Multi-cell search method, device and equipment for synchronization system

Abstract

The invention provides a multi-cell search method of a synchronization system, which can be applied to the technical field of cell search. The multi-cell searching method comprises the following steps: searching candidate cells by utilizing a synchronous searching mode; wherein the number of the candidate cells is not less than 1; determining a reference cell based on the credibility of the candidate cell; determining the wireless frame timing of the candidate cell according to the candidate primary synchronization signal position and the wireless frame position of the candidate cell; based on the frame timing deviation between the wireless frame timing of the candidate cells and the wireless frame timing of the reference cell, screening false detection cells in the candidate cells in the maximum coverage range; and removing false detection cells from the candidate cells to obtain a cell search result. Therefore, according to the multi-cell search method disclosed by the invention, the false detection condition of the cell search is reduced, and the accuracy of the cell search is improved. The invention further provides a multi-cell searching device and equipment of the synchronization system.

Description

Technical Field

[0001] The present disclosure relates to the field of cell search, and more particularly to a multi-cell search method, apparatus, and device for a synchronization system. Background Art

[0002] In a Time Division Duplexing-Long Term Evolution (TDD-LTE) system, the cell search process is an important initial step for a terminal to establish a connection with a network. During this process, the terminal usually searches for multiple cell signals. However, the actual wireless communication environment is quite complex, filled with various noises and interferences. These noises may come from electronic devices, natural environments, etc., while the interferences may come from other wireless signals in the same frequency band or intermodulation interferences within the system. Due to the existence of noises and interferences, there will inevitably be a certain amount of false detections, that is, detecting some cell signals that do not actually exist.

[0003] False detections not only waste the search time and power consumption of the terminal, but may also mislead the subsequent communication process, affecting the reliability and efficiency of communication. Therefore, how to minimize false detections has become a key problem to be solved urgently in the optimization of cell search in the TDD-LTE system. Summary of the Invention

[0004] In view of at least one aspect of the above problems, embodiments of the present disclosure provide a multi-cell search method, apparatus, device, medium, and program product for improving the accuracy of cell search.

[0005] According to a first aspect of the present disclosure, there is provided a multi-cell search method for a synchronization system, applied to the synchronization system, the method including: searching for candidate cells by using a synchronization search method, where the number of candidate cells is not less than 1; determining a reference cell based on the credibility of the candidate cells; determining the radio frame timing of the candidate cells according to the candidate primary synchronization signal positions and radio frame positions of the candidate cells; screening out false detection cells among the candidate cells within the maximum coverage range based on the frame timing deviation between the radio frame timing of the candidate cells and the radio frame timing of the reference cell; and removing the false detection cells from the candidate cells to obtain a cell search result.

[0006] According to an embodiment of the present disclosure, for screening misdetected cells among the candidate cells based on the frame timing deviation between the radio frame timing of the candidate cell and the radio frame timing of the reference cell within the maximum coverage range, it includes: determining a timing deviation threshold value according to the maximum coverage range and the electromagnetic wave propagation speed, where the maximum coverage range is determined by cell coverage range configuration factors; and determining the candidate cells with a frame timing deviation greater than the timing deviation threshold value as the misdetected cells.

[0007] According to an embodiment of the present disclosure, the reliability includes the first normalized correlation value of the candidate cell. Determining a reference cell based on the reliability of the candidate cell includes: determining candidate cells that meet the reliability condition as candidate cells to be selected based on the reliability of the candidate cell; and selecting the cell corresponding to the maximum value among the first normalized correlation values of the candidate cells to be selected as the reference cell.

[0008] According to an embodiment of the present disclosure, the reliability further includes the received power of the candidate cell. The reliability condition includes: the first normalized correlation value of the candidate cell is greater than a first correlation threshold value, and the received power of the candidate cell is greater than a received power threshold value.

[0009] According to an embodiment of the present disclosure, searching for candidate cells using a synchronization search method includes: determining a candidate primary synchronization signal position and a candidate primary synchronization signal identifier through a primary synchronization search method; determining a candidate secondary synchronization signal identifier using a secondary synchronization search method based on the candidate primary synchronization signal position; and determining the candidate cell according to the candidate primary synchronization signal position, the candidate primary synchronization signal identifier, and the candidate secondary synchronization signal identifier.

[0010] According to an embodiment of the present disclosure, determining a candidate secondary synchronization signal identifier using a secondary synchronization search method based on the candidate primary synchronization signal position includes: determining a candidate secondary synchronization signal timing position according to the candidate primary synchronization signal position and the primary-secondary timing deviation; selecting a received secondary synchronization signal according to the candidate secondary synchronization signal timing position; and performing sampling correlation processing on the received secondary synchronization signal and the local secondary synchronization sequence to determine the candidate secondary synchronization signal identifier.

[0011] According to an embodiment of the present disclosure, performing sampling correlation processing on the received secondary synchronization signal and the local secondary synchronization sequence to determine the candidate secondary synchronization signal identifier includes: determining a first correlation result according to the received secondary synchronization signal and the local secondary synchronization sequence; calculating the first normalized correlation value according to the received secondary synchronization signal and the first correlation result; and obtaining the candidate secondary synchronization signal identifier when the first normalized correlation value is greater than a second correlation threshold value.

[0012] According to an embodiment of the present disclosure, determining a candidate primary synchronization signal position and a candidate primary synchronization signal identifier by the primary synchronization search method includes: determining a second correlation result based on a received signal and a local primary synchronization signal; calculating a second normalized correlation value according to the received signal and the second correlation result; and obtaining the candidate primary synchronization signal position and the candidate primary synchronization signal identifier when the second normalized correlation value is greater than a third correlation threshold value.

