Synchronization method and apparatus

Abstract

The present application relates to the technical field of communications, and in particular to a synchronization method and apparatus, used for improving the feedback accuracy of a frequency offset and meeting the requirements of coherent joint transmission in an NTN. The method can be executed by a terminal, and the method comprises: determining a frequency offset on the basis of a received reference signal; and sending a quantized frequency offset value, wherein the quantized frequency offset value is determined by quantizing the frequency offset on the basis of a first frequency offset dynamic range and a first quantization granularity, and the first frequency offset dynamic range and the first quantization granularity satisfy at least one of the following: the value of the first frequency offset dynamic range is L ppm, L being less than 0.01; the value of the first frequency offset dynamic range is 1 / (2^M*Δt), Δt representing a symbol length, and M representing an integer greater than 9; or, the value of the first quantization granularity is 2^N, N representing an integer greater than 8.

Description

A synchronization method and apparatus

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202510114647.5, filed on January 23, 2025, entitled "A Synchronization Method and Apparatus", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of communication technology, and in particular to a synchronization method and apparatus. Background Technology

[0004] Compared to terrestrial networks (TN), non-terrestrial networks (NTN) offer advantages such as wider coverage, longer communication distances, higher reliability, greater flexibility, higher throughput, and immunity to geographical conditions, weather conditions, and natural disasters. They have been widely applied in fields such as aviation communications, maritime communications, and military communications. NTN communications utilizes equipment such as drones, high-altitude platforms, and satellites to create networks that provide data transmission, voice communication, and other services to terminals.

[0005] Due to manufacturing and launch costs, NTN equipment such as satellites and high-altitude platforms have limited data processing capabilities and transmission power, and cannot yet provide terminals with communication rates comparable to terrestrial base stations. To overcome these limitations and improve the overall signal processing capabilities and communication throughput of NTN, operators are planning to increase the number of NTN devices (such as satellites) to compensate for the communication limitations of individual NTN devices. Terminals can be visible to multiple NTN devices, and multiple NTN devices can provide services to terminals through coherent joint transmission.

[0006] Coherent joint transmission of multiple NTN devices requires the terminal to measure information such as the frequency offset of the air interface and feed the measurement results back to the NTN devices. The NTN devices then compensate for the frequency offset based on the feedback measurement results, enabling the signals from multiple NTN devices to be coherently superimposed over the air interface, thus achieving the gain of coherent joint transmission. However, current frequency offset feedback is mainly applicable to TN scenarios. For NTN scenarios, the NTN devices are far from the terminal, and the signal transmission delay between the terminal and the NTN devices is large. The accuracy of current frequency offset feedback cannot meet the requirements of coherent joint transmission of multiple NTN devices in NTN systems. Summary of the Invention

[0007] This application provides a synchronization method and apparatus to improve the feedback accuracy of frequency offset and meet the requirements of coherent joint transmission in NTN.

[0008] In a first aspect, embodiments of this application provide a synchronization method, which can be applied to the terminal side, such as a terminal or 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 (SoC) chip containing a modem core or a system-in-package (SIP) chip), or it can be a logic module or software that can realize all or part of the terminal functions; taking the application of this method to a terminal as an example, the method can include: determining the frequency offset according to the received reference signal; sending a frequency offset quantization value, the frequency offset quantization value being determined by quantizing the frequency offset based on a first frequency offset dynamic range and a first quantization granularity, wherein the first frequency offset dynamic range and the first quantization granularity satisfy at least one of the following: the value of the first frequency offset dynamic range is Lppm, where L is less than 0.01; the value of the first frequency offset dynamic range is 1 / (2^M*Δt), where Δt is the symbol length and M is an integer greater than 9; or, the value of the first quantization granularity is 2^N, where N is an integer greater than 8.

[0009] By using the methods described above, the feedback accuracy of frequency offset can be improved by expanding the dynamic range of frequency offset and / or the value of quantization granularity, thus meeting the requirements of coherent joint transmission in NTN.

[0010] In one possible design, the method further includes: receiving first information indicating a first frequency offset dynamic range and / or a first quantization granularity.

[0011] The above method can enable the network side to configure the first frequency offset dynamic range and / or the first quantization granularity for the terminal, which helps to ensure that the accuracy of the frequency offset reported by the terminal meets the requirements of the network side.

[0012] In one possible design, N is less than or equal to 20.

[0013] Through the above design, while meeting the requirements of coherent joint transmission in NTN, the problem of excessively large range of quantization granularity values ​​can be avoided, which helps to reduce the complexity of frequency offset quantization in the terminal.

[0014] In one possible design, N is 9, 10, 11, or 12.

[0015] The above design considers that when N is 9, 10, 11, or 12, it can already meet the accuracy requirements for frequency offset feedback in most subcarrier spacing (SCS) or frequency bands in NTN scenarios. Limiting the value of N can further reduce the complexity of frequency offset quantization in the terminal.

[0016] In one possible design, L is 0.005, 0.002, 0.001, or 0.0005.

[0017] The above design considers that the accuracy requirements for frequency offset feedback in most frequency bands in NTN scenarios can be met when L takes the values ​​of 0.005, 0.002, 0.001, or 0.0005. Limiting the value of L can further reduce the complexity of frequency offset quantization in the terminal.

[0018] In one possible design, M is 10, 11, 12, or 13.

[0019] Based on the above design, considering that the values ​​of M are 10, 11, 12, or 13, the accuracy requirements for frequency offset feedback in most SCSs under NTN scenarios can be met. Limiting the value of N can further reduce the complexity of frequency offset quantization in the terminal.

[0020] Secondly, embodiments of this application provide a synchronization method, which can be applied to the network side, such as a network device or a communication module or unit in the network device, or a circuit, chip or chip system in the network device responsible for communication functions, or it can be a logic module or software that can realize all or part of the functions of the network device; taking the application of this method to a network device as an example, the method can include: sending a reference signal; receiving a frequency offset quantization value, the frequency offset quantization value being quantized based on a first frequency offset dynamic range and a first quantization granularity, wherein the first frequency offset dynamic range and the first quantization granularity satisfy at least one of the following: the value of the first frequency offset dynamic range is Lppm, where L is less than 0.01; the value of the first frequency offset dynamic range is 1 / (2^M*Δt), where Δt is the symbol length and M is an integer greater than 9; or, the value of the first quantization granularity is 2^N, where N is an integer greater than 8; and performing frequency offset compensation according to the frequency offset quantization value.

[0021] In one possible design, the method further includes: sending first information indicating a first frequency offset dynamic range and / or a first quantization granularity.

[0022] In one possible design, N is less than or equal to 20.

[0023] In one possible design, N is 9, 10, 11, or 12.

[0024] In one possible design, L is 0.005, 0.002, 0.001, or 0.0005.

[0025] In one possible design, M is 10, 11, 12, or 13.

[0026] Thirdly, embodiments of this application provide a synchronization method that can be applied to the terminal side, such as a terminal or a communication module within 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 (SoC) chip or system-in-package (SIP) chip containing a modem core), or it can be a logic module or software capable of implementing all or part of the terminal functions. Taking the application of this method to a terminal as an example, the method may include: determining a target quantization scaling factor based on the orbital height of the network device and the mapping relationship between the orbital height and the quantization scaling factor; determining the frequency offset based on the received reference signal; and transmitting a frequency offset quantization value, wherein the frequency offset quantization value is determined based on a second frequency offset dynamic range, a second quantization granularity, and the target quantization scaling factor.

[0027] The above design enables the adaptive determination of the quantization scaling factor based on the orbital altitude of network devices (such as satellites), adjusting the feedback accuracy of frequency offset, which helps improve the feedback accuracy of frequency offset and meets the requirements of coherent joint transmission in NTN.

[0028] In one possible design, the mapping relationship between track height and quantization scaling factor includes: a mapping relationship between track height and quantization scaling factor of frequency offset dynamic range, and / or a mapping relationship between track height and quantization scaling factor of quantization granularity; the target quantization scaling factor includes: a first target quantization scaling factor determined based on the track height of the network device and the mapping relationship between track height and quantization scaling factor of frequency offset dynamic range, and / or a second target quantization scaling factor determined based on the track height of the network device and the mapping relationship between track height and quantization scaling factor of quantization granularity; the first target quantization scaling factor is used to scale the second frequency offset dynamic range, and the second target quantization scaling factor is used to scale the second quantization granularity. Optionally, the first target quantization scaling factor is less than or equal to 1, and the second target quantization scaling factor is greater than or equal to 1.

[0029] The above design supports scaling (i.e., shrinking or enlarging) the dynamic range and / or quantization granularity of the frequency offset to improve the feedback accuracy of the frequency offset.

[0030] In one possible design, the method also includes receiving the mapping relationship between the orbital height and the quantization scaling factor.

[0031] The above design allows the network side to configure the mapping relationship between track height and quantization scaling factor for the terminal, which is beneficial for the network side to adjust the accuracy of the frequency offset reported by the terminal, so that the accuracy of the frequency offset reported by the terminal meets the requirements of the network side.

[0032] In one possible design, the method further includes receiving second information indicating a second frequency offset dynamic range and / or a second quantization granularity.

[0033] The above method can enable the network side to configure the first frequency offset dynamic range and / or the first quantization granularity for the terminal, which helps to ensure that the accuracy of the frequency offset reported by the terminal meets the requirements of the network side.

