Terminal positioning method and device

Abstract

The invention discloses a terminal positioning method and device. The method comprises the following steps: a terminal obtains ephemeris information; receiving at least N first signals from N satellites; determining K candidate service satellites according to the at least N first signals; determining the positions of the K candidate service satellites according to the information of the relationship between the positions of the K candidate service satellites in the ephemeris information and the time; 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; and accessing one candidate service satellite in the K candidate service satellites according to the position of the terminal. According to the scheme of the invention, the terminal can determine the position of the terminal according to the multi-satellite signal before random access, carries out the timing advance adjustment according to the position of the terminal and the satellite ephemeris, carries out the random access, and improves the access performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of communication, and in particular to a terminal positioning method and device. BACKGROUND

[0002] In a satellite communication system, high-speed movement of a satellite can cause time-frequency offset variation, and a terminal needs to perform time-frequency offset pre-compensation 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.

[0003] Currently, a terminal mainly obtains its own position by using global navigation satellite system (GNSS) signals. However, if the GNSS signals are inaccurate or it takes too long to obtain the GNSS signals in an access stage, the performance of the terminal in accessing the network will be affected.

[0004] 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

[0005] The present application provides a communication method and device to quickly and accurately obtain its own position, thereby improving the performance of accessing the network.

[0006] In a first aspect, a communication method is provided. The method can be applied to a terminal side, for example, a terminal or a communication module in the terminal, or a circuit or chip responsible for a communication function in the terminal (such as a modem chip (also known as a baseband chip), or a system on chip (SoC) chip or a system in package (SIP) chip containing a modem core). Taking the case where the method is applied to a terminal, in the method, 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 service satellites according to the at least N first signals, the N satellites including the K candidate service satellites, K being a positive integer less than or equal to N; determines positions of the K candidate service satellites according to information about a relationship between positions and times of the K candidate service satellites in the ephemeris information; determines a position of the terminal according to the positions of the K candidate service satellites and K first signals from the K candidate service satellites, the at least N first signals including the K first signals; and sends a preamble to one of the K candidate service satellites according to the position of the terminal and ephemeris information of the K candidate service satellites.

[0007] In this aspect, by preconfiguring the ephemeris information in the 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 the multi-satellite and the position of the multi-satellite, and thereby determines 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, and perform random access, thereby improving the access performance.

[0008] In a possible implementation of the first aspect, before the above receiving the at least N first signals from the N satellites, the method further comprises: determining X satellites according to the first time and the ephemeris information, the M satellites comprising the X satellites, the X satellites comprising the N satellites, and the X being an integer greater than or equal to the N and less than or equal to the M.

[0009] In this implementation, since the terminal pre-stores the ephemeris information, the terminal can calculate the currently possible service satellites according to the time information.

[0010] In another 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.

[0011] In this implementation, the terminal determines the position of the terminal according to the result of the energy detection. By selecting the first signal with the strongest signal strength in the K first signals, the coverage area of the satellite sending the first signal is taken as the position of the terminal. With this implementation, the realization is simple, and the calculation cost of the terminal is saved.

[0012] 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. A relatively accurate position of the terminal can be obtained.

[0013] In yet another possible implementation of the first aspect, before the above accessing one of 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.

[0014] In a possible implementation form 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), a synchronization and positioning signal.

[0015] In a possible implementation form 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.

[0016] In this implementation form, 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. A larger bandwidth can be defined for the PRS used in the initial access process. 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.

[0017] In a 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.

[0018] In a possible implementation form of the first aspect, the accessing one of the K candidate service 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 one of the K candidate service satellites.

[0019] In a second aspect, a communication method is provided. The method 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 service satellite generates a first signal, the first signal is used for determining the position of the candidate service satellite, the position of the candidate service satellite, and the position of a terminal; the first signal is sent; and a preamble from the terminal is received.

[0020] In this aspect, by pre-configuring the terminal with ephemeris information, 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 the multi-satellite and the position of the multi-satellite, and thereby determines 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, and perform random access, thereby improving the access performance.

[0021] In a possible implementation of the second aspect, the first signal includes at least one of the following: an SS / PBCH, a PRS, a synchronization and positioning signal.

[0022] In another possible implementation of the second aspect, the first signal includes a synchronization signal and a positioning reference signal, and the positioning reference signal is associated with the synchronization signal.

[0023] In yet another possible implementation of the second 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.

[0024] In a third aspect, a communication apparatus is provided, which has 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 by software or hardware, or by a combination of software and hardware.

[0025] In a fourth aspect, a communication apparatus is provided, which has 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 by software or hardware, or by a combination of software and hardware.

[0026] 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 one of the first aspect, the second aspect, or any one of the implementations. For example, the communication apparatus can include a sending unit, a receiving unit, and can also include 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").

[0027] In a possible implementation form of the third aspect, the processing unit is further configured to determine X satellites according to the first time and the ephemeris information, the M satellites comprise the X satellites, the X satellites comprise the N satellites, and X is an integer greater than or equal to N and less than or equal to M.

[0028] In a possible implementation form of the third aspect, the processing unit is further configured to determine X satellites according to the first time and the ephemeris information, the M satellites comprise the X satellites, the X satellites comprise the N satellites, and X is an integer greater than or equal to N and less than or equal to M.

[0029] In a possible implementation form 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, and determine the position of the terminal according to a result of the energy detection, or determine the position of the terminal according to the result of the energy detection and the positions of the K candidate serving satellites.

[0030] In a possible implementation form 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 positions and time of the K candidate serving satellites in the ephemeris information, and the K first signals.

[0031] In a possible implementation form 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 positions and time of the K candidate serving satellites in the ephemeris information, and strengths of the K first signals.

[0032] In a further possible implementation form of the third aspect, the first signal comprises at least one of: an SS / PBCH, a PRS, a synchronization and positioning signal.