[0013] A multi-cell search device for a synchronization system according to a second aspect of the present disclosure is applied to the synchronization system. The device includes: a synchronization search module configured to search for candidate cells by using a synchronization search method, where the number of candidate cells is not less than 1; a cell determination module configured to determine a reference cell based on the credibility of the candidate cells; a timing determination module configured to determine the radio frame timing of the candidate cells according to the candidate primary synchronization signal positions and radio frame positions of the candidate cells; a screening module configured to screen out misdetected cells among the candidate cells within a maximum coverage range based on a frame timing deviation between the radio frame timing of the candidate cells and the radio frame timing of the reference cell; and an elimination module configured to eliminate the misdetected cells among the candidate cells to obtain a cell search result.

[0014] A third aspect of the present disclosure provides an electronic device, including: one or more processors; a memory configured to store one or more computer programs, where the above one or more processors execute the above one or more computer programs to implement the steps of the above method.

[0015] A fourth aspect of the present disclosure further provides a computer-readable storage medium, on which a computer program or instruction is stored. When the computer program or instruction is executed by a processor, the steps of the above method are implemented.

[0016] A fifth aspect of the present disclosure further provides a computer program product, including a computer program or instruction. When the computer program or instruction is executed by a processor, the steps of the above method are implemented.

[0017] In an embodiment of the present disclosure, since there may be false detections during multi-cell search in a synchronization system, it is necessary to reduce the probability of false detections. By implementing the embodiments of the present disclosure, candidate cells are searched using a synchronization search method; wherein, there is at least one candidate cell; a reference cell is determined based on the credibility of the candidate cell; the radio frame timing of the candidate cell is determined according to the candidate primary synchronization signal position and radio frame position of the candidate cell; based on the frame timing deviation between the radio frame timing of the candidate cell and the radio frame timing of the reference cell, false detection cells among the candidate cells are screened within the maximum coverage range; and the false detection cells are excluded from the candidate cells to obtain a cell search result. By utilizing the finiteness of the frame timing deviation, within the maximum coverage range, false detection cells can be accurately screened and excluded, reducing the situation of false detections and improving the accuracy of cell search. Description of the Drawings

[0018] Through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, the above content and other objects, features, and advantages of the present disclosure will become clearer. In the drawings:

[0019] Figure 1 Schematically shows an application scenario diagram of a multi-cell search method for a synchronization system according to an embodiment of the present disclosure;

[0020] Figure 2 Schematically shows a flowchart of a multi-cell search method for a synchronization system according to an embodiment of the present disclosure;

[0021] Figure 3 Schematically shows a flowchart of searching candidate cells for a multi-cell search method for a synchronization system according to an embodiment of the present disclosure;

[0022] Figure 4 Schematically shows a flowchart of secondary synchronization search for a multi-cell search method for a synchronization system according to an embodiment of the present disclosure;

[0023] Figure 5 Schematically shows a flowchart of determining a reference cell for a multi-cell search method for a synchronization system according to an embodiment of the present disclosure;

[0024] Figure 6 Schematically shows a flowchart of screening false detection cells for a multi-cell search method for a synchronization system according to an embodiment of the present disclosure;

[0025] Figure 7 Schematically shows a block diagram of a multi-cell search device for a synchronization system according to an embodiment of the present disclosure; and

[0026] Figure 8 Schematically shows a block diagram of an electronic device suitable for implementing a multi-cell search method for a synchronization system according to an embodiment of the present disclosure. Detailed implementation manners

[0027] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present disclosure. In the following detailed description, for the sake of explanation, numerous specific details are set forth in order to provide a comprehensive understanding of the embodiments of the present disclosure. However, obviously, one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily obscuring the concepts of the present disclosure.

[0028] The terms used herein are merely for describing specific embodiments and are not intended to limit the present disclosure. The terms "including", "comprising", etc. used herein indicate the presence of features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0029] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0030] In cases where expressions such as "at least one of A, B, and C, etc." are used, generally, it should be interpreted according to the meaning commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include, but not be limited to, a system having only A, having only B, having only C, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.).

[0031] During the cell search process of a TDD-LTE system, generally multiple cells will be detected. However, due to the presence of noise and interference, there will be a certain amount of false detection cases, that is, cells that actually do not exist are detected. Therefore, it is necessary to minimize false detection cases. However, the prior art does not utilize the synchronization characteristics of each cell in the TDD-LTE system to remove false detected cells, resulting in false detection cases still existing in cell search and the accuracy of cell search being not high.

[0032] Embodiments of the present disclosure provide a multi-cell search method for a synchronization system, which is applied to a time division duplex long term evolution system. The method includes: searching for candidate cells by using a synchronization search method, where the number of candidate cells is not less than 1; determining a reference cell based on the credibility of the candidate cells; determining the radio frame timing of the candidate cells according to the candidate primary synchronization signal positions and radio frame positions of the candidate cells; screening out misdetected cells among the candidate cells within the maximum coverage range based on the frame timing deviation between the radio frame timing of the candidate cells and the radio frame timing of the reference cell; and removing the misdetected cells from the candidate cells to obtain a cell search result.

[0033] Figure 1 FIG. schematically shows an application scenario diagram of the multi-cell search method for a synchronization system according to an embodiment of the present disclosure.

[0034] As Figure 1 shown, the application scenario 100 according to this embodiment may include a multi-cell search scenario of a TDD-LTE system. The network 104 is used as a medium for providing a communication link between the first terminal device 101, the second terminal device 102, the third terminal device 103, the server 105, and the base station 106. The network 104 may include various connection types, such as wired, wireless communication links, or fiber optic cables, etc.

[0035] Users can use the first terminal device 101, the second terminal device 102, and the third terminal device 103 to interact with the base station 106 through the network 104. Users can also use the first terminal device 101, the second terminal device 102, and the third terminal device 103 to interact with the server 105 through the network 104 to receive or send messages, etc. Various communication client applications may be installed on the first terminal device 101, the second terminal device 102, and the third terminal device 103, such as shopping applications, web browser applications, search applications, instant messaging tools, email clients, social platform software, etc. (only as examples).

