A communication method, terminal device and readable storage medium

Abstract

The present application relates to the field of communications, and discloses a communication method, a terminal device, and a readable storage medium. In the method, the terminal device establishes communication with a LEO base station, receives and stores the base station signal characteristics broadcast by the LEO base station, and the broadcast base station signal characteristics may include the base station signal characteristics of at least one LEO base station. The base station signal characteristics may include the frequency of the LEO base station, the frequency deviation between the LEO base station and the terminal device, the synchronization time, the delay, the LEO base station identifier, the reference signal strength, etc. When the terminal device periodically searches for the LEO base station, it can directly search for the corresponding LEO base station based on the stored base station signal characteristics and re-measure the base station signal characteristics of the corresponding LEO base station. In this way, each time the terminal device searches for a LEO base station, it can quickly search for the corresponding LEO base station through the base station signal characteristics of the last measurement stored by the terminal device, thereby reducing the search time and power consumption caused by the terminal device searching for the LEO base station in the full frequency band each time.

Description

Technical Field

[0001] The present application relates to the field of communications, and in particular to a communication method, a terminal device, and a readable storage medium. Background Art

[0002] When user equipment (UE) establishes communication with a LEO base station built on a low earth orbit (LEO), the same LEO base station is in continuous motion relative to the UE because LEO rotates around the earth and its revolution period (about 1.61h~1.93h) is lower than the earth's rotation period (24h). When the LEO base station covers the UE and the LEO base station is in continuous motion, the UE may not be able to maintain a stable connection with the LEO base station due to the high-speed movement of the LEO base station or physical obstacles, and the LEO base station still covers the UE. Based on this, the UE will periodically search for the LEO base station covering the UE in case the UE needs to re-establish a connection with the LEO base station.

[0003] However, the periodic search of the UE is based on searching all possible satellite frequency bands to obtain the signal sent by the LEO base station. The search process is time-consuming and will increase the power consumption of the UE. Summary of the invention

[0004] To solve the above problems, the present application provides a communication method, a terminal device and a readable storage medium.

[0005] In a first aspect, the present application provides a communication method, which is applied to a terminal device, and the method includes: establishing a communication connection with a first LEO base station; acquiring and storing base station signal characteristics sent by the first LEO base station, the base station signal characteristics including first base station signal characteristics corresponding to the first LEO base station, wherein the first base station signal characteristics include the frequency of the first LEO base station and the base station identifier of the first LEO base station; detecting that the communication connection with the first LEO base station is disconnected, and searching for the LEO base station based on the first base station signal characteristics; and re-establishing a communication connection with the first LEO base station in response to searching for a synchronization signal sent by the first LEO base station.

[0006] It can be understood that the terminal device can also be called UE, etc., and no specific limitation is made here.

[0007] It can be understood that the LEO base stations whose signals can cover the UE may include one or more. After the UE establishes communication with the first LEO base station, the UE can receive the base station signal characteristics broadcast by the first LEO base station, including the base station identifiers, frequencies and other base station signal characteristics of multiple LEO base stations, which are not limited here.

[0008] It can be understood that when the UE establishes a communication connection with the first LEO base station, the UE can obtain the base station signal characteristics of the first LEO base station, such as the identification, frequency, frequency deviation, synchronization time, delay, reference signal strength, etc. of the first LEO base station, and store them in the UE, which is not limited here.

[0009] It can be understood that the UE can determine the identification, frequency and other information of the neighboring LEO base station that also currently covers the UE through the base station signal characteristics broadcast by the first LEO base station with which it establishes a communication connection. The UE can clearly identify other LEO base stations that currently cover the UE except the first LEO base station through the identification of the neighboring base station.

[0010] Through the above method, when the UE re-searches for the first LEO base station that can cover the UE, the corresponding LEO base station can be preferentially searched quickly based on the base station signal characteristics of the first LEO base station stored on the UE side. In addition, each time the UE searches for the first LEO base station, the base station signal characteristics such as the frequency offset, synchronization time, delay, and reference signal strength between the UE and the first LEO base station can be re-measured, so that the next time the UE searches for the first LEO base station, it can quickly search for the first LEO base station based on the base station signal characteristics re-measured last time, thereby improving the speed and accuracy of each search for the first LEO base station and reducing the search power consumption of the UE.

[0011] In a possible implementation of the first aspect above, the method also includes: determining that the base station signal characteristics sent by the first LEO base station include a base station identifier of a second LEO base station; corresponding to the second base station signal characteristics of the second LEO base station stored in the terminal device, searching for the second LEO base station through the second base station signal characteristics; wherein the second base station signal characteristics include the base station identifier, frequency, frequency deviation, synchronization time, delay, and reference signal strength of the second LEO base station; corresponding to the search for the synchronization signal sent by the second LEO base station, re-measuring the second base station signal characteristics of the second LEO base station to obtain a third base station signal characteristics corresponding to the second LEO base station.

[0012] It can be understood that the second LEO base station may refer to a neighboring LEO base station mentioned in the embodiment of the present application that has not established a communication connection with the UE but also covers the UE.

[0013] Through the above method, for the second LEO base station that stores the base station signal characteristics on the UE side, each time the UE periodically searches for the second LEO base station, it can quickly search for the corresponding LEO base station based on the second base station signal characteristics corresponding to the stored second LEO base station, thereby improving the search speed and reducing the search power consumption of the UE.

[0014] In addition, when the first LEO base station moves to a point where it cannot cover the UE, the UE can use the base station signal characteristics corresponding to the second LEO base station stored in it to quickly search for the corresponding neighboring LEO base station, so that the UE can switch to establish communication with the second LEO base station, avoiding the power consumption caused by the UE scanning all possible satellite frequency bands to search for available LEO base stations, and improving the speed of the UE switching LEO base stations.

[0015] In a possible implementation of the first aspect above, corresponding to searching for a synchronization signal sent by a second LEO base station, re-measuring a second base station signal characteristic of the second LEO base station to obtain a third base station signal characteristic corresponding to the second LEO base station includes: storing the third base station signal characteristic corresponding to the second LEO base station, and updating the second base station signal characteristic of the second LEO base station stored in the terminal device to the third base station signal characteristic.

[0016] It can be understood that the second LEO base station may refer to a neighboring LEO base station mentioned in the embodiment of the present application which has not established a communication connection with the UE but also covers the UE.

[0017] Through the above method, for LEO base stations with base station signal characteristics stored on the UE side, each time the UE periodically searches for LEO base stations, it can quickly search for the corresponding LEO base station based on the stored base station signal characteristics corresponding to different LEO base stations. In addition, the latest base station signal characteristics of the corresponding LEO base station can be re-measured, and the latest base station signal characteristics of the corresponding LEO base station can be used as the base station signal characteristics of the next search for these LEO base stations, so as to achieve fast search, improve search speed, and reduce UE search power consumption.

[0018] In a possible implementation of the first aspect above, the method also includes: determining that the base station signal characteristics sent by the first LEO base station include a base station identifier of a third LEO base station; corresponding to the base station signal characteristics corresponding to the third LEO base station not being stored in the terminal device, searching for the third LEO base station through the base station identifier and frequency of the third LEO base station included in the base station signal characteristics sent by the first LEO base station; corresponding to the synchronization signal sent by the third LEO base station being searched, measuring the base station signal characteristics of the third LEO base station, obtaining a fourth base station signal characteristics corresponding to the third LEO base station, and storing the fourth base station signal characteristics corresponding to the third LEO base station; wherein the fourth base station signal characteristics corresponding to the third LEO base station include the base station identifier, frequency, frequency deviation, synchronization time, delay, and reference signal strength of the third LEO base station.

[0019] Through the above method, for a new LEO base station for which the base station signal characteristics are not stored on the UE side, after the UE searches for the new LEO base station for the first time, the UE can obtain the base station signal characteristics of the new LEO base station and store them on the UE side. In this way, when searching for the LEO base station again next time, a fast search can be achieved based on the stored base station signal characteristics, thereby improving the search speed and reducing the search power consumption of the UE.

[0020] In a possible implementation of the first aspect above, the signal characteristics of the first base station also include the frequency deviation, synchronization time, delay, and reference signal strength of the first LEO base station; and, based on the signal characteristics of the first base station, searching for the synchronization signal of the first LEO base station, and re-establishing a communication connection with the first LEO base station, including: determining the search frequency of the terminal device for searching the first LEO base station based on the frequency point and frequency deviation of the first LEO base station, and determining the search time of the terminal device for searching the first LEO base station based on the synchronization time and delay of the first LEO base station; searching for the synchronization signal corresponding to the first LEO base station using the search frequency at the search time; and re-establishing a communication connection with the first LEO base station when the synchronization signal corresponding to the first LEO base station is searched for at the second time.

