if the above-mentioned cell search method is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer storage medium. Based on this understanding, the technical solution of the embodiments of the present application is essentially or the part that contributes to the relevant technology can be embodied in the form of a software product, which is stored in a storage medium and includes a number of instructions for a terminal device to execute all or part of the methods described in each embodiment of the present application.

FIG17 is a schematic structural diagram of a device according to an embodiment of the present application. The device 1700 shown in FIG17 includes a processor 1701 and a memory 1702.

The memory 1702 stores a computer program that can be executed on the processor 1701.

When the processor 1701 executes the computer program, the steps of the cell search method in any of the above embodiments are implemented.

The device in the embodiment of the present application may be a terminal device or a chip. The terminal device may be referred to as a terminal (Terminal), user equipment (UE), mobile station (MS), mobile terminal (MT), etc. The electronic devices here may include one of the following or a combination of at least two: Internet of Things (IoT) devices, satellite terminals, Wireless Local Loop (WLL) stations, Personal Digital Assistants (PDAs), handheld devices with wireless communication functions, computing devices or other processing devices connected to wireless modems, servers, mobile phones, tablet computers, computers with wireless transceiver functions, PDAs, desktop computers, personal digital assistants, portable media players, smart speakers, navigation devices, smart watches, smart glasses, smart necklaces and other wearable devices, pedometers, digital TVs, Virtual Reality (VR) terminal devices, Augmented Reality (AR) terminal devices, wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in remote medical surgery, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, and wireless terminals in smart homes. The wireless terminals in the Internet of Vehicles (IoV) and the vehicles, on-board equipment, on-board modules, wireless modems, handheld devices, customer premises equipment (CPE), smart home appliances, etc. in the IoV system.

The processor 1701 in the above device 1700 may be a chip, such as an integrated circuit chip, having signal processing capability. In the implementation process, each step of the above method embodiment may be completed by an integrated logic circuit of hardware in the processor or by instructions in software form.

The above-mentioned processor 1701 can also be a general-purpose processor, a digital signal processor (Digital Signal Processor, DSP), an application-specific integrated circuit (Application Specific Integrated Circuit, ASIC), a field programmable gate array (Field Programmable Gate Array, FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc. The steps of the method disclosed in the embodiments of the present application can be directly embodied as a hardware decoding processor to be executed, or the hardware and software modules in the decoding processor can be combined and executed.

The embodiments of the present application may also provide a computer storage medium, which stores one or more programs. The one or more programs can be executed by one or more processors to implement the steps of the cell search method in any of the above embodiments.

It should be noted here that the description of the above storage medium and terminal device embodiments is similar to the description of the above method embodiments, and has similar beneficial effects as the method embodiments. For technical details not disclosed in the storage medium and terminal device embodiments of this application, please refer to the description of the method embodiments of this application for understanding.

The above-mentioned computer storage medium/memory may include one of the following or an integration of multiple of the following: Read Only Memory (ROM), Programmable Read-Only Memory (PROM), Erasable Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Ferromagnetic Random Access Memory (FRAM), Flash Memory, Magnetic Surface Storage, Optical Disc, Compact Disc Read-Only Memory (CD-ROM) and other memories; it may also be various terminals including one or any combination of the above-mentioned memories, such as mobile phones, computers, tablet devices, personal digital assistants, etc.

It should be understood that the "one embodiment" or "an embodiment" or "an embodiment of the present application" or "the aforementioned embodiment" or "some implementations" or "some embodiments" mentioned throughout the specification means that the specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, "in one embodiment" or "in an embodiment" or "an embodiment of the present application" or "the aforementioned embodiment" or "some implementations" or "some embodiments" appearing throughout the specification do not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in various embodiments of the present application, the size of the sequence number of the above-mentioned processes does not mean the order of execution, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present application. The above-mentioned sequence numbers of the embodiments of the present application are only for description and do not represent the advantages and disadvantages of the embodiments.

Unless otherwise specified, the terminal device executes any step in the embodiments of the present application, and the processor of the terminal device may execute the step. Unless otherwise specified, the embodiments of the present application do not limit the order in which the terminal device executes the following steps. In addition, the methods used to process data in different embodiments may be the same method or different methods. It should also be noted that any step in the embodiments of the present application can be independently executed by the terminal device, that is, when the terminal device executes any step in the above embodiments, it may not rely on the execution of other steps.

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

The units described above as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units; they may be located in one place or distributed on multiple network units; some or all of the units may be selected according to actual needs to achieve the purpose of the present 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 a separate unit, or two or more units may be integrated into one unit; the above-mentioned integrated units may be implemented in the form of hardware or in the form of hardware plus software functional units.

The methods disclosed in several method embodiments provided in this application can be arbitrarily combined without conflict to obtain new method embodiments.

The features disclosed in several product embodiments provided in this application can be arbitrarily combined without conflict to obtain new product embodiments.

The features disclosed in several method or device embodiments provided in this application can be arbitrarily combined without conflict to obtain new method embodiments or device embodiments.

Those skilled in the art can understand that all or part of the steps of implementing the above method embodiments can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer storage medium. When the program is executed, it executes the steps of the above method embodiments; and the aforementioned storage medium includes: mobile storage devices, read-only memories (ROM), magnetic disks or optical disks, and other media that can store program codes.