[0036] The first terminal device 101, the second terminal device 102, and the third terminal device 103 may be various electronic devices with a display screen and supporting web browsing, including but not limited to smart phones, tablet computers, laptop portable computers, and desktop computers, etc.

[0037] The base station 106 may be an access device of a mobile communication system and communicate with the first terminal device 101, the second terminal device 102, and the third terminal device 103 through wireless signals.

[0038] Server 105 may be a server that provides various services. For example, it may be a back-end management server (merely an example) that supports websites browsed by users using the first terminal device 101, the second terminal device 102, and the third terminal device 103. The back-end management server may analyze and process data such as user requests received, and feedback the processing results (such as web pages, information, or data obtained or generated according to user requests) to the terminal devices.

[0039] It should be noted that the multi-cell search method of the synchronization system provided by the embodiments of the present disclosure can generally be executed by the first terminal device 101, the second terminal device 102, and the third terminal device 103. Correspondingly, the multi-cell search device provided by the embodiments of the present disclosure can generally be disposed in the first terminal device 101, the second terminal device 102, and the third terminal device 103.

[0040] It should be understood that Figure 1 the numbers of terminal devices, base stations, networks, and servers in

[0041] are merely illustrative. According to implementation needs, there can be any number of terminal devices, base stations, networks, and servers. Figure 1 are merely illustrative. According to implementation needs, there can be any number of terminal devices, base stations, networks, and servers. Figures 2 to 6 The multi-cell search method of the synchronization system of the present disclosure will be described in detail below based on

[0042] Figure 2 FIG. schematically shows a flowchart of the multi-cell search method of the synchronization system according to an embodiment of the present disclosure.

[0043] As Figure 2 shown, the multi-cell search method of the synchronization system of this embodiment is applied to a synchronization system. The synchronization system may be a Time Division Duplexing-Long Term Evolution (TDD-LTE) system, not limited to a certain specific communication protocol, and can be applicable to multiple communication protocols, such as 3G / 4G / 5G and other protocols. This method includes operation S210 to operation S250.

[0044] In operation S210, candidate cells are searched using a synchronization search method; where the number of candidate cells is not less than 1.

[0045] In a TDD-LTE system, candidate cells can be searched using a synchronization search method. Among them, the synchronization search method may include a primary and secondary signal search method, a signal feature search method, a neighboring cell list search method, etc.

[0046] Primary and secondary signal search method: In a TDD-LTE system, the cell initial synchronization and cell identification are achieved by means of the Primary Synchronization Signal (PSS) and the Secondary Synchronization Signal (SSS). The PSS is mainly used for symbol timing and determining the number within the physical layer cell identification group, while the SSS is used for frame synchronization and determining the physical layer cell identification group number. By combining the two, the unique physical layer cell identification can be determined. By adopting the primary and secondary signal search method, symbol timing synchronization can be quickly achieved using the primary synchronization signal to determine the number within the cell identification group, and frame synchronization can be completed with the help of the secondary synchronization signal to clarify the cell identification group number. The two cooperate to efficiently and accurately locate the candidate cells, and can accurately achieve symbol and frame synchronization and cell identification determination. The process is clear, and the candidate cells can be quickly and reliably found to ensure the initial access of the communication system.

[0047] Signal feature search method: By analyzing various features of the received signal, such as signal strength, signal quality, signal spectrum characteristics, etc., to search for candidate cells. The signals of different cells have differences in these features, and the terminal can use these differences to identify and screen candidate cells. Its search process is as follows: (1) Signal feature measurement: The terminal continuously measures various characteristic parameters of the received signal, such as the reference signal received power, the reference signal received quality, etc. (2) Feature analysis and comparison: Analyze and compare the measured characteristic parameters, and determine the cell corresponding to the signal that meets specific conditions (such as the signal strength is higher than a certain threshold, the signal quality reaches a certain standard) as a candidate cell.

[0048] Neighboring cell list search method: In a TDD-LTE system, the base station provides the terminal with a neighboring cell list, which contains information about the cells adjacent to the current serving cell, such as cell identification, frequency, etc. The terminal can search for candidate cells targeted according to this neighboring cell list, thereby improving the search efficiency. Its search process is as follows: (1) Obtain the neighboring cell list: The terminal obtains the neighboring cell list information from the current serving cell. (2) Cell search: The terminal searches for these neighboring cells at the corresponding frequencies and time positions according to the cell information in the neighboring cell list, and determines the candidate cells through methods such as synchronization signal detection and signal feature measurement.

[0049] It should be noted that the TDD-LTE system uses time-division multiplexing technology to perform uplink and downlink data transmission in different time slots of the same frequency band. By flexibly configuring the uplink and downlink time slot ratios, it can better adapt to asymmetric service requirements, such as the case where the data download volume is usually greater than the upload volume.

[0050] The terminal is a user equipment of the TDD-LTE system, such as a mobile phone, a tablet computer, an Internet of Things device, etc. The terminal communicates with the base station in the TDD-LTE system to implement various service functions, such as voice calls, data Internet access, video playback, etc. When the terminal accesses the TDD-LTE system, it needs to perform processes such as cell search and synchronization to establish a connection with the base station and obtain configuration information from the system, such as parameters like bandwidth and power, so as to perform data transmission under the control of the system.

[0051] The base station is the infrastructure of the TDD-LTE system, responsible for wireless communication with the terminal, forwarding the terminal's data to the core network, and sending the core network's data to the terminal. The base station undertakes functions such as signal transmission, reception, and processing in the TDD-LTE system. Through means such as transmit power control and scheduling algorithms, it realizes the management and resource allocation of terminals within the coverage area to ensure the performance and capacity of the system. At the same time, the base stations also need to cooperate with each other, such as handover control and interference coordination, to ensure the communication continuity and stability of the terminal during the movement process.

