Cell selection method and apparatus

Abstract

The present disclosure provides a cell selection method and device, wherein the method comprises: determining downlink frequency offsets of multiple candidate cells existing when performing cell selection; and determining a target cell to be accessed from the multiple candidate cells according to the downlink frequency offsets of the multiple candidate cells. Thus, in the case that multiple candidate cells exist when performing cell selection, the target cell to be accessed can be determined according to the downlink frequency offsets of the multiple candidate cells, the cell to provide a longer service duration can be preferentially selected for access, the number of cell switching can be effectively reduced, the complexity and latency of cell selection can be reduced, and the communication performance can be improved.

Description

Technical Field

[0001] This disclosure relates to the field of satellite communication technology, and in particular to a cell selection method and apparatus. Background Technology

[0002] In related technologies, cell selection is based solely on signal quality, choosing the cell with the highest signal quality. However, due to the Earth's rotation and the rapid movement of satellite base stations relative to the Earth, the selected cell with the highest signal quality may soon become unavailable. In this case, cell reselection will be necessary, leading to frequent cell handovers and impacting communication performance. This is a problem that urgently needs to be solved. Summary of the Invention

[0003] This disclosure provides a cell selection method and apparatus. When multiple candidate cells exist during cell selection, the target cell for access can be determined based on the downlink frequency offset (FO) of the multiple candidate cells. This allows priority to be given to cells that can provide services for longer durations, effectively reducing the number of cell handovers, lowering the complexity and latency of cell selection, and improving communication performance.

[0004] In a first aspect, embodiments of this disclosure provide a cell selection method, the method comprising: determining the downlink frequency offset of a plurality of candidate cells existing during cell selection; and determining a target cell for access from the plurality of candidate cells based on the downlink frequency offset of the plurality of candidate cells.

[0005] In conjunction with some embodiments of the first aspect, in some embodiments, determining the downlink frequency offset of multiple candidate cells existing during cell selection in the above method includes: receiving the synchronization signal blocks (SSBs) of multiple candidate cells existing during cell selection; and determining the downlink frequency offset of the multiple candidate cells based on the SSBs of the multiple candidate cells.

[0006] In conjunction with some embodiments of the first aspect, in some embodiments, the method described above selects a target cell from multiple candidate cells based on downlink frequency offset, including at least one of the following:

[0007] If there is only one candidate cell whose downlink frequency offset is greater than the first threshold, the candidate cell whose downlink frequency offset is greater than the first threshold is determined as the target cell;

[0008] If multiple candidate cells have downlink frequency offsets greater than the first threshold, the target cell is determined based on the signal quality of the multiple candidate cells with downlink frequency offsets greater than the first threshold.

[0009] If the downlink frequency offset of multiple candidate cells is not greater than the first threshold, the target cell is determined based on the signal quality of the multiple candidate cells.

[0010] In conjunction with some embodiments of the first aspect, in some embodiments, the method described above determines the target cell based on the signal quality of multiple candidate cells whose downlink frequency offset is greater than a first threshold, including:

[0011] If, among multiple candidate cells with downlink frequency offset greater than the first threshold, there exists a signal quality difference between two candidate cells greater than the second threshold, then the candidate cell with the highest signal quality among the multiple candidate cells with downlink frequency offset greater than the first threshold is determined as the target cell; or

[0012] If, among multiple candidate cells with downlink frequency offset greater than the first threshold, the difference in signal quality between any two candidate cells is no greater than the second threshold, the target cell is determined based on the beam reception incident angle of the beams received from the multiple candidate cells with downlink frequency offset greater than the first threshold, and the direction of Earth's rotation; or

[0013] Based on the signal quality of multiple candidate cells with downlink frequency offset greater than the first threshold, the candidate cell with the highest signal quality among the multiple candidate cells with downlink frequency offset greater than the first threshold is determined as the target cell.

[0014] In conjunction with some embodiments of the first aspect, in some embodiments, the method described above determines the target cell based on the beam reception incident angle of beams received from multiple candidate cells with downlink frequency offsets greater than a first threshold, and the direction of Earth's rotation, including:

[0015] Based on the beam reception incident angle of the beams received from multiple candidate cells with downlink frequency offset greater than the first threshold, and the direction of Earth's rotation, the candidate cell that stays for the longest time within the range of multiple candidate cells with downlink frequency offset greater than the first threshold is determined as the target cell.

[0016] In conjunction with some embodiments of the first aspect, in some embodiments, the method described above determines the target cell based on the signal quality of multiple candidate cells, including:

[0017] If the difference in signal quality between two candidate cells is greater than a second threshold, the candidate cell with the highest signal quality among the candidate cells is determined as the target cell; or

[0018] If the difference in signal quality between any two candidate cells is no greater than a second threshold, the target cell is determined based on the beam reception incident angle of the beams received from the multiple candidate cells and the direction of Earth's rotation; or

[0019] Based on the signal quality of multiple candidate cells, the candidate cell with the highest signal quality is determined as the target cell.

[0020] In conjunction with some embodiments of the first aspect, in some embodiments, the method described above determines the target cell based on the beam reception incident angle of beams received from multiple candidate cells and the direction of Earth's rotation, including:

[0021] Based on the beam reception incident angles of the beams received from multiple candidate cells and the direction of Earth's rotation, the candidate cell that stays within the range of multiple candidate cells for the longest time is determined as the target cell.

[0022] In conjunction with some embodiments of the first aspect, in some embodiments, cell selection is performed based on the downlink frequency offset of multiple candidate cells to determine the target cell among the multiple candidate cells, including at least one of the following:

[0023] If there is only one candidate cell whose downlink frequency offset is greater than the first threshold, and the signal quality of the candidate cell whose downlink frequency offset is greater than the first threshold is greater than the signal quality threshold, then the candidate cell whose downlink frequency offset is greater than the first threshold is determined as the target cell.

[0024] If the signal quality of all candidate cells with downlink frequency offset greater than the first threshold is not greater than the signal quality threshold, and there is only one candidate cell with signal quality greater than the signal quality threshold among the candidate cells with downlink frequency offset not greater than the first threshold, then the candidate cell with downlink frequency offset not greater than the first threshold and signal quality greater than the signal quality threshold is determined as the target cell.

[0025] If the signal quality of all candidate cells whose downlink frequency offset is greater than the first threshold is not greater than the signal quality threshold, and there are multiple candidate cells whose downlink frequency offset is not greater than the first threshold whose signal quality is greater than the signal quality threshold, the target cell is determined based on the signal quality of the multiple candidate cells whose downlink frequency offset is not greater than the first threshold and whose signal quality is greater than the signal quality threshold.

[0026] If the signal quality of candidate cells with downlink frequency offset greater than the first threshold is not greater than the signal quality threshold, and the signal quality of candidate cells with downlink frequency offset not greater than the first threshold is not greater than the signal quality threshold, the candidate cell with the highest signal quality among the candidate cells with downlink frequency offset greater than the first threshold is determined as the target cell.

[0027] If the downlink frequency offset of multiple candidate cells is not greater than the first threshold, and only one candidate cell among the multiple candidate cells has a signal quality greater than the signal quality threshold, the candidate cell with a signal quality greater than the signal quality threshold is determined as the target cell.

[0028] If the downlink frequency offset of multiple candidate cells is not greater than the first threshold, and there are multiple candidate cells whose signal quality is greater than the signal quality threshold, the target cell is determined based on the signal quality of the multiple candidate cells whose signal quality is greater than the signal quality threshold.

[0029] If the downlink frequency offset of multiple candidate cells is not greater than the first threshold, and the signal quality of multiple candidate cells is not greater than the signal quality threshold, the candidate cell with the highest signal quality among the multiple candidate cells is determined as the target cell.

[0030] In conjunction with some embodiments of the first aspect, in some embodiments, determining a target cell based on the signal quality of a plurality of candidate cells whose downlink frequency offset is not greater than a first threshold and whose signal quality is greater than a signal quality threshold includes:

[0031] If, among multiple candidate cells with downlink frequency offset not greater than a first threshold and signal quality greater than a signal quality threshold, there exists a difference in signal quality between two candidate cells that is greater than a second threshold, then the candidate cell with the highest signal quality among the multiple candidate cells with downlink frequency offset not greater than the first threshold and signal quality greater than a signal quality threshold is determined as the target cell; or

[0032] If, among multiple candidate cells with downlink frequency offset not greater than a first threshold and signal quality greater than a signal quality threshold, the difference in signal quality between any two candidate cells is not greater than a second threshold, the target cell is determined based on the beam reception incident angle of the beams received from the multiple candidate cells with downlink frequency offset not greater than the first threshold and signal quality greater than the signal quality threshold, and the direction of Earth's rotation; or

[0033] Based on the signal quality of multiple candidate cells with downlink frequency offset not greater than the first threshold and signal quality greater than the signal quality threshold, the candidate cell with the highest signal quality among the multiple candidate cells with downlink frequency offset not greater than the first threshold and signal quality greater than the signal quality threshold is determined as the target cell.

[0034] In conjunction with some embodiments of the first aspect, in some embodiments, determining a target cell based on the beam reception incident angle of beams received from multiple candidate cells whose downlink frequency offset is no greater than a first threshold and whose signal quality is greater than a signal quality threshold, and the direction of Earth's rotation, includes:

[0035] Based on the beam reception incident angle of the beams received from multiple candidate cells with downlink frequency offset not greater than the first threshold and signal quality greater than the signal quality threshold, and the direction of Earth's rotation, the candidate cell that stays for the longest time within the range of multiple candidate cells with downlink frequency offset not greater than the first threshold and signal quality greater than the signal quality threshold is determined as the target cell.

[0036] In conjunction with some embodiments of the first aspect, in some embodiments, determining a target cell based on the signal quality of multiple candidate cells whose signal quality is greater than a signal quality threshold includes:

[0037] If, among multiple candidate cells with signal quality greater than a signal quality threshold, the difference in signal quality between two candidate cells exceeds a second threshold, the candidate cell with the highest signal quality among the multiple candidate cells with signal quality greater than the signal quality threshold is determined as the target cell; or

[0038] If the difference in signal quality between any two candidate cells among multiple candidate cells with signal quality greater than the signal quality threshold is no greater than a second threshold, the target cell is determined based on the beam reception incident angle of the beams received from the multiple candidate cells with signal quality greater than the signal quality threshold, and the direction of Earth's rotation; or

[0039] Based on the signal quality of multiple candidate cells with signal quality greater than the signal quality threshold, the candidate cell with the highest signal quality is determined as the target cell.

[0040] In conjunction with some embodiments of the first aspect, in some embodiments, determining a target cell based on the beam reception incident angle of beams received from multiple candidate cells with signal quality greater than a signal quality threshold, and the direction of Earth's rotation, includes:

[0041] Based on the beam reception incident angle of the beams received from multiple candidate cells with signal quality greater than the signal quality threshold, and the direction of Earth's rotation, the candidate cell that stays within the range of multiple candidate cells with signal quality greater than the signal quality threshold for the longest time is determined as the target cell.

