Terminal positioning method and apparatus

Abstract

A terminal positioning method and apparatus. The method comprises: a terminal acquiring ephemeris information; receiving at least N first signals from N satellites; determining K candidate service satellites on the basis of the at least N first signals; determining positions of the K candidate service satellites on the basis of information about the relationship between the positions of the K candidate service satellites and the time in the ephemeris information; determining the position of the terminal on the basis of the positions of the K candidate service satellites and K first signals from the K candidate service satellites; and accessing one of the K candidate service satellites on the basis of the position of the terminal. By means of the solution in the present application, a terminal can determine the position thereof on the basis of signals of multiple satellites prior to random access, and timing advance adjustment is performed on the basis of the position of the terminal and satellite ephemeris, so as to perform random access, thereby improving the access performance.

Description

Terminal positioning method and apparatus

[0001] The present application claims priority from the Chinese patent application No. 202410473018.7 filed on April 18, 2024, and entitled "Terminal positioning method and apparatus", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of communication technology, and in particular to a terminal positioning method and apparatus. BACKGROUND

[0003] In a satellite communication system, the high-speed movement of a satellite can cause time-frequency offset changes, and a terminal needs to pre-compensate for the time-frequency offset according to its own position to ensure network access and communication performance. Therefore, the terminal needs to obtain its own position in a timely and accurate manner.

[0004] Currently, a terminal mainly relies on global navigation satellite system (GNSS) signals to obtain its own position. However, if the GNSS signals are inaccurate or it takes too long to obtain the GNSS signals during the access stage, the performance of the terminal in accessing the network will be affected.

[0005] Therefore, how the terminal quickly and accurately obtains its own position to improve the performance of accessing the network is a problem to be solved. SUMMARY

[0006] The present application provides a communication method and apparatus to quickly and accurately obtain its own position, thereby improving the performance of accessing the network.

[0007] In a first aspect, a communication method is provided, which can be applied to a terminal side, such as a terminal or a communication module in the terminal, or a circuit or a chip (such as a modem chip (also referred to as a baseband chip), or a system on chip (SoC) chip or a system in package (SIP) chip containing a modem core) responsible for a communication function in the terminal. In the method applied to the terminal, the terminal obtains ephemeris information, the ephemeris information including information about a relationship between positions and times of M satellites, M being a positive integer; receives at least N first signals from N satellites, the M satellites including the N satellites, N being a positive integer less than or equal to M; determines K candidate serving satellites according to the at least N first signals, the N satellites including the K candidate serving satellites, K being a positive integer less than or equal to N; determines positions of the K candidate serving satellites according to information about a relationship between the positions and times of the K candidate serving satellites in the ephemeris information; determines a position of the terminal according to the positions of the K candidate serving satellites and K first signals from the K candidate serving satellites, the at least N first signals including the K first signals; and sends a preamble to one of the K candidate serving satellites according to the position of the terminal and ephemeris information of the K candidate serving satellites.

[0008] In this aspect, by preconfiguring ephemeris information in the terminal, the terminal determines one or more candidate serving satellites according to the ephemeris information, detects signals of the one or more candidate serving satellites, determines multiple satellites and positions of the multiple satellites, and thus determines a position of the terminal. Therefore, the terminal can quickly and accurately determine its own position according to multiple satellite signals before random access, and perform timing advance adjustment according to the position of the terminal and satellite ephemeris, and perform random access, thereby improving access performance.

[0009] In a possible implementation of the first aspect, before the receiving of the at least N first signals from the N satellites, the method further includes: determining X satellites according to a first time and the ephemeris information, the M satellites including the X satellites, the X satellites including the N satellites, X being an integer greater than or equal to N and less than or equal to M.

[0010] In this implementation, since the terminal pre-stores ephemeris information, the terminal can calculate currently possible serving satellites according to time information.

[0011] In a possible implementation of the first aspect, the determining the position of the terminal according to the positions of the K candidate service satellites and the K first signals from the K candidate service satellites comprises: performing energy detection on the K first signals from the K candidate service satellites; determining the position of the terminal according to a result of the energy detection; or determining the position of the terminal according to the result of the energy detection and the positions of the K candidate service satellites.

[0012] In this implementation, the terminal determines the position of the terminal according to the result of the energy detection. The terminal selects a first signal with the largest signal strength from the K first signals, and regards a coverage area of a satellite sending the first signal as the position of the terminal. This implementation is simple and saves the calculation cost of the terminal.

[0013] The terminal determines the position of the terminal according to the result of the energy detection and the positions of the K candidate service satellites. The position of the terminal can be more accurate.

[0014] In a possible implementation of the first aspect, before the accessing the one candidate service satellite from the K candidate service satellites, the method further comprises: determining the one candidate service satellite according to at least one of the position of the terminal, the positions of the K candidate service satellites, information about the relationship between the positions of the K candidate service satellites and time in the ephemeris information, and the strengths of the K first signals.

[0015] In a possible implementation of the first aspect, the first signal comprises at least one of a synchronization signal / physical broadcast channel (SS / PBCH), a positioning reference signal (PRS), and a synchronization and positioning signal.

[0016] In a possible implementation of the first aspect, the first signal comprises a synchronization signal and a positioning reference signal, and the positioning reference signal is associated with the synchronization signal.

[0017] In this implementation, the time domain resource and / or the frequency domain resource of the positioning reference signal can be different from those of the synchronization signal. The time domain resource and / or the frequency domain resource of the positioning reference signal can be flexibly configured. When the positioning accuracy requirement is high, more time domain symbols can be configured; when the positioning accuracy requirement is not high, fewer time domain symbols can be configured, so as to avoid resource waste. When the PRS is used in the initial access process, a larger bandwidth can be defined. The larger the bandwidth is, the higher the signal sampling frequency is, and the greater the probability of accurately collecting the first path signal is, and the better the positioning performance is.

[0018] In a further possible implementation form of the first aspect, the time-domain position of the positioning reference signal is adjacent to the time-domain position of the synchronization signal, and / or the beam direction corresponding to the positioning reference signal is the same as the beam direction corresponding to the synchronization signal.

[0019] In a further possible implementation form of the first aspect, the accessing the one of the K candidate serving satellites according to the position of the terminal comprises: determining a first timing advance (TA) according to the position of the terminal; determining a second TA for sending a physical random access channel (PRACH) according to the first TA; and accessing the one of the K candidate serving satellites.

[0020] In a second aspect, a communication method is provided, which can be applied to a satellite side, for example, a satellite or a module (for example, a circuit, a processor, a chip or a chip system, etc.) in the satellite. In the case of the method being applied to the satellite, in the method, a candidate serving satellite generates a first signal, the first signal is used for determination of the candidate serving satellite, a position of the candidate serving satellite and a position of a terminal; the first signal is sent; and a preamble from the terminal is received.

[0021] In this aspect, by pre-configuring ephemeris information for the terminal, the terminal determines one or more candidate serving satellites according to the ephemeris information, and detects signals of the one or more candidate serving satellites to determine the multi-satellite and the position of the multi-satellite, thereby determining the position of the terminal. Thus, the terminal can quickly and accurately determine its own position according to the multi-satellite signals before random access, and perform timing advance adjustment according to the position of the terminal and the satellite ephemeris to perform random access, thereby improving the access performance.

[0022] In a possible implementation form of the second aspect, the first signal comprises at least one of the following signals: SS / PBCH, PRS, synchronization and positioning signal.

[0023] In another possible implementation form of the second aspect, the first signal comprises a synchronization signal and a positioning reference signal, and the positioning reference signal is associated with the synchronization signal.

[0024] In a further possible implementation form of the second aspect, the time-domain position of the positioning reference signal is adjacent to the time-domain position of the synchronization signal, and / or the beam direction corresponding to the positioning reference signal is the same as the beam direction corresponding to the synchronization signal.

[0025] In a third aspect, a communication apparatus is provided with the functions of the first aspect, for example, the communication apparatus includes modules or units or means corresponding to the operations of the first aspect, which can be implemented in software, or in hardware, or in a combination of software and hardware.

[0026] In a fourth aspect, a communication apparatus is provided with the functions of the second aspect, for example, the communication apparatus includes modules or units or means corresponding to the operations of the first aspect, which can be implemented in software, or in hardware, or in a combination of software and hardware.

[0027] In a possible implementation, the communication apparatus in the third aspect to the fourth aspect includes a module or unit for performing the method in any of the first aspect, the second aspect, or any of the implementation forms. For example, the communication apparatus can include a sending unit, a receiving unit, and a processing unit. The sending unit and the receiving unit can be independent or combined together (which can be referred to as a “transceiving unit”).

[0028] When the communication apparatus is used to implement the method in the first aspect or any of the implementation forms of the first aspect, the processing unit is configured to obtain ephemeris information, the ephemeris information including information about the relationship between the positions and the time of M satellites, M being a positive integer; the transceiving unit is configured to receive at least N first signals from N satellites, the M satellites including the N satellites, N being a positive integer less than or equal to M; the processing unit is further configured to determine K candidate serving satellites from the at least N first signals, the N satellites including the K candidate serving satellites, K being a positive integer less than or equal to N; the processing unit is further configured to determine the positions of the K candidate serving satellites according to the information about the relationship between the positions and the time of the K candidate serving satellites in the ephemeris information; the processing unit is further configured to determine the position of a terminal according to the positions of the K candidate serving satellites and the K first signals from the K candidate serving satellites, the at least N first signals including the K first signals; and the transceiving unit is further configured to send a preamble to one of the K candidate serving satellites according to the position of the terminal and the ephemeris information of the K candidate serving satellites.

[0029] In a possible implementation of the third aspect, the processing unit is further configured to determine X satellites according to the first time and the almanac information, the M satellites include the X satellites, the X satellites include the N satellites, and X is an integer greater than or equal to N and less than or equal to M.

[0030] In another possible implementation of the third aspect, the processing unit is further configured to perform energy detection on the K first signals from the K candidate serving satellites, the processing unit is further configured to determine the position of the terminal according to a result of the energy detection, or the processing unit is further configured to determine the position of the terminal according to the result of the energy detection and the positions of the K candidate serving satellites.