[0052] In operation S220, based on the credibility of the candidate cells, a reference cell is determined.

[0053] For the multiple candidate cells obtained by cell search, their credibility can be calculated, and the one with the highest credibility is selected and recorded as the reference cell. Based on the reference cell, the interval of cell timing decision can be determined to accurately find out the misdetected cells.

[0054] In operation S230, based on the candidate primary synchronization signal position and radio frame position of the candidate cell, the radio frame timing of the candidate cell is determined.

[0055] For the candidate primary synchronization signal position (candidate PSS position ) of the candidate cell, according to the known radio frame position of the PSS in the radio frame , the radio frame timing can be determined as .

[0056] In operation S240, based on the frame timing deviation between the radio frame timing of the candidate cell and the radio frame timing of the reference cell, within the maximum coverage range, the misdetected cells in the candidate cells are screened.

[0057] The maximum coverage range represents the maximum coverage radius of the reference cell. Since the frame timing of each cell in the TDD-LTE system is synchronized and the maximum coverage range of each cell is limited, the deviation between the timings at which the synchronization signals of each cell reach the terminal is also limited. By effectively utilizing this feature, misdetected cells with a frame timing deviation from the reference cell exceeding the preset timing deviation threshold can be removed. Here, the frame timing deviation can be a deviation less than one subframe. The number of misdetected cells screened out may be 0, 1, or more.

[0058] In operation S250, misdetected cells are removed from the candidate cells to obtain the cell search result.

[0059] For other candidate cells, if the frame timing deviation from the reference cell is greater than the preset timing deviation threshold, the cell is considered a misdetected cell and is removed from the searched candidate cells to obtain the cell search result. There are no misdetected cells, thereby reducing the probability of misdetection.

[0060] Figure 3 The flowchart of searching for candidate cells of the multi-cell search method of the synchronization system according to an embodiment of the present disclosure is schematically shown.

[0061] As Figure 3 shown, according to an embodiment of the present disclosure, in operation S210, using the synchronization search method, when searching for candidate cells, operations S310 - S330 are included.

[0062] In operation S310, the candidate primary synchronization signal position and the candidate primary synchronization signal identifier are determined by the primary synchronization search method.

[0063] According to an embodiment of the present disclosure, the primary synchronization search method is used to determine the symbol timing, which is a method of sampling and sliding correlation. In determining the candidate primary synchronization signal position and the candidate primary synchronization signal identifier by the primary synchronization search method in operation S310, operations S3101 - S3103 are included.

[0064] In operation S3101, based on the received signal and the local primary synchronization signal, the second correlation result is determined.

[0065] The received signal is , and the local primary synchronization signal (local PSS signal) is , then the second correlation result is

[0066] (1)

[0067] represents the conjugate of the k-th signal in the local PSS signal .

[0068] It should be noted that the received signal refers to the wireless signal from the base station received by the terminal through the antenna. The local PSS signal is a signal related to the primary synchronization signal pre-stored and generated inside the terminal. According to the LTE standard protocol, the terminal knows the specific forms and characteristics of the PSS signals corresponding to different cell identifiers, and will generate these possible PSS signals locally during cell search. The second correlation result represents the correlation between the received signal and the local PSS signal to determine the similarity degree between the received signal and the local PSS signal.

[0069] In operation S3102, according to the received signal and the second correlation result, calculate the second normalized correlation value.

[0070] According to the received signal and the second correlation result , calculate the second normalized correlation value The formula is:

[0071] (2)

[0072] The second normalized correlation value represents the normalized value of the correlation result between the received signal and the local PSS signal. The normalization process eliminates the influence of the received signal strength fluctuation on the correlation result, accurately measures the correlation, and makes the correlation results at different times and different receiving environments comparable.

[0073] In operation S3103, when the second normalized correlation value is greater than the third correlation threshold, obtain the candidate primary synchronization signal position and the candidate primary synchronization signal identifier.

[0074] The third correlation threshold is a preset correlation threshold between the received signal and the local PSS signal. If , then this timing point is considered a candidate primary synchronization signal position (candidate PSS position), and at the same time record the ID of the corresponding local PSS sequence. This PSS ID is the candidate primary synchronization signal identifier.

[0075] Actually, there can be multiple local PSS sequences for the local PSS signal, and there are corresponding different PSS IDs. The method of calculating the candidate timing is the same as the processing of one local PSS signal. Taking 3 different forms of PSS sequences as an example, the process of determining the candidate primary synchronization signal identifier (PSS ID) is as follows:

[0076] (1) Correlation calculation between the received signal and the local PSS sequence:

[0077] The terminal receives the radio frequency signal from the base station, and through operations such as down-conversion and analog-to-digital conversion, converts it into a digital baseband signal ( ).

[0078] Local PSS sequence preparation: In the TDD-LTE system, there are three different forms of PSS sequences, corresponding to three different PSS IDs (0, 1, 2) respectively. These three PSS sequences will be pre-stored locally, denoted as , , ([[]] ).

[0079] Sliding correlation calculation: For each local PSS sequence, the sliding correlation method is used to calculate with the received signal. Taking the local PSS sequence ([[]] = 0, 1, 2) as an example, the calculation formula for the correlation result is , where represents the conjugate of the local PSS sequence .

[0080] (2) Normalized correlation value calculation:

[0081] In order to more accurately measure the similarity between the received signal and the local PSS sequence, it is necessary to normalize the correlation result. Calculate the first normalized correlation value , and the formula is:

[0082] (3)

[0083] (3) Compare with the third correlation threshold value to determine the candidate PSS position and PSS ID:

[0084] Determine the candidate PSS position: Compare the calculated first normalized correlation value with the pre-set first threshold value α. If > α, then it is considered that the timing point n is a candidate PSS position, and at the same time record the ID of the corresponding local PSS sequence.