Alternatively, if the above-mentioned integrated unit of the present application is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer storage medium. Based on such an understanding, the technical solution of the embodiment of the present application can be essentially or partly reflected in the form of a software product that contributes to the relevant technology. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as mobile storage devices, ROMs, magnetic disks, or optical disks.

In the embodiments of the present application, the descriptions of the same steps and the same contents in different embodiments can refer to each other. In the embodiments 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, which means that the terminal device executes A first and then executes B, or the terminal device executes B first and then executes A, or the terminal device executes A and executes B at the same time.

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

It should be noted that in each embodiment involved in the present application, all steps may be executed or part of the steps may be executed as long as a complete technical solution can be formed.

The above is only an implementation method of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims (16)

1. A cell search method, comprising:

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

performing time offset compensation on the first conversion sequence after the discrete conversion of the first correlation sequence 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 secondary synchronization signal SSS frequency domain data; the first SSS frequency domain data is SSS frequency domain data after interference is eliminated in the received time domain data;

The performing time offset compensation on the first transformation sequence after the first correlation sequence is subjected to fourier transformation based on a preset first time offset value to obtain a first correlation compensation sequence, which comprises the following steps:

Performing discrete transformation on the first related sequence to obtain a first transformation sequence;

determining the first correlation compensation sequence corresponding to the first time offset value from the first transformation sequence so as to complete the time offset compensation;

The 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 includes:

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

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

Information of the target cell is determined based on the first correlation compensation sequence and the second correlation compensation sequence.

2. The method of claim 1, wherein the 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.

3. The method of claim 2, wherein the first time offset value comprises: w first time offset values, wherein W is 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 comprise N1 first sub-correlation compensation sequences corresponding to W first time offset values respectively, and N1 is an integer greater than or equal to 1;

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

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

For the W first time offset values, 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; u is an integer greater than or equal to 1 and less than or equal to W N1.

4. The method of claim 3, wherein said determining N1 first peaks based on said N1 first sub-correlation compensation sequences for each of said first time offset values 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 first peak values corresponding to the first sub-correlation compensation sequences based on the energy distribution information corresponding to the first sub-correlation compensation sequences, so as to obtain N1 first peak values corresponding to the N1 first sub-correlation compensation sequences.

5. The method of claim 3 or 4, wherein the subtracting the first candidate peak from the length of the first PSS frequency domain data to obtain the second time offset value comprises:

and performing a 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.

6. The method of claim 1, wherein performing time offset compensation on the second correlation sequence after performing the cross-correlation operation on the first SSS frequency domain data and the 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 the second correlation sequence;

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

And determining the second correlation compensation sequence corresponding to the second time offset value from the second transformation sequence so as to finish the time offset compensation.

7. The method according to any of claims 2 to 4, wherein said determining 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 and a local SSS sequence;

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

8. The method of claim 7, wherein the second time offset value comprises: p second time offset values, P is an integer 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 comprise N2 second sub-correlation compensation sequences corresponding to P second time offset values respectively, and N2 is an integer greater than or equal to 1;

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

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

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

9. The method according to any one of claims 1 to 4, wherein before performing a cross-correlation operation on the first PSS frequency domain data and the local PSS sequence to obtain the first correlation sequence, the method comprises:

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

Eliminating PSS frequency domain data reconstructed for a known cell 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 for the known cell with the same frequency in the second SSS frequency domain data to obtain the first SSS frequency domain data.

10. The method of claim 9, wherein the canceling the PSS frequency domain data reconstructed for the same frequency known cell from the second PSS frequency domain data to obtain the first PSS frequency domain data comprises:

Based on the least square method parameter estimation on the second SSS frequency domain data, obtaining a first channel frequency response of the known cell;

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.

11. The method of claim 10, wherein the canceling the SSS frequency domain data from the second SSS frequency domain data for SSS frequency domain data reconstructed for a same frequency known cell 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.

12. The method of claim 10, wherein the deriving the first channel frequency response of the known cell based on least squares parametric estimation of the second SSS frequency domain data comprises:

Performing least square method 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 a minimum mean square error to obtain the first channel frequency response.

13. The method of any one of claims 1 to 4, wherein the first PSS frequency domain data is PSS frequency domain data after interference of a known cell is canceled for received time domain data, and after the 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 information of a 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.

14. A cell search apparatus, comprising:

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

The compensation module is used for carrying out time offset compensation on the 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 SSS frequency domain data of a first secondary synchronization signal; the first SSS frequency domain data is SSS frequency domain data after interference is eliminated in the received time domain data;

the determining module is used for performing discrete transformation on the first related sequence to obtain the first transformation sequence;

The compensation module is configured to determine, from the first transform sequence, the first correlation compensation sequence corresponding to the offset of the first time offset value, so as to complete the time offset compensation;

The determining module is configured to determine a second time offset value based on the first time offset value and the first correlation compensation sequence;

the processing module is used for performing time offset compensation on the second correlation sequence after the first SSS frequency domain data and the local SSS sequence are subjected to cross correlation operation based on the second time offset value to obtain a second correlation compensation sequence;

The determining module is configured to determine information of the target cell based on the first correlation compensation sequence and the second correlation compensation sequence.

15. An apparatus, the apparatus comprising: a processor and a memory are provided for the processor,

The memory stores a computer program executable on a processor,

The processor, when executing the computer program, implements the method of any one of claims 1 to 13.

16. A computer readable storage medium storing a computer program for causing a computer to perform the method of any one of claims 1 to 13.