[0031] In still another possible implementation of the third aspect, the processing unit is further configured to determine the one candidate serving satellite according to at least one of the position of the terminal, the positions of the K candidate serving satellites, information about the relationship between the positions and the time of the K candidate serving satellites in the almanac information, and the K first signals.

[0032] In still another possible implementation of the third aspect, the processing unit is further configured to determine the one candidate serving satellite according to at least one of the position of the terminal, the positions of the K candidate serving satellites, information about the relationship between the positions and the time of the K candidate serving satellites in the almanac information, and the strengths of the K first signals.

[0033] In still another possible implementation of the third aspect, the first signal includes at least one of the following: an SS / PBCH, a PRS, a synchronization and positioning signal.

[0034] In still another possible implementation of the third aspect, the first signal includes a synchronization signal and a positioning reference signal, and the positioning reference signal is associated with the synchronization signal.

[0035] In still another possible implementation of the third aspect, a time domain position of the positioning reference signal is adjacent to a time domain position of the synchronization signal, and / or a beam direction corresponding to the positioning reference signal is the same as a beam direction corresponding to the synchronization signal.

[0036] In still another possible implementation of the third aspect, the processing unit is further configured to determine a first TA according to the position of the terminal, the processing unit is further configured to determine a second TA for sending a PRACH according to the first TA, and the transceiver is further configured to access one of the K candidate serving satellites.

[0037] The processing unit is configured to generate a first signal, the first signal being used for determination of a candidate serving satellite, a position of the candidate serving satellite, and a position of the terminal; the transceiver is configured to transmit the first signal; and the transceiver is further configured to receive a preamble from the terminal.

[0038] In a further possible implementation form of the fourth aspect, the first signal comprises at least one of the following: SS / PBCH, PRS, synchronization and positioning signal.

[0039] In a further possible implementation form of the fourth aspect, the first signal comprises a synchronization signal and a positioning reference signal, the positioning reference signal being associated with the synchronization signal.

[0040] In a further possible implementation form of the fourth aspect, a time domain position of the positioning reference signal is adjacent to a time domain position of the synchronization signal, and / or a beam direction corresponding to the positioning reference signal is the same as a beam direction corresponding to the synchronization signal.

[0041] In another possible implementation form, the communication apparatus in the third aspect to the fourth aspect comprises a memory and one or more processors. The memory is configured to store part or all of the computer program or instructions necessary for implementing the functions involved in the first aspect or the second aspect. The one or more processors are configured to execute the computer program or instructions, when the computer program or instructions are executed, causing the communication apparatus to implement the method in any possible design or implementation form of the first aspect or the second aspect.

[0042] In a possible design, the communication apparatus can further comprise an interface circuit, and the processor is configured to communicate with other apparatuses or components via the interface circuit.

[0043] In a possible design, the communication apparatus can further comprise the memory.

[0044] When the communication apparatus is configured to implement the functions of the first aspect, the communication apparatus can be a terminal, or a communication module in the terminal, or a chip responsible for communication functions in the terminal, such as a Modem chip (also known as a baseband chip) or a SoC or SIP chip containing a modem module.

[0045] When the communication apparatus is configured to implement the functions of the second aspect, the communication apparatus can be a satellite, or a component in the satellite.

[0046] In a fifth aspect, a computer readable storage medium is provided, and the computer readable storage medium stores a computer program or instructions, and when the computer program or instructions are executed by a computer, the method in the above aspects is implemented.

[0047] In a sixth aspect, a computer program product is provided, and when a computer reads and executes the computer program product, the computer executes the method in the above aspects.

[0048] In a seventh aspect, a communication system is provided, and the communication system includes a terminal and a satellite; wherein the terminal is configured to acquire ephemeris information, the ephemeris information including information about a relationship between positions and times of M satellites, M being a positive integer; N satellites are configured to generate at least N first signals, the M satellites including the N satellites, N being a positive integer less than or equal to M; the N satellites are further configured to send the at least N first signals to the terminal; the terminal is further configured to determine K candidate serving satellites according to the at least N first signals, the N satellites including the K candidate serving satellites, K being a positive integer less than or equal to N; the terminal is further configured to determine positions of the K candidate serving satellites according to information about a relationship between positions and times of the K candidate serving satellites in the ephemeris information; the terminal is further configured to determine a position of the terminal according to the positions of the K candidate serving satellites and K first signals from the K candidate serving satellites, the at least N first signals including the K first signals; and the terminal is further configured to send a preamble to one of the K candidate serving satellites according to the position of the terminal and the ephemeris information of the K candidate serving satellites.

[0049] In a possible implementation form of the seventh aspect, the terminal is further configured to determine the one candidate serving satellite according to at least one of the position of the terminal, the positions of the K candidate serving satellites, information about a relationship between positions and times of the K candidate serving satellites in the ephemeris information, and intensities of the K first signals; and the terminal is further configured to send the preamble to the one candidate serving satellite.

[0050] In another possible implementation form of the seventh aspect, the terminal is further configured to determine X satellites according to a first time and the ephemeris information, the M satellites including the X satellites, the X satellites including the N satellites, X being an integer greater than or equal to N and less than or equal to M.

[0051] In a possible implementation of the seventh aspect, the terminal is further configured to perform energy detection on the K first signals from the K candidate serving satellites; and the terminal is further configured to determine the position of the terminal according to the result of the energy detection, or according to the result of the energy detection and the positions of the K candidate serving satellites.

[0052] In a possible implementation of the seventh aspect, the first signal comprises at least one of a synchronization signal SS / PBCH, a positioning reference signal PRS, and a synchronization and positioning signal.

[0053] In a possible implementation of the seventh aspect, the first signal comprises a synchronization signal and a positioning reference signal, and the positioning reference signal is associated with the synchronization signal.

[0054] In a possible implementation of the seventh aspect, the time-domain position of the positioning reference signal is adjacent to the time-domain position of the synchronization signal, and / or the beam direction corresponding to the positioning reference signal is the same as the beam direction corresponding to the synchronization signal.

[0055] In a possible implementation of the seventh aspect, the terminal is further configured to determine a first timing advance TA according to the position of the terminal; the terminal is further configured to determine a second TA for sending a physical random access channel PRACH according to the first TA; and the terminal is further configured to send the preamble to one of the K candidate serving satellites. BRIEF DESCRIPTION OF DRAWINGS

[0056] FIG. 1 is a simplified schematic diagram of a wireless communication system according to an embodiment of the present application;

[0057] FIG. 2 is a schematic diagram of communication between multiple satellites and a terminal;

[0058] FIG. 3 is a schematic diagram of an initial access procedure and timing advance adjustment for satellite communication;

[0059] FIG. 4 is a schematic diagram of uplink and downlink timing;

[0060] FIG. 5 is a schematic diagram of an initial access procedure in NR;

[0061] FIGS. 6a-6c are schematic diagrams of application scenarios of a satellite-terrestrial integrated network;

[0062] FIG. 7a is a schematic diagram of a transparent repeating scenario for satellite communication;

[0063] FIG. 7b is a schematic diagram of a regenerative mode scenario for satellite communication;

[0064] FIG. 8 is a schematic diagram of a communication method according to an embodiment of the present application;

[0065] FIG. 9 and FIG. 10 are schematic diagrams of multi-star positioning according to an embodiment of the present application;

[0066] FIG. 11-FIG. 13 are schematic diagrams of time-domain patterns of PRS according to an embodiment of the present application;

[0067] FIG. 14 is a schematic diagram of a synchronization and positioning signal according to an embodiment of the present application;

[0068] FIG. 15 and FIG. 16 are schematic diagrams of structures of communication apparatuses according to an embodiment of the present application. DETAILED DESCRIPTION

[0069] The embodiments of the present application will be described below with reference to the accompanying drawings.

[0070] The techniques provided by the present application can be applied to various communication systems. For example, the communication system can be a fourth generation (4G) communication system (e.g., a long term evolution (LTE) system), a fifth generation (5G) communication system, a worldwide interoperability for microwave access (WiMAX) system, a wireless local area network (WLAN) system, a satellite communication system, a converged system of multiple systems, or a future communication system (e.g., a sixth generation (6G) communication system). th th th The techniques provided by the present application can be applied to various communication systems. For example, the communication system can be a fourth generation (4G) communication system (e.g., a long term evolution (LTE) system), a fifth generation (5G) communication system, a worldwide interoperability for microwave access (WiMAX) system, a wireless local area network (WLAN) system, a satellite communication system, a converged system of multiple systems, or a future communication system (e.g., a sixth generation (6G) communication system).

[0071] The present application will present various aspects, embodiments or features around a system that can include a plurality of devices, components, modules, etc. It should be understood and appreciated that each system can include additional devices, components, modules, etc., and / or can not include all of the devices, components, modules, etc., discussed in connection with the figures. Additionally, a combination of these approaches can be used.

[0072] ​​In addition, in the embodiments of the present application, the words "exemplary", "for example", and the like are used solely to indicate examples, instances, or illustrations, and are not intended to imply or designate a crucial or preferred implementation. In fact, the use of the word "exemplary" is intended to present concepts in a concrete manner. In the embodiments of the present application, "of", "corresponding" and "corresponding" are sometimes used interchangeably, and it should be pointed out that when their differences are not emphasized, their meanings are consistent.

[0073] The communication system and service scenarios described in the embodiments of the present application are used to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. Those skilled in the art can know that with the evolution of network architecture and the emergence of new service scenarios, the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems.

[0074] A network element in a communication system can send or receive signals to or from another network element. The signals can include information, signaling, or data, etc. The network element can also be replaced by an entity, a network entity, a device, a terminal, a communication module, a node, a communication node, etc. In the present application, the network element is taken as an example for description. For example, the communication system can include at least one terminal and at least one access network device. The access network device can send downlink signals to the terminal, and / or the terminal can send uplink signals to the access network device. In addition, it can be understood that if the communication system includes multiple terminals, the terminals can also send signals to each other, that is, the sending network element and the receiving network element of the signal can be terminals.