[0085] Determine the final PSS ID: Among all possible combinations of timing points and local PSS sequences, select the PSS ID corresponding to the combination with the largest normalized correlation value and greater than the third correlation threshold value as the finally determined PSS ID. The larger the normalized correlation value, the higher the matching degree between the received signal and the local PSS sequence, and the more likely it is the actual PSS signal.

[0086] In operation S320, based on the candidate primary synchronization signal position, use the secondary synchronization search method to determine the candidate secondary synchronization signal identifier.

[0087] The secondary synchronization search method determines the candidate secondary synchronization signal position (candidate SSS position) based on the timing relationship between the PSS and the SSS on the basis of the candidate PSS position, and then performs a correlation operation on the received SSS signal and the local SSS sequence to determine the candidate secondary synchronization signal identifier (candidate SSS ID).

[0088] In operation S330, based on the candidate primary synchronization signal position, the candidate primary synchronization signal identifier, and the candidate secondary synchronization signal identifier, a candidate cell is determined.

[0089] Combining the candidate PSS position, the candidate PSS ID, and the candidate SSS ID can obtain multiple candidate cells. Each candidate PSS position, the corresponding PSS ID, and the found candidate SSS ID form a unique combination, and these combinations initially represent different candidate cells. In the LTE system, different cells have a unique combination of PSS ID and SSS ID, and the candidate PSS position determines the position of these signals in the received signal. The combination of the three can initially determine the basic characteristics of a cell.

[0090] Figure 4 Schematically shows the secondary synchronization search flow chart of the multi-cell search method of the synchronization system according to an embodiment of the present disclosure.

[0091] As Figure 4 shown, according to an embodiment of the present disclosure, in operation S320, based on the candidate primary synchronization signal position, using the secondary synchronization search method to determine the candidate secondary synchronization signal identifier includes operations S410 - S430.

[0092] In operation S410, based on the candidate primary synchronization signal position and the primary-secondary timing deviation, the candidate secondary synchronization signal timing position is determined.

[0093] After determining the candidate primary synchronization signal position (candidate PSS position ), according to the primary-secondary timing deviation , the candidate secondary synchronization signal timing position (the timing position of the candidate SSS) is determined to be . The primary-secondary timing deviation is the timing deviation between the local SSS signal and the local PSS signal, and it is a fixed value.

[0094] In operation S420, based on the candidate secondary synchronization signal timing position, the received secondary synchronization signal is selected.

[0095] The timing position of the candidate SSS provides an accurate timing starting point for the SSS search, enabling the terminal to search for the SSS signal at the correct time position, improving the search efficiency and accuracy. From The timing position of this candidate SSS starts to select the received signal to obtain the received secondary synchronization signal (received SSS signal), which facilitates SSS-related calculations based on this signal. Therefore, the candidate PSS position By determining the timing, it provides a necessary prerequisite for accurately calculating the candidate SSS-related values and subsequently determining the candidate secondary synchronization signal identifier (candidate SSS ID).

[0096] In operation S430, the received secondary synchronization signal and the local secondary synchronization sequence are subjected to sampling correlation processing to determine the candidate secondary synchronization signal identifier.

[0097] According to an embodiment of the present disclosure, the method for determining the candidate secondary synchronization signal identifier (candidate SSS ID) can use the method of sampling correlation processing. In operation S430, when the received secondary synchronization signal and the local secondary synchronization sequence are subjected to sampling correlation processing to determine the candidate secondary synchronization signal identifier, it includes operations S4301 - S4303.

[0098] In operation S4301, according to the received secondary synchronization signal and the local secondary synchronization sequence, the first correlation result is determined.

[0099] If the received secondary synchronization signal (received SSS signal) is and the local secondary synchronization sequence (local SSS sequence) is , indicating the SSS sequence with local ID q, then the first correlation result is:[[]]

[0100] (4)

[0101] indicating the conjugate of the local SSS sequence .

[0102] The first correlation result is the correlation between the received SSS signal and the local SSS sequence to judge the similarity degree between the received SSS signal and the local SSS sequence.

[0103] In operation S4302, according to the received secondary synchronization signal and the first correlation result, the first normalized correlation value is calculated.

[0104] The first normalized correlation value is:[[]]

[0105] . (5)

[0106] The first normalized correlation value represents the normalized value of the correlation result between the received SSS signal and the local SSS sequence.

[0107] In operation S4303, when the first normalized correlation value is greater than the second correlation threshold, a candidate secondary synchronization signal identifier is obtained.

[0108] The second correlation threshold is a preset correlation threshold between the received SSS signal and the local SSS sequence. If , then the sequence ID is considered a candidate SSS ID, and this SSS ID is the candidate secondary synchronization signal identifier.

[0109] Figure 5 Schematically shows a flowchart of determining a reference cell for a multi-cell search method of a synchronization system according to an embodiment of the present disclosure.

[0110] As Figure 5 shown, according to an embodiment of the present disclosure, the reliability includes the first normalized correlation value of the candidate cell and the received power of the candidate cell. In determining the reference cell based on the reliability of the candidate cell in operation S220, operations S510 - S520 are included.

[0111] In operation S510, based on the reliability of the candidate cell, the cells in the candidate cells that meet the reliability conditions are determined as candidate cells.

[0112] According to an embodiment of the present disclosure, the reliability conditions include: the first normalized correlation value of the candidate cell is greater than the first correlation threshold, and the received power of the candidate cell is greater than the received power threshold.

[0113] Generally, the normalized correlation value of the general SSS decreases as the signal-to-noise ratio decreases, that is, the reliability decreases. At the same time, a decrease in the received power means a decrease in the signal-to-noise ratio of the received signal, so the reliability decreases. Therefore, the received signal power can be used as a measure of the reliability of the search result. Therefore, considering the normalized correlation value and the received power comprehensively can be used as a measure of the reliability of the cell search result.