[0021] In a possible implementation of the first aspect above, after re-establishing a communication connection with the first LEO base station, the method also includes: re-measuring the base station signal characteristics of the first LEO base station to obtain a fifth base station signal characteristic corresponding to the first LEO base station; storing the fifth base station signal characteristic corresponding to the first LEO base station, and updating the first base station signal characteristic of the first LEO base station stored in the terminal device to the fifth base station signal characteristic corresponding to the first LEO base station.

[0022] It can be understood that each time a periodic search is performed, the latest base station signal characteristics of the corresponding LEO base station are re-measured, and the latest base station signal characteristics of the corresponding LEO base station are used as the base station signal characteristics for the next search of these LEO base stations. This can increase the speed of each periodic search and reduce the search power consumption of the UE.

[0023] In a possible implementation of the first aspect above, detecting that the communication connection with the first LEO base station is disconnected includes: determining whether a reference signal strength of the first LEO base station is less than a reference signal strength threshold; corresponding to the reference signal strength of the first LEO base station being less than the reference signal strength threshold, determining that the communication connection with the first LEO base station is disconnected.

[0024] In a possible implementation of the first aspect above, detecting that the communication connection with the first LEO base station is disconnected also includes: determining whether the first LEO base station can be searched through the signal characteristics of the first base station; corresponding to the inability to search for the synchronization signal corresponding to the first LEO base station through the signal characteristics of the first base station, determining that the communication connection with the first LEO base station is disconnected.

[0025] In a possible implementation of the first aspect above, after the first LEO base station is not searched through the first base station signal characteristics, the method also includes: determining the revolution period of the first LEO base station, and re-searching the LEO base station based on the first base station signal characteristics of the first LEO base station in the next revolution period of the first LEO base station.

[0026] In a possible implementation of the first aspect above, the synchronization signal corresponding to the first LEO base station includes a primary synchronization signal and a secondary synchronization signal corresponding to the first LEO base station.

[0027] In a second aspect, an embodiment of the present application provides a terminal device, including a memory for storing instructions; and a processor for executing instructions to implement the communication method provided by the above-mentioned first aspect and various possible implementations of the first aspect.

[0028] In a third aspect, an embodiment of the present application provides a readable storage medium, on which instructions are stored. When the instructions are executed on a terminal device, the terminal device executes the communication method provided by the above-mentioned first aspect and various possible implementations of the first aspect.

[0029] In a fourth aspect, an embodiment of the present application further provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements the communication method provided by the above-mentioned first aspect and various possible implementations of the first aspect.

[0030] The beneficial effects of the second to fourth aspects mentioned above can be referred to the relevant descriptions in the first aspect mentioned above and various possible implementations of the first aspect, and will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 According to the method provided in the embodiment of the present application, a schematic diagram of an application scenario of the communication method is shown;

[0032] Figure 2 According to the method provided in an embodiment of the present application, a schematic diagram of a process of a UE searching for a LEO base station to establish communication is shown;

[0033] Figure 3 According to the method provided in an embodiment of the present application, a schematic diagram of a UE-side neighboring cell list 00 and a UE-side neighboring cell list 01 is shown;

[0034] Figure 4 According to the method provided in an embodiment of the present application, a specific flow chart of updating a neighboring cell list on the UE side is shown;

[0035] Figure 5 According to the method provided in an embodiment of the present application, a schematic diagram of the structure of a terminal device 100 is shown. DETAILED DESCRIPTION

[0036] The illustrative embodiments of the present application include, but are not limited to, a communication method, a readable medium, and a terminal device.

[0037] In order to make the objectives, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and comprehensively described below in conjunction with the accompanying drawings.

[0038] It can be understood that the terminal device in the embodiment of the present application can also be called a terminal, a user equipment, an electronic device, a mobile station (MS), a mobile terminal (MT), etc. The terminal device can be a mobile phone, a smart TV, a wearable device, a tablet computer (Pad), a computer with a wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, etc.

[0039] It can be understood that the technical solution provided by the present application can be applied to various communication systems, such as: the fifth generation (5th generation, 5G) mobile communication system or new radio access technology (new radio access technology, NR), long term evolution (long term evolution, LTE) system, LTE frequency division duplex (frequency division duplex, FDD) system, LTE time division duplex (time division duplex, TDD), universal mobile telecommunication system (universal mobile telecommunication system, UMTS), etc. In addition, the technical solution provided by the present application can also be applied to future communication systems, such as the sixth generation mobile communication system, etc.

[0040] Figure 1 According to an embodiment of the present application, a schematic diagram of an application scenario of a communication method is shown.

[0041] like Figure 1As shown, satellite base station a and satellite base station b are both LEO base stations. Mobile phone 10 is located within the signal coverage of satellite base station a and satellite base station b, and mobile phone 10 communicates with satellite base station a. Satellite base station a and satellite base station b are both in a continuous motion state relative to mobile phone 10. Figure 1 As shown in , taking the movement of satellite base station a as an example, LEO base station a can still cover mobile phone 10 after the movement.

[0042] It can be understood that in other embodiments, the mobile phone 10 may no longer be within the signal coverage of the satellite base station a after the satellite base station a moves. In this case, the mobile phone 10 can establish a communication connection with the searched satellite base station b that can cover the UE.

[0043] As mentioned above, when the LEO base station covers the UE and the LEO base station is in continuous motion, the LEO base station may not be able to maintain a stable connection with the UE due to the high-speed movement of the LEO base station or physical obstacles, and the LEO base station still covers the UE. Based on this, the UE will periodically search for the LEO base station covering the UE in case the UE needs to re-establish a connection with the LEO base station. However, the UE's periodic search is based on searching all possible satellite frequency bands to obtain the signal sent by the LEO base station. The search process is time-consuming and will increase the power consumption of the UE.

[0044] In some schemes, the specific process of the UE periodically searching for the LEO base station may include:

[0045] (1) The UE scans possible frequencies according to the predefined frequency band list. For example, assuming that one of the predefined frequency bands corresponds to the range of 1920-1980 MHz, the UE starts scanning each frequency point in the range of 1920-1980 MHz, trying to detect the synchronization signal sent by the LEO base station.

[0046] (2) When scanning each possible frequency point, the UE first needs to scan the primary synchronization signal (PSS) sent by the LEO base station, obtain time synchronization information and frequency synchronization information based on the scanning result of the PSS signal, and then further scan the secondary synchronization signal (SSS). For example, the UE detects the PSS signal and the SSS signal at the frequency of 1920.1MHz. It can be understood that the PSS signal and the SSS signal are key signals for frame synchronization and LEO base station identification in mobile communication systems. At least one LEO base station will broadcast the PSS signal and the SSS signal at a specific frequency within its coverage area so that the UE can detect and synchronize. Among them, the PSS signal carries the identification document (ID) information N_ID_2. In long term evolution (LTE), that is, the 4G communication system, the value range of N_ID_2 is usually 0 to 2. The UE obtains the time synchronization information and the frequency synchronization information through the PSS signal and aligns with the time of the LEO base station. The SSS signal carries the identification information N_ID_1. In LTE, the value range of N_ID_1 is usually 0 to 167. In the fifth generation mobile communication technology (5G), the value range of N_ID_1 is usually 0 to 355, which is not limited here.

[0047] (3) The UE determines the LEO base station identity document (ID) based on the detected PSS and SSS signals. For example, assume that the UE obtains N_ID_2=1 based on the PSS signal and N_ID_1=127 based on the SSS signal. The corresponding LEO base station ID is calculated using N_ID_1 and N_ID_2. For example, N_ID represents the LEO base station ID. The UE can then determine the LEO base station ID it has searched for based on N_ID=382.

[0048] (4) After searching for the PSS signal and the SSS signal, the UE needs to resolve the physical broadcast channel (packet block channel, PBCH) signal based on information such as N_ID, and obtain the master information block (MIB) information and cyclic redundancy check (CRC) field included in the PBCH signal. The UE can compare the CRC value calculated by the UE with the above-mentioned CRC field. If the two are consistent, the UE can determine that the PBCH signal is complete and correct, and then the UE can determine that the LEO base station has been successfully searched. It can be understood that CRC is a commonly used error detection technology used to verify the integrity of transmitted data. In addition, the UE can obtain parameters such as the frequency deviation and reference signal strength between the target LEO base station. These parameters can evaluate the connection quality between the UE and the target LEO base station, so that the UE can subsequently switch to the target LEO base station for communication.