[0075] Referring to FIG. 1, FIG. 1 is a simplified schematic diagram of a wireless communication system provided by the embodiments of the present application. As shown in FIG. 1, the wireless communication system includes a radio access network (RAN) 100. The radio access network 100 can be a next-generation (for example, 6G or higher version) radio access network, or a traditional (for example, 5G, 4G) radio access network. One or more terminals (120a-120g, collectively referred to as 120) can be connected to each other, or connected to one or more network devices (110a-110c, collectively referred to as 110) in the radio access network 100, and the connection mode can be wired or wireless. Optionally, FIG. 1 is only a schematic diagram, and the wireless communication system can also include other devices, such as core network devices, wireless relay devices, and / or wireless backhaul devices, etc., which are not shown in FIG. 1.

[0076] Optionally, in practical application, the wireless communication system can comprise multiple network devices (also referred to as access network devices) simultaneously, and can also comprise multiple terminals simultaneously. One network device can serve one or more terminals simultaneously. One terminal can access one or more network devices simultaneously. Embodiments of the present application do not limit the number of terminals and network devices comprised in the wireless communication system.

[0077] The network device can be an entity for transmitting or receiving signals on the network side. The network device can be an access device for a terminal to access the wireless communication system by a wireless manner. For example, the network device can be a base station. The base station can cover various names in the following or replace the following names, such as: RAN node, NodeB, evolved NodeB (eNB), next generation NodeB (gNB), satellite base station, access network device in open radio access network (O-RAN), relay station, access point, transmitting and receiving point (TRP), transmitting point (TP), master eNB (MeNB), secondary eNB (SeNB), multi-standard radio (MSR) node, home base station, network controller, access node, wireless node, access point (AP), transmission node, transceiver node, building baseband unit (BBU), remote radio unit (RRU), active antenna unit (AAU), remote radio head (RRH), centralized unit (CU), distributed unit (DU), radio unit (RU), CU control plane (CU-CP) node, CU user plane (CU-UP) node, positioning node, and the like. The base station can be a macro base station, micro base station, relay node, donor node, or the like, or a combination thereof. The network device can also refer to a communication module, modem, or chip for being arranged in the foregoing device or apparatus. The network device can also be a mobile switching center, device-to-device (D2D), vehicle-to-everything (V2X), machine-to-machine (M2M) communication device assuming a base station function, network side device in 6G network, device assuming a base station function in future communication system, and the like. The network device can support networks of the same or different access technologies. The embodiments of the present application do not limit the specific technology and specific device form of the network device.

[0078] The network devices can be fixed or mobile. For example, the base stations 110b, 110c are stationary and responsible for wireless transmission and reception in one or more cells from terminals 120. The helicopter or drone 120c shown in Figure 1 can be configured to act as a mobile base station, and one or more cells can move according to the location of the mobile base station 120c. In other examples, the helicopter or drone (120c) can be configured to act as a terminal that communicates with the satellite base station 110a.

[0079] A terminal can be an entity on the user side for receiving or transmitting signals, such as a mobile phone. The terminal can be used to connect people, things and machines. The terminal can communicate with one or more core networks through a network device. The terminal includes a handheld device with a wireless connection function, another processing device connected to a wireless modem, or a vehicle-mounted device, etc. The terminal can be a portable, pocket-sized, handheld, computer-built-in or vehicle-mounted mobile device. The terminal 120 can be widely used in various scenarios, such as cellular communication, D2D, V2X, point-to-point (P2P), machine-to-machine (M2M), machine type communication (MTC), internet of things (IoT), virtual reality (VR), augmented reality (AR), industrial control, autonomous driving, remote medical treatment, smart power grid, smart furniture, smart office, smart wear, smart transportation, smart city, unmanned aerial vehicle, robot, remote sensing, passive sensing, positioning, navigation and tracking, autonomous delivery and movement, etc.Some examples of the terminal 120 are a user equipment (UE) of a 3GPP standard, a fixed device, a mobile device, a handheld device, a wearable device, a cellular phone, a smart phone, a session initiated protocol (SIP) phone, a notebook, a personal computer, a smart book, a vehicle, a satellite, a global positioning system (GPS) device, a target tracking device, a drone, a helicopter, an aircraft, a ship, a remote control device, a smart home device, an industrial device, a personal communication service (PCS) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a wireless webcam, a tablet, a palm computer, a mobile internet device (MID), a wearable device such as a smart watch, a VR device, an AR device, a wireless terminal in industrial control, a terminal in Internet of Vehicles, a wireless terminal in self driving, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city such as a smart gas tank, a terminal on a high-speed rail, and a wireless terminal in smart home such as a smart speaker, a smart coffee machine, a smart printer, etc. The terminal 120 can be a wireless device in the above various scenarios or an apparatus for being arranged in a wireless device, e.g., a communication module, a modem, or a chip in the above devices. The terminal can also be referred to as a terminal device, a user equipment (UE), a mobile station (MS), a mobile terminal (MT), etc. The terminal can also be a terminal in a future wireless communication system. The terminal can be used in a dedicated network device or a general-purpose device. The embodiments of the present application do not limit the specific technology and specific device form of the terminal.

[0080] Optionally, the terminal can be used to act as a base station. For example, a UE can act as a scheduling entity that provides sidelink signals between UEs in V2X, D2D, or P2P, etc. As shown in FIG. 1, the cellular phone 120a and the car 120b communicate with each other using sidelink signals. The cellular phone 120a and the smart home device 120e communicate without relaying the communication signals through the base station 110b.

[0081] In this application, the communication device for realizing the function of the terminal can be a terminal, can be a terminal with part of the function of the above terminal, or can be a device capable of supporting the realization of the function of the above terminal, such as a chip system, which can be installed in the terminal or matched with the terminal. In this application, the chip system can be composed of a chip, or can include a chip and other discrete devices. In the technical solutions provided in this application, the communication device is taken as an example to describe the terminal.

[0082] Optionally, a wireless communication system is usually composed of a cell, a base station provides management of the cell, and the base station provides communication services to a plurality of mobile stations (MS) in the cell. The base station includes a baseband unit (BBU) and a remote radio unit (RRU). The BBU and the RRU can be placed in different places, for example: the RRU is pulled away and placed in a high traffic area, and the BBU is placed in a central machine room. The BBU and the RRU can also be placed in the same machine room. The BBU and the RRU can also be different components under one rack. Optionally, one cell can correspond to one carrier or a member carrier.

[0083] In some deployments, the network device mentioned in the embodiments of the present application can be a device including a CU, or a DU, or including a CU and a DU, or including a CU-CP, a CU-UP, and a DU node. For example, the network device can include a gNB-CU-CP, a gNB-CU-UP, and a gNB-DU.

[0084] In some deployments, a plurality of RAN nodes cooperate to assist the terminal to realize wireless access, and different RAN nodes realize part of the functions of the base station respectively. For example, the RAN node can be a CU, a DU, a CU-CP, a CU-UP, or an RU, etc. The CU and the DU can be separately arranged, or can be included in the same network element, such as a BBU. The RU can be included in a radio frequency device or a radio frequency unit, such as an RRU, an AAU, or an RRH.

[0085] The RAN node can support one or more types of fronthaul interfaces, different fronthaul interfaces respectively corresponding to DUs and RUs having different functions. If the fronthaul interface between the DU and the RU is a common public radio interface (CPRI), the DU is configured to implement one or more of baseband functions, and the RU is configured to implement one or more of radio frequency functions. If the fronthaul interface between the DU and the RU is another interface, relative to the CPRI, one or more of the following partial baseband functions of the downlink and / or uplink, such as, for the downlink, one or more of precoding, digital beamforming (BF), or inverse fast Fourier transform (IFFT) / add cyclic prefix (CP), are implemented in the RU from the DU, and for the uplink, one or more of digital beamforming (BF), or fast Fourier transform (FFT) / remove CP are implemented in the RU from the DU. In a possible implementation, the interface can be an enhanced common public radio interface (eCPRI). Under the eCPRI architecture, the splitting manner between the DU and the RU is different, corresponding to different categories (Cat) of eCPRI, such as eCPRI Cat A, B, C, D, E, and F.

[0086] Taking eCPRI Cat A as an example, for downlink transmission, taking layer mapping as a cut, the DU is configured to implement one or more functions (i.e., one or more of encoding, rate matching, scrambling, modulation, and layer mapping) before layer mapping, and other functions (e.g., one or more of RE mapping, digital beamforming (BF), or inverse fast Fourier transform (IFFT) / adding a cyclic prefix (CP)) after layer mapping are implemented in the RU. For uplink transmission, taking de-RE mapping as a cut, the DU is configured to implement one or more functions (i.e., one or more of decoding, de-rate matching, de-scrambling, demodulation, inverse discrete Fourier transform (IDFT), channel equalization, and de-RE mapping) before de-mapping, and other functions (e.g., one or more of digital BF or FFT / CP removal) after de-mapping are implemented in the RU. It can be understood that, for the function description of the DU and the RU corresponding to various types of eCPRI, reference can be made to the eCPRI protocol, and details are not described herein.

[0087] In a possible design, a processing unit in the BBU for implementing baseband functions is referred to as a base band high (BBH) unit, and a processing unit in the RRU / AAU / RRH for implementing baseband functions is referred to as a base band low (BBL) unit.

[0088] In different systems, the CU (or CU-CP and CU-UP), the DU, or the RU can also have different names, but a person skilled in the art can understand their meanings. For example, in an ORAN system, the CU can also be referred to as an O-CU (open CU), the DU can also be referred to as an O-DU, the CU-CP can also be referred to as an O-CU-CP, the CU-UP can also be referred to as an O-CU-UP, and the RU can also be referred to as an O-RU. Any of the CU (or CU-CP, CU-UP), the DU, and the RU in this application can be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0089] In an embodiment of this application, the apparatus for implementing the function of the network device can be the network device; or can be an apparatus capable of supporting the network device to implement the function, for example, a chip system, a hardware circuit, a software module, or a hardware circuit plus a software module. The apparatus can be installed in the network device or used in combination with the network device. In this embodiment of this application, only the apparatus for implementing the function of the network device is taken as an example for description, and the solution of this embodiment of this application is not limited in this way.