[0042] In conjunction with some embodiments of the first aspect, in some embodiments, signal quality includes at least one of the following:

[0043] Reference signal receiving power (RSRP) of the synchronization signal;

[0044] The signal-to-noise ratio (SNR) of the synchronization signal;

[0045] The signal-to-interference-plus-noise ratio (SINR) of a synchronization signal;

[0046] Reference signal receiving quality (RSRQ) of the synchronization signal;

[0047] The received signal strength indicator (RSRI) of the synchronization signal;

[0048] The transmission delay of the synchronization signal.

[0049] In conjunction with some embodiments of the first aspect, in some embodiments, the synchronization signal in the above method includes at least one of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS).

[0050] In a second aspect, embodiments of this disclosure provide a communication device, including: a processing module, configured to determine the downlink frequency offset of a plurality of candidate cells existing during cell selection; the processing module is further configured to determine, based on the downlink frequency offset of the plurality of candidate cells, a target cell to be selected for access from the plurality of candidate cells.

[0051] Thirdly, embodiments of this disclosure provide a communication device, including: at least one processor and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the method described in the first aspect.

[0052] Fourthly, embodiments of this disclosure provide a chip including one or more interface circuits and one or more processors; the interface circuits are configured to receive signals from the memory of a communication device and send the received signals to the processors, the received signals including computer instructions stored in the memory, and when the processor executes the computer instructions, the communication device implements the method described in the first aspect of the embodiments of this disclosure.

[0053] Fifthly, embodiments of this disclosure provide a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, can implement the method described in the first aspect of this disclosure.

[0054] In a sixth aspect, embodiments of this disclosure provide a computer program product that, when executed by an instruction processor, implements the method described in the first aspect of embodiments of this disclosure.

[0055] The technical solution provided by the embodiments of this disclosure brings at least the following beneficial effects: by determining the downlink frequency offset of multiple candidate cells when performing cell selection; and by determining the target cell for access from among the multiple candidate cells based on the downlink frequency offset of the multiple candidate cells. Therefore, when multiple candidate cells exist during cell selection, the target cell for access can be determined based on the downlink frequency offset of the multiple candidate cells, prioritizing the selection of cells with longer service durations, effectively reducing the number of cell handovers, lowering the complexity and latency of cell selection, and improving communication performance.

[0056] Additional aspects and advantages of this disclosure will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this disclosure. Attached Figure Description

[0057] The above and / or additional aspects and advantages of this disclosure will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, in which:

[0058] Figure 1 This is a schematic diagram of the architecture of a communication system provided in an embodiment of the present disclosure;

[0059] Figure 2 This is a schematic diagram of a low-Earth orbit satellite constellation provided in an embodiment of the present disclosure;

[0060] Figure 3 This is a top-view schematic diagram of a satellite coverage area provided in an embodiment of the present disclosure;

[0061] Figure 4 A flowchart illustrating a cell selection method provided in an embodiment of this disclosure;

[0062] Figure 5 This is a schematic diagram illustrating beam scanning of a terminal provided in an embodiment of this disclosure;

[0063] Figure 6 A flowchart illustrating a cell selection method provided in an embodiment of this disclosure;

[0064] Figure 7 This is a structural diagram of a communication device provided in an embodiment of the present disclosure;

[0065] Figure 8 This is a block diagram illustrating a communication device for implementing a cell selection method according to an exemplary embodiment;

[0066] Figure 9 This is a structural diagram of a chip according to an exemplary embodiment. Detailed Implementation

[0067] Embodiments of this disclosure are described in detail below. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this disclosure, and should not be construed as limiting this disclosure.

[0068] To better understand the cell selection method and apparatus disclosed in this disclosure, the communication system to which this disclosure applies will be described first.

[0069] Please see Figure 1 , Figure 1 This is a schematic diagram of the architecture of a communication system provided in an embodiment of this disclosure. Figure 1 As shown, the communication system 100 includes a terminal 101 and a network device 102.

[0070] In some embodiments, terminal 101 includes, but is not limited to, at least one of the following: mobile phone, wearable device, Internet of Things device, car with communication function, smart car, tablet computer, computer with wireless transceiver function, virtual reality (VR) terminal, augmented reality (AR) terminal, wireless terminal in industrial control, wireless terminal in self-driving, wireless terminal in remote medical surgery, wireless terminal in smart grid, wireless terminal in transportation safety, wireless terminal in smart city, and wireless terminal in smart home.

[0071] In some embodiments, network device 102 may include at least one of access network device and core network device.

[0072] In some embodiments, the access network device is, for example, a node or device that connects a terminal to a wireless network. The access network device may include, but is not limited to, at least one of the following in a 5G communication system: evolved Node B (eNB), next-generation eNB (ng-eNB), next-generation Node B (gNB), node B (NB), home node B (HNB), home evolved node B (HeNB), radio backhaul device, radio network controller (RNC), base station controller (BSC), base transceiver station (BTS), base band unit (BBU), mobile switching center, base station in a 6G communication system, open RAN, cloud RAN, base station in other communication systems, and access node in a Wi-Fi system.

[0073] In some embodiments, the access network device may be a satellite.

[0074] In some embodiments, the core network equipment may be a single device, multiple devices, or a group of devices, including all or part of a first network element, a second network element, a third network element, a fourth network element, etc. Network elements may be virtual or physical. The core network may include, for example, at least one of an Evolved Packet Core (EPC), a 5G Core Network (5GCN), and a Next Generation Core (NGC).

[0075] It is understood that the communication system described in the embodiments of this disclosure is for the purpose of more clearly illustrating the technical solutions of the embodiments of this disclosure, and does not constitute a limitation on the technical solutions provided in the embodiments of this disclosure. As those skilled in the art will know, with the evolution of system architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of this disclosure are also applicable to similar technical problems.

[0076] Understandably, low-Earth orbit (LEO) satellites are typically located below 1000 kilometers in altitude, closer to Earth than geostationary satellites, allowing for higher resolution and faster data transmission speeds. LEO satellites orbit the Earth at approximately 7 km / s. To provide continuous satellite communication services, operators need to build a constellation system of multiple satellites, creating dynamic satellite beam coverage on the ground to provide users with uninterrupted, always-available internet access.

[0077] Let the aforementioned continuously covered constellation consist of X orbits, with Y satellites in each orbit. Each satellite provides communication services to a large cell, such as... Figure 2 As shown, each white dot represents a low-orbit satellite.

[0078] In some embodiments, such as Figure 3 As shown, in satellite communication systems, the location of the terminal (user equipment, UE) on the ground can be divided into the following situations:

[0079] Terminal location type 1: The location of the terminal is as follows Figure 3 At the location of UE1, only the signal from one satellite can reach the terminal, and the terminal can only receive the signal from one satellite.

[0080] Terminal location type 2: The location of the terminal is as follows Figure 3 At the location of UE2, the terminal is located in the overlapping coverage area of ​​satellites in the same orbit, and at this time the terminal can receive signals from two satellites in the same orbit.

[0081] Terminal location type 3: The location of the terminal is as follows Figure 3 At the location of UE3, the terminal is located in the overlapping coverage area of ​​adjacent orbits, at which point the terminal can receive signals from two satellites in adjacent orbits.

[0082] Terminal location type 4: The location of the terminal is as follows Figure 3 At the location of UE4, the terminal is located in the overlapping coverage area of ​​the same and adjacent orbits, at which time the terminal can receive signals from more than two satellites.

[0083] It should be noted that, Figure 3 The coverage area of ​​the satellite cell is marked as a rectangle, but is not limited to this. Figure 3 For illustrative purposes only, the coverage area of ​​a satellite cell can also be circular, oriented in a straight line, or an irregular shape, etc., and this disclosure does not impose specific limitations on this.

[0084] In some embodiments, when the terminal is located in an area covered by overlapping satellites, the terminal can receive synchronization signals from the two or more satellites, such as PSS and SSS. Figure 3 As shown in Terminal Location Type 2, although the terminal is simultaneously within the signal coverage of both Satellite 1 and Satellite 2, Satellite 1 will soon cease to serve the terminal due to the rapid movement of the satellites. In this scenario, if the terminal could choose to connect to a satellite that will serve its area for a longer period, such as Satellite 2, it could access the cell more quickly and obtain stable service. However, in related technologies, the terminal selects a cell solely based on its signal quality, choosing the cell with the highest signal quality. However, due to the Earth's rotation and the rapid movement of satellite base stations relative to the Earth, the selected cell with the highest signal quality may soon become unavailable. In this case, the terminal will face cell reselection, leading to frequent cell handovers and impacting communication performance. This is a problem that urgently needs to be solved.

[0085] For terminal location type 1, only one satellite serves it, so you can directly select that satellite to access the network.

[0086] For terminal location type 2, such as Figure 3 When the terminal shown is located in an area covered by overlapping satellites in the same orbit and is closer to satellite 1, it receives a stronger signal and has a shorter transmission delay from satellite 1. In this case, according to the scheme in the relevant technology, satellite 1 will be selected for access. However, because low-orbit satellites move very fast, satellite 1 will no longer serve the terminal shown in the figure after a few seconds.

[0087] For terminal location type 3, the terminal is located in the overlapping coverage area of ​​adjacent orbits. At this time, the satellites fly side by side. According to the scheme in the relevant technology, the terminal will select the cell based on the signal quality and TA value. However, due to the existence of the Earth's rotation factor, it can be known that satellite 1 can provide the terminal with a longer service time.

[0088] Terminal location type 4 is a combination of terminal location type 2 and terminal location type 3. The problems with the solutions in related technologies are the same as those of terminal location types 2 and 3.

[0089] Understandably, in satellite communication systems, when a terminal receives information from multiple cells simultaneously, it is generally already at the edge of the cell's frequency range. According to relevant technical solutions, cell selection is performed. However, if the terminal chooses to remain in the cell that has moved away from it, due to the satellite's rapid movement relative to the Earth and the Earth's rotation, the terminal will need to perform cell handover again within a very short time. Figure 3 In terminal location type 2, after the terminal selects to access satellite cell 1, it needs to switch from satellite cell 1 to satellite cell 2 within a very short time due to the rapid movement of the satellite. For example... Figure 3 In the case of terminal location type 3, after the terminal selects to access the cell of satellite 3, it needs to switch from satellite 3 cell to satellite 1 cell in a very short time due to the Earth's rotation.

[0090] On the one hand, the extremely long propagation distance between air and ground results in a significantly longer latency for satellite-to-ground links compared to the transmission latency from the ground base station to the terminal. On the other hand, the increasingly scarce frequency bands and limited frequency domain resources mean that each step in the terminal handover process requires waiting for suitable time-frequency resources, further prolonging the handover latency. Simultaneously, frequent random access attempts by terminals increase system load and signaling overhead, further limiting service resources. Therefore, determining the optimal strategy for terminals to select cells with more stable and persistent service is a crucial issue that needs to be addressed in satellite communication scenarios.

[0091] Understandably, the 3rd Generation Partnership Project (3GPP) Non-Terrestrial Networks (NTN) recommends that the entire timing advance (TA) mechanism be compensated on the terminal side. If the terminal side performs TA and frequency offset (FO) pre-compensation, that is, when performing PSS / SSS blind detection on the terminal side, it can clearly determine whether the detected cell is heading towards or leaving the terminal through FO, and thus prioritize heading towards its own base station to have a longer dwell time.