[0049] It can be seen that each time the UE periodically searches for a LEO base station that may cover the UE, it needs to scan all possible frequencies based on a predefined frequency band list to obtain the PSS signal and SSS signal sent by the LEO base station, and decode the PBCH and perform a CRC check based on the scanning results of the PSS signal and the SSS signal to determine whether the LEO base station is successfully searched. The above process is time-consuming, which greatly increases the power consumption of the UE.

[0050] Therefore, in order to solve the above problems, an embodiment of the present application provides a communication method, which includes: after the UE establishes communication with the first LEO base station, it can receive and store the base station signal characteristics broadcast by the first LEO base station. The base station signal characteristics broadcast by the first LEO base station may include the base station signal characteristics of at least one LEO base station, and the base station signal characteristics may include the frequency of the LEO base station, the frequency deviation between the LEO base station and the UE, the synchronization time, the delay, the LEO base station ID, the reference signal strength and other characteristics. Based on this, during the periodic search process, the UE can quickly search for the corresponding LEO base station based on the stored base station signal characteristics. In this way, each time the UE periodically searches for the LEO base station, it can quickly search for the corresponding LEO base station based on the stored base station signal characteristics, without having to scan all possible satellite frequency bands to find the LEO base station covering the UE, thereby reducing the time consumption of the entire search process and thereby reducing the power consumption of the UE.

[0051] Exemplarily, the UE can set the frequency (e.g., 1920.1MHZ-200Hz=1920.08MHz) when the UE searches for synchronization signals (including PSS signals and SSS signals) by using the frequency point (e.g., 1920.1MHZ) and frequency deviation (e.g., 200Hz) of the first LEO base station in the stored first base station signal characteristics, and set the time for the UE to search for synchronization signals according to the synchronization time and delay of the first LEO base station. Furthermore, the UE can quickly search for the PSS signal and SSS signal sent by the first LEO base station based on the frequency 1920.08MHz and the synchronization time, and after searching for the first LEO base station, re-measure the frequency deviation, synchronization time, delay, reference signal strength and other characteristics of the current first LEO base station ID.

[0052] It can be understood that due to the continuous movement of the LEO base station, the time when the UE receives the synchronization signal sent by the LEO base station will change based on the change in the distance between the LEO base station and the UE. There is a delay between the time when the UE receives the synchronization signal sent by the LEO base station and the time when the LEO base station sends the synchronization signal to the UE, and each time the delay may be different. Therefore, when the UE periodically searches for the LEO base station, each time after successfully searching for the LEO base station, the delay between the UE and the LEO base station can be re-acquired, so that the next time the UE periodically searches for the corresponding LEO base station, the time when the UE searches for the synchronization signal sent by the LEO base station can be set based on the most recently updated delay, so as to search the corresponding LEO base station more quickly.

[0053] In some embodiments of the present application, in the process of the UE periodically searching for the LEO base station covering the UE, in order to avoid the influence of physical obstructions and improve the success rate of the search, the search duration or the number of searches during each periodic search can be increased. For example, the duration for the UE to search for the LEO base station based on the base station signal characteristics such as the ID, frequency, frequency deviation, and delay of the LEO base station is extended, or the search frequency is increased, that is, more searches are performed based on the base station signal characteristics within the same search duration. In addition, if the corresponding LEO base station is not searched based on the pre-stored base station signal characteristics, or if the reference signal strength based on the LEO base station is less than the signal strength threshold, it can indicate that the LEO base station no longer covers the UE, that is, the UE is not within the coverage of the corresponding LEO base station.

[0054] In some embodiments of the present application, the UE receives at least one LEO base station broadcasted by the first LEO base station, which may include other neighboring LEO base stations that cover the UE but have not established a communication connection with the UE. Therefore, the UE can receive and store the base station signal characteristics of the neighboring LEO base station broadcasted by the first LEO base station. Furthermore, the UE can also search for the neighboring LEO base station based on the base station signal characteristics corresponding to the neighboring LEO base station, and measure the base station signal characteristics of the neighboring LEO base station after searching for the corresponding neighboring LEO base station and store them in the UE. Based on this, during the periodic search process, the UE can directly search for the corresponding neighboring LEO base station through the stored base station signal characteristics of the neighboring LEO base station, that is, the ID, frequency, frequency deviation, synchronization time, delay, reference signal strength and other characteristics of the neighboring LEO base station, and re-measure the latest base station signal characteristics corresponding to the searched neighboring LEO base station to update the previously stored base station signal characteristics.

[0055] In addition, when the first LEO base station moves to a point where it cannot cover the UE, the UE can use its stored signal characteristics of the neighboring LEO base station to quickly search for the corresponding neighboring LEO base station, so that the UE can establish communication with the neighboring LEO base station. This avoids the power consumption caused by the UE scanning all possible satellite frequency bands to search for available LEO base stations, and also improves the speed of the UE switching LEO base stations.

[0056] In some embodiments of the present application, after the UE periodically searches for the synchronization signal corresponding to the LEO base station (including the current LEO base station and the neighboring LEO base station) based on the stored base station signal characteristics, the UE can re-measure the frequency deviation, synchronization time, delay, reference signal strength and other information between the UE and the LEO base station, and update the frequency deviation, synchronization time, delay, reference signal strength and other information between different LEO base stations and the UE stored in the UE. Each time the UE periodically searches for the LEO base station, it can quickly search for the corresponding LEO base station based on the periodically updated base station signal characteristics. It can be understood that if the UE does not search for the corresponding LEO base station based on its stored base station signal characteristics, the base station signal characteristics of the corresponding LEO base station stored in the UE will not be updated.

[0057] In some embodiments of the present application, when the first LEO base station moves to the point where it can no longer cover the UE in the current revolution period, the base station signal characteristics of the first LEO base station stored in the UE in the previous revolution period can be called in the next revolution period, so that when the first LEO base station starts to cover the UE in the next revolution period, the UE can quickly search for the first LEO base station based on the stored base station signal characteristics of the first LEO base station. For example, the revolution period of the first LEO base station is 1.61h. Assuming that the UE does not find the first LEO base station when searching for the first LEO base station at time t_x of the current revolution period, the UE can call the base station signal characteristics of the first LEO base station stored on the UE side at time (t_x+1.61h) to search for the first LEO base station. It can be understood that the numerical value corresponding to the revolution period shown above is only an exemplary description and is not limited here.

[0058] It can be understood that when the first LEO base station calls back the base station signal characteristics corresponding to the first LEO base station at the arrival of the next revolution period, considering that there is a certain change in the position of the UE within the current revolution period, when the UE searches for the first LEO base station, the search time for the PSS signal and the SSS signal corresponding to the first LEO base station can be increased, so as to accurately and efficiently re-search the first LEO base station.

[0059] In some embodiments of the present application, the UE may send the base station characteristics of each LEO base station measured periodically to the LEO base station where the current UE resides, so that the LEO base station where the current UE resides can determine whether it is necessary to perform LEO base station switching based on information such as the size of the reference signal strength or the size of the frequency deviation of each LEO base station sent by the UE. For example, it is determined to select the LEO base station with the largest reference signal strength for switching, or it is determined to select the LEO base station with the smallest frequency deviation for switching, etc., which are not limited here. Further, the LEO base station where the current UE resides can send the ID of the LEO base station to which the UE is to switch and the corresponding base station signal characteristics such as the frequency point. After the UE receives the information sent by the resident LEO base station, it can search for the corresponding LEO base station through the base station signal characteristics of the LEO base station to be switched stored on the UE side, and send an uplink synchronization signal to it and reside there after searching.

[0060] In some embodiments of the present application, when the UE detects that the communication connection with the LEO base station in which it is currently located is disconnected, the UE can traverse the base station signal characteristics of other LEO base stations covering the UE stored in the UE, and can search for the corresponding LEO base station based on the base station signal characteristics of the LEO base station with a greater reference signal strength or a smaller frequency deviation, and after searching, send an uplink synchronization signal to it and reside there.

[0061] Figure 2According to an embodiment of the present application, a schematic diagram of a process of a UE searching for a LEO base station to establish communication is shown.