[0034] Fourthly, embodiments of this application provide a synchronization method that can be applied to the network side, such as a network device or a communication module or unit within the network device, or a circuit, chip, or chip system responsible for communication functions within the network device. Alternatively, it can be a logic module or software capable of implementing all or part of the functions of the network device. Taking the application of this method to a network device as an example, the method may include: transmitting a reference signal; receiving a frequency offset quantization value, the frequency offset quantization value being quantized based on a second frequency offset dynamic range, a second quantization granularity, and a target quantization scaling factor, the target quantization scaling factor being determined according to the orbital height of the network device and the mapping relationship between the orbital height and the quantization scaling factor; and performing frequency offset compensation based on the frequency offset quantization value.

[0035] In one possible design, the mapping relationship between track height and quantization scaling factor includes: a mapping relationship between track height and quantization scaling factor of frequency offset dynamic range, and / or a mapping relationship between track height and quantization scaling factor of quantization granularity; the target quantization scaling factor includes: a first target quantization scaling factor determined based on the track height of the network device and the mapping relationship between track height and quantization scaling factor of frequency offset dynamic range, and / or a second target quantization scaling factor determined based on the track height of the network device and the mapping relationship between track height and quantization scaling factor of quantization granularity. The first target quantization scaling factor is used to scale the second frequency offset dynamic range, and the second target quantization scaling factor is used to scale the second quantization granularity.

[0036] In one possible design, the first target quantization scaling factor is less than or equal to 1, and the second target quantization scaling factor is greater than or equal to 1.

[0037] In one possible design, the method also includes: transmitting the mapping relationship between the track height and the quantization scaling factor.

[0038] In one possible design, the method further includes: sending a second message indicating a second frequency offset dynamic range and / or a second quantization granularity.

[0039] Fifthly, embodiments of this application provide a communication device that has the function of implementing the method of any one of the first to fourth aspects described above. The function can be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions, such as an interface unit and a processing unit.

[0040] In one possible design, the device can be a chip or an integrated circuit.

[0041] In one possible design, the device includes a memory and a processor, the memory for storing instructions executed by the processor, and when the instructions are executed by the processor, the device can perform the methods of any one of the first to fourth aspects.

[0042] Sixthly, embodiments of this application provide a communication device including an interface circuit and a processor, wherein the processor and the interface circuit are coupled to each other. The interface circuit is used for inputting and / or outputting signals, and the processor is used to implement the methods of any one of the first to fourth aspects described above through logic circuits or execution instructions. It is understood that the interface circuit can be a transceiver, a transceiver device, or an input / output interface.

[0043] Optionally, the communication device may also include a memory for storing instructions executed by the processor, or storing input data required by the processor to execute instructions, or storing data generated after the processor executes instructions. The memory may be a physically independent unit, or it may be coupled to the processor, or the processor may include the memory (i.e., the processor and the memory are integrated together).

[0044] In one possible implementation, the communication device is a chip.

[0045] In a seventh aspect, embodiments of this application provide a communication system, which includes a terminal and a network device. The terminal is used to implement the method of the first aspect described above, and the network device is used to implement the method of the second aspect described above; or, the terminal is used to implement the method of the third aspect described above, and the network device is used to implement the method of the fourth aspect described above.

[0046] Eighthly, embodiments of this application provide a computer-readable storage medium storing a computer program or instructions that, when executed by a processor, can implement the methods of any one of the first to fourth aspects described above.

[0047] Ninthly, embodiments of this application also provide a computer program product, including a computer program or instructions, which, when executed by a processor, can implement the methods of any one of the first to fourth aspects described above.

[0048] In a tenth aspect, embodiments of this application also provide a chip system including a processor, the processor being coupled to a memory, the memory being used to store programs or instructions, and when the program or instructions are executed by the processor, the methods of any one of the first to fourth aspects described above can be implemented.

[0049] The technical effects that can be achieved by the second, fourth to tenth aspects mentioned above should be referred to the technical effects that can be achieved by the first or third aspects mentioned above, and will not be repeated here. Attached Figure Description

[0050] Figure 1A is a schematic diagram of the architecture of the communication system provided in an embodiment of this application;

[0051] Figure 1B is a schematic diagram of the O-RAN system provided in an embodiment of this application;

[0052] Figure 1C is a schematic diagram of the O-RAN system architecture provided in an embodiment of this application;

[0053] Figure 1D shows the converged network architecture of the transparent transmission mode NTN and the terrestrial network provided in the embodiment of this application;

[0054] Figure 1E shows the fusion network architecture of regeneration mode NTN and terrestrial network provided in the embodiments of this application;

[0055] Figure 1F is a schematic diagram of the network architecture of the air-to-ground communication system provided in an embodiment of this application;

[0056] Figure 2 is a schematic diagram comparing the performance of multi-satellite coherent joint transmission and single-satellite transmission provided in the embodiments of this application;

[0057] Figure 3 is a schematic diagram of one of the synchronization methods provided in the embodiments of this application;

[0058] Figure 4 is a schematic diagram of one of the synchronization methods provided in the embodiments of this application;

[0059] Figures 5 and 6 are schematic diagrams of the communication device provided in the embodiments of this application. Detailed Implementation

[0060] Figure 1A exemplarily illustrates an architecture diagram of a communication system 1000 applicable to an embodiment of this application. As shown in Figure 1A, the communication system includes a wireless access network 100 and a core network 200. Optionally, the communication system 1000 may also include an Internet 300. The wireless access network 100 may include at least one wireless access network device (110a and 110b in Figure 1A) and at least one terminal (120a-120j in Figure 1A). The terminal is wirelessly connected to the wireless access network device, and the wireless access network device is wirelessly or wiredly connected to the core network. The core network device and the wireless access network device may be independent and different physical devices, or the functions of the core network device and the logical functions of the wireless access network device may be integrated on the same physical device, or a single physical device may integrate some of the functions of the core network device and some of the functions of the wireless access network device. Terminals and wireless access network devices can be interconnected via wired or wireless means. Figure 1A is just a schematic diagram. The communication system may also include other network devices, such as wireless relay devices and wireless backhaul devices, which are not shown in Figure 1A.

[0061] The network devices involved in the embodiments of this application include, for example, radio access network (RAN) devices. RAN devices can be base stations, evolved NodeBs (eNodeBs), transmission reception points (TRPs), transmission points (TPs), base stations in 5G mobile communication systems, base stations in future mobile communication systems, etc.; they can also be modules or units that perform some of the functions of a base station, for example, they can be central units (CUs), distributed units (DUs), or radio units (RUs). The CU (Radio Control Unit) performs the functions of the radio resource control protocol and packet data convergence protocol (PDCP) of the base station, and can also perform the functions of the service data adaptation protocol (SDAP). The DU (Radio Link Control Unit) performs the functions of the radio link control layer and medium access control (MAC) layer of the base station, and can also perform some or all of the physical layer functions. For specific descriptions of the above-mentioned protocol layers, please refer to the relevant technical specifications of the 3rd Generation Partnership Project (3GPP). The CU and DU can be set up separately, or they can be included in the same network element, such as in the baseband unit (BBU). The RU (Radio Receiver Unit) can be included in radio frequency equipment or radio frequency units, such as in the remote radio unit (RRU), active antenna unit (AAU), or remote radio head (RRH). In different systems, CU, DU, or RU may also have different names, but those skilled in the art will understand their meaning. For example, in an open radio access network (O-RAN or ORAN) system, a CU can also be called an open CU (open-CU, O-CU), a DU can also be called an open DU (open-DU, O-DU), and a RU can also be called an open RU (open-RU, O-RU).In this application, any of the following units—CU (or CU control plane (CU-CP), CU user plane (CU-UP), DU, and RU)—can be implemented through software modules, hardware modules, or a combination of software and hardware modules. CU-CP can also be called open-CU-CP (O-CU-CP), and CU-UP can also be called open-CU-UP (O-CU-UP).

[0062] Figure 1B illustrates an exemplary O-RAN system according to an embodiment of this application. The O-RAN system in the embodiments provided in this application may include components other than those shown in Figure 1B. As shown in Figure 1B, the access network device (RAN, for example, may be an eNB, gNB, or access network device in a future mobile communication system) communicates with the core network (CN) via a backhaul link and with user equipment (UE) via an air interface. For example, the baseband unit (BBU) in the access network device communicates with the core network via a backhaul link, and the radio unit (RU) in the access network device communicates with at least one UE via an air interface. The BBU communicates with at least one RU via a fronthaul link; the BBU and RU may or may not be co-located. The BBU includes at least one control unit (CU) and at least one distributed unit (DU), which can communicate via at least one midhaul link.

[0063] Figure 1C exemplarily illustrates a schematic diagram of an O-RAN system architecture provided in an embodiment of this application. As shown in Figure 1C, O-RAN may include O-CU-CP, O-CU-UP, O-DU, and O-RU. This system architecture may also include an open cloud (O-cloud), a service management and orchestration framework, an open eNB (O-eNB), a near-real-time (RT) RAN intelligent controller (RIC), and a non-real-time (non-RT) RIC. The non-RT RIC can monitor, configure, manage, and control radio resources of at least one of multiple O-CU-CP, O-CU-UP, DU, or O-eNB. As shown in Figure 1C, the interfaces defined by 3GPP include, for example: E1, F1 (e.g., F1-c, F1-u), NG (e.g., NG-c, NG-u), Xn (e.g., Xn-c, Xn-u), and X2 (e.g., X2-c, X2-u). For example, O-RAN communication systems also include interfaces such as O1, O2, E2, A1, and open fronthaul (FH) interfaces (e.g., open-FH control (M)-plane, and open-FH control, user, and synchronization (CUS)-plane). The names of the interfaces and the connection methods of the units shown in Figure 1C are an example; in practical applications, O-RAN systems may include more or fewer interfaces, or more or fewer units.