[0090] It can be understood that the present application can be applied between a network device and a terminal.

[0091] The communication between the network device and the terminal follows a certain protocol layer structure. The protocol layer structure can include a control plane protocol layer structure and a user plane protocol layer structure. For example, the control plane protocol layer structure can include the functions of protocol layers such as a radio resource control (RRC) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, a medium access control (MAC) layer, and a physical layer. For example, the user plane protocol layer structure can include the functions of protocol layers such as a PDCP layer, an RLC layer, a MAC layer, and a physical layer, and in a possible implementation, a service data adaptation protocol (SDAP) layer can be further included above the PDCP layer.

[0092] Optionally, the protocol layer structure between the network device and the terminal can further include an artificial intelligence (AI) layer for transmitting data related to AI functions.

[0093] Taking data transmission between the network device and the terminal as an example, the data transmission needs to pass through the user plane protocol layers, such as the SDAP layer, the PDCP layer, the RLC layer, the MAC layer, and the physical layer. Among them, the SDAP layer, the PDCP layer, the RLC layer, the MAC layer, and the physical layer can also be collectively referred to as an access layer. According to the transmission direction of the data, each layer is divided into a sending part and a receiving part. Taking the following downlink data transmission as an example, the PDCP layer obtains data from the upper layer, transmits the data to the RLC layer and the MAC layer, generates a transport block by the MAC layer, and then performs wireless transmission through the physical layer. The data is encapsulated in each layer. For example, the data received by a certain layer from the upper layer of the layer is regarded as a service data unit (SDU) of the layer, and after encapsulation by the layer, it becomes a protocol data unit (PDU) and is transmitted to the next layer.

[0094] Exemplarily, the terminal can also have an application layer and a non-access layer. The application layer can be used to provide services to the application program installed in the terminal, for example, the downlink data received by the terminal can be transmitted to the application layer in sequence by the physical layer, and then provided to the application program by the application layer; for another example, the application layer can obtain the data generated by the application program, and transmit the data to the physical layer in sequence to send to other communication devices. The non-access layer can be used to forward user data, for example, to forward the uplink data received from the application layer to the SDAP layer, or to forward the downlink data received from the SDAP layer to the application layer.

[0095] It should be understood that the number and type of devices in the communication system shown in FIG. 1 are only illustrative, and the present application is not limited thereto. In actual application, more terminals, more access network devices, and other network elements, such as core network devices and / or network elements for implementing artificial intelligence functions, can also be included in the communication system.

[0096] It can be understood that all or part of the functions of one or more of the terminal, the access network device, the core network device, or the network element for implementing artificial intelligence functions can be virtualized, that is, implemented by one or more of a special processor or a general processor and a corresponding software module. Among them, the terminal and the access network device involve the interface of air interface transmission, and the transceiving function of the interface can be realized by hardware. The core network device, such as the operation administration and maintenance (OAM) network element, can be virtualized. Optionally, one or more functions of the virtualized terminal, access network device, core network device, or network element for implementing artificial intelligence functions can be implemented by a cloud device, such as a cloud device in an over the top (OTT) system.

[0097] Satellite communication has been introduced as one of the communication scenarios for 5G communication, referred to as non-terrestrial network (NTN). NTN refers to a network using radio frequency resources on a platform such as a satellite platform (including low earth orbit (LEO), middle earth orbit (MEO), and geostaionary earth orbit (GEO)), unmanned aerial vehicle (UAV), or high altitude platform station (HAPS) to provide communication services. Compared with a terrestrial cellular network (e.g., 5G NR), an NTN network has characteristics such as wider coverage, higher path loss, larger latency, faster speed, and lower cost. As a supplement and extension of a terrestrial network, an NTN can achieve the purpose of seamless coverage in a wide area that cannot be achieved by a wired telephone network and a terrestrial mobile communication network, and effectively solve the problem of Internet access in areas where communication infrastructure is scarce. For example, when a large number of satellites are arranged in low earth orbit, through reasonable constellation construction, seamless coverage of the ground can be achieved, and the round-trip transmission delay of data between the satellite and the ground terminal can also be greatly reduced to tens of milliseconds compared with a synchronous orbit satellite. With the use of high-frequency bands, multi-point beams, and frequency reuse, the communication capability of the satellite has been significantly improved, and the unit wideband cost has been reduced, so as to meet the demand of high information rate services. Compared with a terrestrial 5G network and submarine optical cable and other communication infrastructure, an NTN also has a significant cost advantage. The cost of modern small satellites is low, and software-defined technology can further extend the on-orbit satellite service life. In addition to global coverage (such as remote areas, ocean-going ships, etc.), an NTN can also be used for emergency rescue (such as disaster monitoring and emergency communication), Internet of Things, high-speed mobile (such as high-speed rail, aircraft), and other scenarios.

[0098] Because of the advantages such as not being easily affected by natural disasters or external damage, satellites are currently being researched as access network devices (such as base stations) of a mobile communication system to provide communication services for some areas such as oceans and forests. Unlike a terrestrial base station, a satellite has a relatively large ground movement speed and a longer signal propagation distance, so that the signal path loss of the satellite as a base station is larger. The communication mechanism designed in the current mobile communication system for a terminal and a terrestrial base station cannot be directly applied between a terminal and a satellite base station.

[0099] Compared with the ground communication system, the single-satellite coverage area is wider, and the transmission distance is far. Providing services to terminals through wide coverage is a significant feature of satellite communication systems. As shown in FIG. 2, it is a schematic diagram of communication between multiple satellites and terminals. In the future, with large-scale networking of satellites, the number and capacity of satellites gradually increase, and a terminal can receive signals from multiple satellites (physical cell identifier (PCI)

[0100] #1~PCIN corresponds to the satellite, and N is a positive integer). And with future evolution, the terminal side will gradually improve its capabilities, and the terminal side will be able to have the ability to receive multiple beams.

[0101] In the satellite communication system, the high-speed movement of the satellite causes the time-frequency offset to change, and the terminal side needs to pre-compensate the time-frequency offset according to its own position to ensure the performance of network access and communication. Therefore, how to quickly and accurately obtain the position of the terminal to improve the subsequent network access performance is very important.

[0102] Timing advance adjustment based on GNSS signals:

[0103] Currently, in the initial access process of satellite communication, the terminal obtains its own position based on GNSS signals. And the terminal determines the timing advance (TA) based on its own position and ephemeris information to make timing advance adjustment.

[0104] As shown in FIG. 3, it is a schematic diagram of the initial access process of satellite communication and timing advance adjustment. In the initial access process, the steps related to timing advance are as follows:

[0105] First, the terminal performs timing estimation by detecting the primary synchronization signal (PSS) / secondary synchronization signal (SSS), and obtains cell information and ephemeris information from system information block 1 (SIB1) and system information block 19 (SIB19).

[0106] Second, the terminal determines the TA and makes timing advance adjustment, and sends the physical random access channel (PRACH).

[0107] As shown in FIG. 4, it is a schematic diagram of uplink and downlink timing. The terminal performs timing advance T TA for the uplink frame number i, and the T TASatisfies:

[0108] Where N TA and N TA,offset is defined according to the description in TS 38.213, when n-TimingAdvanceOffset is configured, N TA,offset is taken; if not configured, the default value is taken according to TS 38.133. N TA,offset is determined by the duplex mode and frequency band in which the uplink transmission occurs, according to the table defined in Section 7 of TS 38.133.

[0109] N TA is 0 when transmitting PRACH, and can be updated by the Timing Advance Command field in message 2 (Msg2) / message B (MsgB) and the Timing Advance Command MAC CE.

[0110] If the high-level parameters TACommon, TACommonDrift, and TACommonDriftVariation are configured, then is determined according to the network configuration parameters; if not configured, is 0. Where TACommon indicates the network-controlled common timing advance value, which can include any timing offset that the network deems necessary; TACommonDrift indicates the drift rate of the common TA;

[0111] TACommonDriftVariation represents the drift rate variation of the common TA.

[0112] The one-way propagation delay Delay common (t) between the reference point and the satellite is

[0113] If the relevant high-level parameters of the service satellite ephemeris are configured, then is determined by the terminal according to the terminal's location and satellite ephemeris; otherwise, it is 0.

[0114] Initial access procedure of NR:

[0115] As shown in FIG. 5, it is a schematic diagram of the initial access procedure in NR. The network device transmits the synchronization signal synchronization channel using a wide beam, and other channels are associated with the synchronization signal beam. The details are as follows:

[0116] First step, the terminal determines the random access channel occasion (RO) resource according to the received or selected synchronization signal (referred to as "access occasion" for short), and sends PRACH on the RO resource associated with the synchronization signal.

[0117] Second step, the network device receives PRACH and sends a random access response (RAR) to schedule the terminal to send message 3 (Msg3) (i.e. RRCSetupRequest) for RRC establishment request.

[0118] Third step, the terminal starts a window to listen to RAR after sending PRACH.

[0119] If no RAR message is listened to within the window, PRACH continues to be sent until RAR is received or preambleTransMax is reached without receiving RAR. preambleTransMax is the maximum number of random access preamble transmissions, which is configured by the network device. Otherwise, the access fails and the network is changed.

[0120] Fourth step, the terminal sends message 3 (Msg3) to the network device.

[0121] Fifth step, the network device sends message 4 (Msg4) (i.e. RRCSetup) for RRC establishment, and the terminal sends message 5 (Msg5) to complete the initial access process.

[0122] NR downlink positioning:

[0123] Downlink positioning reference signals are defined in NR. The network device can send positioning reference signals during the data transmission stage, the terminal receives the positioning reference signals and reports the measurement results to the network device, and the network device estimates the position of the terminal according to the reported results to obtain the positioning information of the terminal.