[0062] Understandably, Figure 2 The process shown in is the process from UE not yet establishing communication with LEO base station to searching and establishing communication with LEO base station. In addition, Figure 2 The execution entities of each step in the process shown can be electronic devices such as mobile phones, tablet computers, smart wearable devices, smart home devices, and vehicle-mounted devices, which are not limited here.

[0063] Specifically, Figure 2 The process shown may include:

[0064] S201: Determine whether the UE-side neighboring cell list includes prior information.

[0065] If the judgment result is yes, go to S202, search for the PSS signal and SSS signal sent by the target LEO base station according to the prior information, and complete synchronization and residence based on the target LEO base station.

[0066] If the judgment result is no, go to S205, search for PSS signals and SSS signals based on different frequency bands, determine the target LEO base station, and complete synchronization and residency based on the target LEO base station.

[0067] In some embodiments of the present application, the UE side neighbor list refers to a set of LEO base stations that have covered the UE and are stored on the UE side, and the prior information may refer to base station signal characteristics such as frequency, frequency offset, LEO base station ID, synchronization time, delay, reference signal strength, etc. of different LEO base stations measured by the UE and stored in the UE, which are not limited here. In addition, the UE may include prior information of one or more LEO base stations.

[0068] S202: Search for the PSS signal and SSS signal sent by the target LEO base station according to the prior information, and complete synchronization and residency based on the target LEO base station.

[0069] In some embodiments of the present application, after determining that the UE includes prior information, a LEO base station in the prior information can be used as the target LEO base station, and a search can be performed based on the prior information corresponding to the target LEO base station, so that the PSS signal and SSS signal sent by the target LEO base station can be quickly searched. Furthermore, the UE can perform time synchronization and frequency synchronization with the target LEO base station based on the PSS signal. If the PBCH is decoded based on the scanning results of the PSS signal and the SSS signal and the CRC check is successful, it can be determined that the target LEO base station has been successfully searched. In addition, the current base station signal characteristics of the target LEO base station are measured and updated as the prior information of the target LEO base station on the UE side. The UE can choose to reside in the target LEO base station based on the search for the target LEO base station.

[0070] For example, the prior information included in the UE includes: the prior information of the first LEO base station and the prior information of the second LEO base station, etc. Among them, the prior information of the first LEO base station may include the first LEO base station ID, frequency deviation, synchronization time, delay, reference signal strength, etc.; the prior information of the second LEO base station may include the second LEO base station ID, frequency, frequency deviation, synchronization time, delay, reference signal strength, etc., which are not limited here.

[0071] Similarly, in other embodiments of the present application, referring to the above-mentioned process of UE searching for the first LEO base station, the UE can also use the second LEO base station as the target LEO base station and search and reside in the second LEO base station based on the prior information of the second LEO base station, which is not limited here.

[0072] In addition, the UE can also search for the first LEO base station and the second LEO base station respectively through the prior information of the first LEO base station and the prior information of the second LEO base station, and obtain the reference signal strength of the current first LEO base station and the reference signal strength of the second LEO base station respectively. Furthermore, the UE can compare the currently obtained reference signal strength of the first LEO base station with the reference signal strength of the second LEO base station, and synchronize and reside on the LEO base station with a greater reference signal strength as the target LEO base station. For example, if the reference signal strength of the first LEO base station is greater than the reference signal strength of the second LEO base station, the UE synchronizes based on the PSS signal and SSS signal sent by the first LEO base station and chooses to reside on the first LEO base station, which is not limited here.

[0073] It can be understood that if the UE fails to search for the PSS and SSS signals corresponding to the target LEO base station based on the prior information of the target LEO base station, or the UE searches for the target LEO base station based on the prior information of the target LEO base station and finds that the reference signal strength of the target LEO base station is lower than the signal strength threshold, it can be understood that the UE is no longer within the coverage of the target LEO base station, and the prior information corresponding to the target LEO base station may be temporarily not displayed in the UE-side neighboring area list.

[0074] It can be understood that after the UE determines that the first LEO base station has been searched, the synchronization and residence process is explained by taking the UE synchronizing and residing based on the PSS signal and SSS signal sent by the first LEO base station as an example. Exemplarily, the PSS signal can be used to assist the UE in determining the start of a new frame (radio frame). In the LTE FDD duplex mode and normal cp mode, each new frame may include 10 subframes, each subframe may include two time slots, and the PSS signal may be transmitted in the last orthogonal frequency division multiplexing (OFDM) symbol of the 0th time slot of the 0th subframe of each new frame, or the PSS signal may also be transmitted in the last OFDM symbol of the 0th time slot of the 5th subframe of each new frame. It can be understood that a radio frame is a basic time unit for transmitting data. The SSS signal is used to further refine the time synchronization of the UE. The SSS signal can be transmitted before the PSS signal, and the SSS signal can be transmitted in the second-to-last OFDM symbol of the 0th time slot of the 0th subframe of each new frame, or the SSS signal can also be transmitted in the second-to-last OFDM symbol of the 0th time slot of the 5th subframe of each new frame. Based on this, the process of time synchronization between the UE and the first LEO base station may include: assuming that the UE is ready to receive the PSS signal at time t0, and the time when the first LEO base station sends the PSS signal is time t1, the UE needs to adjust the time point when it receives the PSS signal to time t1. Further, assuming that the UE is preparing to receive the SSS signal at time t2, and the time when the first LEO actually sends the SSS signal is time t3, the UE needs to adjust the time point when it receives the SSS signal to time t3. It can be understood that the above-mentioned time t3 of sending the SSS signal can be earlier than the time t2 of sending the PSS signal, which is not limited here.

[0075] It can be understood that in LTE, two duplex modes, FDD and TDD, can be included to define how the LTE network implements uplink and downlink communications in spectrum and time. In addition, in LTE, two technologies, normal cyclic prefix (normal cp) and extended cyclic prefix (extended cp), can be included to reduce the inter-symbol interference caused by multipath effects to improve the performance and reliability of the system. When normal cp is used, each time slot can include 7 OFDM symbols, and when extended cp is used, each time slot can include 6 OFDM symbols.

[0076] It can be understood that when sending PSS signals and SSS signals, the LEO base station can select the LTE mode based on FDD duplex mode and normal cp, or the LTE mode based on FDD duplex mode and extended cp, or the LTE mode based on TDD duplex mode and normal cp, or the LTE mode based on TDD duplex mode and extended cp, and there is no limitation here.

[0077] It can be understood that the above-mentioned frame structure corresponding to the LTE system is used as an example to illustrate the process of time synchronization between the UE and the LEO base station through the corresponding PSS signal and SSS signal, which is only an exemplary description. In other embodiments, such as in communication systems such as NR, based on the frame structure of NR, the UE can also perform time synchronization with the LEO base station through the corresponding PSS signal and SSS signal, and in communication systems such as NR, when the LEO base station sends the corresponding PSS signal and SSS signal, the position of the PSS signal and the SSS signal in the wireless frame may be different from that in LTE, which is not limited here.

[0078] Further, the process of frequency synchronization between the UE and the first LEO base station is: obtaining the frequency deviation between the first LEO base station and the UE. For example, the frequency of the first LEO base station sending the signal is f1, and the frequency of the UE receiving the signal is f2, then the frequency deviation is , then the UE uses the frequency offset Adjust its receiving frequency. Secondly, the process of UE camping on the first LEO base station includes: after the UE completes time and frequency synchronization with the first LEO base station, the UE sends a random access request (RAR) to the first LEO base station, and the first LEO base station responds with a random access response (RAS). After the random access is successful, the UE and the first LEO base station will establish a radio resource control (RRC) connection. After the RRC connection is established, the UE successfully camps on the LEO base station, and the UE can start sending and receiving data.

[0079] It can be understood that the synchronization and residence of the UE with the first LEO base station in the above S202 is only an exemplary description. In other embodiments, the UE may also synchronize and reside with the second LEO base station, etc., which is not limited here.

[0080] S203: Receive the neighboring cell list broadcasted by the target LEO base station.

[0081] In some embodiments of the present application, when the UE establishes communication with the first LEO base station as the target LEO base station, the UE may obtain the neighboring cell list broadcast by the first LEO base station, and the neighboring cell list broadcast by the first LEO base station may include other neighboring LEO base stations that can cover the UE, such as neighboring cell base station IDs, frequencies, frequency offsets, synchronization times, delays, reference signal strengths, etc. of different neighboring LEO base stations. In addition, the UE may remeasure the base station signal characteristics between the UE and the first LEO base station, such as the frequency offset, synchronization time, delay, reference signal strength, etc. of the first LEO base station.