[0033] In a further possible implementation form of the third aspect, the first signal comprises a synchronization signal and a positioning reference signal, the positioning reference signal being associated with the synchronization signal.

[0034] In a further possible implementation form 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.

[0035] In a further possible implementation form of the third aspect, the processing unit is further configured to determine the first TA based on a position of the terminal, the processing unit is further configured to determine a second TA for transmitting a PRACH based on the first TA, and the transceiver is further configured to access one of the K candidate serving satellites.

[0036] In a further possible implementation form of the third aspect, 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.

[0037] In a further possible implementation form of the fourth aspect, the first signal comprises at least one of: an SS / PBCH, a PRS, a synchronization and positioning signal.

[0038] 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.

[0039] 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.

[0040] In another possible implementation, the communication apparatus in the third aspect to the fourth aspect above includes a memory and one or more processors. The memory is configured to store part or all of the computer programs or instructions necessary to implement the functions involved in the first aspect or the second aspect above. The one or more processors are configured to execute the computer programs or instructions, when the computer programs or instructions are executed, causing the communication apparatus to implement the method in any possible design or implementation of the first aspect or the second aspect above.

[0041] In a possible design, the communication apparatus can further include an interface circuit, and the processor is configured to communicate with other apparatuses or components through the interface circuit.

[0042] In a possible design, the communication apparatus can further include the memory.

[0043] When the communication apparatus is used 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 referred to as a baseband chip) or a SoC or SIP chip containing a modem module.

[0044] When the communication apparatus is used to implement the functions of the second aspect, the communication apparatus can be a satellite, or a component in the satellite.

[0045] The fifth aspect provides a computer-readable storage medium, and the computer-readable storage medium stores computer programs or instructions. When the computer programs or instructions are executed by a computer, the method in the aspects above is implemented.

[0046] The sixth aspect provides a computer program product. When a computer reads and executes the computer program product, the computer executes the method in the aspects above.

[0047] In a seventh aspect, a communication system is provided, the communication system comprising a terminal and a plurality of satellites; wherein the terminal is configured to obtain ephemeris information, the ephemeris information comprising information of a relationship between positions and time of the plurality of satellites, the plurality of satellites comprising M satellites, M being a positive integer; the plurality of satellites comprising N satellites, N being a positive integer less than or equal to M, are configured to generate at least N first signals, the at least N first signals comprising K first signals, K being a positive integer less than or equal to N; the plurality of satellites are further configured to transmit the at least N first signals to the terminal; the terminal is further configured to determine K candidate serving satellites from the at least N first signals, the K candidate serving satellites comprising the N satellites, the K candidate serving satellites comprising the K first signals; the terminal is further configured to determine positions of the K candidate serving satellites from the information of the relationship between the positions and time of the K candidate serving satellites in the ephemeris information; the terminal is further configured to determine a position of the terminal from the positions of the K candidate serving satellites and the K first signals from the K candidate serving satellites; and the terminal is further configured to transmit a preamble to one of the K candidate serving satellites based on the position of the terminal and the ephemeris information of the K candidate serving satellites.

[0048] In a possible implementation form of the seventh aspect, the terminal is further configured to determine the one of the K candidate serving satellites based on at least one of the position of the terminal, the positions of the K candidate serving satellites, the information of the relationship between the positions and time of the K candidate serving satellites in the ephemeris information, and intensities of the K first signals; and the terminal is further configured to transmit the preamble to the one of the K candidate serving satellites.

[0049] In another possible implementation form of the seventh aspect, the terminal is further configured to determine X satellites from a first time and the ephemeris information, the plurality of 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.

[0050] In yet another possible implementation form of the seventh aspect, the terminal is further configured to perform energy detection on the K first signals from the K candidate serving satellites; the terminal is further configured to determine the position of the terminal based on a result of the energy detection; or determine the position of the terminal based on the result of the energy detection and the positions of the K candidate serving satellites.

[0051] In yet another possible implementation form of the seventh aspect, the first signals comprise at least one of the following: synchronization signal / physical broadcast channel (SS / PBCH), positioning reference signal (PRS), synchronization and positioning signal.

[0052] In a possible implementation form 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.

[0053] In a possible implementation form of the seventh 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.

[0054] In a possible implementation form of the seventh aspect, the terminal is further configured to determine a first timing advance TA according to a position of the terminal, determine a second TA for sending a physical random access channel PRACH according to the first TA, and send the preamble to one of the K candidate serving satellites. BRIEF DESCRIPTION OF DRAWINGS

[0055] Figure 1 A simplified schematic diagram of a wireless communication system provided by the embodiments of the present application;

[0056] Figure 2 A schematic diagram of communication between multiple satellites and a terminal;

[0057] Figure 3 A schematic diagram of an initial access procedure and timing advance adjustment for satellite communication;

[0058] Figure 4 A schematic diagram of uplink and downlink timing;

[0059] Figure 5 A schematic diagram of an initial access procedure in NR;

[0060] Figures 6a-6c A schematic diagram of an application scenario of a satellite-terrestrial integrated network;

[0061] Figure 7a A schematic diagram of a transparent forwarding scenario for satellite communication;

[0062] Figure 7b A schematic diagram of a regenerative mode scenario for satellite communication;

[0063] Figure 8 A schematic diagram of a communication method provided by the embodiments of the present application;

[0064] Figure 9 And Figure 10 A schematic diagram of multi-satellite positioning according to an example of the embodiments of the present application;

[0065] Figures 11-13 A schematic diagram of a time domain pattern of PRS according to an example of the embodiments of the present application;

[0066] Figure 14 FIG. 1 shows a schematic diagram of a synchronization and positioning signal according to an embodiment of the present application;

[0067] Figure 15 and Figure 16 FIG. 2 shows a schematic diagram of a communication device according to an embodiment of the present application. DETAILED DESCRIPTION

[0068] The embodiments of the present application will be described below with reference to the drawings.