[0124] The following downlink-time difference of arrival (DL-TDOA) positioning is taken as an example. A terminal performs a downlink reference signal time difference (DL RSTD) measurement on a positioning reference signal (PRS) sent by a transmission and receiving point (TRP), and then reports the DL RSTD measurement information to a location management function (LMF) network element. The LMF calculates the specific position of the terminal using the known TRP position and the RSTD measurement result. This method requires multiple network devices to cooperate with positioning, and assumes that the network devices are completely synchronized. The higher the synchronization accuracy of multiple network devices, the better the performance, and vice versa.

[0125] This positioning process requires the terminal to report the positioning capability to the LMF. The LMF needs to provide the terminal with auxiliary data such as NR GCI, transmission and receiving point identifier (TRP ID), PRS configuration of the TRP, and time and frequency domain occupation of the synchronization signal. At the same time, the LMF needs to provide the network device with auxiliary data such as NR GCI, TRP ID, and PRS configuration of the TRP. The LMF returns the positioning result to the access and mobility function (AMF) network element, including success, failure, and error information. Then the AMF sends the positioning result to the terminal.

[0126] As can be seen from the above, the TA determined according to the terminal position is used to send PRACH in the initial access process, so as to complete the subsequent access process. If the GNSS (GEO or positioning satellite sent) signal obtained by the terminal is inaccurate or the time consumed for obtaining the GNSS signal in the access stage is too long, the performance of the terminal accessing the network will be affected. Specifically, since the accurate GNSS signal cannot be quickly obtained (the time consumed for obtaining the GNSS signal may be long, or the frequency point of the GNSS signal and the communication signal is adjacent, which causes strong interference and affects the terminal to obtain the accurate self-position, etc.), the TA determined by the terminal for sending PRACH is inaccurate. After the PRACH is sent, the RAR sent by the network device cannot be received, the terminal keeps trying to resend, and the access is considered to fail, thereby affecting the access performance.

[0127] Therefore, the application provides a communication scheme. By pre-configuring ephemeris information for a terminal, the terminal determines one or more candidate service satellites according to the ephemeris information, detects signals of the one or more candidate service satellites, determines multiple satellites and positions of the multiple satellites, and determines a position of the terminal. Therefore, the terminal can quickly and accurately determine its own position according to signals of multiple satellites before random access, and perform timing advance adjustment according to the position of the terminal and satellite ephemeris, and perform random access, thereby improving access performance.

[0128] The application is not limited to the satellite scenario, and is still applicable in future 6G evolution.

[0129] As shown in FIGS. 6a-6c, the application scenario of the satellite-ground integrated network is shown. The terminal on the ground can access the network through an air interface (which can be various types of air interfaces, such as a 5G air interface). In FIG. 6a, the base station can be deployed on the ground and connected to the satellite ground station; in FIG. 6b, the base station can be deployed on the satellite. The satellite is connected to the ground station through a wireless link. The ground station and the ground base station are connected to the core network through a wired or wireless connection. There can be a wireless link between satellites. If the satellite only has a transparent forwarding function (i.e., the corresponding base station is deployed on the ground), the transparent forwarding between satellites is implemented. If the base station or part of the base station function is deployed on the satellite, the signaling interaction and user data transmission between base stations can be completed between satellites as shown in FIG. 6c.

[0130] The typical scenarios of terminal access provided by the NTN network include transparent payload and regenerative payload. As shown in FIG. 7a, a schematic diagram of a transparent forwarding scenario of satellite communication, transparent forwarding refers to that the satellite only plays a role of frequency conversion and forwarding, that is, it is equivalent to an analog radio frequency repeater. Therefore, the satellite copies the NR Uu wireless interface signal from the feeder link (between the NTN gateway and the satellite) to the service link (between the satellite and the terminal), and vice versa. The satellite wireless interface transmission on the feeder link is the NR-Uu interface signal, that is, the satellite does not terminate the NR Uu interface signal, but copies the signal. The NTN gateway supports all necessary functions for forwarding all NR-Uu interface signals. Different transmission satellites can be connected to the same ground base station. As shown in FIG. 7b, a schematic diagram of a regenerative mode scenario of satellite communication, the regenerative mode refers to that the satellite contains a network device or a digital processing unit (DU). In this architecture, the satellite acts as a base station, and realizes regeneration of the received signal from the ground, that is, the NR-Uu wireless interface signal is transmitted between the terminal and the satellite on the service link, and the satellite wireless interface signal is transmitted between the NTN gateway and the satellite on the feeder link. The SRI interface is a transmission link between the NTN gateway and the satellite. The NG interface signal is transmitted to the NTN gateway through the SRI interface, and then forwarded by the NTN gateway to the core network device on the ground.

[0131] Based on the above communication system, a communication method provided by the present application is described as follows:

[0132] As shown in FIG. 8, a flowchart of a communication method provided by an embodiment of the present application is shown. In FIG. 8, the satellite and the terminal are taken as an example to illustrate the execution subject of the interaction, but the present application does not limit the execution subject of the interaction. For example, the method executed by the satellite in FIG. 8 can also be executed by a module (such as a circuit, a processor, a chip or a chip system, etc.) applied to the satellite; the method executed by the terminal in FIG. 8 can also be executed by a communication module in the terminal, or a circuit or a chip (such as a modem chip (also known as a baseband chip), or a system on chip or a system in package chip containing a modem core) responsible for communication function in the terminal. Exemplarily, the method can include the following steps:

[0133] S801. The terminal acquires ephemeris information.

[0134] In one example, the ephemeris information can be configured to the terminal by the ground base station.

[0135] Exemplarily, the ephemeris information of the current satellite and / or the neighbor satellites can be carried in SIB19. The SIB19 carries the assistance information of NTN access, including the ephemeris information of the current satellite, the ephemeris information of the neighbor satellites, the distance threshold, the NTN configuration (ntn-Config), etc. The SIB19 supports carrying the ephemeris information of 8 neighbor satellites. In the ntn-Config, the parameters required by the terminal to access the NTN network are provided, such as ephemeris data, common TA parameters, K_offset, the validity period of the uplink synchronization information, and the reference time, etc.

[0136] In another example, the ephemeris information can also be provided to the terminal in a preconfigured manner. For example, the ephemeris information is burned into the terminal when the terminal is manufactured.

[0137] In the embodiment, the ephemeris information includes the information of the relationship between the positions of the M satellites and the time. The terminal can calculate the positions of the satellites at a fixed time according to the ephemeris information. M is a positive integer.

[0138] Exemplarily, the relationship between the positions of the satellites and the time can be represented in at least one of the following forms: a table, a mapping relationship, and function coefficients.

[0139] S802. The N satellites send at least N first signals to the terminal. Correspondingly, the terminal receives at least N first signals from the N satellites.

[0140] Exemplarily, since the terminal pre-stores the ephemeris information, the terminal can first calculate the currently possible serving satellites according to the time information. Before step S802, the method can further include the following step: the terminal determines X satellites according to the first time and the ephemeris information. The M satellites include the X satellites, and X is an integer less than or equal to M.

[0141] In the implementation, since the ephemeris information includes the information of the relationship between the positions of the M satellites and the time, the terminal can determine the positions of the M satellites according to the current time (for example, the first time) and the information of the relationship between the positions of the M satellites and the time. Then, the terminal determines the distances from the M satellites to the terminal respectively by combining the positions of the M satellites and the position of the terminal. Finally, the terminal determines X satellites satisfying the distance threshold condition by combining the distance threshold, for example, the distance from the satellite to the terminal being less than or equal to the distance threshold. The distance from the satellite to the terminal can be tens of km or hundreds of km. Exemplarily, the distance threshold can be pre-stored in the terminal or sent to the terminal by the ground base station (when the terminal is in the coverage of the ground network, it has obtained some information about the satellites from the ground base station in advance, including the above-mentioned distance threshold, and can use the obtained information about the satellites when it enters the coverage of the satellite network).

[0142] After the terminal calculates X satellites that can currently provide services, in actual situations, the terminal can receive signals from N satellites. The X satellites include the N satellites, and X is greater than or equal to N.

[0143] The N satellites send at least N first signals to the terminal. The M satellites include the N satellites. N is a positive integer less than or equal to M.

[0144] The N satellites send at least N first signals to the terminal. The M satellites include the N satellites. N is a positive integer less than or equal to M.

[0145] In one implementation, the N satellites send N first signals to the terminal, that is, each of the N satellites sends one first signal to the terminal.

[0146] In another implementation, the N satellites send more than N first signals to the terminal. This means that the terminal receives multiple first signals from at least one of the N satellites, and then the terminal can filter out the first signal with the strongest intensity from the multiple first signals. After filtering, it can be considered that the terminal receives only one first signal from each of the N satellites, and then determines K candidate satellites from the N satellites according to the N first signals.

[0147] Exemplarily, the first signal can include at least one of the following signals: a synchronization signal, a PRS, a synchronization and positioning signal, and the like.

[0148] S803. The terminal determines K candidate service satellites according to the at least N first signals.

[0149] The terminal can perform signal detection to determine which satellites in the N satellites can currently receive signals.

[0150] In the step S802, the N satellites send at least N first signals to the terminal, and the terminal attempts to receive at least N first signals from the N satellites. However, due to interference, satellite movement, etc., the terminal only receives at least K first signals from K satellites, so the terminal can determine that the K satellites are candidate service satellites. The N satellites include the K candidate service satellites. K is a positive integer less than or equal to N.

[0151] S804. The terminal determines the positions of the K candidate service satellites according to the information about the relationship between the positions and times of the K candidate service satellites in the ephemeris information.

[0152] After the terminal determines the K candidate service satellites, the terminal can determine the positions of the K candidate service satellites at the first time according to the information about the relationship between the positions and times of the K candidate service satellites in the ephemeris information.

[0153] Therefore, the terminal can determine the positions of the multiple satellites at the current time according to the determined multiple satellites and ephemeris information.