[0082] S204: Based on the neighbor cell list broadcast by the target LEO base station, update the neighbor cell list on the UE side.

[0083] In some embodiments of the present application, the UE may update the neighbor list on the UE side according to the neighbor list broadcasted by the target LEO base station, that is, update the base station signal characteristics of the LEO base station in the neighbor list on the UE side according to the base station signal characteristics of the LEO base station in the broadcast neighbor list.

[0084] For example, Figure 3 FIG. 1 shows a schematic diagram of a UE side neighboring cell list 00 before updating and a UE side neighboring cell list 01 after updating. Figure 3As shown, the UE side neighbor list 00 is the base station signal characteristics of the LEO base stations that can cover the UE and have been stored before the UE resides on the target LEO base station. It can be understood that the base station signal characteristics of each LEO base station in the UE side neighbor list 00 is also a kind of prior information. For example, suppose that the UE side neighbor list 00 includes the base station signal characteristics of the first LEO base station and the base station signal characteristics of the second LEO base station, where the base station signal characteristics of the first LEO base station include: ID1, f1, , t1, P1; the base station signal characteristics of the second LEO base station include: ID2, f2, , t2, P2.

[0085] When the UE camps on the first LEO base station and receives the broadcast neighbor list, the UE can obtain the base station signal characteristics of the LEO base station broadcast by the first LEO base station. For example, the neighbor list broadcast by the first LEO base station includes the base station signal characteristics of the first LEO base station, the second LEO base station and the third LEO base station.

[0086] Corresponding to the communication between the UE and the first LEO base station, the UE can re-measure and update the frequency offset, synchronization time, reference signal strength, etc. of the first LEO base station in the UE side neighbor list. Figure 3 In the updated UE side neighboring cell list 01 shown in , the frequency offset of the first LEO base station is updated to , the synchronization time is updated to t1.2, and the reference signal strength is updated to P1.2.

[0087] The neighboring cell list corresponding to the broadcast includes the second LEO base station, and the second LEO base station stores the verification information corresponding to the second LEO base station in the neighboring cell list 00 on the UE side. The UE receives the ID2, f2, and , t2, P2 search for the PSS signal and SSS signal corresponding to the second LEO base station, and after successfully searching for the second LEO base station, obtain the frequency offset, synchronization time, reference signal strength, etc. between the current UE and the second LEO base station, and update it to the UE side neighbor list as the latest prior information of the second LEO base station. Figure 3 In the updated UE side neighboring cell list 01 shown in , the frequency offset of the second LEO base station is updated to , the synchronization time is still t2, and the reference signal strength is still P2.

[0088] The neighbor list corresponding to the broadcast includes a third LEO base station, and the third LEO base station does not have the prior information corresponding to the third LEO base station in the neighbor list 00 on the UE side, then the UE can search for the PSS signal and SSS signal of the third LEO base station based on the frequency point and ID of the third LEO base station in the neighbor list of the broadcast to obtain the frequency deviation, synchronization time, reference signal strength, etc. of the third LEO base station. For example Figure 3 In the updated UE side neighboring cell list 01 shown in FIG, the ID of the third LEO base station is added: ID3, frequency point f3, frequency offset , synchronization time t3, reference signal strength P3.

[0089] Based on this, the UE side neighbor list is updated from the UE side neighbor list 00 to the UE side neighbor list 01, that is, the prior information on the UE side is updated from the base station signal characteristics in the UE side neighbor list 00 to the base station signal characteristics in the UE side neighbor list 01. In addition, the base station signal characteristics of the LEO base station in the UE side neighbor list 01 can be used as prior information to assist the UE in quickly searching for the PSS signal and SSS signal sent by the corresponding LEO base station when the UE searches for the corresponding LEO base station next time, thereby improving the speed of searching for the corresponding LEO base station.

[0090] It can be understood that the above-mentioned first LEO base station is used as the target LEO base station, and the second LEO base station and the third LEO base station are used as neighboring LEO base stations covering the UE, which is only an exemplary description. In other embodiments, other LEO base stations can also be used as target LEO base stations, and there can also be more neighboring LEO base stations covering the UE, which is not limited here.

[0091] It can be understood that in other embodiments, the neighboring cell list of the UE broadcast by the target LEO base station does not include all neighboring LEO base stations that can cover the UE. Based on this, after the UE completes the search for the neighboring LEO base station in the broadcasted neighboring cell list, the UE can also perform a blind search for PSS signals and SSS signals on other possible frequency points, and add the ID, frequency point, frequency deviation, synchronization point position, and reference signal strength of the corresponding searched neighboring LEO base station to the neighboring cell list on the UE side, so as to enrich the prior information corresponding to the LEO base station covering the UE stored in the neighboring cell list on the UE side.

[0092] S205: Search for PSS signals and SSS signals based on different frequency bands, determine a target LEO base station, and complete synchronization and residency based on the target LEO base station.

[0093] In some embodiments of the present application, when the UE side neighbor list does not include the prior information of the relevant LEO base station, when searching for the LEO base station, the UE can search for the PSS signal and SSS signal sent by the LEO base station based on the possible frequency bands that the current UE supports searching. When searching for at least one LEO base station ID and the reference signal strength of the corresponding LEO base station, the LEO base station with the largest reference signal strength is used as the target LEO base station, and then the UE can synchronize with the target LEO base station and reside in the target LEO base station.

[0094] S206: Receive the neighboring cell list broadcasted by the target LEO base station.

[0095] In some embodiments of the present application, assuming that the target LEO base station determined by S205 is the first LEO base station, S206 may refer to the description of S203 above, which will not be described in detail herein.

[0096] It can be understood that in other embodiments, the target LEO base station may also be other LEO base stations covering the UE, which is not limited here.

[0097] S207: Based on the neighbor cell list broadcast by the target LEO base station, update the neighbor cell list on the UE side.

[0098] In some embodiments of the present application, by receiving the neighboring cell list broadcast by the target LEO base station, the UE can obtain the base station signal characteristics of the target LEO base station, and can also obtain the frequency and ID of the neighboring LEO base station. Further, the UE can search for the PSS signal and SSS signal sent by the neighboring LEO base station according to the frequency and ID of the neighboring LEO base station, and after searching for the corresponding neighboring LEO base station, measure and store the neighboring LEO base station ID, frequency, frequency deviation between the UE and the neighboring LEO base station, synchronization time, delay, reference signal strength and other characteristics.

[0099] Based on this, the UE stores the base station signal characteristics of the target LEO base station and the base station signal characteristics of the neighboring LEO base station in the UE-side neighboring cell list. The base station signal characteristics of the LEO base station in the UE-side neighboring cell list can be used as prior information to assist the UE in searching for the synchronization signal sent by the corresponding LEO base station the next time the UE searches for the corresponding LEO base station, thereby improving the speed of searching for the LEO base station and reducing the UE's search power consumption.

[0100] Through the above method, when the UE searches for a LEO base station covering the UE, it can preferentially search for the corresponding LEO base station based on the base station signal characteristics of the LEO base station in the neighboring cell list on the UE side (as prior information) quickly. In addition, since the LEO base station is continuously running, each time the UE re-searches the corresponding LEO base station, it re-measures the frequency offset, synchronization time, delay, reference signal strength, etc. between the UE and the corresponding LEO base station, that is, updates the prior information of the corresponding LEO base station on the UE side to improve the speed of the next search for the LEO base station.

[0101] Figure 4 According to an embodiment of the present application, a specific flow chart of a UE updating a UE-side neighboring cell list is shown.

[0102] Figure 4 The execution entities of each process in the illustrated process may be electronic devices such as mobile phones, tablet computers, smart wearable devices, smart home devices, and vehicle-mounted devices, and are not limited here.

[0103] Specifically, Figure 4 The process shown may include the following steps:

[0104] S401: Receive a neighboring cell list broadcasted by a target LEO base station.

[0105] In some embodiments of the present application, when the UE establishes communication with the target LEO base station, for example, the target LEO base station may be the first LEO base station, the UE establishes communication with the first LEO base station, and the UE receives the neighbor list broadcasted by the first LEO base station.

[0106] S402: Determine whether the broadcast neighbor cell list includes a newly added neighbor LEO base station that is not included in the neighbor cell list on the UE side.