[0114] Among them, the received power of each candidate cell is:

[0115] (6)

[0116] The first normalized correlation value of each candidate cell is:

[0117] . (7)

[0118] In operation S520, the cell corresponding to the maximum value of the first normalized correlation value of the candidate cells is selected as the reference cell.

[0119] Select the cell with the largest first normalized correlation value (the normalized correlation value calculated during the secondary synchronization search process). If this cell and the received power of this cell , then this cell is used as the reference cell. They are the first correlation threshold and the received power threshold respectively. The first correlation threshold is the preset correlation threshold for selecting the reference cell, and the received power threshold is the preset received power threshold for selecting the reference cell.

[0120] Figure 6 Schematically shows a flowchart for screening misdetected cells of the multi-cell search method of the synchronization system according to an embodiment of the present disclosure.

[0121] As Figure 6 shown, according to an embodiment of the present disclosure, in operation S240, based on the frame timing deviation between the radio frame timing of the candidate cell and the radio frame timing of the reference cell, within the maximum coverage range, misdetected cells among the candidate cells are screened, including operations S610 - S620.

[0122] In operation S610, determine the timing deviation threshold according to the maximum coverage range and the electromagnetic wave propagation speed; wherein, the maximum coverage range is determined by the cell coverage range configuration factor.

[0123] The timing deviation threshold , is the maximum coverage range, that is, the maximum coverage radius of the cell, c is the electromagnetic wave propagation speed.

[0124] The timing deviation threshold and the maximum coverage radius of the cell are in a proportional relationship. The maximum coverage radius of the cell can be determined according to the cell coverage range configuration factor. For example, it can be determined by communication resources. Signals in different frequency bands have different propagation characteristics. Signals in the low-frequency band have small propagation loss and large coverage range; signals in the high-frequency band have large propagation loss and small coverage range. According to the propagation model and loss parameters corresponding to the frequency band, combined with parameters such as the base station transmit power, antenna gain, and receiving sensitivity, the theoretical maximum coverage distance in different frequency bands is calculated. For example, for the 900 MHz frequency band and the 2.6 GHz frequency band, the maximum coverage distances under the same transmit power and antenna gain conditions are calculated using the propagation loss formulas of their respective frequency bands. Generally, the coverage distance of the 900 MHz frequency band is greater than that of the 2.6 GHz frequency band.

[0125] It is also possible to determine the maximum coverage radius according to the maximum value of the TA command in the random access response . The formula is:

[0126] (8)

[0127] The TA command is the Timing Advance command, which is used to instruct the terminal to adjust the uplink transmission time to ensure that the uplink signal can reach the base station accurately. The maximum value represents the maximum value that this command can reach.

[0128] The maximum coverage radius can also be externally configured according to the actual working scenario and flexibly adjusted according to specific application scenarios and service requirements. In densely populated places such as shopping malls and schools, in order to meet the communication needs of a large number of users, a smaller cell coverage range is adopted to increase the system capacity. At this time, even if the theoretically calculated maximum cell coverage range is large, the coverage range will be limited to a smaller area during actual configuration, and the capacity is increased by increasing the number of base stations. In remote areas such as rural areas and deserts, where the population is sparse and the service demand is low, the cell coverage range can be expanded to reduce the base station construction cost, and at this time it will be close to or reach the theoretically maximum coverage range.

[0129] In operation S620, candidate cells with a frame timing deviation greater than the timing deviation threshold are determined as misdetected cells.

[0130] The radio frame timing of the synchronization signal of the reference cell is , and the radio frame timing of the synchronization signal of a detected candidate cell is , then the frame timing deviation between this candidate cell and the reference cell is .

[0131] In the TDD-LTE system, the frame timings of each cell are synchronized. At the same time, the maximum coverage range of each cell is limited, so the deviation between the frame timings of the synchronization signals of each cell reaching the terminal is also limited, that is , then when , this candidate cell is a misdetected cell, and the misdetected cell is determined.

[0132] After selecting a reference cell, the validity of the searched cells is judged according to whether the frame timing deviation between the candidate cell and the reference cell is within the maximum coverage range, and the misdetected cells are determined, which is beneficial to removing these misdetected cells whose frame timing deviation from the reference cell exceeds the timing deviation threshold.

[0133] Based on the multi-cell search method of the above synchronization system, the present disclosure also provides a multi-cell search method device for the synchronization system. The following will be combined with Figure 7 to describe this device in detail.

[0134] Figure 7 Schematically shows the structural block diagram of the multi-cell search device for the synchronization system according to an embodiment of the present disclosure.

[0135] As Figure 7 shown, the multi-cell search device 700 of this embodiment is applied to a synchronization system, which may be a Time Division Duplexing-Long Term Evolution (TDD-LTE) system. The device 700 includes a synchronization search module 710, a cell determination module 720, a timing determination module 730, a screening module 740, and an elimination module 750.

[0136] The synchronization search module 710 is used to search for candidate cells by using a synchronization search method; among them, the number of candidate cells is not less than 1. In one embodiment, the synchronization search module 710 can be used to perform the operation S210 described above, which will not be elaborated here.

[0137] The cell determination module 720 is used to determine a reference cell based on the credibility of the candidate cells. In one embodiment, the cell determination module 720 can be used to perform the operation S220 described above, which will not be elaborated here.

[0138] The timing determination module 730 is used to determine the radio frame timing of the candidate cells according to the candidate primary synchronization signal position and the radio frame position of the candidate cells. In one embodiment, the timing determination module 730 can be used to perform the operation S230 described above, which will not be elaborated here.

[0139] The screening module 740 is used to screen out the misdetected cells among the candidate cells within the maximum coverage range based on the frame timing deviation between the radio frame timing of the candidate cells and the radio frame timing of the reference cell. In one embodiment, the screening module 740 can be used to perform the operation S240 described above, which will not be elaborated here.