[0154] As shown in FIG. 9, FIG. 9 is a schematic diagram of a multi-star positioning according to an embodiment of the present application. It is assumed that there are N satellites in a multi-star network, and a terminal can receive signals from multiple satellites. As shown in FIG. 9, satellite PCI#0, satellite PCI#1 and satellite PCI#2 can all provide services for the terminal, and the terminal can receive signals from the three satellites.

[0155] S805. The terminal determines the position of the terminal according to the positions of the K candidate serving satellites and the K first signals from the K candidate serving satellites.

[0156] After determining the positions of the K candidate serving satellites, the terminal can determine the position of the terminal according to the positions of the K candidate serving satellites and the K first signals from the K candidate serving satellites. The at least N first signals include the K first signals.

[0157] Exemplarily, step S805 can have the following two implementations.

[0158] In one implementation, the terminal can perform energy detection on the K first signals from the K candidate serving satellites, and determine the position of the terminal according to the result of the energy detection. The energy detection can be one or more of measurement of reference signal receiving power (RSRP), reference signal receiving quality (RSRQ) and reference signal strength indication (RSSI). Taking detection of RSRP as an example, it is assumed that K=3, the terminal measures the energy of the first signals respectively sent by satellite 1, satellite 2 and satellite 3, and the RSRP of the first signal sent by satellite 1 is the largest. It can be determined that the terminal is located closer to satellite 1 and is located in the coverage range of satellite 1. Then, the terminal can take the coverage range of satellite 1 as the position of the terminal.

[0159] In this implementation, the coverage area of the satellite sending the first signal with the largest signal strength in the K first signals is taken as the position of the terminal. With this implementation, the implementation is simple, and the calculation overhead of the terminal is saved.

[0160] In another implementation, energy detection can be performed on the K first signals from the K candidate serving satellites, and the position of the terminal can be determined according to the result of the energy detection and the positions of the K candidate serving satellites.

[0161] First, the terminal may perform energy detection on the K first signals from the K candidate serving satellites. The energy detection on the K first signals from the K candidate serving satellites may be performed as described above and will not be repeated here.

[0162] Then, the terminal may determine the distances from the K candidate serving satellites to the terminal according to the energy intensities of the K first signals.

[0163] Finally, the terminal can infer its location by combining the positions of K candidate service satellites.

[0164] As shown in FIG10 , which is another schematic diagram of multi-satellite positioning according to an embodiment of the present application, the terminal can determine the distance d from K satellites to the terminal based on the energy intensity of K first signals. UE-Sat . Based on the positioning method of field strength, there can be PL LOS Meet: PL LOS =K1+K2log 10 (d UE-Sat )+K3log 10 (f c )+K4 (Formula 2), where K1, K2, K3, and K4 are constants with different values ​​in different scenarios. According to the definition in TR 38.901, under LOS path, PL LOS Meet: PL LOS =31.84+21.50log 10 (d UE-Sat )+19.00log 10 (f c )(Formula 3). Where, PL LOS is the RSRP of the first signal measured by the terminal, etc., f c is the current frequency, d UE-Sat is the distance from the terminal to the satellite. Then, according to the coordinate positions of satellite 1, satellite 2, satellite 3 and the distances from the terminal to satellite 1, satellite 2, satellite 3 respectively, the terminal position (x UE ,y UE ) satisfies: (x Sat1 -x UE ) 2 +(y Sat1 -y UE ) 2 =d UE-Sat1 2 ; (x Sat2 -x UE ) 2 +(y Sat2 -y UE ) 2 =d UE-Sat2 2 ; (xSat3 - x UE ) 2 + (y Sat3 - y UE ) 2 = d UE-Sat3 2 ; ……Equation 4

[0165] where (x Sat1 , y Sat1 ), (x Sat2 , y Sat2 ), (x Sat3 , y Sat3 ) are the coordinate positions of satellite 1, satellite 2, satellite 3 respectively. d UE-Sat1 , d UE-Sat2 , d UE-Sat3 are the distances from the terminal to satellite 1, satellite 2, satellite 3 respectively. Above, as shown in Figure 10, the distances from the satellites to the terminal can be obtained by the measured RSRP of the signals, and the position of the terminal can be obtained according to the position equation, the positions of satellite 1, satellite 2, satellite 3, that is, the position of the terminal can be obtained by the intersection of three circles.

[0166] It is worth noting that if K = 1, the position of the terminal will be on a circle, and the accuracy is low; K = 2, the position of the terminal can have one solution (two circles are tangent) or two solutions (two circles intersect); K is greater than 2, the position of the terminal has a unique solution (common intersection point of more than three circles).

[0167] Thus, when K is greater than 2, the terminal positioning is accurate, but additional calculation and signaling overhead are required.

[0168] With this implementation, a more accurate position of the terminal can be obtained than the above implementation.

[0169] S806. The terminal sends a preamble to one of the K candidate serving satellites according to the position of the terminal and the ephemeris information of the K candidate serving satellites. Correspondingly, the candidate serving satellite receives the preamble.

[0170] After the terminal determines the K candidate serving satellites, the positions of the K candidate serving satellites, and the position of the terminal, since the satellites are always moving at high speed, and it takes a certain amount of time for the terminal to access the candidate serving satellites, the terminal determines the candidate serving satellite that can be accessed at the current time according to the strength of the K first signals and the like, but at the next time (the time when the terminal completes the access preparation), the candidate serving satellite can have been displaced. Therefore, before step S806, the method can further include the following step: determining a candidate serving satellite according to at least one of the position of the terminal, the positions of the K candidate serving satellites, the information about the relationship between the positions of the K candidate serving satellites in the ephemeris information and the time, and the strength of the K first signals. That is, the terminal can determine a candidate serving satellite according to one or more of the above information.

[0171] After the terminal determines the candidate serving satellite, the terminal sends a preamble to the candidate serving satellite.

[0172] Exemplarily, the access to the candidate serving satellite can specifically include the following steps:

[0173] First, the terminal determines the first TA according to the position of the terminal. The first TA is T1 in the above formula 1.

[0174] Then, the terminal determines the second TA for sending the PRACH according to the first TA. The second TA is T2 in the above formula 1. TA .

[0175] Finally, the terminal sends a preamble to one of the K candidate serving satellites to access the candidate serving satellite.

[0176] Wherein, the terminal accessing a candidate serving satellite can refer to the initial access process in NR as shown in FIG. 5, that is, the terminal first receives system messages such as SIB1 to determine the RO resource. Then, according to the second TA, the terminal sends a preamble to the candidate serving satellite. Then, the terminal receives the RAR from the candidate serving satellite. Then, the terminal sends Msg3 to the candidate serving satellite. Then, the candidate serving satellite sends Msg4 to the terminal for RRC establishment. Finally, the terminal sends Msg5 to the candidate serving satellite to complete the initial access process.

[0177] According to the communication method provided in the embodiment of the present application, the terminal is pre-configured with ephemeris information, the terminal determines one or more candidate service satellites according to the ephemeris information, and detects signals of the one or more candidate service satellites to determine multiple satellites and positions of the multiple satellites, thereby determining the position of the terminal. Therefore, the terminal can quickly and accurately determine its own position according to the signals of the multiple satellites before random access, and perform timing advance adjustment according to the position of the terminal and satellite ephemeris, and perform random access, thereby improving the access performance.

[0178] The problem of inaccurate GNSS acquisition caused by signal interference between GNSS signals and communication signals is avoided.

[0179] In the prior art, the terminal first accesses the network and then performs positioning of the terminal. In the embodiment, the terminal first performs positioning and then accesses the network, thereby improving the access performance and the positioning accuracy.

[0180] It is described above that the first signal includes at least one of the following signals: a synchronization signal and a PRS.

[0181] In the following embodiments, the case where the first signal includes both the synchronization signal and the PRS will be further described. That is, before initial access, the terminal can receive the synchronization signals and PRSs of multiple satellites simultaneously through multi-beam reception; or the multiple satellites can time-divisionally transmit the synchronization signals and PRSs, and the terminal can receive the synchronization signals and PRSs from the multiple satellites at different times. Here, the PRS is transmitted by the candidate service satellite to the terminal, and thus can also be referred to as a downlink-positioning reference signal (DL-PRS).

[0182] In one implementation, the time-domain resource positions of the synchronization signal and the PRS can be predefined fixed positions, and the PRS is associated with the synchronization signal. As shown in FIG. 11, which is a time-domain pattern diagram of a PRS according to an example of the embodiment of the present application, the synchronization signal occupies 4 symbols, and the DL-PRS occupies 2 symbols. The DL-PRS is transmitted immediately after the symbol of the synchronization signal, that is, the time-domain position of the DL-PRS is adjacent to the time-domain position of the synchronization signal. The synchronization signal #0 and the DL-PRS #0 use the same beam direction. With this implementation, the signals of the same beam direction can be transmitted on consecutive symbols, so that the terminal can quickly acquire the related signals (synchronization signal and PRS) of the satellite, thereby enabling downlink positioning in the initial access process to obtain the position information of the terminal, thereby improving the performance of the subsequent random access process.

[0183] The difference between this embodiment and the embodiment shown in FIG. 8 is step S805. In this embodiment, the terminal receives the synchronization signals and PRSs from the K candidate service satellites, performs positioning according to the PRSs (for example, a DL-TDOA or angle-of-arrival (AOA) positioning method can be used), and determines the position of the terminal.

[0184] After the terminal determines its own position, the terminal can access one of the K candidate service satellites according to the position of the terminal.

[0185] In another implementation, as shown in FIG. 12, which is another time-domain pattern diagram of a PRS according to an embodiment of the present application, the candidate service satellite can first transmit synchronization signals with different indexes (SS / PBCH index, corresponding to different beam directions) one by one, and then transmit DL-PRSs associated with the different synchronization signals. For example, synchronization signal #0 is associated with DL-PRS #0, indicating that the DL-PRS #0 and the synchronization signal #0 have a quasi co-location-Type D (QCL-Type D) relationship, that is, the beam directions of the DL-PRS #0 and the synchronization signal #0 are the same, and the coverage area of the beam on the ground is the same area.