[0064] Wireless access network equipment can be a macro base station (as shown in Figure 1A, 110a), a micro base station or an indoor station (as shown in Figure 1A, 110b), or a relay node or donor node, etc. The embodiments of this application do not limit the specific technology or equipment form used in the wireless access network equipment. For ease of description, a base station is used as an example of wireless access network equipment in the following description.

[0065] A terminal can also be referred to as a user equipment (UE), mobile station, mobile terminal, or terminal device. Terminals can be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), the Internet of Things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, smart transportation, and smart cities. Terminals can be mobile phones, tablets, computers with wireless transceiver capabilities, wearable devices, vehicles, drones, helicopters, airplanes, ships, robots, robotic arms, smart home devices, sensors, etc. The embodiments of this application do not limit the specific technologies or device forms used in the terminals.

[0066] Base stations and terminals can be fixed or mobile. They can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; and they can be deployed in the air on aircraft, balloons, and artificial satellites. The embodiments of this application do not limit the application scenarios of base stations and terminals.

[0067] The roles of base stations and terminals can be relative. For example, the helicopter or drone 120i in Figure 1A can be configured as a mobile base station. For terminals 120j that access the wireless access network 100 through 120i, terminal 120i is a base station; however, for base station 110a, 120i is a terminal, meaning that 110a and 120i communicate via a wireless air interface protocol. Of course, 110a and 120i can also communicate via a base station-to-base station interface protocol. In this case, relative to 110a, 120i is also a base station. Therefore, both base stations and terminals can be collectively referred to as communication devices. 110a and 110b in Figure 1A can be called communication devices with base station functions, and 120a-120j in Figure 1A can be called communication devices with terminal functions. In the embodiments of this application, the protocol can also be called a standard, technical standard, specification, or technical specification.

[0068] Communication between base stations and terminals, between base stations, and between terminals can be conducted using licensed spectrum, unlicensed spectrum, or both simultaneously. Communication can be conducted using spectrum below 6 GHz, spectrum above 6 GHz, or both simultaneously. The embodiments of this application do not limit the spectrum resources used for wireless communication.

[0069] In the embodiments of this application, the functions of the base station can be executed by modules (such as chips) within the base station, or by a control subsystem that includes base station functions. This control subsystem, including base station functions, can be a control center in the aforementioned application scenarios such as smart grids, industrial control, intelligent transportation, and smart cities. Similarly, the functions of the terminal can be executed by modules (such as chips or modems) within the terminal, or by a device that includes terminal functions.

[0070] In this application, the base station sends downlink signals or downlink information to the terminal, with the downlink information carried on the downlink channel; the terminal sends uplink signals or uplink information to the base station, with the uplink information carried on the uplink channel. In order to communicate with the base station, the terminal needs to establish a radio connection with a cell controlled by the base station. The cell with which the terminal has established a radio connection is called the terminal's serving cell. When the terminal communicates with this serving cell, it is also subject to interference from signals from neighboring cells.

[0071] In the embodiments of this application, the time-domain symbol can be an orthogonal frequency division multiplexing (OFDM) symbol or a discrete fourier transform-spread-OFDM (DFT-s-OFDM) symbol. Unless otherwise specified, the symbols in the embodiments of this application refer to time-domain symbols.

[0072] Figures 1A, 1B, and 1C are only schematic diagrams. This wireless communication system may also include other devices, such as core network devices, wireless relay devices, and / or wireless backhaul devices, which are not all shown in the figures.

[0073] Figures 1D and 1E exemplarily illustrate network architecture diagrams of several communication systems applicable to embodiments of this application. The communication system may include satellites, network devices, and terminals, etc. The communication system may also include gateways and core network devices. Figures 1D and 1E exemplarily illustrate a converged network architecture of NTN and terrestrial networks. A description is provided below with reference to the accompanying drawings.

[0074] The satellite can be a highly elliptical orbit (HEO) satellite, a geostationary earth orbit (GEO) satellite, a medium earth orbit (MEO) satellite, or a low-earth orbit (LEO) satellite. This application does not limit the satellite's operating mode; for example, the satellite can operate in transparent mode or regenerative mode. Figure 1D illustrates the satellite operating in transparent mode as an example, and Figure 1E illustrates the satellite operating in regenerative mode as an example.

[0075] When a satellite operates in transparent mode, it provides transparent relay forwarding functionality. A gateway possesses the functions of a network device (such as a base station) or some of the functions of a network device (such as a base station); in this case, the gateway can be considered a network device (such as a base station). Alternatively, the network device (such as a base station) can be deployed separately from the gateway. In this case, the feeder link latency includes both the latency from the satellite to the gateway and the latency from the gateway to the gNB. The transparent mode discussed later assumes that the gateway and gNB are located together or close to each other. For cases where the gateway and gNB are far apart, the feeder link latency is simply the sum of the latency from the satellite to the gateway and the latency from the gateway to the gNB.

[0076] When a satellite is operating in regenerative mode, it has data processing capabilities and functions as a network device (such as a base station) or partially functions as a network device (such as a base station). In this case, the satellite can be regarded as a network device (such as a base station).

[0077] A gateway (also known as a ground station, earth station, or gateway) is a network device used to connect satellites and ground-based networks (such as ground base stations). One or more satellites can connect to one or more ground-based network devices (such as ground base stations) through one or more gateways; this is not a limitation. The link between a satellite and a terminal is called a service link, and the link between a satellite and a gateway is called a feeder link. Network devices can be deployed separately from gateways; therefore, the latency of the feeder link can include both the latency from the satellite to the gateway and the latency from the gateway to the network device.

[0078] The network devices in this application embodiment may include network devices deployed on satellites (such as satellite base stations), network devices deployed on gateways, or network devices deployed on the ground (such as ground base stations). For example, the network devices may be radio access network (RAN) nodes, RAN nodes in O-RAN systems, etc., as shown in Figures 1A, 1B, and 1C. Related details are as described above and will not be repeated here.

[0079] A core network (CN) is a device located on the ground that can communicate with NTN devices in the NTN system. For example, a CN can be the CN shown in Figures 1A, 1B, and 1C. See the foregoing description for related details, which will not be repeated here.

[0080] The terminal can be the terminal involved in Figures 1A, 1B and 1C. For relevant details, please refer to the above description and we will not repeat them here.

[0081] The embodiments of this application can also be applied to other communication system architectures, such as air-to-ground (ATG) communication systems, which include at least one network device and at least one high-altitude terminal. High-altitude terminals include, for example, high-altitude aircraft and onboard terminals. The satellites in Figures 1D and 1E can also be replaced with other relay devices, such as high-altitude platform stations (HAPS) or other NTN devices. The communication system shown in Figure 1D or 1E is merely an example and does not limit the communication systems to which the methods provided in the embodiments of this application are applicable.

[0082] It is understood that the embodiments of this application can also be applied to air-to-ground (ATG) communication systems. As an example, please refer to Figure 1F, which is a schematic diagram of the network architecture of another communication system to which the embodiments of this application are applicable. The communication system includes at least one network device and at least one high-altitude terminal. The high-altitude terminal includes, for example, high-altitude aircraft and onboard terminals.

[0083] To facilitate understanding by those skilled in the art, some terms used in this application are explained below.

[0084] 1) Coherent joint transmission (CJT).

[0085] Coherent Joint Transmission (CJT) refers to the transmission of data to a terminal by multiple stations, such as multiple Transmission Points (TRPs), through coherent transmission. These multiple TRPs know all the data information and their channel state information (CSI) with the terminal. Therefore, these multiple TRPs are like distributed antenna arrays, capable of jointly precoding the same layer of data to be transmitted. "Coherent transmission" means that multiple TRPs can jointly transmit a data stream, allowing their transmitted signals to superimpose in the same direction upon reaching the terminal. This significantly increases the power of the received signal and greatly reduces interference. In other words, coherent transmission can transform all interference between multiple TRPs into useful signals, avoiding mutual interference and significantly improving data transmission performance.

[0086] 2) Frequency offset and time domain offset.

[0087] Frequency offset, also known as frequency deviation, refers to the deviation between a signal frequency and the measured parameter. For example, it can refer to the deviation between the frequency (e.g., center frequency) of the signal received at the receiver and the frequency (e.g., center frequency) of the signal transmitted at the transmitter. Currently, the frequency offset dynamic range supported for quantization includes 0.01ppm, 0.1ppm, 0.2ppm, Δf, Δf / 2, Δf / 4, Δf / 8, 1 / (4Δt), 1 / (8Δt), 1 / (16Δt), 1 / (32Δt), and 1 / (512Δt). Supported quantization granularities include 32, 64, 128, and 256. Here, Δf is the subcarrier spacing (SCS), and Δt is the symbol length. ppm stands for parts per million. When used to represent frequency offset, it indicates the allowable offset value at a specific center frequency. Frequency is measured in Hertz (Hz). The conversion between ppm and Hertz is as follows: Δf = (f * ppm) / 10^6, where f is the center frequency (in Hz). Based on the ratio of the adopted frequency offset dynamic range to the adopted quantization granularity, the accuracy of frequency offset feedback can be calculated under the adopted frequency offset dynamic range and quantization granularity. In other words, the smaller the frequency offset dynamic range and the larger the quantization granularity, the higher the accuracy of frequency offset feedback.