[0092] Based on this, this disclosure provides a cell selection method and apparatus, wherein the method includes: determining the downlink frequency offset of multiple candidate cells existing during cell selection; and determining a target cell for access from the multiple candidate cells based on the downlink frequency offset of the multiple candidate cells. Therefore, when multiple candidate cells exist during cell selection, the target cell for access can be determined based on the downlink frequency offset of the multiple candidate cells, prioritizing the selection of cells with longer service durations, effectively reducing the number of cell handovers, lowering the complexity and latency of cell selection, and improving communication performance.

[0093] The cell selection method and apparatus of this disclosure are described below with reference to the accompanying drawings.

[0094] Figure 4 This is a schematic diagram illustrating the interactive flow of a cell selection method provided in an embodiment of this disclosure. It should be noted that the cell selection method of this disclosure can be applied to a communication device. In some possible embodiments, the device can be configured in an electronic device or chip to enable the electronic device or chip to perform cell selection functions. For example, the electronic device can be... Figure 1 In addition to the terminal in the device, in some possible embodiments, the communication device can also be software in an electronic device, such as communication software. Figure 4 As shown, the method for selecting this cell may include, but is not limited to, the following steps:

[0095] S1: Determine the downlink frequency offset of multiple candidate cells when performing cell selection.

[0096] In this embodiment of the disclosure, when selecting a cell, if there are multiple candidate cells, the downlink frequency offset of the multiple candidate cells can be determined.

[0097] It is understandable that the high-speed movement of a satellite generates Doppler frequency offset. For the downlink signal from the satellite to the terminal, the generated Doppler frequency offset can also be called the downlink frequency offset. The Doppler frequency offset is calculated using the formula f. d =f DL *v*cosθ / c, where f DL Let v be the downlink carrier frequency, c be the speed of the satellite relative to the terminal, θ be the speed of light, and θ be the angle between the direction of the satellite's movement and the terminal. It can be seen that the Doppler frequency offset of the signal from the satellite flying towards the terminal is positive, and the Doppler frequency offset of the signal from the satellite flying away from the terminal is negative.

[0098] In some embodiments, the terminal determines the downlink frequency offset of multiple candidate cells existing during cell selection, including: receiving synchronization signal blocks (SSBs) of multiple candidate cells existing during cell selection; and determining the downlink frequency offset of the multiple candidate cells based on the SSBs of the multiple candidate cells.

[0099] In some embodiments, the terminal receives synchronization signals from multiple candidate cells to form a candidate cell list. The terminal calculates the downlink frequency offset of the candidate cells based on the synchronization signals from the multiple candidate cells in the candidate cell list.

[0100] In some embodiments, the synchronization signal includes at least one of the primary synchronization signal PSS and the secondary synchronization signal SSS.

[0101] In some embodiments, when a terminal determines the downlink frequency offset of multiple candidate cells during cell selection, it can determine whether the satellite base station corresponding to the candidate cell is flying towards or away from the terminal based on the downlink frequency offset of the candidate cell.

[0102] It is understood that multiple candidate cells may correspond to the same or different satellite base stations, and this disclosure does not impose specific limitations on this.

[0103] In some embodiments, when a terminal performs initial cell access, it performs cell selection and determines the downlink frequency offset of multiple candidate cells that exist during cell selection.

[0104] In some embodiments, when performing cell selection, the terminal determines the downlink frequency offset of multiple candidate cells that exist during cell selection.

[0105] In some embodiments, when the terminal performs cell reselection, it performs cell selection and determines the downlink frequency offset of multiple candidate cells that exist during cell selection.

[0106] In some embodiments, when a terminal is performing a cell handover, it performs cell selection and determines the downlink frequency offset of multiple candidate cells that exist during cell selection.

[0107] In some embodiments, when the terminal performs frequency selection, it performs cell selection and determines the downlink frequency offset of multiple candidate cells that exist during cell selection.

[0108] In some embodiments, when the terminal performs frequency reselection, it performs cell selection and determines the downlink frequency offset of multiple candidate cells that exist during cell selection.

[0109] To facilitate understanding of the embodiments of this disclosure, a scenario illustration of cell selection is provided.

[0110] In one implementation scenario, the terminal is in a non-connected state, such as an idle or inactive state. When the terminal needs to enter a connected state, it determines to perform cell selection and then obtains the downlink frequency offset of multiple candidate cells.

[0111] In another implementation scenario, the service provided by the cell that the terminal is connected to is close to saturation and can no longer provide services to the terminal. In this case, the terminal can be instructed to perform cell reselection, or the terminal can decide to perform cell reselection on its own. In this case, the terminal obtains the downlink frequency offset of multiple candidate cells.

[0112] S2: Based on the downlink frequency offset of multiple candidate cells, select the target cell for access from among the multiple candidate cells.

[0113] In this embodiment of the disclosure, when it is determined that there are multiple candidate cells with downlink frequency offsets when selecting a cell, the target cell for access can be determined from the multiple candidate cells based on the downlink frequency offsets of the multiple candidate cells.

[0114] Understandably, after identifying a target cell from multiple candidate cells, the terminal can initiate a random access procedure to the target cell. For example, the terminal sends a random access request to the satellite base station corresponding to the target cell, requesting access to the target cell. Optionally, the random access procedure for the terminal to access the target cell can employ a two-step random access method or a four-step random access method; this disclosure does not impose specific limitations on this approach.

[0115] It is understood that a positive downlink frequency offset for a candidate cell indicates that the satellite corresponding to the candidate cell is flying towards the terminal, while a negative downlink frequency offset indicates that the satellite corresponding to the candidate cell is flying away from the terminal. In this embodiment of the present disclosure, the candidate cell with a satellite flying towards the terminal can be selected as the target cell based on the downlink frequency offsets of multiple candidate cells. If multiple candidate cells have satellites that are all flying towards the terminal, the terminal can select the candidate cell with the highest signal quality as the target cell based on the signal quality of the candidate cells.

[0116] In some embodiments, a target cell for access is selected from multiple candidate cells based on their downlink frequency offsets. If only one candidate cell has a downlink frequency offset greater than 0, meaning only one candidate cell is destined for the terminal, the terminal can select that candidate cell as the target cell for access. Alternatively, if multiple candidate cells have downlink frequency offsets greater than 0, the terminal can select the candidate cell with the highest signal quality among those with downlink frequency offsets greater than 0 as the target cell for access. The terminal can also determine the target cell based on the signal quality of the multiple candidate cells with downlink frequency offsets greater than 0.

[0117] In some embodiments, the terminal determines one of the candidate cells with downlink frequency offset greater than 0 as the target cell for access based on the signal quality of multiple candidate cells with downlink frequency offset greater than 0. If the difference in signal quality between two candidate cells with downlink frequency offset greater than 0 is greater than a second threshold, the terminal can determine the candidate cell with the highest signal quality among the multiple candidate cells with downlink frequency offset greater than 0 as the target cell. If the difference in signal quality between any two candidate cells with downlink frequency offset greater than 0 is not greater than the second threshold, the terminal can determine the candidate cell with the longest dwell time among the multiple candidate cells with downlink frequency offset greater than 0 as the target cell based on the satellite position of the multiple candidate cells with downlink frequency offset greater than 0 relative to the terminal and the Earth's rotation direction at the terminal's current position.

[0118] In some embodiments, cell selection is performed based on the downlink frequency offset of multiple candidate cells to determine the target cell among the multiple candidate cells, including at least one of the following:

[0119] If there is only one candidate cell whose downlink frequency offset is greater than the first threshold, the candidate cell whose downlink frequency offset is greater than the first threshold is determined as the target cell;

[0120] If multiple candidate cells have downlink frequency offsets greater than the first threshold, the target cell is determined based on the signal quality of the multiple candidate cells with downlink frequency offsets greater than the first threshold.

[0121] If the downlink frequency offset of multiple candidate cells is not greater than the first threshold, the target cell is determined based on the signal quality of the multiple candidate cells.

[0122] In this embodiment of the disclosure, when it is determined that there are multiple candidate cells with downlink frequency offsets when selecting a cell, the target cell for access is selected from the multiple candidate cells based on the downlink frequency offsets of the multiple candidate cells. If there is only one candidate cell with a downlink frequency offset greater than a first threshold, the candidate cell with a downlink frequency offset greater than the first threshold is determined as the target cell.

[0123] In some embodiments, the first threshold is 0.

[0124] In this embodiment of the disclosure, when it is determined that there are multiple candidate cells with downlink frequency offsets when cell selection is performed, the target cell for access is selected from the multiple candidate cells based on the downlink frequency offsets of the multiple candidate cells. If there are multiple candidate cells with downlink frequency offsets greater than a first threshold, the target cell is determined based on the signal quality of the multiple candidate cells with downlink frequency offsets greater than the first threshold.

[0125] In some embodiments, determining a target cell based on the signal quality of multiple candidate cells with downlink frequency offsets greater than a first threshold includes:

[0126] If, among multiple candidate cells with downlink frequency offset greater than the first threshold, there exists a signal quality difference between two candidate cells greater than the second threshold, then the candidate cell with the highest signal quality among the multiple candidate cells with downlink frequency offset greater than the first threshold is determined as the target cell; or

[0127] If, among multiple candidate cells with downlink frequency offset greater than the first threshold, the difference in signal quality between any two candidate cells is no greater than the second threshold, the target cell is determined based on the beam reception incident angle of the beams received from the multiple candidate cells with downlink frequency offset greater than the first threshold, and the direction of Earth's rotation; or

[0128] Based on the signal quality of multiple candidate cells with downlink frequency offset greater than the first threshold, the candidate cell with the highest signal quality among the multiple candidate cells with downlink frequency offset greater than the first threshold is determined as the target cell.

[0129] In this embodiment of the disclosure, if there are multiple candidate cells with downlink frequency offset greater than a first threshold, a target cell is determined based on the signal quality of the multiple candidate cells with downlink frequency offset greater than the first threshold. If, among the multiple candidate cells with downlink frequency offset greater than the first threshold, there is a difference in signal quality between two candidate cells that is greater than a second threshold, the candidate cell with the highest signal quality among the multiple candidate cells with downlink frequency offset greater than the first threshold is determined as the target cell.

[0130] In this embodiment of the disclosure, if there are multiple candidate cells with downlink frequency offsets greater than a first threshold, a target cell is determined based on the signal quality of the multiple candidate cells with downlink frequency offsets greater than the first threshold. If the difference in signal quality between any two candidate cells among the multiple candidate cells with downlink frequency offsets greater than the first threshold is not greater than a second threshold, the target cell is determined based on the beam reception incident angle of the beams received from the multiple candidate cells with downlink frequency offsets greater than the first threshold, and the direction of Earth's rotation.

[0131] In some embodiments, determining a target cell based on the beam reception incident angle of beams received from multiple candidate cells with downlink frequency offset greater than a first threshold and the direction of Earth's rotation includes: determining the candidate cell that stays for the longest time within the range of multiple candidate cells with downlink frequency offset greater than the first threshold as the target cell based on the beam reception incident angle of beams received from multiple candidate cells with downlink frequency offset greater than the first threshold and the direction of Earth's rotation.