[0107] If the judgment result is yes, go to S403, search according to the frequency and ID of the newly added neighboring LEO base station, and add the entry information corresponding to the newly added neighboring LEO base station to the neighboring cell list on the UE side;

[0108] If the judgment result is no, go to S407 and re-measure the base station signal characteristics of the corresponding neighboring LEO base station based on the base station signal characteristics of the neighboring LEO base station in the neighboring cell list on the UE side.

[0109] In some embodiments of the present application, the neighbor LEO base station ID included in the neighbor list broadcast by the first LEO base station (target LEO base station) can be compared with the neighbor LEO base station ID included in the neighbor list on the UE side to determine whether the broadcast neighbor list includes a newly added neighbor LEO base station that is not included in the neighbor list on the UE side.

[0110] S403: Search according to the frequency and ID of the newly added neighboring LEO base station, and add entry information corresponding to the newly added neighboring LEO base station to the neighboring cell list on the UE side.

[0111] In some embodiments of the present application, it is determined that the broadcast neighbor cell list includes a newly added neighbor cell LEO base station that is not included in the UE side neighbor cell list. The UE can search according to the frequency and ID of the newly added neighbor cell LEO base station, and add the entry information corresponding to the newly added neighbor cell LEO base station to the UE side neighbor cell list.

[0112] For example, it is assumed that the neighbor list broadcast by the first LEO base station obtained based on the above S401 includes the first LEO base station ID, the second LEO base station ID, the third LEO base station ID, etc. The neighbor list on the UE side includes the first LEO base station ID and the second LEO base station ID. Further, by comparison, it can be determined that the neighbor list broadcast by the first LEO base station includes a newly added third LEO base station that is not included in the neighbor list on the UE side, then the ID, frequency and other entry information of the third LEO base station can be added to the neighbor list on the UE side.

[0113] S404: Determine whether a newly added neighboring LEO base station is found.

[0114] If the judgment result is yes, go to S405 and record the base station signal characteristics of the newly added neighboring LEO base station in the neighboring cell list on the UE side;

[0115] If the judgment result is no, go to S406 and delete the entry information corresponding to the newly added neighboring LEO base station in the neighboring cell list on the UE side.

[0116] S405: Record the base station signal characteristics of the newly added neighboring LEO base station in the neighboring cell list on the UE side.

[0117] In some embodiments of the present application, when searching for the PSS signal and SSS signal sent by the third LEO base station through the frequency point and ID of the newly added third LEO base station, and successfully searching for the third LEO base station, the UE can measure the base station signal characteristics such as the frequency deviation, synchronization time, delay, and reference signal strength of the third LEO base station, and store the ID, frequency point, and base station signal characteristics such as the frequency deviation, synchronization time, delay, and reference signal strength of the third LEO base station in the UE side neighboring area list, and it can be used as prior information when the UE searches for the third LEO base station next time.

[0118] S406: Delete the entry information corresponding to the newly added neighboring LEO base station in the neighboring cell list on the UE side.

[0119] In some embodiments of the present application, if the PSS signal and SSS signal sent by the third LEO base station are not searched based on the frequency and ID of the third LEO base station, that is, the UE does not search for the third LEO base station, the UE can delete the entry information corresponding to the third LEO base station added in S403, that is, delete the frequency, ID and other entry information of the third LEO base station in the UE side neighboring area list.

[0120] S407: Re-measure the base station signal characteristics of the corresponding neighboring LEO base station based on the base station signal characteristics of the neighboring LEO base station in the neighboring cell list on the UE side.

[0121] In some embodiments of the present application, it is determined that the neighboring LEO base stations included in the neighboring cell list broadcast by the first LEO base station (target LEO base station) are all included in the neighboring cell list on the UE side, and the UE can re-measure the base station signal characteristics of the corresponding neighboring LEO base station according to the base station signal characteristics of the neighboring LEO base station in the UE side neighboring cell list.

[0122] For example, assuming that the neighbor list broadcast by the first LEO base station (target LEO base station) includes the first neighbor LEO base station and the second LEO base station, it is determined that the LEO base stations currently covering the UE include the first LEO base station and the second LEO base station, and the UE-side neighbor list also includes the first LEO base station and the second LEO base station, then the UE can quickly search for the first LEO base station and the second LEO base station based on the prior information in the UE-side neighbor list, that is, the base station signal characteristics of the first LEO base station and the second LEO base station in the UE-side neighbor list, and re-measure the base station signal characteristics of the first LEO base station and the second LEO base station, and update them to the UE-side neighbor list as the latest prior information of the first LEO base station and the second LEO base station.

[0123] S408: Determine whether the corresponding neighboring LEO base station is found.

[0124] If the judgment result is yes, go to S409 and update the base station signal characteristics of the corresponding neighboring LEO base station in the neighboring cell list on the UE side;

[0125] If the judgment result is no, go to S410, calculate the revolution period of the LEO base station, and call the base station signal characteristics of the corresponding LEO base station in the UE side neighboring cell list again in the next revolution period to search for the corresponding LEO base station.

[0126] In some embodiments of the present application, when the UE searches for the corresponding LEO base station based on the base station signal characteristics of the LEO base station stored in the UE side neighboring cell list, it is necessary to determine whether the corresponding LEO base station can be successfully searched. It can be understood that successfully searching for the LEO base station means that the UE can search for the synchronization signal (PSS signal and SSS signal) sent by the corresponding LEO base station based on the base station signal characteristics (prior information) of the LEO base station stored in the UE side neighboring cell list, and decode the corresponding PBCH according to the scanning result of the synchronization signal and the CRC check is successful.

[0127] It can be understood that the base station signal characteristics of the LEO base station in the UE-side neighboring cell list are also the prior information of the LEO base station.

[0128] S409: Update the latest base station signal characteristics of the corresponding neighboring LEO base station in the neighboring cell list on the UE side.

[0129] In some embodiments of the present application, when the corresponding LEO base station can be searched based on the base station signal characteristics of the LEO base station in the UE-side neighboring area list, for example, when the second LEO base station is searched based on the frequency point, frequency deviation, ID, synchronization time, delay, etc. of the second LEO base station in the UE-side neighboring area list, the UE can re-acquire the frequency deviation, synchronization time, delay, reference signal strength, etc. of the current UE and the second LEO base station, and update the base station signal characteristics of the second LEO base station in the UE-side neighboring area list to the re-acquired frequency deviation, synchronization time, delay, reference signal strength, etc. of the UE and the second LEO base station, that is, update the latest base station signal characteristics of the second LEO base station in the UE-side neighboring area list as the prior information of the second LEO base station.

[0130] S410: Calculate the revolution period of the LEO base station, and call the base station signal characteristics of the corresponding LEO base station in the neighboring base station on the UE side to search for the corresponding LEO base station in the next revolution period.

[0131] In some embodiments of the present application, when the corresponding LEO base station is not searched based on the base station signal characteristics of the LEO base station in the UE-side neighboring cell list, for example, when the second LEO base station is not searched based on the frequency point, frequency deviation, ID, synchronization time, delay, reference signal strength, etc. of the second LEO base station in the UE-side neighboring cell list, the UE can re-search for the second LEO base station based on the base station signal characteristics of the second LEO base station in the UE-side neighboring cell list at the corresponding moment of the next revolution period based on the revolution period of the LEO base station.

[0132] It can be understood that the revolution period of different LEO base stations can be calculated based on their altitude relative to the earth and the universal Kepler's third law. For example, the revolution period of the second LEO base station is 1.61h. Assuming that the UE does not search for the second LEO base station when searching for the second LEO base station at time t_x of the current revolution period, the UE can call the base station signal feature of the second LEO base station in the neighboring base station on the UE side at time (t_x+1.61h) to search for the second LEO base station.

[0133] based on Figure 4 In the process shown, when the target LEO base station where the UE resides periodically broadcasts a neighbor list to the UE, the UE can compare the LEO base stations in the broadcast neighbor list with the neighbor list on the UE side. If there is a neighbor LEO base station in the broadcast neighbor list that is not included in the neighbor list on the UE side, it can be said that there is a newly added LEO base station covering the UE. The UE can search based on the newly added LEO base station ID and frequency point, and measure the base station signal characteristics of the newly added LEO base station after successfully searching for the LEO base station, and store it in the neighbor list on the UE side as a priori information for the next search for the newly added LEO base station, so that the UE can search for the newly added LEO base station based on the stored base station of the newly added LEO base station next time, thereby improving the search speed and reducing the search power consumption of the UE.