[0088] Time offset, also known as time deviation, refers to the offset of the time at which the receiver receives the signal relative to the time at which the transmitter sends the signal. Currently, the supported dynamic ranges for time offset quantization include: 0.5 cyclic prefix (CP), 0.75CP, 1CP, 1.5CP, 1 / (4Δf), 1 / (12Δf), and 1 / (24Δf). Supported quantization granularities include 32, 64, 128, and 256. Based on the ratio of the adopted dynamic range to the adopted quantization granularity, the accuracy of the time offset feedback can be calculated. In other words, the smaller the dynamic range and the larger the quantization granularity, the higher the accuracy of the time offset feedback.

[0089] 3) Sending messages.

[0090] In this application, "sending information" can be understood as one device sending information to another device, or as one logic module within a device sending information to another logic module. For example, "device A sending information" can be understood as device A sending information to another device (device B), or as logic module 1 in device A sending information to logic module 2 in device A. In this application, "receiving information" can be understood as one device receiving information from another device, or as one logic module within a device receiving information from another logic module. For example, "device A receiving information" can be understood as device A receiving information from another device (such as device B), or as logic module 1 in device A receiving information from logic module 2 in device A. In this application, "sending information to… (e.g., device B)" or the related illustrations in the accompanying drawings can be understood as the destination of the information being device B. This can include sending information directly or indirectly to device B. The phrases "receiving information from... (e.g., device A)," "receiving information from... (e.g., device A)," or "receiving information sent by (e.g., device A)," or the relevant illustrations in the accompanying drawings, can be understood as indicating that the source of the information is device A, which may include receiving information directly or indirectly from device A. The information may undergo necessary processing between the source and destination, such as format changes, but the destination can understand the valid information from the source. Similar expressions in this application can be interpreted similarly and will not be repeated here.

[0091] NTN devices such as satellites and high-altitude platforms are limited by manufacturing and launch costs, and both their data processing capabilities and transmission powers are restricted. NTN devices are also unable to provide communication rates comparable to those of terrestrial base stations for terminals. To break through this limitation and improve the overall signal processing capabilities and communication throughput of NTN, operators are preparing to compensate for the limitations of the communication capabilities of individual NTN devices by increasing the number of NTN devices. Terminals can be visible to multiple NTN devices (such as satellites), and multiple NTN devices can provide services to terminals through coherent joint transmission. Referring to Figure 2 shows the performance comparison between two-satellite coherent joint transmission and single-satellite transmission. From the schematic diagram of the performance comparison between two-satellite coherent joint transmission and single-satellite transmission provided by Figure 2, it can be seen that for different modulation and coding schemes (MCS), the coherent joint transmission can obtain gains compared to single-satellite transmission. For example, when the MCS is MCS0, MCS4, and MCS10, the signal-to-noise ratio (SNR) of the two-satellite joint transmission compared to the single-satellite transmission at a block error rate (BLER) of 0.01 can obtain a gain of more than 8 dB.

[0092] For LEO satellites, their maximum orbital altitude is 2000 km. For GEO satellites, the orbital altitude can reach 35768 km. At an elevation angle of 10°, the one-way transmission delay of the regenerative satellite is 272.375 ms, while the one-way transmission delay of the transparent satellite doubles to 544.751 ms. For such a large feedback delay, the required frequency offset accuracy requirements are also relatively high. For example, for a phase error of 30°, the impact on the performance of coherent joint transmission is relatively small. To achieve this phase error, even if the feedback delay is 0, at a transmission delay of 544.751 ms, the required feedback accuracy of the frequency offset is approximately 0.15 Hz. Among them, the required feedback accuracy of the frequency offset under a certain phase error requirement can be expressed as 2*pi*f*t<theta, where theta represents the phase error (unit: degree), t represents the transmission delay (unit: second), pi represents the radian value of 180 degrees (or π, π represents the radian value of 180 degrees), and f represents the required feedback accuracy of the frequency offset. For a phase error requirement of 30°, that is, theta = 30, so f<theta / (2*pi*t) = 30 / (360*0.544751) ≈ 0.1530 Hz. If the feedback delay caused by uplink scheduling is considered, the required feedback accuracy of the frequency offset will be higher.

[0093] As can be seen from the above introduction on frequency offset, the minimum frequency offset dynamic range is 0.01ppm or 1 / (512Δt), while the maximum quantization granularity is 256. The combination of the two will produce the minimum frequency offset accuracy.

[0094] Table 1 shows the feedback accuracy of the minimum frequency offset under different SCS for the new radio (NR) with a frequency offset dynamic range of 1 / (512Δt) and a quantization granularity of 256. The subcarrier spacing Δf is negatively correlated with the symbol length Δt, and 1 / (512Δt) can also be expressed as Δf / 512. Therefore, the feedback accuracy of the minimum frequency offset can be expressed as Δf / (512*256), in Hz. Taking a subcarrier spacing of 15kHz (i.e., 15*10^3Hz) as an example, the feedback accuracy of the minimum frequency offset is 15*10^3 / (512*256)≈0.11Hz, where ^ represents squaring, and 10^3 can also be expressed as 10 3 .

[0095] Table 1

[0096] In Table 1, Mu represents the subcarrier spacing configuration, and the relationship between SCS and Mu is: SCS = 2^Mu * 15kHz. As shown in Table 1, in the scenario where the required frequency offset feedback accuracy for the aforementioned joint coherent transmission is 0.15Hz, only an SCS of 15kHz can meet the frequency offset feedback accuracy requirement.

[0097] With a frequency offset dynamic range of 0.01ppm and a quantization granularity of 256, the feedback accuracy of the minimum frequency offset for typical NTN bands, such as L-band, S-band, C-band, Ku-band, and Ka-band, is shown in Table 2. Taking the L-band as an example, 2GHz = 2 * 10^9 Hz, 0.01ppm = 0.01 * (2 * 10^9) / 10^6 = 20Hz, so the feedback accuracy of the minimum frequency offset is 20 / 256 ≈ 0.08Hz.

[0098] Table 2

[0099] As shown in Table 2 above, in the scenario where the required frequency offset feedback accuracy for the aforementioned joint coherent transmission is 0.15Hz, only the L band can meet the frequency offset feedback accuracy requirement.

[0100] Therefore, based on Tables 1 and 2 above, it can be concluded that, currently, for typical NTN bands and NR SCS, multiple combinations of bands and SCS cannot meet the frequency offset feedback accuracy requirements of NTN systems.

[0101] Based on this, embodiments of this application provide a synchronization method and apparatus for improving the feedback accuracy of frequency offset and meeting the requirements of coherent joint transmission in NTN. The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0102] Furthermore, in the description of this application, terms such as "first" and "second" are used only to distinguish multiple objects and are not used to limit the size, content, order, timing, priority, or importance of the multiple objects. For example, the first frequency offset dynamic range and the second frequency offset dynamic range do not indicate a difference in priority or importance between the two pieces of information.

[0103] In this application embodiment, the number of nouns, unless otherwise specified, refers to "singular nouns or plural nouns," that is, "one or more." "At least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, or B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the related objects before and after are in an "or" relationship. For example, A / B means: A or B. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c means: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, and c can be single or multiple.

[0104] The synchronization method provided in this application can be executed by a terminal and a network device. Here, "terminal" can refer to the terminal itself, a component of the terminal (e.g., a processor, module, chip, or chip system), or a device used in conjunction with the terminal. Similarly, "network device" can refer to the network device itself, a component of the network device (e.g., a processor, module, chip, or chip system), or a device used in conjunction with the network device. The following example illustrates the synchronization method provided in this application using a terminal and a network device (such as a satellite, HAPS, aircraft, NTN gateway, satellite base station, or airborne base station).

[0105] Figure 3 is a schematic diagram of a synchronization method provided in an embodiment of this application. The method includes:

[0106] S301: The network device sends a reference signal, and the terminal receives the reference signal accordingly to determine the frequency offset.

[0107] In one possible implementation, when a terminal is within the coverage area of ​​a network device, it can receive a reference signal from the network device and determine the frequency offset corresponding to that network device based on the reference signal. The reference signal may include one or more of the following: a channel-state information (CSI) reference signal (CSI-RS) or a tracking reference signal (TRS).

[0108] As an example: The terminal can determine the frequency A of the received reference signal based on the reference signal received from the network device, and determine the frequency offset of the network device based on the frequency A and the frequency B corresponding to the signal transmitted by the network device (or the frequency B configured by the network device to transmit the reference signal), such as determining the frequency offset based on the difference between frequency A and frequency B.

[0109] At least one of the information such as frequency domain resources or time domain resources for transmitting reference signals can be predefined and configured in the terminal by a protocol, or the network device can send configuration information of the reference signals to the terminal to configure at least one of the information such as frequency domain resources or time domain resources of the reference signals. The network device can send the configuration information of the reference signals to the terminal via broadcast, multicast, or unicast, and this application does not limit the method by which the network device sends the configuration information of the reference signals to the terminal.

[0110] S302: The terminal sends a frequency offset quantized value, and the network device receives the frequency offset quantized value accordingly. This frequency offset quantized value is determined based on a first frequency offset dynamic range and a first quantization granularity.

[0111] Wherein, the first frequency offset dynamic range and the first quantization granularity satisfy at least one of the following: the value of the first frequency offset dynamic range is Lppm, where L is less than 0.01; the value of the first frequency offset dynamic range is 1 / (2^M*Δt), where Δt is the symbol length and M is an integer greater than 9; or, the value of the first quantization granularity is 2^N, where N is an integer greater than 8.

[0112] In this embodiment, considering scenarios such as NTN, where the distance between network devices (e.g., satellites) and terminals is relatively long, resulting in significant signal transmission delays and low frequency offset feedback accuracy, thus failing to meet the requirements for joint coherent transmission of multiple network devices, feedback accuracy can be increased by expanding the dynamic range of frequency offset and / or the value of quantization granularity. The following description uses different implementation examples.