[0132] In this embodiment of the disclosure, if there are multiple candidate cells with downlink frequency offsets greater than a first threshold, a target cell is determined based on the signal quality of the multiple candidate cells with downlink frequency offsets greater than the first threshold. If the difference in signal quality between any two candidate cells among the multiple candidate cells with downlink frequency offsets greater than the first threshold is not greater than a second threshold, the target cell is determined based on the beam reception incident angle of the received beams from the multiple candidate cells with downlink frequency offsets greater than the first threshold and the direction of Earth's rotation. The candidate cell that stays within the range of the multiple candidate cells with downlink frequency offsets greater than the first threshold for the longest time is determined as the target cell based on the beam reception incident angle of the received beams from the multiple candidate cells with downlink frequency offsets greater than the first threshold and the direction of Earth's rotation.

[0133] For example, such as Figure 5 As shown, the terminal has an antenna with beamforming capability, such as a planar antenna or a parabolic antenna. During the initial access phase, the terminal's antenna scans beams in different directions, receiving signals from candidate cells in different directions. This allows the terminal to determine the beam reception incident angle and signal strength of different candidate cells, further identifying the location of the satellite corresponding to each candidate cell.

[0134] like Figure 3 and 5 As shown, taking terminal location type 4 as an example, when the terminal selects a cell, it will scan in different directions. The received signal strength is stronger at times t1 and t3. The terminal knows the installation of the antenna and the incident angle of the beam received by the scanned beam at times t1 and t3. It can be known that satellite 4 is west of satellite 2. Since the Earth rotates from west to east, selecting the orbit of satellite 2 will result in a longer service duration. The terminal can determine that it stays within the coverage area of ​​satellite 2 for the longest time and can determine the candidate cell of satellite 2 as the target cell.

[0135] In this embodiment of the disclosure, based on the beam reception incident angle of the beams received from multiple candidate cells with downlink frequency offset greater than a first threshold, and the direction of Earth's rotation, the candidate cell that stays for the longest time within the range of multiple candidate cells with downlink frequency offset greater than the first threshold is determined as the target cell.

[0136] For example, multiple candidate cells with downlink frequency offset greater than the first threshold include candidate cell 1 and candidate cell 2. The beam receiving incident angle of the beam from candidate cell 1 is smaller than that of the beam from candidate cell 2. Determining the direction of Earth's rotation will cause the beam receiving incident angle of the beam to gradually decrease. It can be seen that the beam receiving incident angle of the beam from candidate cell 1 will decrease to 0 first, while the beam receiving incident angle of the beam from candidate cell 2 will decrease to 0 later. It can be seen that the time spent in the range of candidate cell 2 is the longest, and thus candidate cell 2 is determined as the target cell.

[0137] For example, the multiple candidate cells with downlink frequency offset greater than the first threshold include candidate cell 1 and candidate cell 2. The beam receiving incident angle of the beam from candidate cell 1 is 60 degrees, and the beam receiving incident angle of the beam from candidate cell 2 is 150 degrees. Determining the direction of Earth's rotation will cause the beam receiving incident angle of the beam to gradually decrease. It can be seen that the beam receiving incident angle of the beam from candidate cell 1 will decrease to 0 first, while the beam receiving incident angle of the beam from candidate cell 2 will decrease to 0 later. It can be seen that the time spent in the range of candidate cell 2 is the longest, and thus candidate cell 2 is determined as the target cell.

[0138] In this embodiment of the disclosure, if there are multiple candidate cells with downlink frequency offset greater than a first threshold, the candidate cell with the highest signal quality among the multiple candidate cells with downlink frequency offset greater than the first threshold is determined as the target cell based on the signal quality of the multiple candidate cells with downlink frequency offset greater than the first threshold.

[0139] In this embodiment of the disclosure, when it is determined that there are multiple candidate cells with downlink frequency offsets when cell selection is performed, the target cell for access is determined from the multiple candidate cells based on the downlink frequency offsets of the multiple candidate cells. If the downlink frequency offsets of the multiple candidate cells are not greater than a first threshold, the target cell is determined based on the signal quality of the multiple candidate cells.

[0140] In some embodiments, determining a target cell based on the signal quality of multiple candidate cells includes:

[0141] If the difference in signal quality between two candidate cells is greater than a second threshold, the candidate cell with the highest signal quality among the candidate cells is determined as the target cell; or

[0142] If the difference in signal quality between any two candidate cells is no greater than a second threshold, the target cell is determined based on the beam reception incident angle of the beams received from the multiple candidate cells and the direction of Earth's rotation; or

[0143] Based on the signal quality of multiple candidate cells, the candidate cell with the highest signal quality is determined as the target cell.

[0144] In this embodiment of the disclosure, when determining the downlink frequency offset of multiple candidate cells during cell selection, the target cell for access is selected from the multiple candidate cells based on the downlink frequency offset of the multiple candidate cells. If the downlink frequency offset of the multiple candidate cells is not greater than a first threshold, the target cell is determined based on the signal quality of the multiple candidate cells. If the difference in signal quality between two candidate cells is greater than a second threshold, the candidate cell with the highest signal quality among the multiple candidate cells is determined as the target cell.

[0145] In this embodiment of the disclosure, when it is determined that there are multiple candidate cells with downlink frequency offsets during cell selection, the target cell for access is selected from the multiple candidate cells based on the downlink frequency offsets of the multiple candidate cells. If the downlink frequency offsets of the multiple candidate cells are not greater than a first threshold, the target cell is determined based on the signal quality of the multiple candidate cells. If the difference in signal quality between any two candidate cells is not greater than a second threshold, the target cell is determined based on the beam reception incident angle of the beams received from the multiple candidate cells and the direction of Earth's rotation.

[0146] In some embodiments, determining a target cell based on the beam reception incident angle of beams received from multiple candidate cells and the direction of Earth's rotation includes:

[0147] Based on the beam reception incident angles of the beams received from multiple candidate cells and the direction of Earth's rotation, the candidate cell that stays within the range of multiple candidate cells for the longest time is determined as the target cell.

[0148] It should be noted that the description of determining the target cell based on the beam reception incident angle of the beams received from multiple candidate cells and the direction of Earth's rotation can be found in the relevant description of the foregoing embodiments, and will not be repeated here.

[0149] In this embodiment of the disclosure, when it is determined that there are multiple candidate cells with downlink frequency offsets when selecting a cell, the target cell for access is selected from the multiple candidate cells based on the downlink frequency offsets of the multiple candidate cells. If the downlink frequency offsets of the multiple candidate cells are not greater than a first threshold, the target cell is determined based on the signal quality of the multiple candidate cells. Specifically, the candidate cell with the highest signal quality is determined as the target cell based on the signal quality of the multiple candidate cells.

[0150] In some embodiments, signal quality includes at least one of the following:

[0151] Reference signal received power RSRP of the synchronization signal;

[0152] The signal-to-noise ratio (SNR) of the synchronization signal;

[0153] The signal-to-interference-plus-noise ratio (SINR) of the synchronization signal;

[0154] The reference signal reception quality (RSRQ) of the synchronization signal;

[0155] The strength indicator of the received synchronization signal (RSRI).

[0156] The transmission delay of the synchronization signal.

[0157] To facilitate understanding of the embodiments of this disclosure, an exemplary embodiment is provided.

[0158] In an exemplary embodiment, such as Figure 3 As shown, when the terminal is in location type 2, it is located in an area with overlapping coverage from adjacent satellites on the same orbit. At this time, the terminal can receive synchronization signals from both satellite cells, Satellite 1 and Satellite 2. The terminal obtains the physical cell ID by blindly searching the PSS / SSS signals, forming a candidate cell list. Two satellites in the candidate list are located on different satellites; one is en route to the terminal, and the other is moving away. Satellite 1 is moving away from the terminal, and Satellite 2 is en route to the terminal. The terminal uses the PSS / SSS synchronization signals to calculate the downlink FO (Frequency Offset) of the candidate cells. It selects the candidate cell from the satellite en route to the terminal as the target cell for access based on whether the downlink frequency offset is greater than a first threshold. This allows the terminal to obtain more stable service and effectively reduces the pressure on the communication system caused by frequent terminal handovers, thus improving the performance of the communication system.

[0159] When the terminal is located at the edge of an adjacent cell, such as Figure 3 As shown, when the terminal is of terminal location type 3, it can receive synchronization signals from two satellite cells, Satellite 1 and Satellite 3. The terminal obtains the physical cell ID by blindly searching the PSS / SSS signals, forming a candidate cell list. At this time, the downlink FO of the candidate cells is calculated using the PSS / SSS signals. It can be seen that the two FOs have the same sign. Since the Earth rotates at a speed of 466 m / s, which is much slower than the satellite's movement speed, the quality difference of the synchronization signals received from the candidate cells of the two satellites is used as a judgment condition. If the signal quality difference between the two candidate cells is greater than the second threshold, the candidate cell with the highest signal quality is determined as the target cell, and the terminal accesses the candidate cell with the highest signal quality. Conversely, if the signal quality difference between the two candidate cells is not greater than the second threshold, the terminal determines the candidate cell in which it stays for the longest time within the candidate cell range based on the beam reception incident angle of the candidate cell's beam and the Earth's rotation direction, which is the candidate cell in the Earth's rotation direction, i.e., the candidate cell of Satellite 1.

[0160] For example, such as Figure 6The diagram shows a possible implementation method.

[0161] Step 1: The terminal performs blind detection on the PSS / SSS signal to form a candidate cell list. During the blind detection process, the candidate cell ID and downlink frequency offset FO can be calculated.

[0162] Step 2: Determine if the number of candidate cells in the candidate cell list is greater than 1. If it is not greater than 1, proceed to step 3; otherwise, proceed to step 4.

[0163] Step 3: At this point, the terminal detects only one candidate cell, selects that candidate cell for access, and jumps to step 11.

[0164] Step 4: Determine whether there are candidate cells in the candidate cell list with a positive downlink FO (i.e., downlink frequency offset greater than the first threshold in the aforementioned embodiment), that is, candidate cells with satellites flying to the terminal. If there are, proceed to step 5; otherwise, proceed to step 10.

[0165] Step 5: Determine if only one candidate cell has a positive downlink FO. If so, proceed to step 6; otherwise, proceed to step 7.

[0166] Step 6: The candidate cell with a positive downlink FO is the candidate cell for the satellite flying to the terminal. This candidate cell will provide services to the terminal for a relatively long period of time. Select this candidate cell for access and determine it as the target cell.

[0167] Step 7: Measure the signal quality (RSRP) of the synchronization signals of multiple candidate cells with positive downlink FO. If the difference in signal quality between two candidate cells among the multiple candidate cells with positive downlink FO is greater than the second threshold, proceed to step 8; otherwise, skip to step 9.

[0168] Step 8: Select the candidate cell with the highest signal quality for access, then skip to step 11.

[0169] Step 9: Terminals equipped with small antenna arrays can further select cells covered by satellites in adjacent orbits based on the beam reception incident angle and the Earth's rotation direction. Figure 3 Satellites 1 and 2 shown are satellites that are aligned with the Earth's rotation direction. Skip to step 11; the omnidirectional antenna terminal selects candidate cells based on signal quality. Skip to step 11.