[0140] The elimination module 750 is used to eliminate the misdetected cells from the candidate cells to obtain the cell search result. In one embodiment, the elimination module 750 can be used to perform the operation S250 described above, which will not be elaborated here.

[0141] According to an embodiment of the present disclosure, any multiple of the synchronization search module 710, the cell determination module 720, the timing determination module 730, the screening module 740, and the elimination module 750 may be combined and implemented in one module, or any one of them may be split into multiple modules. Alternatively, at least part of the functions of one or more of these modules may be combined with at least part of the functions of other modules and implemented in one module. According to an embodiment of the present disclosure, at least one of the synchronization search module 710, the cell determination module 720, the timing determination module 730, the screening module 740, and the elimination module 750 may be at least partially implemented as a hardware circuit, such as a field-programmable gate array (FPGA), a programmable logic array (PLA), a system-on-chip, a system-on-substrate, a system-on-package, an application-specific integrated circuit (ASIC), or any other reasonable way of integrating or packaging circuits, etc., implemented by hardware or firmware, or implemented in any one of the three implementation manners of software, hardware, and firmware, or in an appropriate combination of any several of them. Alternatively, at least one of the synchronization search module 710, the cell determination module 720, the timing determination module 730, the screening module 740, and the elimination module 750 may be at least partially implemented as a computer program module, and when the computer program module is run, the corresponding functions may be executed.

[0142] Figure 8 Schematically shows a block diagram of an electronic device suitable for implementing a multi-cell search method of a synchronization system according to an embodiment of the present disclosure.

[0143] As Figure 8 shown, the electronic device 800 according to an embodiment of the present disclosure includes a processor 801, which may perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 802 or a program loaded from a storage section 808 into a random access memory (RAM) 803. The processor 801 may include, for example, a general microprocessor (such as a CPU), an instruction set processor, and / or a related chipset, and / or a dedicated microprocessor (such as an application-specific integrated circuit (ASIC)), etc. The processor 801 may also include on-board memory for caching purposes. The processor 801 may include a single processing unit or multiple processing units for performing different actions of the method flow according to an embodiment of the present disclosure.

[0144] In the RAM 803, various programs and data required for the operation of the electronic device 800 are stored. The processor 801, the ROM 802, and the RAM 803 are connected to each other via a bus 804. The processor 801 performs various operations of the method flow according to the embodiments of the present disclosure by executing the programs in the ROM 802 and / or the RAM 803. It should be noted that the programs can also be stored in one or more memories other than the ROM 802 and the RAM 803. The processor 801 can also perform various operations of the method flow according to the embodiments of the present disclosure by executing the programs stored in one or more memories.

[0145] According to an embodiment of the present disclosure, the electronic device 800 may further include an input / output (I / O) interface 805, and the input / output (I / O) interface 805 is also connected to the bus 804. The electronic device 800 may further include one or more of the following components connected to the input / output (I / O) interface 805: an input section 806 including a keyboard, a mouse, etc.; an output section 807 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc. and a speaker, etc.; a storage section 808 including a hard disk, etc.; and a communication section 809 including a network interface card such as a LAN card, a modem, etc. The communication section 809 performs communication processing via a network such as the Internet. A drive 810 is also connected to the input / output (I / O) interface 805 as needed. A removable medium 811, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 810 as needed so that a computer program read from it can be installed into the storage section 808 as needed.

[0146] The present disclosure also provides a computer-readable storage medium, which may be included in the device / apparatus / system described in the above embodiments; or may exist separately without being assembled into the device / apparatus / system. The above computer-readable storage medium carries one or more programs, and when the above one or more programs are executed, the method according to the embodiments of the present disclosure is implemented.

[0147] According to an embodiment of the present disclosure, the computer-readable storage medium may be a non-volatile computer-readable storage medium, which may include, for example, but is not limited to: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the above. In the present disclosure, the computer-readable storage medium may be any tangible medium that contains or stores a program, which can be used by or in conjunction with an instruction execution system, apparatus, or device. For example, according to an embodiment of the present disclosure, the computer-readable storage medium may include one or more memories other than the above-described ROM 802 and / or RAM 803 and / or ROM 802 and RAM 803.

[0148] An embodiment of the present disclosure also includes a computer program product, which includes a computer program that contains program code for executing the method shown in the flowchart. When the computer program product runs in a computer system, the program code is used to enable the computer system to implement the multi-cell search method of the synchronization system provided by the embodiments of the present disclosure.

[0149] When the computer program is executed by the processor 801, it executes the above functions defined in the system / apparatus of the embodiments of the present disclosure. According to an embodiment of the present disclosure, the above-described systems, apparatuses, modules, units, etc. may be implemented by computer program modules.

[0150] In one embodiment, the computer program may rely on tangible storage media such as optical storage devices and magnetic storage devices. In another embodiment, the computer program may also be transmitted and distributed in the form of a signal on a network medium and downloaded and installed through the communication part 809, and / or installed from the removable medium 811. The program code included in the computer program may be transmitted using any suitable network medium, including but not limited to: wireless, wired, etc., or any suitable combination of the above.

[0151] In such an embodiment, the computer program may be downloaded and installed from the network through the communication part 809, and / or installed from the removable medium 811. When the computer program is executed by the processor 801, it executes the above functions defined in the system of the embodiments of the present disclosure. According to an embodiment of the present disclosure, the above-described systems, devices, apparatuses, modules, units, etc. may be implemented by computer program modules.

[0152] In accordance with embodiments of the present disclosure, program code for executing the computer programs provided by the embodiments of the present disclosure can be written in any combination of one or more programming languages. Specifically, these computing programs can be implemented using high-level procedural and / or object-oriented programming languages, and / or assembly / machine languages. Programming languages include, but are not limited to, such as Java, C++, Python, the "C" language, or similar programming languages. The program code can be executed entirely on the user's computing device, partially on the user's device, partially on a remote computing device, or entirely on a remote computing device or server. In cases involving a remote computing device, the remote computing device can be connected to the user's computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computing device (e.g., by connecting through the Internet using an Internet service provider).