[0113] Implementation A: Without changing the existing frequency offset dynamic range A_FO, expand the value of the quantization granularity M_FO. The value of the first quantization granularity used to quantize the frequency offset can be 2^N, where N is an integer greater than 8, that is, the first quantization granularity is an integer greater than 256.

[0114] With the first quantization granularity value remaining constant, a smaller first frequency offset dynamic range value used for quantizing the frequency offset results in higher quantization accuracy. For the SCS, as described above regarding frequency and time offset, the supported values ​​for the current frequency offset dynamic range include: 1 / (4Δt), 1 / (8Δt), 1 / (16Δt), 1 / (32Δt), and 1 / (512Δt). This means that when the first frequency offset dynamic range is at its minimum value of 1 / (512Δt), the combination of the first frequency offset dynamic range and the first quantization granularity yields the highest quantization accuracy, resulting in the minimum frequency offset feedback accuracy. Table 3 illustrates the minimum frequency offset feedback accuracy values ​​for different SCS and different first quantization granularity values, with the first frequency offset dynamic range value being 1 / (512Δt).

[0115] Table 3

[0116] Taking an SCS of 15kHz and a first quantization granularity of 512 as an example, the subcarrier spacing Δf is negatively correlated with the symbol length Δt. 1 / (512Δt) can also be expressed as Δf / 512. Therefore, the feedback accuracy of the minimum frequency offset can be expressed as Δf / (512*512), in Hz. That is, the feedback accuracy of the minimum frequency offset is 15*10^3 / (512*512)≈0.06Hz. As shown in Table 3 above, by expanding the value of the quantization granularity M_FO, the feedback accuracy of the minimum frequency offset under different SCS values ​​can be increased. Taking the scenario where the required frequency offset feedback accuracy for the joint coherent transmission is 0.15Hz as an example, when the first quantization granularity is 512, SCS of 15kHz and 30kHz can both meet the minimum frequency offset feedback accuracy requirement; when the first quantization granularity is 1024, SCS of 15kHz, 30kHz, and 60kHz can all meet the minimum frequency offset feedback accuracy requirement; when the first quantization granularity is 2048, SCS of 15kHz, 30kHz, 60kHz, and 120kHz can all meet the minimum frequency offset feedback accuracy requirement; when the first quantization granularity is 4096, SCS of 15kHz, 30kHz, 60kHz, 120kHz, and 120kHz can all meet the minimum frequency offset feedback accuracy requirement.

[0117] Regarding frequency bands, as described above in the sections on frequency offset and time offset, the current supported values ​​for the frequency offset dynamic range include 0.01ppm, 0.1ppm, and 0.2ppm. This means that when the minimum value of the first frequency offset dynamic range is 0.01ppm, the combination of the first frequency offset dynamic range and the first quantization granularity yields the highest quantization accuracy, resulting in the minimum frequency offset feedback accuracy. Taking the first quantization granularity values ​​of 512, 1024, 2048, and 4096 as examples, Table 4 illustrates the minimum frequency offset feedback accuracy for different frequency bands and with different first quantization granularity values, when the first frequency offset dynamic range is 0.01ppm.

[0118] Table 4

[0119] Taking the L-band and a first quantization granularity of 512 as an example, 2GHz = 2 * 10^9 Hz, 0.01ppm = 0.01 * (2 * 10^9) / 10^6 = 20Hz, then the feedback accuracy of the minimum frequency offset is 20 / 512 ≈ 0.04Hz. As shown in Table 4 above, by expanding the value of the quantization granularity M_FO, the feedback accuracy of the minimum frequency offset in different frequency bands can be increased. Taking the scenario where the required frequency offset feedback accuracy for the aforementioned joint coherent transmission is 0.15Hz as an example, when the first quantization granularity is 512, both the L-band and S-band can meet the minimum frequency offset feedback accuracy requirement; when the first quantization granularity is 1024, the L-band, S-band, C-band, and X-band can all meet the minimum frequency offset feedback accuracy requirement; when the first quantization granularity is 2048, the L-band, S-band, C-band, X-band, Ku-band, and K-band can all meet the minimum frequency offset feedback accuracy requirement; and when the first quantization granularity is 4096, the L-band, S-band, C-band, X-band, Ku-band, K-band, and Ka-band can all meet the minimum frequency offset feedback accuracy requirement.

[0120] In some embodiments, in order to reduce the complexity of frequency offset quantization by the terminal, the value of N can be less than or equal to 20, that is, the value of the first quantization granularity can be an integer greater than 2^8 and less than or equal to 2^20.

[0121] In other embodiments, considering that the accuracy requirements for frequency offset feedback in most SCS or frequency bands in NTN scenarios can be met when the first quantization granularity is 512, 1024, 2048, or 4096, in order to further reduce the complexity of frequency offset quantization in the terminal, the value of N can also be 9, 10, 11, or 12, that is, the value of quantization granularity can be extended to 512, 1024, 2048, or 4096.

[0122] The following assumes a first frequency offset dynamic range of 1 / (512Δt) and a first quantization granularity of 512. If the SCS (Search Channel Switching) for communication between the terminal and the network device is 15kHz, then for this SCS, Δt = T_data + T_cp = 1 / Δf + 144 / 2048 * T_data ≈ 71.35us, where T_data = 1 / Δf, and 71.35us is equivalent to 71.35 / 10^6s. The quantization formula can be FO_i = i * A_FO / (M_FO - 1), where FO_i represents the frequency offset quantization value, i represents the frequency offset, A_FO represents the frequency offset dynamic range (here, the first frequency offset dynamic range), and M_FO represents the quantization granularity (here, the first quantization granularity). For this example, we know that A_FO = 1 / (512Δt) = 27.3739Hz. For the i-th quantization value, in the scenario where the first quantization granularity is M_FO = 512, we know that FO_i = i*A_FO / (M_FO-1) = i*27.3739 / (512–1).

[0123] Implementation B: Without changing the existing quantization granularity M_FO, expand the value of the frequency offset dynamic range A_FO. The value of the first quantization granularity used to quantize the frequency offset can be 1 / (2^M*Δt), where Δt is the symbol length and M is an integer greater than 9; or, the value of the first frequency offset dynamic range can be Lppm, where L is less than 0.01.

[0124] With the first frequency offset dynamic range remaining constant, a larger first quantization granularity value used to quantize the frequency offset results in higher quantization accuracy. For the SCS, as described above regarding frequency and time offsets, the currently supported quantization granularity values ​​are 32, 64, 128, and 256. That is, when the first granularity value is 256, the combination of the first frequency offset dynamic range and the first granularity yields the highest quantization accuracy, producing the minimum frequency offset feedback accuracy. Taking first frequency offset dynamic ranges of 1 / (1024Δt), 1 / (2048Δt), 1 / (4096Δt), and 1 / (8192Δt) as examples, Table 5 illustrates the minimum frequency offset feedback accuracy values ​​for different SCS and different first quantization granularity values ​​when the first granularity value is 256.

[0125] Table 5

[0126] Taking a subcarrier spacing of 15kHz and a first frequency offset dynamic range of 1 / (1024Δt) as an example, where the subcarrier spacing Δf is negatively correlated with the symbol length Δt, 1 / (1024Δt) can also be expressed as Δf / 1024. Therefore, the feedback accuracy of the minimum frequency offset can be expressed as Δf / (1024*256), in Hz. That is, the feedback accuracy of the minimum frequency offset is 15*10^3 / (1024*256)≈0.06. As shown in Table 5 above, by expanding the value of the frequency offset dynamic range M_AF, the feedback accuracy of the minimum frequency offset under different SCS can be increased. Taking the scenario where the required frequency offset feedback accuracy for the joint coherent transmission is 0.15Hz as an example, when the first frequency offset dynamic range is 1 / (1024Δt), SCS of 15kHz and 30kHz can both meet the minimum frequency offset feedback accuracy requirement; when the first frequency offset dynamic range is 1 / (2048Δt), SCS of 15kHz, 30kHz, and 60kHz can all meet the minimum frequency offset feedback accuracy requirement; when the first frequency offset dynamic range is 1 / (4096Δt), SCS of 15kHz, 30kHz, 60kHz, and 120kHz can all meet the minimum frequency offset feedback accuracy requirement; when the first frequency offset dynamic range is 1 / (8192Δt), SCS of 15kHz, 30kHz, 60kHz, 120kHz, and 120kHz can all meet the minimum frequency offset feedback accuracy requirement.

[0127] For frequency bands, taking the first frequency offset dynamic ranges of 0.005ppm, 0.002ppm, 0.001ppm, and 0.0005ppm as examples, Table 6 shows the feedback accuracy of the minimum frequency offset for different frequency bands and different values ​​of the first quantization granularity when the first quantization granularity is 256.

[0128] Table 6

[0129] Taking the L-band and a first frequency offset dynamic range of 0.005ppm as an example, 2GHz = 2 * 10^9 Hz, 0.005ppm = 0.005 * (2 * 10^9) / 10^6 = 10Hz, then the feedback accuracy of the minimum frequency offset is 10 / 256 ≈ 0.04Hz. As shown in Table 6 above, by expanding the value of the frequency offset dynamic range M_AF, the feedback accuracy of the minimum frequency offset in different frequency bands can be increased. Taking the scenario where the required frequency offset feedback accuracy for the aforementioned joint coherent transmission is 0.15Hz as an example, when the first frequency offset dynamic range is 0.005ppm, both the L-band and S-band can meet the minimum frequency offset feedback accuracy requirement; when the first frequency offset dynamic range is 0.002ppm, the L-band, S-band, C-band, X-band, and Ku-band can all meet the minimum frequency offset feedback accuracy requirement; when the first frequency offset dynamic range is 0.001ppm, the L-band, S-band, C-band, X-band, Ku-band, and K-band can all meet the minimum frequency offset feedback accuracy requirement; and when the first frequency offset dynamic range is 0.0005ppm, the L-band, S-band, C-band, X-band, Ku-band, K-band, Ka-band, and V-band can all meet the minimum frequency offset feedback accuracy requirement.