[0170] Step 10: If there are multiple candidate cells with negative downlink FO, proceed to step 12.

[0171] Step 12: Measure the signal quality (RSRP) of the synchronization signals of multiple candidate cells with negative downlink FO symbols. If the difference in signal quality between two candidate cells among the multiple candidate cells with negative downlink FO is greater than the second threshold, then proceed to step 8; otherwise, skip to step 9.

[0172] Step 11: The terminal initiates access, and the cell selection process ends.

[0173] It should be noted that the signal quality of the synchronization signal can be either the RSRP or the SNR of the synchronization signal. This embodiment does not limit the measurement method of the synchronization signal's signal quality; the same standard can be used between candidate cells. Furthermore, for terminals with omnidirectional receiving antennas (such as existing mobile terminals), it is difficult to determine the angle of incidence, i.e., it is impossible to determine the location of the candidate cell within the terminal. In other words, it is impossible to obtain satellites in adjacent orbits aligned with the Earth's rotation direction solely based on the synchronization signal. In this case, a number less than or equal to 0 can be set. For some terminals with small antenna arrays, the selection of cells covered by satellites in adjacent orbits can be further performed based on the received angle of incidence and the Earth's rotation direction (in this case, the angle of incidence aligned with the Earth's rotation direction is preferred).

[0174] In this embodiment, the cell selection principles are as follows: (1) For terminals in the overlapping coverage area of ​​adjacent satellites on the same orbit, the satellite with a longer service time is selected for access to avoid access failure or short-term handover due to the satellite rapidly leaving the terminal's area; (2) For terminals in the overlapping coverage area of ​​adjacent satellites on adjacent orbits, those that can distinguish the incident angle of the satellite signal, such as terminals with small phased arrays, can select satellite cell access based on the Earth's rotation direction; otherwise, they can only rely on signal quality for selection. The cell selection method proposed in this embodiment relies only on blind detection of the synchronization signal and does not rely on ephemeris information, enabling rapid access without affecting or increasing the overall initial access delay; the downlink frequency offset obtained by the terminal through initial frequency offset capture can be used to determine whether the satellite is leaving or heading towards the terminal. This parameter is an intermediate parameter obtained during downlink time-frequency synchronization and does not need to be obtained separately, so this scheme does not introduce additional complexity.

[0175] In this embodiment, cell selection can be completed simply by receiving the synchronization signal and obtaining the downlink FO and RSRP. The terminal does not need to complete the SIB19 detection, obtain ephemeris information, and then estimate the TA before making a cell selection decision. Utilizing downlink FO information to prioritize access to satellite cells with longer service times significantly reduces network access complexity and latency, effectively reduces handover frequency, and decreases the computational burden on the terminal and system load. This scheme is not limited to initial cell access; it can also be used for cell selection, cell reselection / cell handover, and beam position selection / reselection, and it has no requirements regarding network standards.

[0176] In some embodiments, the target cell for access is determined from among the multiple candidate cells based on the downlink frequency offset of the multiple candidate cells. If only one candidate cell has a downlink frequency offset greater than 0, and the signal quality of the candidate cell with a downlink frequency offset greater than 0 is greater than the signal quality threshold, then the terminal can select that candidate cell as the target cell for access. If the signal quality of the candidate cell with a downlink frequency offset greater than 0 is less than the signal quality threshold, and the signal quality of at least one candidate cell among the candidate cells with a downlink frequency offset not greater than 0 is greater than the signal quality threshold, then the terminal can select the candidate cell with a downlink frequency offset not greater than 0 and the highest signal quality as the target cell for access.

[0177] If multiple candidate cells have downlink frequency offsets greater than 0, and at least one of these candidate cells has a signal quality greater than a signal quality threshold, the terminal can select the candidate cell with the highest signal quality among the multiple candidate cells with downlink frequency offsets greater than 0 as the target cell for access. Alternatively, the terminal can determine one of the multiple candidate cells with downlink frequency offsets greater than 0 as the target cell for access based on their signal quality. If the signal quality of all multiple candidate cells with downlink frequency offsets greater than 0 is not greater than a signal quality threshold, and at least one candidate cell with a downlink frequency offset not greater than 0 has a signal quality greater than the signal quality threshold, the terminal can select the candidate cell with a downlink frequency offset not greater than 0 and the highest signal quality as the target cell for access.

[0178] In some embodiments, cell selection is performed based on the downlink frequency offset of multiple candidate cells to determine the target cell among the multiple candidate cells, including at least one of the following:

[0179] If there is only one candidate cell whose downlink frequency offset is greater than the first threshold, and the signal quality of the candidate cell whose downlink frequency offset is greater than the first threshold is greater than the signal quality threshold, then the candidate cell whose downlink frequency offset is greater than the first threshold is determined as the target cell.

[0180] If the signal quality of all candidate cells with downlink frequency offset greater than the first threshold is not greater than the signal quality threshold, and there is only one candidate cell with signal quality greater than the signal quality threshold among the candidate cells with downlink frequency offset not greater than the first threshold, then the candidate cell with downlink frequency offset not greater than the first threshold and signal quality greater than the signal quality threshold is determined as the target cell.

[0181] If the signal quality of all candidate cells whose downlink frequency offset is greater than the first threshold is not greater than the signal quality threshold, and there are multiple candidate cells whose downlink frequency offset is not greater than the first threshold whose signal quality is greater than the signal quality threshold, the target cell is determined based on the signal quality of the multiple candidate cells whose downlink frequency offset is not greater than the first threshold and whose signal quality is greater than the signal quality threshold.

[0182] If the signal quality of candidate cells with downlink frequency offset greater than the first threshold is not greater than the signal quality threshold, and the signal quality of candidate cells with downlink frequency offset not greater than the first threshold is not greater than the signal quality threshold, the candidate cell with the highest signal quality among the candidate cells with downlink frequency offset greater than the first threshold is determined as the target cell.

[0183] If the downlink frequency offset of multiple candidate cells is not greater than the first threshold, and only one candidate cell among the multiple candidate cells has a signal quality greater than the signal quality threshold, the candidate cell with a signal quality greater than the signal quality threshold is determined as the target cell.

[0184] If the downlink frequency offset of multiple candidate cells is not greater than the first threshold, and there are multiple candidate cells whose signal quality is greater than the signal quality threshold, the target cell is determined based on the signal quality of the multiple candidate cells whose signal quality is greater than the signal quality threshold.

[0185] If the downlink frequency offset of multiple candidate cells is not greater than the first threshold, and the signal quality of multiple candidate cells is not greater than the signal quality threshold, the candidate cell with the highest signal quality among the multiple candidate cells is determined as the target cell.

[0186] In this embodiment of the disclosure, when it is determined that there are multiple candidate cells with downlink frequency offsets when cell selection is performed, the target cell for access is selected from the multiple candidate cells based on the downlink frequency offsets of the multiple candidate cells. If there is only one candidate cell with a downlink frequency offset greater than a first threshold, and the signal quality of the candidate cell with a downlink frequency offset greater than the first threshold is greater than the signal quality threshold, the candidate cell with a downlink frequency offset greater than the first threshold is determined as the target cell.

[0187] In this embodiment of the disclosure, when determining the downlink frequency offset of multiple candidate cells during cell selection, the target cell for access is selected from the multiple candidate cells based on the downlink frequency offset of the multiple candidate cells. If the signal quality of all candidate cells with downlink frequency offset greater than a first threshold is not greater than a signal quality threshold, and only one candidate cell among the candidate cells with downlink frequency offset not greater than the first threshold has a signal quality greater than the signal quality threshold, the candidate cell with downlink frequency offset not greater than the first threshold and signal quality greater than the signal quality threshold is determined as the target cell.

[0188] In this embodiment of the disclosure, when determining the downlink frequency offset of multiple candidate cells during cell selection, the target cell for access is selected from the multiple candidate cells based on the downlink frequency offset of the multiple candidate cells. If the signal quality of the candidate cells whose downlink frequency offset is greater than a first threshold is not greater than a signal quality threshold, and there are multiple candidate cells whose downlink frequency offset is not greater than the first threshold whose signal quality is greater than the signal quality threshold, the target cell is determined based on the signal quality of the multiple candidate cells whose downlink frequency offset is not greater than the first threshold and whose signal quality is greater than the signal quality threshold.

[0189] In some embodiments, determining a target cell based on the signal quality of multiple candidate cells whose downlink frequency offset is not greater than a first threshold and whose signal quality is greater than a signal quality threshold includes:

[0190] If, among multiple candidate cells with downlink frequency offset not greater than a first threshold and signal quality greater than a signal quality threshold, there exists a difference in signal quality between two candidate cells that is greater than a second threshold, then the candidate cell with the highest signal quality among the multiple candidate cells with downlink frequency offset not greater than the first threshold and signal quality greater than a signal quality threshold is determined as the target cell; or

[0191] If, among multiple candidate cells with downlink frequency offset not greater than a first threshold and signal quality greater than a signal quality threshold, the difference in signal quality between any two candidate cells is not greater than a second threshold, the target cell is determined based on the beam reception incident angle of the beams received from the multiple candidate cells with downlink frequency offset not greater than the first threshold and signal quality greater than the signal quality threshold, and the direction of Earth's rotation; or

[0192] Based on the signal quality of multiple candidate cells with downlink frequency offset not greater than the first threshold and signal quality greater than the signal quality threshold, the candidate cell with the highest signal quality among the multiple candidate cells with downlink frequency offset not greater than the first threshold and signal quality greater than the signal quality threshold is determined as the target cell.

[0193] In this embodiment of the disclosure, when determining the downlink frequency offset of multiple candidate cells during cell selection, a target cell for access is selected from the multiple candidate cells based on the downlink frequency offset of the multiple candidate cells. If the signal quality of candidate cells with downlink frequency offset greater than a first threshold is not greater than a signal quality threshold, and there are multiple candidate cells with downlink frequency offset not greater than the first threshold whose signal quality is greater than the signal quality threshold, the target cell is determined based on the signal quality of the multiple candidate cells with downlink frequency offset not greater than the first threshold and signal quality greater than the signal quality threshold. If, among the multiple candidate cells with downlink frequency offset not greater than the first threshold and signal quality greater than the signal quality threshold, there is a difference in signal quality between two candidate cells that is greater than a second threshold, the candidate cell with the highest signal quality among the multiple candidate cells with downlink frequency offset not greater than the first threshold and signal quality greater than the signal quality threshold is determined as the target cell.

[0194] In this embodiment of the disclosure, when determining the downlink frequency offset of multiple candidate cells during cell selection, a target cell for access is selected from the multiple candidate cells based on the downlink frequency offset of the multiple candidate cells. Specifically, if the signal quality of all candidate cells with downlink frequency offset greater than a first threshold is not greater than a signal quality threshold, and multiple candidate cells with downlink frequency offset less than the first threshold have signal quality greater than the signal quality threshold, the target cell is determined based on the signal quality of the multiple candidate cells with downlink frequency offset less than the first threshold and signal quality greater than the signal quality threshold. Furthermore, if the difference in signal quality between any two candidate cells among the multiple candidate cells with downlink frequency offset less than the first threshold and signal quality greater than the signal quality threshold is not greater than a second threshold, the target cell is determined based on the beam reception incident angle of the beams received from the multiple candidate cells with downlink frequency offset less than the first threshold and signal quality greater than the signal quality threshold, and the Earth's rotation direction.