[0186] In FIG. 12, the synchronization signals #0-7 occupy the first 4 slots (for 30 kHz subcarrier spacing) in a system frame (system frame number (SFN) #0 in the example in FIG. 12) and the 8 downlink positioning reference signals corresponding to the 8 synchronization signals occupy 2 slots in the empty slots after the synchronization signals. The number of slots here is only an example, and other values can be selected in practice. As can be seen in FIG. 12, the synchronization signals and the downlink positioning reference signals are separated by 4 slots, which is also only an example, and other values of the number of slots can be used in practice. The blank slots are to take into account the processing delay of the terminal when demodulating data, the beam switching delay of the candidate service satellite when transmitting signals with different beam directions, and the like, so generally some slots are left empty. If the terminal and the candidate service satellite have strong capabilities, these delays are small, and the interval can be 0.

[0187] Using the time-domain distribution of the synchronization signal and PRS, the candidate service satellite can concentrate on sending synchronization signals in different beam directions (the beam directions of the synchronization signal beams corresponding to different SS / PBCH indexes are different, and the geographical areas covered are different). In this way, the terminal can concentrate on detecting the synchronization signal, so as to determine which candidate service satellites can be received at the current time, and determine multiple satellites. And according to the ephemeris information, the current position of the candidate service satellite is determined. Then, according to the synchronization signal, the position of the downlink positioning reference signal corresponding to the synchronization signal is determined, and the downlink positioning reference signal transmitted by the candidate service satellite in the geographical area is received. According to the received downlink positioning reference signals of multiple satellites, the positioning estimation is performed to determine the position of the terminal.

[0188] In yet another implementation, as shown in FIG. 13, which is a schematic diagram of another time-domain pattern of PRS according to an embodiment of the present application, compared with the pattern of PRS in FIG. 12, the number of repetitions of DL-PRS is increased to improve the reliability of transmission. As shown in FIG. 13, the DL-PRS is repeated twice, thereby improving the performance of the downlink positioning reference performance. The number of repetitions can be indicated and configured by bits in the synchronization signal, and different numbers of repetitions can be supported.

[0189] In the above implementation, the position of the DL-PRS can be the same as the position of the synchronization signal, and the positions of the terminal and the satellite are known. In addition, the position of the DL-PRS can also be determined according to the position of the synchronization signal (SS / PBCH index).

[0190] In this embodiment, the PRS and the synchronization signal have the following differences:

[0191] On the one hand, the time-domain resources of the PRS and the synchronization signal are different. The time-domain resource of the synchronization signal is a fixed position, occupying 4 symbols, which is used for terminal cell search and downlink synchronization, from which the cell identifier (such as PCI) and frame timing are obtained. Here, the time-domain resource position of the PRS is only an example, and the PRS can also occupy different number of symbols, such as 1 symbol, 2 symbols, 3 symbols, 4 symbols, etc. The more the number of symbols, the larger the coverage range, which can meet the needs of different positioning accuracy. When the positioning accuracy requirement is high, more time-domain symbols can be configured; when the positioning accuracy requirement is not high, fewer time-domain symbols can be configured, thereby avoiding resource waste.

[0192] On the other hand, the frequency domain resource of PRS and synchronization signal is different. The bandwidth of synchronization signal is 20 resource blocks (RB), and the function of synchronization signal is mainly used for terminal to perform cell search and downlink synchronization, to obtain cell identification (such as PCI) and frame timing, etc. While for PRS used in initial access process, a larger bandwidth can be defined, the larger the bandwidth, the higher the signal sampling frequency, the greater the probability of accurately collecting the first path signal, and the better the positioning performance. The signal bandwidth of PRS can be defined as 24 RB, 36 RB, 48 RB, 96 RB, etc., and the signal bandwidth of PRS can be indicated in the synchronization signal.

[0193] In summary, the time-frequency resource of PRS can be indicated by predefining a table of time-frequency resources of PRS (such as Table 1), and by indicating the index of different configurations in the synchronization signal:

[0194] Table 1

[0195] In Table 1, when the index of the configuration indicated by the synchronization signal is "0", the PRS occupies 1 symbol and the bandwidth is 24 RB; when the index of the configuration indicated by the synchronization signal is "1", the PRS occupies 2 symbols and the bandwidth is 24 RB; and so on.

[0196] It can be understood that the above Table 1 is only an example, and in actual configuration, any row or multiple rows, any column or multiple columns in the table can be configured.

[0197] In yet another implementation, as shown in FIG. 14, it is a schematic diagram of a synchronization and positioning signal according to an embodiment of the present application. In this implementation, a synchronization and positioning signal can also be designed, which is sent to the terminal by the network side, and the terminal side performs timing synchronization and position positioning based on the signal. As shown in FIG. 14, 1 system frame includes 8 synchronization and positioning signals: synchronization and positioning signal #0 to synchronization and positioning signal #7, which occupy 8 time slots. The number of time slots and the number of synchronization and positioning signals are only examples, and other values can be used in actual implementation. These synchronization and positioning signals can be in different beam directions and cover different geographical areas.

[0198] The above describes the scheme provided by the embodiments of the present application from the perspective of interaction between the terminal and the satellite. Accordingly, the embodiments of the present application further provide a communication apparatus for implementing the above methods. The communication apparatus can be the terminal in the above method embodiments, or a communication module in the terminal, or a circuit or chip (such as a modem chip (also known as a baseband chip), or a system on chip or system in package chip containing a modem core) responsible for the communication function in the terminal; or the communication apparatus can be the satellite in the above method embodiments, or a module (such as a circuit, processor, chip or chip system) applied to the satellite. It can be understood that the communication apparatus contains the corresponding hardware structure and / or software module for executing each function in order to implement the above functions. Those skilled in the art should easily realize that, in combination with the units and algorithm steps of the examples described in the embodiments disclosed herein, the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a certain function is implemented in hardware or computer software driven hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0199] The embodiments of the present application can divide the functions of the communication apparatus according to the above method embodiments, for example, each function module can be divided according to each function, or two or more functions can be integrated in one processing unit. The above integrated module can be implemented in the form of hardware or software function module. It should be noted that the division of the modules in the embodiments of the present application is illustrative, and is only a logical function division. There can be another division manner in actual implementation.

[0200] Based on the same concept of the above communication method, the present application further provides a communication apparatus as follows:

[0201] As shown in FIG. 15, it is a structure schematic diagram of a communication apparatus provided by the embodiments of the present application. The communication apparatus 1500 includes a transceiver unit 1501 and a processing unit 1502; wherein:

[0202] When the communication apparatus is used to implement the functions of the terminal in the above method embodiments, the transceiver unit 1501 is used to perform one or more of the operations performed by the terminal in steps S802 and S806 of the embodiment shown in FIG. 8, and the processing unit 1502 is used to perform one or more of steps S801, S803-S805 of the embodiment shown in FIG. 8.

[0203] The transceiver 1501 is configured to implement the functions of the satellite in the method embodiments described above.

[0204] The specific implementation of the transceiver 1501 and the processing unit 1502 is described above.

[0205] As shown in FIG. 16, FIG. 16 is a structural schematic diagram of another communication device provided by the embodiments of the present application. The communication device 1600 includes one or more processors 1601 (one processor is shown in the figure). Optionally, the communication device 1600 can also include an interface circuit 1602 (shown in the figure with a dashed line), and the processor 1601 and the interface circuit 1602 are coupled to each other. It can be understood that the interface circuit 1602 can be a transceiver or an input / output interface. Optionally, the communication device 1600 can also include a memory 1603 (shown in the figure with a dashed line). The memory 1603 is used to store instructions executed by the processor 1601, or to store input data required by the processor 1601 to run instructions, or to store data generated after the processor 1601 runs instructions.

[0206] When the communication device is used to implement the functions of the terminal in the method embodiments described above, the interface circuit 1602 is configured to implement one or more of the operations performed by the terminal in steps S802 and S806 in the embodiment shown in FIG. 8, and the processor 1601 is configured to implement one or more of steps S801 and S803-S805 in the embodiment shown in FIG. 8.

[0207] When the communication device is used to implement the functions of the satellite in the method embodiments described above, the interface circuit 1602 is configured to implement one or more of the operations performed by the satellite in steps S802 and S806 in the embodiment shown in FIG. 8.

[0208] When the communication device is a chip applied to a terminal, the chip implements the functions of the terminal in the method embodiments described above. The chip receives information from other modules (such as a radio frequency module or an antenna) in the terminal, and the information is sent by the satellite to the terminal; or the chip sends information to other modules (such as a radio frequency module or an antenna) in the terminal, and the information is sent by the terminal to the satellite.

[0209] When the communication device is a chip applied to a satellite, the chip implements the functions of the satellite in the method embodiments described above. The chip receives information from other modules (such as a radio frequency module or an antenna) in the satellite, and the information is sent by the terminal to the satellite; or the chip sends information to other modules (such as a radio frequency module or an antenna) in the satellite, and the information is sent by the satellite to the terminal.

[0210] In addition, it should be noted that the aforementioned transceiver unit and / or processing unit can be implemented by a virtual module, for example, the processing unit can be implemented by a software function unit or a virtual device, and the transceiver unit can be implemented by a software function or a virtual device. Alternatively, the processing unit or the transceiver unit can also be implemented by an entity device, for example, if the device is implemented by a chip / chip circuit, the transceiver unit can be an input / output circuit and / or a communication interface, which performs an input operation (corresponding to the aforementioned receiving operation) and an output operation (corresponding to the aforementioned sending operation); the processing unit is an integrated processor or a microprocessor or an integrated circuit.

[0211] The division of the modules in the present application is illustrative, and is only a logical function division. In actual implementation, there can be another division manner. In addition, each function module in each example of the present application can be integrated in one processor, or can be a separate physical existence, or two or more modules can be integrated in one module. The integrated module can be realized in the form of hardware or in the form of a software function module.