[0069] The techniques provided by this application can be applied to various communications systems. For example, the communications system can be a fourth generation (4G) communications system (e.g., a long term evolution (LTE) system), a fifth generation (5G) communications system, a worldwide interoperability for microwave access (WiMAX) system, a wireless local area network (WLAN) system, a satellite communications system, a converged system of multiple systems, or a future communications system, such as a sixth generation (6G) communications system, etc. The 5G communications system can also be referred to as a new radio (NR) system. th th th

[0070] 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.

[0071] In addition, in the embodiments of the present application, the words "exemplary", "for example", "for instance", etc. are used to mean example, illustration, or description. Any embodiment or design presented as "exemplary" in the present application should not be interpreted as being more preferred or advantageous than other embodiments or design schemes. Rather, the word "exemplary" is used to present concepts in a particular manner. In the embodiments of the present application, "of", "corresponding" and "corresponding" can be used interchangeably, and it should be pointed out that when their differences are not emphasized, their meanings are consistent.

[0072] ​​​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 appearance of new service scenarios, the technical solutions provided by the embodiments of the present application are also applicable to similar technical problems.

[0073] A network element in a communication system can send a signal to another network element or receive a signal from another network element. The signal can include information, signaling, data, and the like. 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, and the like. The network element is taken as an example for description in the present application. For example, the communication system can include at least one terminal and at least one access network device. The access network device can send a downlink signal to the terminal, and / or the terminal can send an uplink signal 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.

[0074] Referring to Figure 1 , Figure 1 A simplified schematic diagram of a wireless communication system provided by the embodiments of the present application is shown. As shown in Figure 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, Figure 1 This 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 Figure 1 .

[0075] Optionally, in actual applications, the wireless communication system can simultaneously include multiple network devices (also referred to as access network devices), and can also simultaneously include multiple terminals. One network device can simultaneously serve one or more terminals. One terminal can also simultaneously access one or more network devices. The number of terminals and network devices included in the wireless communication system is not limited by the embodiments of the present application.

[0076] 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, Node B, evolved Node B (eNB), next generation Node B (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.

[0077] Network devices can be either fixed or mobile. For example, base stations 110b, 110c are stationary and responsible for wireless transmission and reception in one or more cells from terminals 120. Figure 1 A helicopter or drone 120c shown in the middle 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 function as a terminal that communicates with the satellite base station 110a.

[0078] 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.

[0079] Optionally, the terminal can be used to act as a base station. For example, a UE can act as a scheduling entity which provides a sidelink signal 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 a sidelink signal. The cellular phone 120a and the smart home device 120e communicate without relaying the communication signal through the base station 110b. Figure 1 As shown in FIG. 1, the cellular phone 120a and the car 120b communicate with each other using a sidelink signal. The cellular phone 120a and the smart home device 120e communicate without relaying the communication signal through the base station 110b.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] Taking eCPRI Cat A as an example, for downlink transmission, with layer mapping as the 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 cyclic prefix (CP)) after layer mapping are implemented in the RU. For uplink transmission, with de-RE mapping as the 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, which is not described herein.

[0086] In a possible design, the processing unit in the BBU for implementing baseband functions is referred to as a baseband high (BBH) unit, and the processing unit in the RRU / AAU / RRH for implementing baseband functions is referred to as a baseband low (BBL) unit.

[0087] 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.

[0088] 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 in this embodiment of this application is not limited in this way.

[0089] It can be understood that the present application can be applied between a network device and a terminal.

[0090] 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 one possible implementation, a service data adaptation protocol (SDAP) layer can be further included above the PDCP layer.

[0091] Optionally, the protocol layer structure between the network device and the terminal can further include an artificial intelligence (AI) layer for transmitting AI function related data.

[0092] Taking the 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 the 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 transmits the data wirelessly 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 the 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.

[0093] Exemplarily, the terminal can also have an application layer and a non-access layer. The application layer can be used to provide services to applications installed in the terminal, for example, the downlink data received by the terminal can be sequentially transmitted to the application layer by the physical layer, and then provided to the application by the application layer; for another example, the application layer can obtain the data generated by the application, and sequentially transmit the data to the physical layer 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.

[0094] It should be understood that Figure 1 The number and type of devices in the illustrated communication system are merely illustrative, and the present application is not limited thereto. In actual applications, more terminals and more access network devices can be included in the communication system, and other network elements can also be included, for example, core network devices and / or network elements for implementing artificial intelligence functions.

[0095] 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.

[0096] 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. 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 fiber cables 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.

[0097] Currently, satellites are 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, because satellites have advantages such as not being easily affected by natural disasters or external damage. 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.

[0098] Compared with a terrestrial communication system, a single satellite has a wider coverage area and a longer transmission distance, and it is a significant feature of a satellite communication system to provide services to terminals through wide coverage. For example, Figure 2As shown in the figure, it is a schematic diagram of communication between multiple satellites and terminals. In the future, with the large-scale networking of satellites, the number and capabilities of satellites will gradually increase. A terminal can receive signals from multiple satellites (physical cell identifier (PCI)

[0099] #1 to PCI N (where N is a positive integer). Furthermore, with future evolution, terminal capabilities will gradually improve, enabling multi-beam reception.

[0100] In satellite communication systems, high-speed satellite movement causes time and frequency offset variations. Terminals must pre-compensate for this offset based on their own location to ensure network access and communication performance. Therefore, it is crucial to quickly and accurately determine the terminal's location to improve subsequent network access performance.

[0101] Timing advance adjustment based on GNSS signals:

[0102] Currently, during the initial access process of satellite communications, the terminal obtains its own position based on GNSS signals. It also determines the timing advance (TA) based on its own position and ephemeris information and makes TA adjustments.

[0103] Among them, such as Figure 3 The following is a schematic diagram of the initial access process and timing advance adjustment for satellite communications. During the initial access process, the steps related to timing advance are as follows:

[0104] In the first step, 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).