[0134] In addition, for LEO base stations that store base station signal characteristics (prior information) in the UE side neighboring cell list, each time the UE periodically searches for LEO base stations, it can quickly search for the corresponding LEO base stations based on the prior information of these LEO base stations, and obtain the latest base station signal characteristics of these LEO base stations, and use the latest base station signal characteristics of these LEO base stations as the prior information for the next search for these LEO base stations. Based on this, each time the UE periodically searches for LEO base stations, it can quickly search for the corresponding LEO base stations based on the prior information stored in the UE side neighboring cell list.

[0135] Figure 5 According to an embodiment of the present application, a schematic structural diagram of a terminal device 100 is shown.

[0136] In the embodiment of the present application, the terminal device 100 may be the above Figure 1 The electronic devices such as the mobile phone 10 in the illustrated scene are not limited here.

[0137] like Figure 5As shown, the terminal device 100 may include a processor 110, an external memory interface 120, an internal memory 121, a universal serial bus (USB) interface 130, a charging management module 140, a power management module 141, a battery 142, an antenna 1, an antenna 2, a mobile communication module 150, a wireless communication module 160, an audio module 170, a speaker 170A, a receiver 170B, a microphone 170C, an earphone interface 170D, a sensor module 180, a button 190, a motor 191, an indicator 192, a camera 193, a display screen 194, and a subscriber identification module (SIM) card interface 195, a communication device 196, etc. The sensor module 180 may include a pressure sensor 180A, a gyroscope sensor 180B, an air pressure sensor 180C, a magnetic sensor 180D, an acceleration sensor 180E, a distance sensor 180F, a proximity light sensor 180G, a fingerprint sensor 180H, a temperature sensor 180J, a touch sensor 180K, an ambient light sensor 180L, a bone conduction sensor 180M, etc. Among them:

[0138] The processor 110 may include one or more processing units, for example, the processor 110 may include an application processor (AP), a modem processor, a graphics processor (GPU), an image signal processor (ISP), a controller, a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural-network processing unit (NPU), etc. Different processing units may be independent devices or integrated into one or more processors.

[0139] The controller can generate operation control signals according to the instruction operation code and timing signal to complete the control of instruction fetching and execution.

[0140] The processor 110 may also be provided with a memory for storing instructions and data.

[0141] The USB interface 130 is an interface that complies with the USB standard specification, and specifically can be a Mini USB interface, a Micro USB interface, a USB Type C interface, etc. The USB interface 130 can be used to connect a charger to charge the terminal device 100, and can also be used to send data between the terminal device 100 and a peripheral device. It can also be used to connect headphones to play audio through the headphones. The interface can also be used to connect other electronic devices, such as AR devices, etc.

[0142] The charging management module 140 is used to receive charging input from a charger. While the charging management module 140 is charging the battery 142 , it can also power the electronic device through the power management module 141 .

[0143] The power management module 141 is used to connect the battery 142, the charging management module 140 and the processor 110. The power management module 141 receives input from the battery 142 and / or the charging management module 140 to power the processor 110, the internal memory 121, the display screen 194, the camera 193, and the wireless communication module 160.

[0144] The wireless communication function of the terminal device 100 can be implemented through antenna 1, antenna 2, mobile communication module 150, wireless communication module 160, modem processor and baseband processor, etc. Antenna 1 and antenna 2 can be used to send and receive electromagnetic wave signals, that is, wireless carrier information.

[0145] The mobile communication module 150 can provide solutions for wireless communications including 2G / 3G / 4G / 5G / 6G applied to the terminal device 100. The mobile communication module 150 may include at least one filter, a switch, a power amplifier, a low noise amplifier (LNA), etc. The mobile communication module 150 can receive electromagnetic waves from the antenna 1, and filter, amplify, and process the received electromagnetic waves, and transmit them to the modulation and demodulation processor for demodulation. The mobile communication module 150 can also amplify the signal modulated by the modulation and demodulation processor, and convert it into electromagnetic waves for radiation through the antenna 1.

[0146] The wireless communication module 160 can provide wireless communication solutions including wireless local area networks (WLAN) (such as wireless fidelity (Wi-Fi) networks), Bluetooth (BT), global navigation satellite system (GNSS), frequency modulation (FM), near field communication (NFC), infrared (IR) and ultra wide band (UWB) for application on the mobile phone 10. The wireless communication module 160 can be one or more devices integrating at least one communication processing module. The wireless communication module 160 can receive electromagnetic waves from the antenna 2, and filter, amplify and process the received electromagnetic waves, and transmit them to the modulation and demodulation processor for demodulation. The wireless communication module 160 can also amplify the signal modulated by the modulation and demodulation processor, and convert it into electromagnetic waves for radiation through the antenna 2.

[0147] The terminal device 100 implements the display function through a GPU, a display screen 194, and an application processor. The GPU is a microprocessor for image processing, which connects the display screen 194 and the application processor. The GPU is used to perform mathematical and geometric calculations for graphics rendering. The processor 110 may include one or more GPUs, which execute program instructions to generate or change display information.

[0148] The display screen 194 is used to display images, videos, etc. The display screen 194 includes a display panel. The display panel can be a liquid crystal display (LCD), an organic light-emitting diode (OLED), an active-matrix organic light-emitting diode or an active-matrix organic light-emitting diode (AMOLED), a flexible light-emitting diode (FLED), Mini-LED, micro-LED, Micro-OLED, quantum dot light-emitting diodes (QLED), etc.

[0149] Camera 193 is used to capture still images or videos. The object generates an optical image through the lens and projects it onto the photosensitive element. The photosensitive element can be a charge coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) phototransistor. The photosensitive element converts the light signal into an electrical signal, and then transmits the electrical signal to the ISP for conversion into a digital image signal. The ISP outputs the digital image signal to the DSP for processing. The DSP converts the digital image signal into an image signal in a standard RGB, YUV or other format.

[0150] The external memory interface 120 can be used to connect an external memory card, such as a Micro SD card, to expand the storage capacity of the terminal device 100. The external memory card communicates with the processor 110 through the external memory interface 120 to implement a data storage function, such as storing music, video and other files in the external memory card.

[0151] The internal memory 121 can be used to store computer executable program codes, and the executable program codes include instructions, such as the aforementioned memory 103. The internal memory 121 may include a program storage area and a data storage area. Among them, the program storage area may store an operating system, an application required for at least one function, etc. The data storage area may store data created during the use of the terminal device 100, etc., for example, it may be used to store a control identifier of a security control, a screenshot redrawing strategy identifier corresponding to the security control, and a pattern, image, text, etc. corresponding to the screenshot redrawing strategy. In addition, the internal memory 121 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, a universal flash storage (UFS), etc. The processor 110 executes various functional applications of the terminal device 100 by running instructions stored in the internal memory 121 and / or instructions stored in a memory provided in the processor 110. In some embodiments of the present application, the memory of the mobile phone 10 may store a UE side neighbor list, that is, base station signal characteristics such as frequency, frequency deviation, ID, synchronization time, delay, and reference signal strength of the LEO base station covering the UE.

[0152] The terminal device 100 can implement audio functions through the audio module 170, the speaker 170A, the receiver 170B, the microphone 170C, the headphone interface 170D, and the application processor.

[0153] The acceleration sensor 180E can detect the magnitude of the acceleration of the terminal device 100 in various directions (generally three axes). When the terminal device 100 is stationary, the magnitude and direction of gravity can be detected. It can also be used to identify the posture of the terminal device 100.

[0154] The touch sensor 180K is also called a "touch control device". The touch sensor 180K can be set on the display screen 194. The touch sensor 180K and the display screen 194 form a touch screen, also called a "touch control screen". The touch sensor 180K is used to detect a touch operation acting on or near it. The touch sensor can pass the detected touch operation to the application processor to determine the type of touch event. Visual output related to the touch operation can be provided through the display screen 194.

[0155] Motor 191 can generate vibration prompts.

[0156] Indicator 192 may be an indicator light, which may be used to indicate charging status, power changes, messages, missed calls, notifications, etc.

[0157] The SIM card interface 195 is used to connect a SIM card.

[0158] It is understood that the structure of the terminal device 100 shown in the embodiment of the present application does not constitute a specific limitation on the terminal device 100. In other embodiments of the present application, the terminal device 100 may include more or fewer components than shown in the figure, or combine certain components, or split certain components, or arrange the components differently. The components shown in the figure may be implemented in hardware, software, or a combination of software and hardware.