[0130] In some embodiments, for different SCSs, considering that the value of the first frequency offset dynamic range is 1 / (1024Δt), 1 / (2048Δt), 1 / (4096Δt), or 1 / (8192Δt), it is sufficient to meet the accuracy requirements for frequency offset feedback in most SCSs in the NTN scenario. In order to further reduce the complexity of frequency offset quantization by the terminal, M in the value of the first frequency offset dynamic range 1 / (2^M*Δt) can be 10, 11, 12, or 13, that is, the value of the frequency offset dynamic range can be extended to 1 / (1024Δt), 1 / (2048Δt), 1 / (4096Δt), or 1 / (8192Δt).

[0131] In some embodiments, for different frequency bands, considering that the value of the first dynamic range is 0.005ppm, 0.002ppm, 0.001ppm, or 0.0005ppm, it is already sufficient to meet the accuracy requirements for frequency offset feedback in most frequency bands in NTN scenarios. In order to further reduce the complexity of frequency offset quantization by the terminal, the L in the value Lppm of the first frequency offset dynamic range can be 0.005, 0.002, 0.001, or 0.0005, that is, the value of the dynamic range of frequency offset can be extended to 0.005ppm, 0.002ppm, 0.001ppm, or 0.0005ppm.

[0132] Implementation C: The values ​​of the frequency offset dynamic range A_FO and the quantization granularity M_FO can be expanded. For example, the first quantization granularity used to quantize the frequency offset can be 2^N, where N is an integer greater than 8; the first quantization granularity used to quantize the frequency offset can be 1 / (2^M*Δt), where M is an integer greater than 9; or, the first frequency offset dynamic range used to quantize the frequency offset can be Lppm, where L is less than 0.01.

[0133] S303: Network devices perform frequency offset compensation based on the frequency offset quantization value.

[0134] When a network device receives a frequency offset quantization value, it can perform frequency offset compensation based on this value (such as adjusting the frequency of the signal sent to the terminal according to the frequency offset quantization value) to achieve synchronization with the terminal frequency.

[0135] The above example illustrates how extending the dynamic range of frequency offset A_FO and / or the quantization granularity M_FO can improve the feedback accuracy of frequency offset. In some embodiments, the existing dynamic range of frequency offset A_FO and the quantization granularity M_FO can be left unchanged, and the quantization scaling factor can be adaptively determined based on the orbital altitude of the network device (such as a satellite) to meet the feedback progress requirements of frequency offset.

[0136] Figure 4 is a second schematic diagram of the synchronization method provided in an embodiment of this application. The method includes:

[0137] S401: The terminal determines the target quantization scaling factor based on the orbital height of the network device and the mapping relationship between orbital height and quantization scaling factor.

[0138] In this embodiment, the mapping relationship between orbital height and quantization scaling factor may include: a mapping relationship between orbital height and quantization scaling factor of frequency offset dynamic range, and / or a mapping relationship between orbital height and quantization scaling factor of quantization granularity. The target quantization scaling factor may include: a first target quantization scaling factor determined based on the orbital height of the network device and the mapping relationship between orbital height and quantization scaling factor of frequency offset dynamic range, and / or a second target quantization scaling factor determined based on the orbital height of the network device and the mapping relationship between orbital height and quantization scaling factor of quantization granularity.

[0139] The mapping relationship between orbital height and quantization scaling factor can be predefined and configured in the terminal by protocols, or it can be determined and sent to the terminal by network devices. This application does not limit the way the terminal obtains the mapping relationship between orbital height and quantization scaling factor.

[0140] The network device can send the mapping relationship between track height and quantization scaling factor to the terminal through broadcast messages, multicast messages, or unicast messages. This application does not limit the method by which the network device sends the mapping relationship between track height and quantization scaling factor to the terminal. For example, the network device can broadcast the mapping relationship between track height and quantization scaling factor through a system information block (SIB), and the terminal can obtain the mapping relationship between track height and quantization scaling factor by receiving the SIB.

[0141] Table 7 provides an example of the mapping relationship between orbital height and the quantization scaling factor of the frequency offset dynamic range, including: the mapping relationship between orbital height interval_1 and the quantization scaling factor S11 of the frequency offset dynamic range; the mapping relationship between orbital height interval_2 and the quantization scaling factor S12 of the frequency offset dynamic range; ..., the mapping relationship between orbital height interval_N and the quantization scaling factor S1N of the frequency offset dynamic range. Wherein, the maximum orbital height in orbital height interval_i can be less than or equal to the minimum orbital height in orbital height interval_i+1, i can be a positive integer less than or equal to N-1, and N can be an integer greater than or equal to 2.

[0142] Table 7

[0143] Furthermore, considering that the smaller the value of the frequency offset dynamic range, the higher the quantization accuracy of the frequency offset, when the quantization granularity remains unchanged, the quantization scaling factor (such as S11, S12, ..., or S1N) of the frequency offset dynamic range in this embodiment can be less than or equal to 1. When it is equal to 1, it is equivalent to no scaling; when it is less than 1, scaling is performed. For example, if the quantization scaling factor is 1 / 2, the frequency offset dynamic range is 1 / 2 of the original, and the feedback accuracy of the frequency offset can be improved by 2 times.

[0144] Table 8 provides an example of the mapping relationship between orbital height and quantization scaling factor of quantization granularity, including: the mapping relationship between orbital height interval_1 and quantization scaling factor S21; the mapping relationship between orbital height interval_2 and quantization scaling factor S22; ..., the mapping relationship between orbital height interval_N and quantization scaling factor S2N. Wherein, the maximum orbital height in orbital height interval_i can be less than or equal to the minimum orbital height in orbital height interval_i+1, i can be a positive integer less than or equal to N-1, and N can be an integer greater than or equal to 2.

[0145] Table 8

[0146] Furthermore, considering that the smaller the quantization granularity, the higher the quantization accuracy of the frequency offset, when the value of the frequency offset dynamic range remains unchanged, the quantization scaling factor (such as S21, S22, ..., or S2N) of the quantization granularity in this embodiment can be a value greater than or equal to 1. When it is equal to 1, it is equivalent to no scaling; when it is greater than 1, scaling is performed. For example, if the quantization scaling factor is 2, the quantization granularity is twice the original, and the feedback accuracy of the frequency offset can be improved by 2 times.

[0147] The terminal can determine the orbital altitude of the network device based on the ephemeris information of the network device, and then determine the first target quantization scaling factor based on the mapping relationship between the orbital altitude and the quantization scaling factor of the frequency offset dynamic range, and / or determine the second target quantization scaling factor based on the mapping relationship between the orbital altitude and the quantization scaling factor of the quantization granularity.

[0148] For example, the network device sends the mapping relationship between orbital height and quantization scaling factor of quantization granularity as shown in Table 8 to the terminal. Based on the ephemeris information of the network device, the terminal determines that the orbital height of the network device belongs to orbital height interval _2, and the terminal can determine that the second target quantization scaling factor is S22.

[0149] Understandably, orbital altitude ranges can also be replaced with orbital types or orbital altitude groups, etc. For example, orbital altitude range_1 can be replaced with orbital type_1, orbital altitude range_2 can be replaced with orbital type_2, orbital altitude range_3 can be replaced with orbital type_3, and so on. Here, orbital type_1 can be a low-Earth orbit (LEO), orbital type_2 can be a medium-Earth orbit (MEO), orbital type_3 can be a high-Earth orbit (HEO), etc. The terminal can also determine the orbital type of the network device based on its ephemeris information, and thus determine the target quantization scaling factor.

[0150] For example, the network device sends the mapping relationship between the orbit type and the quantization scaling factor of the quantization granularity to the terminal. Based on the ephemeris information of the network device, the terminal determines that the orbit type of the network device is orbit type_2, and the terminal can determine that the second target quantization scaling factor is S22.

[0151] S402: The network device sends a reference signal, and the terminal determines the frequency offset based on the received reference signal.

[0152] The implementation of S402 can be referred to the implementation of step S301 above, and will not be repeated here.

[0153] S403: The terminal transmits the frequency offset quantization value, and the network device receives the frequency offset quantization value accordingly.

[0154] The frequency offset quantization value is determined based on the second frequency offset dynamic range, the second quantization granularity, and the target quantization scaling factor.

[0155] The second frequency offset dynamic range and the second quantization granularity can be determined by the terminal or configured by the network device for the terminal.

[0156] For example, in scenarios where the network device is an NTN device such as a satellite, the terminal can, by default, select the minimum frequency offset dynamic range as the second frequency offset dynamic range from the existing selectable frequency offset dynamic ranges, and select the maximum quantization granularity as the second quantization granularity from the existing selectable quantization granularities, etc. Alternatively, the network device can also send second information to the terminal to indicate the second frequency offset dynamic range and / or the second quantization granularity, and the terminal can determine the second frequency offset dynamic range and / or the second quantization granularity based on the second information from the network device.