[0105] In the second step, the terminal determines the TA, makes timing advance adjustment, and sends a physical random access channel (PRACH).

[0106] Among them, such as Figure 4 As shown in the figure, it is a schematic diagram of the uplink and downlink timing. The terminal is in advance of T in the downlink frame number i. TA is the uplink frame number i, the T TA satisfy:

[0107]

[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 according to TS 38.133 is taken. N TA,offset is determined by the duplex mode and frequency range 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 higher layer parameters TACommon, TACommonDrift, TACommonDriftVariation are configured, N is determined according to the network configuration parameters; if not configured, 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; and TACommonDriftVariation represents the drift rate variation of the common TA.

[0111] The one-way propagation delay Delay common (t) between the reference point and the satellite is

[0112] If the relevant higher layer parameters of the serving satellite ephemeris are configured, N is determined by the terminal according to the terminal's position and satellite ephemeris; otherwise, it is 0.

[0113] Initial access procedure of NR:

[0114] As shown in Figure 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 specific implementation is as follows:

[0115] 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.

[0116] 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. RRC setup request (RRCSetupRequest)) for RRC setup request.

[0117] Third step, the terminal starts a window to listen to RAR after sending PRACH.

[0118] 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.

[0119] Fourth step, the terminal sends message 3 (Msg3) to the network device.

[0120] Fifth step, the network device sends message 4 (Msg4) (i.e. RRC setup (RRCSetup)) for RRC setup, and the terminal sends message 5 (Msg5) to complete the initial access process.

[0121] NR downlink positioning:

[0122] Downlink positioning reference signals are defined in NR. The network device can send positioning reference signals in 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.

[0123] 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) to the terminal, and then reports the DL RSTD measurement information to a location management function (LMF) network element. The LMF uses the known TRP position and the RSTD measurement result to solve the specific position of the terminal. 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, the worse the performance.

[0124] This positioning process requires the terminal to report the positioning capability to the LMF. The LMF needs to provide the terminal with NR GCI, transmission and receiving point identification (TRP ID), PRS configuration of the TRP, time and frequency domain occupation of the synchronization signal, and other auxiliary data. 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.

[0125] As can be seen from the above, in the initial access process, the PRACH is sent with a timing advance determined according to the terminal position, 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, because the accurate GNSS signal cannot be quickly obtained (possibly because the time consumed for obtaining the GNSS signal is long, or because the frequency points of the GNSS signal and the communication signal are adjacent, strong interference exists, and the terminal side cannot obtain the accurate own position, etc.), the TA for sending the PRACH determined by the terminal 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.

[0126] Therefore, the application provides a communication scheme. The terminal is preconfigured with ephemeris information. 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 the position of the terminal according to the signals of the multiple satellites before random access, and performs timing advance adjustment according to the position of the terminal and satellite ephemeris, and performs random access, thereby improving access performance.

[0127] The application is not limited to the satellite scenario, and is still applicable in future 6G evolution.

[0128] As shown in Figures 6a-6c , it is a schematic diagram of an application scenario of a satellite-ground fusion network. A terminal on the ground can access the network through an air interface (the air interface can be various types of air interfaces, such as a 5G air interface). In Figure 6a , a base station can be deployed on the ground and connected to a ground station that communicates with a satellite; in Figure 6b , a base station can be deployed on a 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 (that is, the corresponding base station is deployed on the ground), the satellite only implements transparent forwarding between satellites. If the base station or part of the base station function is deployed on the satellite, the satellite can complete signaling interaction and user data transmission between base stations. Figure 6c

[0129] The typical scenarios in which the NTN network provides terminal access are transparent payload and regenerative payload. As shown in Figure 7a , it is a schematic diagram of a transparent forwarding scenario of satellite communication. Transparent forwarding means that the satellite only functions as a frequency converter and a forwarder, that is, it is equivalent to an analog radio frequency repeater. Therefore, the satellite replicates 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 replicates 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. Figure 7b ​The figure shows a schematic diagram of a regenerative mode scenario for satellite communications. Regenerative mode refers to the inclusion of network equipment or a digital processing unit (DU) on the satellite. In this architecture, the satellite acts as a base station, regenerating signals received from the ground. Specifically, the service link between the terminal and the satellite transmits NR-Uu radio interface signals, while the feeder link between the NTN gateway and the satellite transmits satellite radio interface signals. The SRI interface is a transmission link between the NTN gateway and the satellite. NG interface signals are transmitted to the NTN gateway via the SRI interface, where they are forwarded by the NTN gateway and delivered to core network equipment on the ground.

[0130] The following describes the communication method provided by this application based on the above communication system:

[0131] like Figure 8 , which is a flow chart of a communication method provided in an embodiment of the present application. Figure 8 The method is illustrated by taking the satellite and the terminal as the execution subjects of the interactive diagram as an example, but the present application does not limit the execution subjects of the interactive diagram. Figure 8 The method performed by the satellite may also be performed by a module (such as a circuit, a processor, a chip or a chip system, etc.) applied to the satellite; Figure 8 The method executed by the terminal in the embodiment may also be executed by a communication module in the terminal, or a circuit or chip in the terminal responsible for communication functions (such as a modem chip (also known as a baseband chip), or a system-on-chip chip or system-in-package chip containing a modem core). Exemplarily, the method may include the following steps:

[0132] S801. The terminal obtains ephemeris information.

[0133] In one example, the ephemeris information may be configured to the terminal by a ground base station.

[0134] For example, ephemeris information for the local satellite and / or neighboring satellites can be carried in SIB19. SIB19 carries auxiliary information for NTN access, including ephemeris information for the local satellite, ephemeris information for neighboring satellites, range thresholds, and NTN configuration (ntn-Config). SIB19 supports configuration of ephemeris information for eight neighboring satellites. ntn-Config provides parameters required for terminal access to the NTN network, such as ephemeris data, common TA parameters, K_offset, and the validity period and reference time of uplink synchronization information.