[0195] In some embodiments, determining a target cell based on the beam reception incident angle of beams received from multiple candidate cells with downlink frequency offset not greater than a first threshold and signal quality greater than a signal quality threshold, and the direction of Earth's rotation, includes: determining the candidate cell that stays the longest within the range of multiple candidate cells with downlink frequency offset not greater than the first threshold and signal quality greater than a signal quality threshold as the target cell based on the beam reception incident angle of beams received from multiple candidate cells with downlink frequency offset not greater than the first threshold and signal quality greater than a signal quality threshold, and the direction of Earth's rotation.

[0196] In this embodiment of the disclosure, when determining the downlink frequency offset of multiple candidate cells during cell selection, a target cell for access is selected from the multiple candidate cells based on the downlink frequency offset of the multiple candidate cells. Specifically, if the signal quality of all candidate cells with downlink frequency offsets greater than a first threshold is not greater than a signal quality threshold, and multiple candidate cells with downlink frequency offsets not greater than the first threshold have signal quality greater than the signal quality threshold, the target cell is determined based on the signal quality of these multiple candidate cells with downlink frequency offsets not greater than the first threshold and signal quality greater than the signal quality threshold. Among the candidate cells, the difference in signal quality between any two candidate cells is no greater than a second threshold. Based on the beam reception incident angle of the beams received from multiple candidate cells with downlink frequency offset no greater than a first threshold and signal quality greater than a signal quality threshold, and the direction of Earth's rotation, the target cell is determined. Specifically, based on the beam reception incident angle of the beams received from multiple candidate cells with downlink frequency offset no greater than a first threshold and signal quality greater than a signal quality threshold, and the direction of Earth's rotation, the candidate cell that stays within the range of multiple candidate cells with downlink frequency offset no greater than a first threshold and signal quality greater than a signal quality threshold for the longest time is determined as the target cell.

[0197] In this embodiment of the disclosure, when determining the downlink frequency offset of multiple candidate cells during cell selection, a target cell for access is selected from the multiple candidate cells based on the downlink frequency offset of the multiple candidate cells. If the signal quality of all candidate cells with downlink frequency offset greater than a first threshold is not greater than a signal quality threshold, and there are multiple candidate cells with downlink frequency offset not greater than the first threshold whose signal quality is greater than the signal quality threshold, the target cell is determined based on the signal quality of the multiple candidate cells with downlink frequency offset not greater than the first threshold and signal quality greater than the signal quality threshold. Specifically, based on the signal quality of the multiple candidate cells with downlink frequency offset not greater than the first threshold and signal quality greater than the signal quality threshold, the candidate cell with the highest signal quality among the multiple candidate cells with downlink frequency offset not greater than the first threshold and signal quality greater than the signal quality threshold is determined as the target cell.

[0198] In this embodiment of the disclosure, when it is determined that there are multiple candidate cells with downlink frequency offsets during cell selection, the target cell for access is selected from the multiple candidate cells based on the downlink frequency offsets of the multiple candidate cells. If the signal quality of the candidate cells with downlink frequency offsets greater than a first threshold is not greater than a signal quality threshold, and the signal quality of the candidate cells with downlink frequency offsets not greater than the first threshold is not greater than a signal quality threshold, the candidate cell with the highest signal quality among the candidate cells with downlink frequency offsets greater than the first threshold is determined as the target cell.

[0199] In this embodiment of the disclosure, when it is determined that there are multiple candidate cells with downlink frequency offsets when cell selection is performed, the target cell for access is selected from the multiple candidate cells based on the downlink frequency offsets of the multiple candidate cells. If the downlink frequency offsets of the multiple candidate cells are all not greater than a first threshold, and only one candidate cell among the multiple candidate cells has a signal quality greater than a signal quality threshold, the candidate cell with a signal quality greater than the signal quality threshold is determined as the target cell.

[0200] In this embodiment of the disclosure, when it is determined that there are multiple candidate cells with downlink frequency offsets when cell selection is performed, the target cell for access is selected from the multiple candidate cells based on the downlink frequency offsets of the multiple candidate cells. If the downlink frequency offsets of the multiple candidate cells are all not greater than a first threshold, and there are multiple candidate cells with signal quality greater than a signal quality threshold, the target cell is determined based on the signal quality of the multiple candidate cells with signal quality greater than the signal quality threshold.

[0201] In some embodiments, determining a target cell based on the signal quality of multiple candidate cells whose signal quality is greater than a signal quality threshold includes:

[0202] If, among multiple candidate cells with signal quality greater than a signal quality threshold, the difference in signal quality between two candidate cells exceeds a second threshold, the candidate cell with the highest signal quality among the multiple candidate cells with signal quality greater than the signal quality threshold is determined as the target cell; or

[0203] If the difference in signal quality between any two candidate cells among multiple candidate cells with signal quality greater than the signal quality threshold is no greater than a second threshold, the target cell is determined based on the beam reception incident angle of the beams received from the multiple candidate cells with signal quality greater than the signal quality threshold, and the direction of Earth's rotation; or

[0204] Based on the signal quality of multiple candidate cells with signal quality greater than the signal quality threshold, the candidate cell with the highest signal quality is determined as the target cell.

[0205] In this embodiment of the disclosure, when determining the downlink frequency offset of multiple candidate cells during cell selection, a target cell for access is selected from the multiple candidate cells based on the downlink frequency offset of the multiple candidate cells. If the downlink frequency offset of the multiple candidate cells is not greater than a first threshold, and the signal quality of multiple candidate cells is greater than a signal quality threshold, the target cell is determined based on the signal quality of the multiple candidate cells with signal quality greater than the signal quality threshold. If the difference in signal quality between two candidate cells with signal quality greater than the signal quality threshold is greater than a second threshold, the candidate cell with the highest signal quality among the multiple candidate cells with signal quality greater than the signal quality threshold is determined as the target cell.

[0206] In this embodiment of the disclosure, when determining the downlink frequency offset of multiple candidate cells during cell selection, a target cell for access is selected from the multiple candidate cells based on the downlink frequency offset of the multiple candidate cells. If the downlink frequency offset of the multiple candidate cells is not greater than a first threshold, and the signal quality of multiple candidate cells is greater than a signal quality threshold, the target cell is determined based on the signal quality of the multiple candidate cells with signal quality greater than the signal quality threshold. If the difference in signal quality between any two candidate cells with signal quality greater than the signal quality threshold is not greater than a second threshold, the target cell is determined based on the beam reception incident angle of the beam received from the multiple candidate cells with signal quality greater than the signal quality threshold and the direction of Earth's rotation.

[0207] In some embodiments, determining a target cell based on the beam reception incident angle of beams received from multiple candidate cells with signal quality greater than a signal quality threshold and the direction of Earth's rotation includes: determining the candidate cell that stays for the longest time within the range of multiple candidate cells with signal quality greater than a signal quality threshold as the target cell based on the beam reception incident angle of beams received from multiple candidate cells with signal quality greater than a signal quality threshold and the direction of Earth's rotation.

[0208] In this embodiment of the disclosure, when determining the downlink frequency offset of multiple candidate cells during cell selection, a target cell for access is selected from the multiple candidate cells based on the downlink frequency offset of the multiple candidate cells. If the downlink frequency offset of all multiple candidate cells is not greater than a first threshold, and the signal quality of multiple candidate cells is greater than a signal quality threshold, the target cell is determined based on the signal quality of the multiple candidate cells with signal quality greater than the signal quality threshold. If the difference in signal quality between any two candidate cells among the multiple candidate cells with signal quality greater than the signal quality threshold is not greater than a second threshold, the target cell is determined based on the beam reception incident angle of the received beam from the multiple candidate cells with signal quality greater than the signal quality threshold and the Earth's rotation direction. Furthermore, based on the beam reception incident angle of the received beam from the multiple candidate cells with signal quality greater than the signal quality threshold and the Earth's rotation direction, the candidate cell that stays within the range of the multiple candidate cells with signal quality greater than the signal quality threshold for the longest time is determined as the target cell.

[0209] In this embodiment of the disclosure, when determining the downlink frequency offset of multiple candidate cells during cell selection, the target cell for access is selected from the multiple candidate cells based on the downlink frequency offset of the multiple candidate cells. If the downlink frequency offset of the multiple candidate cells is not greater than a first threshold, and the signal quality of multiple candidate cells is greater than a signal quality threshold, the target cell is determined based on the signal quality of the multiple candidate cells with signal quality greater than the signal quality threshold. Specifically, the candidate cell with the highest signal quality is determined as the target cell based on the signal quality of the multiple candidate cells with signal quality greater than the signal quality threshold.

[0210] In this embodiment of the disclosure, when it is determined that there are multiple candidate cells with downlink frequency offsets when cell selection is performed, the target cell for access is selected from the multiple candidate cells based on the downlink frequency offsets of the multiple candidate cells. If the downlink frequency offsets of the multiple candidate cells are all not greater than a first threshold and the signal quality of the multiple candidate cells is not greater than a signal quality threshold, the candidate cell with the highest signal quality among the multiple candidate cells is determined as the target cell.

[0211] Figure 7 This is a structural diagram of a communication device 10 provided in an embodiment of this disclosure. Figure 7 As shown, the communication device 10 includes a processing module 11.

[0212] The processing module 11 is used to determine the downlink frequency offset of multiple candidate cells when performing cell selection; the processing module 11 is also used to determine the target cell for access from multiple candidate cells based on the downlink frequency offset of multiple candidate cells.

[0213] In some embodiments, the processing module 11 is specifically configured to perform cell selection based on the downlink frequency offset of multiple candidate cells, and determine the target cell among the multiple candidate cells, including at least one of the following:

[0214] If there is only one candidate cell whose downlink frequency offset is greater than the first threshold, the candidate cell whose downlink frequency offset is greater than the first threshold is determined as the target cell;

[0215] If multiple candidate cells have downlink frequency offsets greater than the first threshold, the target cell is determined based on the signal quality of the multiple candidate cells with downlink frequency offsets greater than the first threshold.

[0216] If the downlink frequency offset of multiple candidate cells is not greater than the first threshold, the target cell is determined based on the signal quality of the multiple candidate cells.

[0217] In some embodiments, the processing module 11 is specifically configured to, if among a plurality of candidate cells with downlink frequency offset greater than a first threshold, there exists a difference in signal quality between two candidate cells that is greater than a second threshold, determine the candidate cell with the highest signal quality among the plurality of candidate cells with downlink frequency offset greater than the first threshold as the target cell; or

[0218] If, among multiple candidate cells with downlink frequency offset greater than the first threshold, the difference in signal quality between any two candidate cells is no greater than the second threshold, the target cell is determined based on the beam reception incident angle of the beams received from the multiple candidate cells with downlink frequency offset greater than the first threshold, and the direction of Earth's rotation; or

[0219] Based on the signal quality of multiple candidate cells with downlink frequency offset greater than the first threshold, the candidate cell with the highest signal quality among the multiple candidate cells with downlink frequency offset greater than the first threshold is determined as the target cell.