[0157] After determining the target quantization scaling factor, the terminal can scale the second frequency offset dynamic range and / or the second quantization granularity based on the target quantization scaling factor to obtain a new second frequency offset dynamic range and / or second quantization granularity, and quantize the frequency offset based on the new second frequency offset dynamic range and / or second quantization granularity to obtain the frequency offset quantized value.

[0158] Taking the second frequency offset dynamic range as M_AO, the second quantization granularity as M_FO, and the target quantization scaling factor including the second target quantization factor s_i used to scale the quantization granularity as an example, the new second quantization granularity M_FO_new obtained after scaling by the second target quantization factor s_i is M_FO_new = M_FO*s_i. The terminal can quantize the frequency offset based on M_FO_new and M_AO to obtain the frequency quantization value.

[0159] S404: Network devices perform frequency offset compensation based on the frequency offset quantization value.

[0160] When a network device receives a frequency offset quantization value, it can perform frequency offset compensation based on this value (such as adjusting the frequency of the signal sent to the terminal according to the frequency offset quantization value) to achieve synchronization with the terminal frequency.

[0161] It is understood that the synchronization method provided in this application embodiment can also be applied to the synchronization of time offset between terminals and network devices. The feedback accuracy of time offset can be improved by expanding the value range of the dynamic range of time offset and / or the value range of quantization granularity. Alternatively, without changing the existing value range of the dynamic range of time offset and the value range of quantization granularity, the quantization scaling factor can be adaptively determined based on the orbital altitude of the network device (such as a satellite), and the dynamic range of time offset and / or quantization granularity can be adjusted by the quantization scaling factor to meet the feedback accuracy requirements of time offset.

[0162] It is understood that, in order to achieve the functions in the above embodiments, the terminal and network device include hardware structures and / or software modules corresponding to perform each function. Those skilled in the art should readily recognize that, based on the units and method steps of the various examples described in conjunction with the embodiments disclosed in this application, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application scenario and design constraints of the technical solution.

[0163] Figures 5 and 6 are schematic diagrams of possible communication devices provided in embodiments of this application. These communication devices can be used to implement the functions of the terminal or network device in the above method embodiments, and thus can also achieve the beneficial effects of the above method embodiments. In the embodiments of this application, the communication device can be the terminal 120 shown in Figure 1A, the network device 110 shown in Figure 1A, or a module (such as a chip) applied to the terminal or network device.

[0164] Please refer to Figure 5, which is a schematic diagram of a communication device according to an embodiment of this application. The communication device may include units or modules corresponding to all or part of the steps in the above method embodiments, and can be used to execute the steps executed by the terminal or network device in the above embodiments. For details, please refer to the relevant descriptions in the above method embodiments.

[0165] As shown in Figure 5, the communication device 500 includes a processing unit 510 and an interface unit 520. The processing unit 510 can be a processor or a processing circuit, and the interface unit 520 can be a transceiver unit or an input / output interface. The communication device 500 can be used to implement the steps performed by the terminal or network device in the above embodiments.

[0166] When the communication device 500 is used to implement the steps performed by the terminal in the above embodiments:

[0167] The processing unit 510 is used to determine the frequency offset based on the received reference signal;

[0168] Interface unit 520 is used to transmit frequency offset quantization values. The frequency offset quantization values ​​are determined by quantizing the frequency offset based on a first frequency offset dynamic range and a first quantization granularity. The first frequency offset dynamic range and the first quantization granularity satisfy at least one of the following: the value of the first frequency offset dynamic range is Lppm, where L is less than 0.01; the value of the first frequency offset dynamic range is 1 / (2^M*Δt), where Δt is the symbol length and M is an integer greater than 9; or the value of the first quantization granularity is 2^N, where N is an integer greater than 8.

[0169] In one possible design, the interface unit 520 is also configured to receive first information indicating a first frequency offset dynamic range and / or a first quantization granularity.

[0170] In one possible design, N is less than or equal to 20.

[0171] In one possible design, N is 9, 10, 11, or 12.

[0172] In one possible design, L is 0.005, 0.002, 0.001, or 0.0005.

[0173] In one possible design, M is 10, 11, 12, or 13.

[0174] Alternatively, processing unit 510 is used to determine the target quantization scaling factor based on the orbital height of the network device and the mapping relationship between orbital height and quantization scaling factor; and to determine the frequency offset based on the received reference signal.

[0175] Interface unit 520 is used to send frequency offset quantization values, which are determined based on a second frequency offset dynamic range, a second quantization granularity, and a target quantization scaling factor.

[0176] In one possible design, the mapping relationship between track height and quantization scaling factor includes: a mapping relationship between track height and quantization scaling factor of frequency offset dynamic range, and / or a mapping relationship between track height and quantization scaling factor of quantization granularity; the target quantization scaling factor includes: a first target quantization scaling factor determined based on the track height of the network device and the mapping relationship between track height and quantization scaling factor of frequency offset dynamic range, and / or a second target quantization scaling factor determined based on the track height of the network device and the mapping relationship between track height and quantization scaling factor of quantization granularity; the first target quantization scaling factor is used to scale the second frequency offset dynamic range, and the second target quantization scaling factor is used to scale the second quantization granularity.

[0177] In one possible design, the first target quantization scaling factor is less than or equal to 1, and the second target quantization scaling factor is greater than or equal to 1.

[0178] In one possible design, interface unit 520 is also used to receive the mapping relationship between track height and quantization scaling factor.

[0179] In one possible design, the interface unit 520 is also used to receive second information, which indicates a second frequency offset dynamic range and / or a second quantization granularity.

[0180] When the communication device 500 is used to implement the steps performed by the network device in the above embodiments:

[0181] Interface unit 520 is used to transmit a reference signal and receive a frequency offset quantization value, the frequency offset quantization value being quantized based on a first frequency offset dynamic range and a first quantization granularity, wherein the first frequency offset dynamic range and the first quantization granularity satisfy at least one of the following: the first frequency offset dynamic range is Lppm, where L is less than 0.01; the first frequency offset dynamic range is 1 / (2^M*Δt), where Δt is the symbol length and M is an integer greater than 9; or, the first quantization granularity is 2^N, where N is an integer greater than 8.

[0182] The processing unit 510 is used to perform frequency offset compensation based on the frequency offset quantization value.

[0183] In one possible design, the interface unit 520 is also used to send first information, the first information indicating a first frequency offset dynamic range and / or a first quantization granularity.

[0184] In one possible design, N is less than or equal to 20.

[0185] In one possible design, N is 9, 10, 11, or 12.

[0186] In one possible design, L is 0.005, 0.002, 0.001, or 0.0005.

[0187] In one possible design, M is 10, 11, 12, or 13.

[0188] Alternatively, interface unit 520 is used to transmit a reference signal; and to receive a frequency offset quantization value, the frequency offset quantization value being quantized based on a second frequency offset dynamic range, a second quantization granularity and a target quantization scaling factor, the target quantization scaling factor being determined according to the orbital height of the network device and the mapping relationship between the orbital height and the quantization scaling factor;

[0189] The processing unit 510 is used to perform frequency offset compensation based on the frequency offset quantization value.

[0190] In one possible design, the mapping relationship between track height and quantization scaling factor includes: a mapping relationship between track height and quantization scaling factor of frequency offset dynamic range, and / or a mapping relationship between track height and quantization scaling factor of quantization granularity; the target quantization scaling factor includes: a first target quantization scaling factor determined based on the track height of the network device and the mapping relationship between track height and quantization scaling factor of frequency offset dynamic range, and / or a second target quantization scaling factor determined based on the track height of the network device and the mapping relationship between track height and quantization scaling factor of quantization granularity; the first target quantization scaling factor is used to scale the second frequency offset dynamic range, and the second target quantization scaling factor is used to scale the second quantization granularity.

[0191] In one possible design, the first target quantization scaling factor is less than or equal to 1, and the second target quantization scaling factor is greater than or equal to 1.

[0192] In one possible design, interface unit 520 is also used to transmit the mapping relationship between track height and quantization scaling factor.

[0193] In one possible design, the interface unit 520 is also used to send second information, which indicates a second frequency offset dynamic range and / or a second quantization granularity.

[0194] As shown in Figure 6, this application also provides a communication device 600, including a processor 610 and potentially a communication interface 620. The processor 610 and the communication interface 620 are coupled to each other. It is understood that the communication interface 620 can be a transceiver, input / output interface, input interface, output interface, interface circuit, etc. Optionally, the communication device 600 may further include a memory 630 for storing instructions executed by the processor 610, or storing input data required by the processor 610 to execute instructions, or storing data generated after the processor 610 executes instructions. The memory 630 can be a physically independent unit, or it can be coupled to the processor 610, or the processor 610 may include the memory 630.

[0195] When the communication device 600 is used to implement the steps performed by the terminal or network device in the above embodiments, the processor 610 can be used to implement the function of the processing unit 510, and the communication interface 620 can be used to implement the function of the interface unit 520.

[0196] When the aforementioned communication device is a chip applied to a terminal, the terminal chip implements the functions of the terminal in the above method embodiments. The terminal chip receives information from a network device, which can be understood as the information being first received by other modules in the terminal (such as an RF module or antenna), and then sent to the terminal chip by these modules. The terminal chip sends information to a network device, which can be understood as the information being first sent to other modules in the terminal (such as an RF module or antenna), and then sent to the network device by these modules.

[0197] When the aforementioned communication device is a chip used in network equipment (such as a base station), the network equipment chip implements the functions of the network equipment in the above method embodiments. The network equipment chip receives information from the terminal, which can be understood as the information being first received by other modules (such as radio frequency modules or antennas) in the network equipment, and then sent to the network equipment chip by these modules. The network equipment chip sends information to the terminal, which can be understood as the information being sent down to other modules (such as radio frequency modules or antennas) in the network equipment, and then sent to the terminal by these modules.