[0135] In another example, the ephemeris information may be provided to the terminal in a pre-configured manner. For example, the ephemeris information is burned into the terminal when the terminal leaves the factory.

[0136] In the embodiment, the ephemeris information includes information of the relationship between the positions of the M satellites and time. The terminal can calculate the positions of the satellites at a fixed time according to the ephemeris information. M is a positive integer.

[0137] For example, the relationship between the positions of the satellites and time can be represented in at least one of the following forms: a table, a mapping relationship, and function coefficients.

[0138] 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.

[0139] For example, since the terminal pre-stores the ephemeris information, the terminal can first calculate the X satellites that can currently serve according to the time information. Before step S802, the method can further include the following step: the terminal determines the 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.

[0140] In a specific implementation, since the ephemeris information includes information of the relationship between the positions of the M satellites and 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 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 the X satellites that satisfy the distance threshold condition by combining the distance threshold value. For example, satisfying the distance threshold condition can mean that the distance from a satellite to the terminal is less than or equal to the distance threshold value. The distance from a satellite to the terminal can be tens of kilometers or hundreds of kilometers. For example, the distance threshold value can be pre-stored in the terminal or sent to the terminal by a ground base station (when the terminal is in the coverage range of the ground network, it pre-acquires some information about the satellites from the ground base station, including the above distance threshold value, and can use the acquired information about the satellites when it enters the coverage range of the satellite network).

[0141] After the terminal calculates the X satellites that can currently serve, in an actual scenario, the terminal can receive signals of the N satellites. The X satellites include the N satellites, and X is greater than or equal to N.

[0142] 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.

[0143] For example, the N satellites send at least N first signals to the terminal, which can include the following two implementations:

[0144] 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.

[0145] 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 strength from the multiple first signals. After the filtering, it can be regarded that the terminal receives only one first signal from each of the N satellites, and then determines the K candidate satellites from the N satellites according to the N first signals.

[0146] 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.

[0147] S803. The terminal determines K candidate service satellites according to the at least N first signals.

[0148] The terminal can perform signal detection to determine which satellites of the N satellites can be currently received.

[0149] 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, and the like, the terminal only receives at least K first signals from K satellites, so that the terminal can determine the K satellites as candidate service satellites. The N satellites include the K candidate service satellites. K is a positive integer less than or equal to N.

[0150] S804. The terminal determines the positions of the K candidate service satellites according to the information about the relationship between the positions and the time of the K candidate service satellites in the ephemeris information.

[0151] 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 the time of the K candidate service satellites in the ephemeris information.

[0152] Therefore, the terminal can determine the positions of the multiple satellites at the current time according to the determined multiple satellites and ephemeris information.

[0153] As shown in FIG. 1, it is a schematic diagram of a multiple satellite positioning example of an embodiment of the present application. It is assumed that there are N satellites in a multiple satellite network, and the terminal can receive signals from multiple satellites, Figure 9 In the figure, it is illustrated that the satellites PCI#0, PCI#1, and PCI#2 can all provide services for the terminal, and the terminal can receive signals from the three satellites. Figure 9

[0154] S805. The terminal determines 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.

[0155] ​After the terminal determines 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. Among them, at least N first signals include the K first signals.

[0156] Exemplarily, step S805 can have the following two implementations:

[0157] 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. Among them, the energy detection can be one or more of the reference signal receiving power (RSRP), the reference signal receiving quality (RSRQ), and the reference signal strength indication (RSSI) of the first signal. Taking the detection of RSRP as an example, assuming K = 3, the terminal measures the energy of the first signals sent by satellite 1, satellite 2, and satellite 3 respectively, and the RSRP of the first signal sent by satellite 1 is the largest, it can be determined that the position of the terminal is 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.

[0158] In this implementation, by screening the first signal with the largest signal strength in the K first signals, the coverage area of the satellite sending the first signal is taken as the position of the terminal. With this implementation, the implementation is simple and saves the computing overhead of the terminal.

[0159] 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.

[0160] Firstly, the terminal can perform energy detection on the K first signals from the K candidate serving satellites. Among them, the energy detection on the K first signals from the K candidate serving satellites can refer to the description in the foregoing, which will not be repeated here.

[0161] Then, the terminal can determine the distance from the K candidate serving satellites to the terminal according to the energy strength of the K first signals.

[0162] Finally, the terminal can further determine the position of the terminal in combination with the positions of the K candidate serving satellites.

[0163] For example, Figure 10As shown, another multi-star positioning diagram of the embodiment example of the present application is shown. The terminal can determine the distances d UE-sat of the K satellites to the terminal according to the energy strengths of the K first signals LOS . Based on the field strength positioning method, there can be PL LOS satisfying: PL 10 = K1+ K2log UE-Sat (d 10 )+ K3log c (f LOS )+ K4 (formula 2), where K1, K2, K3, K4 are constants, and the values are different in different scenarios. According to the definition in TR 38.901, under the LOS path, PL LOS satisfies: PL 10 = 31.84+ 21.50log UE-Sat (d 10 )+ 19.00log c (f LOS ) (formula 3). Wherein, PL c is the RSRP of the first signal measured by the terminal, f UE-Sat is the current frequency point, and d UE 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, the position (x UE , y Sat1 ) of the terminal satisfies:

[0164] (x UE -x 2 ) Sat1 +(y UE -y 2 ) UE-Sat1 = d 2 ;

[0165] (x Sat2 -x UE ) 2 +(y Sat2 -y UE ) 2 = d UE-Sat2 2 ;

[0166] (x Sat3 -x UE ) 2 +(y Sat3 -y UE ) 2 = d UE-Sat3 2 ;

[0167] ……formula 4

[0168] wherein (x Sat1 , y Sat1 ), (x Sat2 , y Sat2 ), (x Sat3 , y sat3 ) are the coordinate positions of satellite 1, satellite 2, satellite 3 respectively. UE-Sat1 , d UE-Sat2 , d UE-Sat3 are the distances from the terminal to satellite 1, satellite 2, satellite 3 respectively. Figure 10 As shown in the above, the distances from the satellites to the terminal can be obtained by the RSRP of the measured signals, and the position of the terminal can be obtained according to the position equation, the positions of satellite 1, satellite 2, satellite 3, i.e., the position of the terminal can be obtained by the intersection of the three circles.