[0220] In some embodiments, the processing module 11 is specifically used to determine the candidate cell that stays the longest within the range of the multiple candidate cells with downlink frequency offset greater than the first threshold as the target cell, based on the beam receiving incident angle of the beams received from multiple candidate cells with downlink frequency offset greater than the first threshold and the direction of Earth's rotation.

[0221] In some embodiments, the processing module 11 is specifically configured to determine a target cell based on the signal quality of multiple candidate cells, including:

[0222] If the difference in signal quality between two candidate cells is greater than a second threshold, the candidate cell with the highest signal quality among the candidate cells is determined as the target cell; or

[0223] If the difference in signal quality between any two candidate cells is no greater than a second threshold, the target cell is determined based on the beam reception incident angle of the beams received from the multiple candidate cells and the direction of Earth's rotation; or

[0224] Based on the signal quality of multiple candidate cells, the candidate cell with the highest signal quality is determined as the target cell.

[0225] In some embodiments, the processing module 11 is specifically configured to determine a target cell based on the beam reception incident angle of the beams received from multiple candidate cells and the direction of Earth's rotation, including:

[0226] Based on the beam reception incident angles of the beams received from multiple candidate cells and the direction of Earth's rotation, the candidate cell that stays within the range of multiple candidate cells for the longest time is determined as the target cell.

[0227] In some embodiments, the processing module 11 is specifically configured to perform cell selection based on the downlink frequency offset of multiple candidate cells, and determine the target cell among the multiple candidate cells, including at least one of the following:

[0228] If there is only one candidate cell whose downlink frequency offset is greater than the first threshold, and the signal quality of the candidate cell whose downlink frequency offset is greater than the first threshold is greater than the signal quality threshold, then the candidate cell whose downlink frequency offset is greater than the first threshold is determined as the target cell.

[0229] If the signal quality of all candidate cells with downlink frequency offset greater than the first threshold is not greater than the signal quality threshold, and there is only one candidate cell with signal quality greater than the signal quality threshold among the candidate cells with downlink frequency offset not greater than the first threshold, then the candidate cell with downlink frequency offset not greater than the first threshold and signal quality greater than the signal quality threshold is determined as the target cell.

[0230] If the signal quality of all candidate cells whose downlink frequency offset is greater than the first threshold is not greater than the signal quality threshold, and there are multiple candidate cells whose downlink frequency offset is not greater than the first threshold whose signal quality is greater than the signal quality threshold, the target cell is determined based on the signal quality of the multiple candidate cells whose downlink frequency offset is not greater than the first threshold and whose signal quality is greater than the signal quality threshold.

[0231] If the signal quality of candidate cells with downlink frequency offset greater than the first threshold is not greater than the signal quality threshold, and the signal quality of candidate cells with downlink frequency offset not greater than the first threshold is not greater than the signal quality threshold, the candidate cell with the highest signal quality among the candidate cells with downlink frequency offset greater than the first threshold is determined as the target cell.

[0232] If the downlink frequency offset of multiple candidate cells is not greater than the first threshold, and only one candidate cell among the multiple candidate cells has a signal quality greater than the signal quality threshold, the candidate cell with a signal quality greater than the signal quality threshold is determined as the target cell.

[0233] If the downlink frequency offset of multiple candidate cells is not greater than the first threshold, and there are multiple candidate cells whose signal quality is greater than the signal quality threshold, the target cell is determined based on the signal quality of the multiple candidate cells whose signal quality is greater than the signal quality threshold.

[0234] If the downlink frequency offset of multiple candidate cells is not greater than the first threshold, and the signal quality of multiple candidate cells is not greater than the signal quality threshold, the candidate cell with the highest signal quality among the multiple candidate cells is determined as the target cell.

[0235] In some embodiments, the processing module 11 is specifically configured to determine a target cell based on the signal quality of a plurality of candidate cells whose downlink frequency offset is not greater than a first threshold and whose signal quality is greater than a signal quality threshold, including:

[0236] If, among multiple candidate cells with downlink frequency offset not greater than a first threshold and signal quality greater than a signal quality threshold, there exists a difference in signal quality between two candidate cells that is greater than a second threshold, then the candidate cell with the highest signal quality among the multiple candidate cells with downlink frequency offset not greater than the first threshold and signal quality greater than a signal quality threshold is determined as the target cell; or

[0237] If, among multiple candidate cells with downlink frequency offset not greater than a first threshold and signal quality greater than a signal quality threshold, the difference in signal quality between any two candidate cells is not greater than a second threshold, the target cell is determined based on the beam reception incident angle of the beams received from the multiple candidate cells with downlink frequency offset not greater than the first threshold and signal quality greater than the signal quality threshold, and the direction of Earth's rotation; or

[0238] Based on the signal quality of multiple candidate cells with downlink frequency offset not greater than the first threshold and signal quality greater than the signal quality threshold, the candidate cell with the highest signal quality among the multiple candidate cells with downlink frequency offset not greater than the first threshold and signal quality greater than the signal quality threshold is determined as the target cell.

[0239] In some embodiments, the processing module 11 is specifically configured to determine a target cell based on the beam reception incident angle of beams received from multiple candidate cells whose downlink frequency offset is not greater than a first threshold and whose signal quality is greater than a signal quality threshold, and the Earth's rotation direction, including:

[0240] Based on the beam reception incident angle of the beams received from multiple candidate cells with downlink frequency offset not greater than the first threshold and signal quality greater than the signal quality threshold, and the direction of Earth's rotation, the candidate cell that stays for the longest time within the range of multiple candidate cells with downlink frequency offset not greater than the first threshold and signal quality greater than the signal quality threshold is determined as the target cell.

[0241] In some embodiments, the processing module 11 is specifically configured to determine a target cell based on the signal quality of a plurality of candidate cells whose signal quality is greater than a signal quality threshold, including:

[0242] If, among multiple candidate cells with signal quality greater than a signal quality threshold, the difference in signal quality between two candidate cells exceeds a second threshold, the candidate cell with the highest signal quality among the multiple candidate cells with signal quality greater than the signal quality threshold is determined as the target cell; or

[0243] If the difference in signal quality between any two candidate cells among multiple candidate cells with signal quality greater than the signal quality threshold is no greater than a second threshold, the target cell is determined based on the beam reception incident angle of the beams received from the multiple candidate cells with signal quality greater than the signal quality threshold, and the direction of Earth's rotation; or

[0244] Based on the signal quality of multiple candidate cells with signal quality greater than the signal quality threshold, the candidate cell with the highest signal quality is determined as the target cell.

[0245] In some embodiments, the processing module 11 is specifically used to determine the candidate cell that stays the longest within the range of the multiple candidate cells with signal quality greater than the signal quality threshold as the target cell, based on the beam reception incident angle of the beams received from multiple candidate cells with signal quality greater than the signal quality threshold and the direction of Earth's rotation.

[0246] In some embodiments, signal quality includes at least one of the following:

[0247] Reference signal received power RSRP of the synchronization signal;

[0248] The signal-to-noise ratio (SNR) of the synchronization signal;

[0249] The signal-to-interference-plus-noise ratio (SINR) of the synchronization signal;

[0250] The reference signal reception quality (RSRQ) of the synchronization signal;

[0251] The strength indicator of the received synchronization signal (RSRI).

[0252] The transmission delay of the synchronization signal.

[0253] In some embodiments, the synchronization signal includes at least one of the primary synchronization signal PSS and the secondary synchronization signal SSS.

[0254] It should be noted that the explanations and descriptions of the cell selection method embodiments in the foregoing embodiments also apply to the communication equipment in this embodiment, and will not be repeated here.

[0255] It should be noted that the beneficial effects achieved by the communication equipment are the same as those achieved by the cell selection method in the aforementioned embodiments, and will not be repeated here.

[0256] Figure 8 This is a block diagram illustrating a communication device for implementing a cell selection method according to an exemplary embodiment. It should be noted that the communication device 1800 in this embodiment can be used to implement the method described in the above method embodiments; please refer to the description in the above method embodiments for details. Figure 8 As shown, the aforementioned communication device 1800 includes:

[0257] One or more processors 1801. Processor 1801 can be a general-purpose processor or a special-purpose processor, such as a baseband processor or a central processing unit (CPU). The baseband processor can be used to process communication protocols and communication data, while the CPU can be used to control communication devices (e.g., base stations, baseband chips, terminals, terminal chips, distributed units (DUs) or centralized units (CUs), execute programs, and process program data. Processor 1801 is used to invoke instructions to cause communication device 1800 to execute any of the above methods.

[0258] In some embodiments, the communication device 1800 further includes one or more memories 1802 for storing instructions. In some embodiments, all or part of the memories 1802 may also be located outside the communication device 1800. In some embodiments, the communication device 1800 further includes one or more transceivers 1803. When the communication device 1800 includes one or more transceivers 1803, the communication steps such as sending and receiving in the above method are performed by the transceivers 1803, and other steps are performed by the processor 1801.

[0259] In some embodiments, transceiver 1803 may include a receiver and a transmitter, which may be separate or integrated. In some embodiments, the terms transceiver, transceiver unit, transceiver, and transceiver circuit are interchangeable; the terms transmitter, transmitting unit, transmitter, and transmitting circuit are interchangeable; and the terms receiver, receiving unit, receiver, and receiving circuit are interchangeable. In some embodiments, communication device 1800 further includes one or more interface circuits 1804 connected to memory 1802. Interface circuits 1804 can be used to receive signals from memory 1802 or other devices, and can be used to send signals to memory 1802 or other devices. For example, interface circuit 1804 can read instructions stored in memory 1802 and send those instructions to processor 1801.

[0260] The communication device 1800 described in the above embodiments may be a network device or a space terminal, but the scope of the communication device 1800 described in this disclosure is not limited thereto, and the structure of the communication device 1800 may vary. Figure 8The limitations. Communication equipment can be a standalone device or part of a larger device. For example, communication equipment can be: (1) a standalone integrated circuit (IC), or chip, or chip system or subsystem; (2) a collection of one or more ICs, in some embodiments of which the IC collection may also include storage components for storing data and programs; (3) an ASIC, such as a modem; (4) a module that can be embedded in other devices; (5) a receiver, terminal, smart terminal, cellular phone, wireless device, handheld device, mobile unit, vehicle device, network device, cloud device, artificial intelligence device, etc.; (6) others, etc.

[0261] It should be noted that the implementation process and technical principles of the communication device in this embodiment are explained in the foregoing description of the cell selection method of this disclosure embodiment, and will not be repeated here.

[0262] Embodiments of this disclosure also propose a chip. Figure 9 This is a structural diagram of a chip according to an exemplary embodiment.

[0263] like Figure 9 As shown, the chip 1900 includes a processor 1901 and an interface circuit 1902. The number of processors 1901 and the number of interface circuits 1902 can be one or more.

[0264] Optionally, the chip also includes a memory 1903 for storing necessary computer programs and data; an interface circuit 1902 for receiving signals from the memory 1903 and sending signals to the processor 1901, the signals including computer instructions stored in the memory 1903, which, when executed by the processor 1901, cause the communication device to perform the cell selection method described in the above embodiments of this disclosure.