[0153] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of systems, methods, and computer program products according to various embodiments of the present disclosure. In this regard, each block in the flowchart or block diagram can represent a module, a program segment, or a part of code, and the above-mentioned module, program segment, or part of code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order from that marked in the accompanying drawings. For example, two consecutive blocks shown may actually be executed substantially in parallel, and they may sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram or flowchart, and the combination of blocks in the block diagram or flowchart, can be implemented by a dedicated hardware-based system for performing the specified functions or operations, or can be implemented by a combination of dedicated hardware and computer instructions.

[0154] Those skilled in the art can understand that the features described in the various embodiments of the present disclosure can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in the present disclosure. In particular, without departing from the spirit and teachings of the present disclosure, the features described in the various embodiments of the present disclosure can be combined and / or combined in various ways. All such combinations and / or combinations fall within the scope of the present disclosure.

[0155] The above describes the embodiments of the present disclosure. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Although the embodiments are described separately above, this does not mean that the measures in each embodiment cannot be used advantageously in combination. Without departing from the scope of the present disclosure, those skilled in the art can make various substitutions and modifications, and all such substitutions and modifications should fall within the scope of the present disclosure.

Claims

1. A multi-cell search method for a synchronization system, characterized in that Applied to the synchronization system, the method includes: Searching for candidate cells using a synchronization search method; wherein, there is at least one candidate cell; Determining a reference cell based on the credibility of the candidate cells; Determining the radio frame timing of the candidate cells according to the candidate primary synchronization signal position and radio frame position of the candidate cells; Based on the frame timing deviation between the radio frame timing of the candidate cells and the radio frame timing of the reference cell, screening out misdetected cells among the candidate cells within the maximum coverage range; and Eliminating the misdetected cells from the candidate cells to obtain a cell search result.

2. The method according to claim 1, wherein The screening out misdetected cells among the candidate cells within the maximum coverage range based on the frame timing deviation between the radio frame timing of the candidate cells and the radio frame timing of the reference cell includes: Determining a timing deviation threshold according to the maximum coverage range and the electromagnetic wave propagation speed; wherein, the maximum coverage range is determined by cell coverage range configuration factors; and Determining the candidate cells corresponding to the frame timing deviation greater than the timing deviation threshold as the misdetected cells.

3. The method according to claim 1, wherein The credibility includes the first normalized correlation value of the candidate cells; the determining a reference cell based on the credibility of the candidate cells includes: Based on the credibility of the candidate cells, determining the cells that meet the credibility conditions among the candidate cells as candidate cells; and Selecting the cell corresponding to the maximum value of the first normalized correlation values of the candidate cells as the reference cell.

4. The method according to claim 3, wherein The credibility further includes the received power of the candidate cells; The credibility conditions include: the first normalized correlation value of the candidate cell is greater than a first correlation threshold, and the received power of the candidate cell is greater than a received power threshold.

5. The method according to claim 3, wherein The searching for candidate cells using a synchronization search method includes: Determining a candidate primary synchronization signal position and a candidate primary synchronization signal identifier through a primary synchronization search method; Based on the candidate primary synchronization signal position, using a secondary synchronization search method to determine a candidate secondary synchronization signal identifier; and Determining the candidate cells according to the candidate primary synchronization signal position, the candidate primary synchronization signal identifier, and the candidate secondary synchronization signal identifier.

6. The method according to claim 5, characterized in that, The using a secondary synchronization search method to determine a candidate secondary synchronization signal identifier based on the candidate primary synchronization signal position includes: Determining a candidate secondary synchronization signal timing position according to the candidate primary synchronization signal position and the primary-secondary timing deviation; Selecting a received secondary synchronization signal according to the candidate secondary synchronization signal timing position; and Performing sampling correlation processing on the received secondary synchronization signal and a local secondary synchronization sequence to determine the candidate secondary synchronization signal identifier.

7. The method according to claim 6, characterized in that, The performing sampling correlation processing on the received secondary synchronization signal and a local secondary synchronization sequence to determine the candidate secondary synchronization signal identifier includes: Determining a first correlation result according to the received secondary synchronization signal and the local secondary synchronization sequence; Calculating the first normalized correlation value according to the received secondary synchronization signal and the first correlation result; and Obtaining the candidate secondary synchronization signal identifier when the first normalized correlation value is greater than a second correlation threshold.

8. The method according to claim 5, wherein Determining the candidate primary synchronization signal position and the candidate primary synchronization signal identifier through the primary synchronization search method includes: Determining a second correlation result based on the received signal and the local primary synchronization signal; Calculating a second normalized correlation value according to the received signal and the second correlation result; and Obtaining the candidate primary synchronization signal position and the candidate primary synchronization signal identifier when the second normalized correlation value is greater than a third correlation threshold value.

9. A multi-cell search device for a synchronization system, characterized in that, Applied to the synchronization system, the device includes: A synchronization search module for searching for candidate cells by using a synchronization search method; wherein, there is at least one candidate cell; A cell determination module for determining a reference cell based on the credibility of the candidate cells; A timing determination module for determining the radio frame timing of the candidate cells according to the candidate primary synchronization signal position and the radio frame position of the candidate cells; A screening module for screening misdetected cells among the candidate cells within the maximum coverage range based on the frame timing deviation between the radio frame timing of the candidate cells and the radio frame timing of the reference cell; and An elimination module for eliminating the misdetected cells among the candidate cells to obtain a cell search result.

10. An electronic device, comprising: One or more processors; A memory for storing one or more computer programs, Characterized in that the one or more processors execute the one or more computer programs to implement the steps of the method according to any one of claims 1 to 8.

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