[0169] It is worth noting that if K = 1, the position of the terminal will be on a circle, and the accuracy is low; if K = 2, the position of the terminal can have one solution (two circles are tangent) or two solutions (two circles intersect); if K is greater than 2, the position of the terminal has a unique solution (common intersection point of more than three circles).

[0170] Thus, when K is greater than 2, the terminal positioning is accurate, but additional calculation and signaling overhead are required.

[0171] By using this implementation, a more accurate position of the terminal can be obtained than the above implementation.

[0172] 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.

[0173] 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 a high speed, and it takes a certain time for the terminal to access the candidate serving satellites, the terminal determines the candidate serving satellites that can be accessed at the current time according to the strengths of the K first signals, but at the next time (the time when the terminal completes the access preparation), the candidate serving satellite can have been displaced, and thus, before step S806, the method can further include the following step: determining 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 of the K candidate serving satellites in the ephemeris information and the time, and the strengths of the K first signals. That is, the terminal can determine one candidate serving satellite according to one or more of the above information.

[0174] After the terminal determines one candidate serving satellite, the terminal sends a preamble to the candidate serving satellite.

[0175] Exemplarily, accessing the candidate serving satellite may specifically include the following steps:

[0176] First, the terminal determines the first TA according to the terminal's location. The first TA is the value in the above formula 1.

[0177] Then, the terminal determines the second TA for sending the PRACH based on the first TA. The second TA is T in the above formula 1. TA .

[0178] Finally, the terminal sends a preamble code to one of the K candidate serving satellites to access the candidate serving satellite.

[0179] Among them, the terminal accesses a candidate service satellite, which can be referred to as Figure 5 The initial access process in NR shown in the figure first involves the terminal receiving system information such as SIB1 to determine the RO resource. Then, based on the second TA, the terminal sends a preamble to the candidate serving satellite. Next, the terminal receives the RAR from the candidate serving satellite. Next, the terminal sends Msg3 to the candidate serving satellite. Next, the candidate serving satellite sends Msg4 to the terminal to establish RRC. Finally, the terminal sends Msg5 and other messages to the candidate serving satellite to complete the initial access process.

[0180] According to a communication method provided by an embodiment of the present application, ephemeris information is preconfigured for a terminal. The terminal then determines one or more candidate serving satellites based on this ephemeris information and detects signals from one or more candidate serving satellites to determine multiple satellites and their positions, thereby determining the terminal's position. This allows the terminal to quickly and accurately determine its own position based on multiple satellite signals before random access, and to perform timing advance adjustments based on the terminal's position and satellite ephemeris for random access, thereby improving access performance.

[0181] This avoids problems such as inaccurate GNSS acquisition caused by signal interference caused by the GNSS signal and communication signal being at adjacent frequencies.

[0182] In the prior art, generally, a terminal first accesses the network and then performs positioning of the terminal. However, in this embodiment, the terminal first performs positioning and then accesses the network, thereby improving access performance and positioning accuracy.

[0183] It is described above that the first signal includes at least one of the following signals: a synchronization signal and a PRS.

[0184] 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 signal and the PRS of multiple satellites simultaneously through multiple beams; or, the multiple satellites can time-division transmit the synchronization signal and the PRS, and the terminal can receive the synchronization signal and the PRS from the multiple satellites at different times. Here, the PRS is transmitted by the candidate serving satellite to the terminal, and thus can also be referred to as a downlink-positioning reference signal (DL-PRS).

[0185] In one implementation, the time-domain resource location of the synchronization signal and the PRS can be a predefined fixed location, and the PRS is associated with the synchronization signal. As shown in Figure 11 FIG. 1 is a schematic diagram of a time-domain pattern of a PRS according to an embodiment of the present application, where the synchronization signal occupies 4 symbols, and the DL-PRS occupies 2 symbols, and the DL-PRS is transmitted immediately after the symbol following the synchronization signal, that is, the time-domain location of the DL-PRS is adjacent to the time-domain location of the synchronization signal. The synchronization signal #0 and the DL-PRS #0 use the same beam direction. With this implementation, the same beam direction signal can be transmitted on consecutive symbols, enabling the terminal to acquire the relevant signals (synchronization signal and PRS) of the satellite more quickly, so that downlink positioning can be performed in the initial access process to obtain the position information of the terminal, thereby improving the performance of the subsequent random access process.

[0186] The difference between this embodiment and the embodiment shown in Figure 8 is step S805. In this embodiment, the terminal receives the synchronization signal and the PRS from the K candidate serving satellites, performs positioning based on the PRS (for example, a DL-TDOA or angle-of-arrival (AOA) positioning method can be used), and determines the position of the terminal.

[0187] After the terminal determines its own position, it can access one of the K candidate serving satellites according to the position of the terminal.

[0188] In another implementation, as shown in Figure 12As shown, a schematic diagram of another PRS time domain pattern according to an embodiment of the present application is provided. A candidate serving satellite may first transmit synchronization signals of different indices (SS / PBCH indices, corresponding to different beam directions) one by one, and then subsequently transmit DL-PRSs associated with different synchronization signals. For example, synchronization signal #0 is associated with DL-PRS #0, indicating that DL-PRS #0 and synchronization signal #0 have a quasi co-location relationship (Type D, QCL-Type D). This means that DL-PRS #0 and synchronization signal #0 have the same beam direction, and the beams cover the same area on the ground.