[0265] To implement the above embodiments, this disclosure also proposes a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the cell selection method of the above embodiments.

[0266] To implement the above embodiments, this disclosure also provides a computer program product that, when executed by an instruction processor, performs the cell selection method of the above embodiments.

[0267] It should be noted that in the description of this disclosure, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this disclosure, unless otherwise stated, "a plurality of" means two or more.

[0268] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of preferred embodiments of this disclosure includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the function involved, as will be understood by those skilled in the art to which embodiments of this disclosure pertain.

[0269] It should be understood that various parts of this disclosure can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0270] Those skilled in the art will understand that all or part of the steps of the methods described in the above embodiments can be implemented by a program instructing related hardware, and the program can be stored in a computer-readable storage medium. When executed, the program includes one or a combination of the steps of the method embodiments.

[0271] Furthermore, the functional units in the various embodiments of this disclosure can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. The aforementioned storage medium can be a read-only memory, a disk, or an optical disk, etc.

[0272] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0273] Although embodiments of the present disclosure have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present disclosure. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present disclosure.

Claims

1. A method for selecting a cell, characterized in that, include: Determine the downlink frequency offset of multiple candidate cells when selecting a cell; Based on the downlink frequency offset of the multiple candidate cells, the target cell for access is determined from the multiple candidate cells.

2. The method as described in claim 1, characterized in that, The determination of the downlink frequency offset of multiple candidate cells during cell selection includes: Receive the synchronization signal block (SSB) of multiple candidate cells that exist during cell selection; The downlink frequency offset of the multiple candidate cells is determined based on their SSBs.

3. The method as described in claim 1, characterized in that, The step of determining the target cell for access from the plurality of candidate cells based on the downlink frequency offset of the plurality of candidate cells includes at least one of the following: If only one candidate cell has a downlink frequency offset greater than the first threshold, the candidate cell with a downlink frequency offset greater than the first threshold is determined as the target cell; If multiple candidate cells have downlink frequency offsets greater than a first threshold, the target cell is determined based on the signal quality of the multiple candidate cells with downlink frequency offsets greater than the first threshold. If the downlink frequency offset of the plurality of candidate cells is not greater than the first threshold, the target cell is determined based on the signal quality of the plurality of candidate cells.

4. The method as described in claim 3, characterized in that, The step of determining the target cell based on the signal quality of multiple candidate cells whose downlink frequency offset is greater than the first threshold includes: If, among multiple candidate cells with downlink frequency offset greater than the first threshold, there exists a signal quality difference between two candidate cells greater than the second threshold, then the candidate cell with the highest signal quality among the multiple candidate cells with downlink frequency offset greater than the first threshold is determined as the target cell; or If, among multiple candidate cells with downlink frequency offset greater than the first threshold, the difference in signal quality between any two candidate cells is no greater than the second threshold, the target cell is determined based on the beam reception incident angle of the beams received from the multiple candidate cells with downlink frequency offset greater than the first threshold, and the direction of Earth's rotation; or Based on the signal quality of multiple candidate cells with downlink frequency offset greater than the first threshold, the candidate cell with the highest signal quality among the multiple candidate cells with downlink frequency offset greater than the first threshold is determined as the target cell.

5. The method as described in claim 4, characterized in that, The step of determining the target cell based on the beam reception incident angle of beams received from multiple candidate cells with downlink frequency offsets greater than the first threshold, and the Earth's rotation direction, includes: Based on the beam reception incident angle of the beams received from multiple candidate cells with downlink frequency offset greater than the first threshold, and the direction of Earth's rotation, the candidate cell that stays for the longest time within the range of multiple candidate cells with downlink frequency offset greater than the first threshold is determined as the target cell.

6. The method as described in claim 3, characterized in that, The step of determining the target cell based on the signal quality of the plurality of candidate cells includes: If the difference in signal quality between any two candidate cells among the plurality of candidate cells is greater than a second threshold, the candidate cell with the highest signal quality among the plurality of candidate cells is determined as the target cell; or If the difference in signal quality between any two candidate cells is not greater than a second threshold, the target cell is determined based on the beam reception incident angle of the beams received from the candidate cells and the Earth's rotation direction; or Based on the signal quality of the multiple candidate cells, the candidate cell with the highest signal quality is determined as the target cell.

7. The method as described in claim 6, characterized in that, The step of determining the target cell based on the beam reception incident angle of the beams received from the plurality of candidate cells and the direction of Earth's rotation includes: Based on the beam reception incident angle of the beams received from the multiple candidate cells and the direction of Earth's rotation, the candidate cell that stays within the range of the multiple candidate cells for the longest time is determined as the target cell.

8. The method as described in claim 1, characterized in that, The step of determining the target cell for access from the plurality of candidate cells based on the downlink frequency offset of the plurality of candidate cells includes at least one of the following: If there is only one candidate cell whose downlink frequency offset is greater than the first threshold, and the signal quality of the candidate cell whose downlink frequency offset is greater than the first threshold is greater than the signal quality threshold, then the candidate cell whose downlink frequency offset is greater than the first threshold is determined as the target cell. If the signal quality of all candidate cells with downlink frequency offset greater than the first threshold is not greater than the signal quality threshold, and there is only one candidate cell with signal quality greater than the signal quality threshold among the candidate cells with downlink frequency offset not greater than the first threshold, then the candidate cell with downlink frequency offset not greater than the first threshold and signal quality greater than the signal quality threshold is determined as the target cell. If the signal quality of all candidate cells whose downlink frequency offset is greater than the first threshold is not greater than the signal quality threshold, and there are multiple candidate cells among the candidate cells whose downlink frequency offset is not greater than the first threshold whose signal quality is greater than the signal quality threshold, the target cell is determined based on the signal quality of the multiple candidate cells whose downlink frequency offset is not greater than the first threshold and whose signal quality is greater than the signal quality threshold. If the signal quality of all candidate cells with downlink frequency offset greater than the first threshold is not greater than the signal quality threshold, and the signal quality of all candidate cells with downlink frequency offset not greater than the first threshold is not greater than the signal quality threshold, the candidate cell with the highest signal quality among the candidate cells with downlink frequency offset greater than the first threshold is determined as the target cell; If the downlink frequency offset of all the candidate cells is not greater than the first threshold, and only one of the candidate cells has a signal quality greater than the signal quality threshold, the candidate cell with a signal quality greater than the signal quality threshold is determined as the target cell. If the downlink frequency offset of the plurality of candidate cells is not greater than the first threshold, and there are multiple candidate cells whose signal quality is greater than the signal quality threshold, the target cell is determined based on the signal quality of the multiple candidate cells whose signal quality is greater than the signal quality threshold. If the downlink frequency offset of the plurality of candidate cells is not greater than the first threshold, and the signal quality of the plurality of candidate cells is not greater than the signal quality threshold, the candidate cell with the highest signal quality among the plurality of candidate cells is determined as the target cell.

9. The method as described in claim 8, characterized in that, The step of determining the target cell based on the signal quality of multiple candidate cells whose downlink frequency offset is not greater than a first threshold and whose signal quality is greater than a signal quality threshold includes: If, among multiple candidate cells with downlink frequency offset not greater than a first threshold and signal quality greater than a signal quality threshold, there exists a difference in signal quality between two candidate cells that is greater than a second threshold, then the candidate cell with the highest signal quality among the multiple candidate cells with downlink frequency offset not greater than the first threshold and signal quality greater than a signal quality threshold is determined as the target cell; or If, among multiple candidate cells whose downlink frequency offset is no greater than a first threshold and whose signal quality is greater than a signal quality threshold, the difference in signal quality between any two candidate cells is no greater than a second threshold, the target cell is determined based on the beam reception incident angle of the beams received from the multiple candidate cells whose downlink frequency offset is no greater than the first threshold and whose signal quality is greater than the signal quality threshold, and the direction of Earth's rotation; or Based on the signal quality of multiple candidate cells with downlink frequency offset not greater than a first threshold and signal quality greater than a signal quality threshold, the candidate cell with the highest signal quality among the multiple candidate cells with downlink frequency offset not greater than a first threshold and signal quality greater than a signal quality threshold is determined as the target cell.

10. The method as described in claim 9, characterized in that, The step of determining the target cell based on the beam reception incident angle of beams received from multiple candidate cells whose downlink frequency offset is not greater than a first threshold and whose signal quality is greater than a signal quality threshold, and the direction of Earth's rotation, includes: Based on the beam reception incident angle of the beams received from multiple candidate cells with downlink frequency offset not greater than a first threshold and signal quality greater than a signal quality threshold, and the direction of Earth's rotation, the candidate cell that stays for the longest time within the range of multiple candidate cells with downlink frequency offset not greater than a first threshold and signal quality greater than a signal quality threshold is determined as the target cell.

11. The method as described in claim 8, characterized in that, The step of determining the target cell based on the signal quality of multiple candidate cells whose signal quality is greater than a signal quality threshold includes: If, among multiple candidate cells with signal quality greater than a signal quality threshold, the difference in signal quality between two candidate cells exceeds a second threshold, then the candidate cell with the highest signal quality among the multiple candidate cells with signal quality greater than the signal quality threshold is determined as the target cell; or If the difference in signal quality between any two candidate cells among a plurality of candidate cells with signal quality greater than a signal quality threshold is not greater than a second threshold, the target cell is determined based on the beam reception incident angle of the beams received from the plurality of candidate cells with signal quality greater than the signal quality threshold, and the direction of Earth's rotation; or Based on the signal quality of multiple candidate cells whose signal quality is greater than the signal quality threshold, the candidate cell with the highest signal quality is determined as the target cell.

12. The method as described in claim 11, characterized in that, The step of determining the target cell based on the beam reception incident angle of beams received from multiple candidate cells with signal quality greater than a signal quality threshold, and the Earth's rotation direction, includes: Based on the beam reception incident angle of the beams received from multiple candidate cells with signal quality greater than the signal quality threshold, and the direction of Earth's rotation, the candidate cell that stays for the longest time within the range of multiple candidate cells with signal quality greater than the signal quality threshold is determined as the target cell.

13. The method according to any one of claims 3 to 12, characterized in that, The signal quality includes at least one of the following: Reference signal received power RSRP of the synchronization signal; The signal-to-noise ratio (SNR) of the synchronization signal; The signal-to-interference-plus-noise ratio (SINR) of the synchronization signal; The reference signal reception quality (RSRQ) of the synchronization signal; The strength indicator of the received synchronization signal (RSRI). The transmission delay of the synchronization signal.

14. The method as described in claim 13, characterized in that, The synchronization signal includes at least one of the primary synchronization signal PSS and the secondary synchronization signal SSS.

15. A communication device, characterized in that, include: The processing module is used to determine the downlink frequency offset of multiple candidate cells when performing cell selection; The processing module is further configured to determine the target cell for access from the plurality of candidate cells based on the downlink frequency offset of the plurality of candidate cells.

16. A communication device, characterized in that, include: At least one processor; as well as A memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the method of any one of claims 1 to 14.

17. A computer storage medium, characterized in that, The computer storage medium stores computer-executable instructions, which, when executed by a processor, enable the implementation of the method according to any one of claims 1 to 14.

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