[0212] It can be understood that the processor in the embodiments of the present application can be a central processing unit (CPU), and can also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs) or other programmable logic devices, transistor logic devices, hardware components or any combination thereof. The general-purpose processor can be a microprocessor or any conventional processor.

[0213] The embodiments of the present application further provide a computer readable storage medium, which stores a computer program or instructions, when the computer program or instructions are executed, the method in the above embodiments is implemented.

[0214] The embodiments of the present application further provide a computer program product containing instructions, when the instructions are run on a computer, the computer is caused to execute the method in the above embodiments.

[0215] The embodiments of the present application further provide a communication system, which comprises the communication device described above.

[0216] The embodiments of the present application further provide a circuit, which is coupled with a memory, and is used for executing the method shown in the above embodiments. The circuit can include a chip circuit.

[0217] When the communication device is a satellite module, the satellite module implements the functions of the satellite in the method embodiments. The satellite module receives information from other modules (such as a radio frequency module or an antenna) in the satellite, and the information is sent by the terminal to the satellite; or the satellite module sends information to other modules (such as a radio frequency module or an antenna) in the satellite, and the information is sent by the satellite to the terminal. The satellite module here can be a baseband chip of the satellite, or a CU, a DU or other modules, or a device under the O-RAN architecture, such as an open CU, an open DU, etc.

[0218] It should be noted that one or more of the above units or units can be realized by software, hardware or a combination of both. When any of the above units or units is realized by software, the software exists in the form of computer program instructions and is stored in the memory, and the processor can be used to execute the program instructions and realize the above method flow.

[0219] In this application, the processor can be a general processor, a digital signal processor, an application specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, or all or part of the circuits of the foregoing devices for implementing processing functions. The general processor can be a microprocessor or any conventional processor. The steps of the method disclosed in the present application can be directly embodied as hardware processor execution or executed by a combination of hardware and software modules in the processor.

[0220] When the above units or units are realized by hardware, the hardware can be any one or any combination of CPU, microprocessor, digital signal processing (DSP) chip, microcontroller unit (MCU), artificial intelligence processor, ASIC, SoC, FPGA, PLD, special digital circuit, hardware accelerator or non-integrated discrete device, which can run necessary software or not rely on software to execute the above method flow.

[0221] Optionally, the embodiments of the present application also provide a chip system, comprising: at least one processor and an interface, the at least one processor is coupled with the memory through the interface, when the at least one processor runs the computer program or instructions in the memory, so that the chip system executes the method in any of the above method embodiments. Optionally, the chip system can be composed of a chip, or can include a chip and other discrete devices, and the embodiments of the present application do not make specific limitation to this.

[0222] The memory in the present application can also be a circuit or other any device capable of realizing the storage function, used for storing program instructions and / or data. The memory is any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but is not limited thereto. For example, the memory can be a non-volatile memory such as a digital versatile disc (DVD), a hard disk drive (HDD), or a solid-state drive (SSD), etc., and can also be a volatile memory such as a random-access memory (RAM).

[0223] The terms "comprising" and "having" and any variations thereof as mentioned in the present application are intended to cover the unexhaustive inclusion. For example, a process, method, system, product, or apparatus that includes a list of steps or units is not limited to the listed steps or units, but can optionally include other steps or units not listed, or can optionally include other steps or units inherent to the process, method, product, or apparatus. It should be noted that the words "exemplary" or "for example" in the present application are used to mean serving as an example, instance, or illustration. Any method or design scheme described as "exemplary" or "for example" in the present application should not be interpreted as more preferred or advantageous than other methods or design schemes. Rather, the use of "exemplary" or "for example" is intended to present the relevant concept in a specific manner.

[0224] It should be understood that, in the description of the present application, unless otherwise specified, " / " represents that the objects associated in front and back are in an "or" relationship, for example, A / B can represent A or B; wherein A, B can be singular or plural. And, in the description of the present application, unless otherwise specified, "multiple" means two or more than two. "At least one of the following" or the like means any combination of the items, including any combination of single or multiple items. For example, at least one of a, b, or c can represent: a, b, c, a-b, a-c, b-c, or a-b-c, wherein a, b, c can be single or multiple. In addition, in order to clearly describe the technical solutions of the embodiments of the present application, in the embodiments of the present application, the same items or similar items with basically the same function and role are distinguished by using "first", "second", etc. The skilled in the art can understand that "first", "second", etc. do not limit the quantity and execution order, and "first", "second", etc. do not necessarily mean different. At the same time, in the embodiments of the present application, "exemplary" or "for example" means to serve as an example, illustration or description. Any embodiment or design scheme described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as more preferred or more advantageous than other embodiments or design schemes. Rather, the use of "exemplary" or "for example" is intended to present the relevant concept in a specific manner, for understanding.

[0225] In the above embodiments, all or part can be realized by software, hardware, firmware or any combination thereof. When realized by software, all or part can be realized in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, the computer instructions can be transmitted from one website, computer, network device or data center to another website, computer, network device or data center through wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.).

[0226] Although the present application is described in conjunction with the embodiments thereof, other changes and modifications to the described embodiments can be understood and effected by those skilled in the art in view of the foregoing description, the drawings and the appended claims. In the claims, a single processor or other unit can carry out several functions in the claims. Measures described in mutually different dependent claims can be combined and carried out in a single claim.

[0227] It can be understood that various digital numbers involved in the embodiments of the present application are only distinguished for convenience of description, and are not used to limit the scope of the embodiments of the present application. The size of the serial number of the above processes does not mean the order of execution, and the execution order of the processes should be determined according to its function and inherent logic.

[0228] In the above embodiments, the description of each embodiment is focused on, and the part not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0229] The components in the device of the embodiments of the present application can be combined, divided and deleted according to actual needs. Those skilled in the art can combine or combine the features of different embodiments and different embodiments described in the specification.

[0230] In the present application, the examples can be referred to each other without logical contradiction, for example, the methods and / or terms between the method embodiments can be referred to each other, for example, the functions and / or terms between the device embodiments can be referred to each other, for example, the functions and / or terms between the device examples and the method examples can be referred to each other.

Claims

1. A communication method characterized by comprising: The method comprises: obtaining ephemeris information, the ephemeris information comprising information about the relationship between the positions and times of M satellites, M being a positive integer; receiving at least N first signals from N satellites, the M satellites comprising the N satellites, N being a positive integer less than or equal to M; determining K candidate serving satellites from the at least N first signals, the N satellites comprising the K candidate serving satellites, K being a positive integer less than or equal to N; determining the positions of the K candidate serving satellites from the information about the relationship between the positions and times of the K candidate serving satellites in the ephemeris information; determining the position of a terminal from the positions of the K candidate serving satellites and the K first signals from the K candidate serving satellites, the at least N first signals comprising the K first signals; sending a preamble to one of the K candidate serving satellites according to the position of the terminal and the ephemeris information of the K candidate serving satellites.

2. The method of claim 1, wherein, The sending of the preamble to one of the K candidate serving satellites according to the position of the terminal and the ephemeris information of the K candidate serving satellites comprises: determining the one candidate serving satellite according to at least one of the position of the terminal, the positions of the K candidate serving satellites, the information about the relationship between the positions and times of the K candidate serving satellites in the ephemeris information, and the intensities of the K first signals; sending the preamble to the one candidate serving satellite.

3. The method of claim 1 or 2, wherein, Before the receiving of the at least N first signals from the N satellites, the method further comprises: determining X satellites from a first time and the ephemeris information, the M satellites comprising the X satellites, the X satellites comprising the N satellites, X being an integer greater than or equal to N and less than or equal to M.

4. The method of any one of claims 1-3, wherein, The determining of the position of the terminal from the positions of the K candidate serving satellites and the K first signals from the K candidate serving satellites comprises: performing energy detection on the K first signals from the K candidate serving satellites; determining the position of the terminal according to the result of the energy detection; or determining the position of the terminal according to the result of the energy detection and the positions of the K candidate serving satellites.

5. The method of any one of claims 1-4, wherein, The first signals comprise at least one of the following signals: synchronization signals SS / PBCH, positioning reference signals PRS, synchronization and positioning signals.

6. The method of claim 5, wherein, The first signals comprise synchronization signals and positioning reference signals, the positioning reference signals being associated with the synchronization signals.

7. The method of claim 6, wherein, The time-domain position of the positioning reference signals is adjacent to the time-domain position of the synchronization signals, and / or the beam direction corresponding to the positioning reference signals is the same as the beam direction corresponding to the synchronization signals.

8. The method of any one of claims 1-7, wherein, The accessing of one of the K candidate serving satellites according to the position of the terminal comprises: determining a first timing advance TA according to the position of the terminal; determining a second TA for sending a physical random access channel PRACH according to the first TA; accessing one of the K candidate serving satellites.

9. A communication method characterized by comprising: The method comprises: generating a first signal, the first signal being used for determination of a candidate service satellite, a position of the candidate service satellite and a position of a terminal; transmitting the first signal; receiving a preamble from the terminal.

10. The method of claim 9, wherein, The first signal comprises at least one of the following signals: a synchronization signal SS / PBCH, a positioning reference signal PRS, a synchronization and positioning signal.

11. The method of claim 10, wherein, The first signal comprises a synchronization signal and a positioning reference signal, the positioning reference signal being associated with the synchronization signal.

12. The method of claim 11, wherein, A time domain position of the positioning reference signal is adjacent to a time domain position of the synchronization signal, and / or a beam direction corresponding to the positioning reference signal is the same as a beam direction corresponding to the synchronization signal.

13. A communications device, characterized by The apparatus comprises modules or units for implementing the method according to any one of claims 1-8.

14. A communications device, characterized by The apparatus comprises modules or units for implementing the method according to any one of claims 9-12.

15. A computer-readable storage medium, characterized in that, The computer readable storage medium stores a computer program or instructions, when the computer program or instructions are executed by a computer, the method according to any one of claims 1-12 is implemented.

16. A computer program product, characterised in that, When the computer reads and executes the computer program product, the computer is caused to execute the method according to any one of claims 1-12.

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