[0189] Figure 12 In the system, synchronization signals #0-7 occupy one system frame (SF) ( Figure 12 The example in the figure shows the first four time slots (for a 30kHz subcarrier spacing) in the system frame corresponding to system frame number (SFN) #0. The eight downlink positioning reference signals corresponding to the eight synchronization signals occupy two time slots in the free time slots after the synchronization signal. The number of time slots here is only an example, and other values ​​can be selected in practice. As you can see, Figure 12 In the example, the interval between the synchronization signal and the downlink positioning reference signal is four slots. This is for example only; other intervals are possible. Blank slots are used to account for processing delays when the terminal demodulates data and beam switching delays when the candidate serving satellite transmits signals in different beam directions. Therefore, some slots are typically left blank. If the terminal and candidate serving satellite have strong capabilities and these delays are minimal, the interval can be zero.

[0190] Using this time-domain distributed synchronization signal and PRS, candidate serving satellites can collectively transmit synchronization signals in different beam directions (different SS / PBCH indices correspond to different synchronization signal beam directions and cover different geographical areas). This allows the terminal to centrally detect the synchronization signal, thereby determining which candidate serving satellites can currently receive signals and identifying multiple satellites. The terminal then determines the current position of the candidate serving satellite based on the ephemeris information. The terminal then determines the position of the downlink positioning reference signal corresponding to the synchronization signal based on the synchronization signal and receives the downlink positioning reference signal sent by the candidate serving satellite in the geographical area. The terminal then estimates its position based on the downlink positioning reference signals received from multiple satellites to determine its own position.

[0191] In yet another implementation, Figure 13 As shown, it is a schematic diagram of a time domain pattern of another PRS according to an embodiment of the present application. Figure 12The pattern of DL-PRS is increased to improve the reliability of transmission. As shown in FIG. 6, the DL-PRS is repeated twice to improve the performance of downlink positioning reference. The number of repetitions can be indicated and configured by bits in the synchronization signal, and different numbers of repetitions can be supported. Figure 13

[0192] In the above implementation, the location of the DL-PRS can be a predefined location as the synchronization signal, and both the terminal and the satellite know their locations. In addition, the location of the DL-PRS can also be determined according to the location of the synchronization signal (SS / PBCH index).

[0193] In this embodiment, the PRS and the synchronization signal have the following differences:

[0194] 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 location, occupying 4 symbols, which is used for terminal cell search and downlink synchronization to obtain cell identification (such as PCI) and frame timing, etc. Here, the time domain resource location 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, 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.

[0195] On the other hand, the frequency domain resources of the PRS and the synchronization signal are different. The bandwidth of the synchronization signal is 20 resource blocks (RB), and the function of the synchronization signal is mainly used for terminal cell search and downlink synchronization to obtain cell identification (such as PCI) and frame timing, etc. For the initial access process using PRS, 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 the PRS can be defined as 24 RB, 36 RB, 48 RB, 96 RB, etc., and the signal bandwidth of the PRS can be indicated in the synchronization signal.

[0196] In summary, the time-frequency resources of the PRS can be defined by a table of time-frequency resources of the PRS (as shown in Table 1), and different configurations can be indicated by the index in the synchronization signal:

[0197] Table 1

[0198]

[0199]

[0200] ​In Table 1, when the index of the synchronization signal indication configuration is "0", the PRS occupies 1 symbol and the bandwidth is 24RB; when the index of the synchronization signal indication configuration is "1", the PRS occupies 2 symbols and the bandwidth is 24RB; and so on.

[0201] It is understandable that the above Table 1 is only an example. In actual configuration, it can be configured as any row or multiple rows, any column or combination of multiple columns in the table.

[0202] In yet another implementation, Figure 14 As shown in FIG, a schematic diagram of a synchronization and positioning signal of an example embodiment of the present application. In this implementation, a synchronization and positioning signal can also be designed and sent to the terminal through the network side, and the terminal side performs timing synchronization and position positioning based on the signal. Figure 14 As shown, a system frame includes eight synchronization and positioning signals: synchronization and positioning signal #0 to synchronization and positioning signal #7, occupying a total of eight time slots. The specific number of time slots and synchronization and positioning signals is only an example and can be other values. These synchronization and positioning signals can have different beam directions and cover different geographical areas.

[0203] The above mainly introduces the solution provided by the embodiment of the present application from the perspective of the interaction between the terminal and the satellite. Accordingly, the embodiment of the present application also provides a communication device, which is used to implement the various methods described above. The communication device can be the terminal in the above method embodiment, or a communication module in the terminal, or a circuit or chip in the terminal responsible for the communication function (such as a modem chip (also known as a baseband chip), or a system-on-chip chip or system-level package chip containing a modem core); or, the communication device can be the satellite in the above method embodiment, or a module applied to the satellite (such as a circuit, a processor, a chip or a chip system, etc.). It can be understood that in order to implement the above functions, the communication device includes hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should easily realize that, in combination with the units and algorithm steps of the various 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 function is executed in a hardware or computer software-driven hardware manner depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0204] The embodiments of the present application can divide the functions of the communication device according to the method embodiments described above, 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 integrated module can be realized in the form of hardware or in the form of a 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. When actually implemented, another division mode can be used.

[0205] Based on the same concept of the above communication method, the present application also provides a communication device as follows:

[0206] As shown in Figure 15 , a structural schematic diagram of a communication device provided by an embodiment of the present application, the communication device 1500 includes a transceiver unit 1501 and a processing unit 1502; wherein:

[0207] When the communication device is used to realize the functions of the terminal in the above method embodiments, the transceiver unit 1501 is configured to perform one or more of the operations performed by the terminal in steps S802 and S806 in the embodiments shown in Figure 8 , and the processing unit 1502 is configured to perform one or more of steps S801, S803-S805 in the embodiments shown in Figure 8 .

[0208] When the communication device is used to realize the functions of the satellite in the above method embodiments, the transceiver unit 1501 is configured to perform one or more of the operations performed by the satellite in steps S802 and S806 in the embodiments shown in Figure 8 .