[0159] The various embodiments of the mechanism disclosed in the present application can be implemented in hardware, software, firmware or a combination of these implementation methods. The embodiments of the present application can be implemented as a computer program or program code executed on a programmable system, which includes at least one processor, a storage system (including volatile and non-volatile memory and / or storage elements), at least one input device and at least one output device.

[0160] Program code may be applied to input instructions to perform the functions described herein and generate output information. The output information may be applied to one or more output devices in a known manner. For purposes of this application, a processing system includes any system having a processor such as, for example, a digital signal processor (DSP), a microcontroller, an application specific integrated circuit (ASIC), or a microprocessor.

[0161] Program code can be implemented with high-level programming language or object-oriented programming language to communicate with the processing system. When necessary, program code can also be implemented with assembly language or machine language. In fact, the mechanism described in this application is not limited to the scope of any specific programming language. In either case, the language can be a compiled language or an interpreted language.

[0162] In some cases, the disclosed embodiments may be implemented in hardware, firmware, software, or any combination thereof. The disclosed embodiments may also be implemented as instructions carried or stored on one or more temporary or non-temporary machine-readable (e.g., computer-readable) storage media, which may be read and executed by one or more processors. For example, the instructions may be distributed over a network or through other computer-readable media. Therefore, a machine-readable medium may include any mechanism for storing or transmitting information in a machine (e.g., computer) readable form, including but not limited to floppy disks, optical disks, optical disks, compact disc read-only memories (CD-ROMs), magneto-optical disks, read-only memories (ROMs), random access memories (RAMs), erasable programmable read-only memories (EPROMs), electrically erasable programmable read-only memories (EEPROMs), magnetic or optical cards, flash memory, or a tangible machine-readable memory for transmitting information (e.g., carrier waves, infrared signals, digital signals, etc.) using the Internet in electrical, optical, acoustic, or other forms of propagation signals. Accordingly, machine-readable media include any type of machine-readable media suitable for storing or transmitting electronic instructions or information in a form readable by a machine (eg, a computer).

[0163] In the accompanying drawings, some structural or method features may be shown in a specific arrangement and / or order. However, it should be understood that such a specific arrangement and / or order may not be required. Instead, in some embodiments, these features may be arranged in a manner and / or order different from that shown in the illustrative drawings. In addition, the inclusion of structural or method features in a particular figure does not mean that such features are required in all embodiments, and in some embodiments, these features may not be included or may be combined with other features.

[0164] It should be noted that the units / modules mentioned in the various device embodiments of the present application are all logical units / modules. Physically, a logical unit / module can be a physical unit / module, or a part of a physical unit / module, or can be implemented as a combination of multiple physical units / modules. The physical implementation method of these logical units / modules themselves is not the most important. The combination of functions implemented by these logical units / modules is the key to solving the technical problems proposed by the present application. In addition, in order to highlight the innovative part of the present application, the above-mentioned device embodiments of the present application do not introduce units / modules that are not closely related to solving the technical problems proposed by the present application, which does not mean that there are no other units / modules in the above-mentioned device embodiments.

[0165] It should be noted that in the examples and description of this patent, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the term "includes" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "includes one" do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0166] Although the present application has been illustrated and described with reference to certain preferred embodiments thereof, it will be apparent to those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present application.

Claims

1. A communication method, characterized in that: Applied to a terminal device, the method comprises: Establishing a communication connection with a first LEO base station; Acquire and store base station signal characteristics sent by the first LEO base station, the base station signal characteristics including first base station signal characteristics corresponding to the first LEO base station, wherein the first base station signal characteristics include the frequency of the first LEO base station and the base station identifier of the first LEO base station, as well as the frequency deviation, synchronization time, delay, and reference signal strength of the first LEO base station; detecting that the communication connection with the first LEO base station is disconnected, and performing a LEO base station search based on a signal characteristic of the first base station; In response to searching for a synchronization signal sent by a first LEO base station, re-establishing a communication connection with the first LEO base station; Determining that the base station signal characteristics sent by the first LEO base station include a base station identifier of a second LEO base station; Corresponding to the second base station signal feature of the second LEO base station being stored in the terminal device, searching for the second LEO base station by using the second base station signal feature; The signal characteristics of the second base station include the base station identifier, frequency, frequency offset, synchronization time, delay, and reference signal strength of the second LEO base station; In response to searching for the synchronization signal sent by the second LEO base station, the second base station signal characteristic of the second LEO base station is remeasured to obtain the third base station signal characteristic corresponding to the second LEO base station.

2. The method according to claim 1, characterized in that The step of re-measuring the second base station signal characteristic of the second LEO base station in response to searching for the synchronization signal sent by the second LEO base station to obtain the third base station signal characteristic corresponding to the second LEO base station includes: The third base station signal characteristic corresponding to the second LEO base station is stored, and the second base station signal characteristic of the second LEO base station stored in the terminal device is updated to the third base station signal characteristic.

3. The method according to claim 1, characterized in that The method further comprises: Determining that the base station signal characteristics sent by the first LEO base station include a base station identifier of a third LEO base station; Corresponding to the fact that the base station signal characteristics corresponding to the third LEO base station are not stored in the terminal device, searching for the third LEO base station through the base station identifier and frequency of the third LEO base station included in the base station signal characteristics sent by the first LEO base station; In response to searching for a synchronization signal sent by the third LEO base station, measuring a base station signal characteristic of the third LEO base station, obtaining a fourth base station signal characteristic corresponding to the third LEO base station, and storing the fourth base station signal characteristic corresponding to the third LEO base station; Among them, the fourth base station signal characteristics corresponding to the third LEO base station include the base station identifier, frequency, frequency deviation, synchronization time, delay, and reference signal strength of the third LEO base station.

4. The method according to claim 1, characterized in that: The searching for the synchronization signal of the first LEO base station based on the signal characteristic of the first base station and re-establishing a communication connection with the first LEO base station includes: Based on the frequency point and frequency offset of the first LEO base station, determine the search frequency of the terminal device searching for the first LEO base station and based on the synchronization time and delay of the first LEO base station, determine the search time of the terminal device searching for the first LEO base station; Searching for a synchronization signal corresponding to the first LEO base station using the search frequency at the search time; When the synchronization signal corresponding to the first LEO base station is searched for at the second moment, a communication connection is re-established with the first LEO base station.

5. The method according to claim 4, characterized in that After re-establishing the communication connection with the first LEO base station, the method further includes: Re-measuring a base station signal characteristic of the first LEO base station to obtain a fifth base station signal characteristic corresponding to the first LEO base station; The fifth base station signal characteristic corresponding to the first LEO base station is stored, and the first base station signal characteristic of the first LEO base station stored in the terminal device is updated to the fifth base station signal characteristic corresponding to the first LEO base station.

6. The method according to claim 1, characterized in that The detecting that the communication connection with the first LEO base station is disconnected includes: Determine whether the reference signal strength of the first LEO base station is less than a reference signal strength threshold; Corresponding to the reference signal strength of the first LEO base station being less than the reference signal strength threshold, it is determined that the communication connection with the first LEO base station is disconnected.

7. The method according to claim 6, characterized in that The detecting that the communication connection with the first LEO base station is disconnected also includes: Determining whether a first LEO base station can be searched through the first base station signal characteristics; Corresponding to the failure to search for the synchronization signal corresponding to the first LEO base station through the signal characteristics of the first base station, it is determined that the communication connection with the first LEO base station is disconnected.

8. The method according to claim 7, characterized in that After the first LEO base station is not found by searching the first base station signal feature, the method further includes: The revolution period of the first LEO base station is determined, and the LEO base station search is performed again based on the first base station signal characteristic of the first LEO base station in the next revolution period of the first LEO base station.

9. The method according to claim 4, characterized in that The synchronization signal corresponding to the first LEO base station includes a primary synchronization signal and a secondary synchronization signal corresponding to the first LEO base station.

10. A terminal device, characterized in that: include: A processor and a memory, wherein the memory includes a physical memory and an external memory, and is used to store instructions executed by one or more processors of the terminal device; And, a processor, configured to execute the instructions so that the terminal device implements the communication method according to any one of claims 1 to 9.

11. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a terminal device, the terminal device implements the communication method according to any one of claims 1 to 9.

12. A computer program product, characterized in that The computer program comprises a computer program / instruction. When the computer program product is run on a terminal device, the terminal device implements the communication method according to any one of claims 1 to 9.

Images