[0209] For specific implementation of the transceiver unit 1501 and the processing unit 1502, reference can be made to the description in the above method embodiments.

[0210] As shown in Figure 16 , a structural schematic diagram of another communication device provided by an embodiment 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 (indicated by a dashed line in the figure), 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 (indicated by a dashed line in the figure). 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.

[0211] When the communication apparatus is applied to the terminal, the interface circuit 1602 is configured to perform one or more of the operations performed by the terminal in steps S802, S806 in the embodiment shown in Figure 8 Figure 8 The processor 1601 is configured to perform one or more of steps S801, S803-S805 in the embodiment shown in

[0212] When the communication apparatus is applied to the satellite, the interface circuit 802 is configured to perform one or more of the operations performed by the satellite in steps S802, S806 in the embodiment shown in Figure 8

[0213] When the communication apparatus is a chip applied to the terminal, the chip implements the functions of the terminal in the method embodiments. 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.

[0214] When the communication apparatus is a chip applied to the satellite, the chip implements the functions of the satellite in the method embodiments. 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.

[0215] 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.

[0216] The division of the modules in the present application is schematic, and is only a logical function division. When actually implemented, there can be another division manner. In addition, each functional module in each example in 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.

[0217] ​​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.

[0218] The embodiments of the present application also provide a computer readable storage medium, which stores a computer program or instructions, and when the computer program or instructions are executed, the method in the above embodiments is implemented.

[0219] The embodiments of the present application also provide a computer program product containing instructions, which, when executed on a computer, cause the computer to perform the method in the above embodiments.

[0220] The embodiments of the present application also provide a communication system, which includes the above communication device.

[0221] The embodiments of the present application also provide a circuit, which is coupled with a memory, and is used to execute the method shown in the above embodiments. The circuit can include a chip circuit.

[0222] When the above communication device is a satellite module, the satellite module implements the functions of the satellite in the above method embodiments. The satellite module receives information from other modules (such as radio frequency modules or antennas) 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 radio frequency modules or antennas) 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, DU or other module, or an apparatus under the O-RAN architecture, such as an open CU, an open DU, etc.

[0223] It should be noted that the above unit or one or more of the units can be realized by software, hardware or a combination of both. When any of the above units is realized by software, the software exists in the form of computer program instructions, and is stored in the memory. The processor can be used to execute the program instructions and realize the above method flow.

[0224] In this application, the processor can be a general purpose processor, a digital signal processor, an application specific integrated circuit, a field programmable gate array or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or all or part of the above-mentioned devices for implementing processing functions, which can implement or execute the disclosed methods, steps and logic block diagrams in this application. The general purpose processor can be a microprocessor or any conventional processor, etc. The steps of the method disclosed in this application can be directly embodied as hardware processor execution or executed by a combination of hardware and software modules in the processor.

[0225] When the above units or units are implemented in hardware, the hardware can be any one or any combination of a CPU, a microprocessor, a digital signal processing (DSP) chip, a microcontroller unit (MCU), an artificial intelligence processor, an ASIC, a SoC, a FPGA, a PLD, a dedicated digital circuit, a hardware accelerator, or a non-integrated discrete device, which can run necessary software or not rely on software to perform the above method flows.

[0226] Optionally, the embodiments of the present application further provide a chip system, comprising: at least one processor and an interface, the at least one processor is coupled with a memory through the interface, when the at least one processor runs a computer program or instructions in the memory, 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 contain a chip and other discrete devices, the embodiments of the present application do not make specific limitations hereon.

[0227] The memory in this application can also be a circuit or other any device capable of realizing storage function, used for storing program instructions and / or data. The memory can be any other medium capable of carrying or storing desired program code in the form of instructions or data structures and capable of being accessed by a computer, but is not limited to this. 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).

[0228] The terms "including", "containing", "having" and their conjugates, as used throughout this application and in the claims, shall mean "comprising" as "comprising" is interpreted in the broadest form possible, not limited to members in a list of steps or components. For example, a process, method, article, or apparatus that comprises a list of steps or components, does not necessarily comprise only those steps or components in the list, but can also comprise additional steps or components not expressly listed or inherent to such process, method, article, or apparatus. It is noted that, as used in this application, the terms "exemplary" or "for example" set forth on any aspect, can refer to the purpose(s) of that aspect and / or function of that aspect and / or model of that aspect and / or example of that aspect, and should not necessarily be construed as preferred or advantageous over other aspects or with regard to other aspects. Rather, use of "exemplary" or "for example" is intended to present concepts in a concrete manner.

[0229] It should be understood that, in the description of the present application, unless otherwise specified, " / " means that the objects associated in front and back are in a "or" relationship, for example, A / B can mean 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 single item or combination of multiple items. For example, at least one of a, b, or c, can mean 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 "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" is used to represent 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.

[0230] In the above embodiments, all or part of the embodiments can be implemented by software, hardware, firmware or any combination thereof. When implemented by software, all or part of the embodiments can be implemented 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 computer readable storage medium, 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.) mode.

[0231] Although the present application is described herein in conjunction with various embodiments, those skilled in the art, with the benefit of the description and drawings presented herein, will appreciate other variations of the disclosed embodiments. In the claims, a single processor or other unit can implement several items recited in the claims. Some measures are described in mutually different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0232] It can be understood that various numerical numbers involved in the embodiments of the present application are only for differentiation for convenience of description, and are not used to limit the scope of the embodiments of the present application. The size of the serial numbers 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.

[0233] In the above embodiments, the description of each embodiment has its own focus, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0234] 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.

[0235] In the present application, the examples can be mutually quoted without logical contradiction, for example, the methods and / or terms between the method embodiments can be mutually quoted, for example, the functions and / or terms between the device embodiments can be mutually quoted, for example, the functions and / or terms between the device examples and the method examples can be mutually quoted.

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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