[0198] This application also provides a computer-readable storage medium storing a computer program or instructions for implementing the methods executed by a terminal or network device in the above method embodiments.

[0199] For example, when the computer program or instructions are executed by a processor, the processor can implement the methods executed by the terminal or network device in the above method embodiments.

[0200] This application also provides a computer program product containing a computer program or instructions, which, when executed by a processor, cause the processor to implement the method executed by a terminal or network device in the above method embodiments.

[0201] This application also provides a communication system, which includes the terminal and network device described in the above embodiments.

[0202] In this application embodiment, the processor can be one or more central processing units (CPUs). If the processor is a CPU, it can be a single-core CPU or a multi-core CPU. The processor can also be one or a combination of several of the following: CPU, general-purpose processor, application-specific integrated circuit (ASIC), digital signal processor, microprocessor, microcontroller, graphics processor, field-programmable gate array or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, artificial intelligence processor, or neural network processor. The processor can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The steps of the methods disclosed in the embodiments of this application can be directly manifested as being executed by a hardware processor, or executed by a combination of hardware and software modules within the processor.

[0203] In this application embodiment, the memory may include, but is not limited to, cache, read-only memory (ROM), random access memory, synchronous dynamic random access memory, hard disk or solid-state drive, erasable programmable read-only memory, or compact disc read-only memory (CD-ROM), etc. Memory is any other medium capable of carrying or storing desired program code in the form of instructions or data structures that can be accessed by a computer, but is not limited to this. The memory in this application embodiment may also be a circuit or any other device capable of implementing storage functions for storing computer programs or instructions, and / or data.

[0204] It is understood that the method steps in the embodiments of this application can be implemented in hardware or by a processor executing software instructions. The software instructions can consist of corresponding software modules, which can be stored in random access memory, flash memory, read-only memory, programmable read-only memory, erasable programmable read-only memory, electrically erasable programmable read-only memory, registers, hard disks, portable hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and storage medium can reside in an ASIC. Additionally, the ASIC can reside in a network device or terminal. Alternatively, the processor and storage medium can exist as discrete components in the network device or terminal.

[0205] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer programs or instructions. When the computer program or instructions are loaded and executed on a computer, the processes or functions described in the embodiments of this application are performed entirely or partially. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user equipment, or other programmable device. The computer program or instructions can be stored in a computer-readable storage medium or transferred from one computer-readable storage medium to another. For example, the computer program or instructions can be transferred from one network device, terminal, computer, server, or data center to another network device, terminal, computer, server, or data center via wired or wireless means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium, such as a floppy disk, hard disk, or magnetic tape; it can also be an optical medium, such as a digital video optical disc; or it can be a semiconductor medium, such as a solid-state drive. The computer-readable storage medium may be a volatile or non-volatile storage medium, or may include both types of storage media.

[0206] In the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terminology and / or descriptions of different embodiments are consistent and can be referenced by each other. The technical features of different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0207] Additionally, it should be understood that in the embodiments of this application, the term "exemplary" is used to indicate that it is an example, illustration, or description. Any embodiment or design scheme described as "exemplary" in this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of the term "exemplary" is intended to present the concept in a concrete manner.

[0208] It is understood that the various numerical designations used in the embodiments of this application are merely for descriptive convenience and are not intended to limit the scope of the embodiments of this application. The order of the process numbers described above does not imply the order of execution; the execution order of each process should be determined by its function and internal logic.

Claims

1. A synchronization method, characterized in that, include: Determine the frequency offset based on the received reference signal; A frequency offset quantized value is transmitted, the frequency offset quantized value being determined by quantizing the frequency offset based on a first frequency offset dynamic range and a first quantization granularity, wherein the first frequency offset dynamic range and the first quantization granularity satisfy at least one of the following: The value of the first frequency offset dynamic range is Lppm, where L is less than 0.01; The value of the first frequency offset dynamic range is 1 / (2^M*Δt), where Δt is the symbol length and M is an integer greater than 9; or, The first quantization granularity is 2^N, where N is an integer greater than 8.

2. The method as described in claim 1, characterized in that, The method further includes: Receive first information, which indicates the first frequency offset dynamic range and / or the first quantization granularity.

3. The method as described in claim 1 or 2, characterized in that, The N is less than or equal to 20.

4. The method as described in claim 3, characterized in that, The N is 9, 10, 11, or 12.

5. The method according to any one of claims 1-4, characterized in that, The value of L is 0.005, 0.002, 0.001, or 0.0005.

6. The method according to any one of claims 1-4, characterized in that, M is 10, 11, 12, or 13.

7. A synchronization method, characterized in that, include: Send a reference signal; The receiver receives a frequency offset quantized value, which is quantized based on a first frequency offset dynamic range and a first quantization granularity, wherein the first frequency offset dynamic range and the first quantization granularity satisfy at least one of the following: the first frequency offset dynamic range is Lppm, where L is less than 0.01; the first frequency offset dynamic range is 1 / (2^M*Δt), where Δt is the symbol length and M is an integer greater than 9; or, the first quantization granularity is 2^N, where N is an integer greater than 8. Frequency offset compensation is performed based on the frequency offset quantization value.

8. The method as described in claim 7, characterized in that, The method further includes: Send a first message, which indicates the first frequency offset dynamic range and / or the first quantization granularity.

9. The method as described in claim 7 or 8, characterized in that, The N is less than or equal to 20.

10. The method as described in claim 9, characterized in that, The N is 9, 10, 11, or 12.

11. The method according to any one of claims 7-10, characterized in that, The value of L is 0.005, 0.002, 0.001, or 0.0005.

12. The method according to any one of claims 7-10, characterized in that, M is 10, 11, 12, or 13.

13. A synchronization method, characterized in that, include: The target quantization scaling factor is determined based on the orbital height of the network device and the mapping relationship between orbital height and quantization scaling factor. Determine the frequency offset based on the received reference signal; A frequency offset quantization value is transmitted, which is determined by quantizing the frequency offset based on a second frequency offset dynamic range, a second quantization granularity, and the target quantization scaling factor.

14. The method as described in claim 13, characterized in that, The mapping relationship between the orbital height and the quantization scaling factor includes: The mapping relationship between orbital height and the quantization scaling factor of frequency offset dynamic range, and / or the mapping relationship between orbital height and the quantization scaling factor of quantization granularity; The target quantization scaling factor includes: A first target quantization scaling factor determined based on the mapping relationship between the orbital height of the network device and the quantization scaling factor of the orbital height and the frequency offset dynamic range, and / or a second target quantization scaling factor determined based on the mapping relationship between the orbital height of the network device and the quantization scaling factor of the orbital height and the quantization granularity. The first target quantization scaling factor is used to scale the second frequency offset dynamic range, and the second target quantization scaling factor is used to scale the second quantization granularity.

15. The method as described in claim 14, characterized in that, The first target quantization scaling factor is less than or equal to 1, and the second target quantization scaling factor is greater than or equal to 1.

16. The method according to any one of claims 13-15, characterized in that, The method further includes: Receive the mapping relationship between the orbital height and the quantization scaling factor.

17. The method according to any one of claims 13-16, characterized in that, The method further includes: Receive second information, which indicates the second frequency offset dynamic range and / or the second quantization granularity.

18. A synchronization method, characterized in that, include: Send a reference signal; The frequency offset quantization value is received, which is based on a second frequency offset dynamic range, a second quantization granularity, and a target quantization scaling factor. The target quantization scaling factor is determined according to the orbital height of the network device and the mapping relationship between the orbital height and the quantization scaling factor. Frequency offset compensation is performed based on the frequency offset quantization value.

19. The method as described in claim 18, characterized in that, The mapping relationship between the orbital height and the quantization scaling factor includes: The mapping relationship between orbital height and the quantization scaling factor of frequency offset dynamic range, and / or the mapping relationship between orbital height and the quantization scaling factor of quantization granularity; The target quantization scaling factor includes: A first target quantization scaling factor determined based on the mapping relationship between the orbital height of the network device and the quantization scaling factor of the orbital height and the frequency offset dynamic range, and / or a second target quantization scaling factor determined based on the mapping relationship between the orbital height of the network device and the quantization scaling factor of the orbital height and the quantization granularity. The first target quantization scaling factor is used to scale the second frequency offset dynamic range, and the second target quantization scaling factor is used to scale the second quantization granularity.

20. The method as described in claim 19, characterized in that, The first target quantization scaling factor is less than or equal to 1, and the second target quantization scaling factor is greater than or equal to 1.

21. The method according to any one of claims 18-20, characterized in that, The method further includes: Send the mapping relationship between the orbital height and the quantization scaling factor.

22. The method according to any one of claims 18-21, characterized in that, The method further includes: Send a second message, which indicates the second frequency offset dynamic range and / or the second quantization granularity.

23. A communication device, characterized in that, It includes modules or units for performing the method as described in any one of claims 1-6; or, it includes modules or units for performing the method as described in any one of claims 7-12; or, it includes modules or units for performing the method as described in any one of claims 13-17; or, it includes modules or units for performing the method as described in any one of claims 18-22.

24. A communication device, characterized in that, The device includes a processor and an interface circuit, the interface circuit being used to input and / or output signals, and the processor being used to implement the method as described in any one of claims 1-6 via logic circuits or execution instructions; or, to implement the method as described in any one of claims 7-12; or, to implement the method as described in any one of claims 13-17; or, to implement the method as described in any one of claims 18-22.

25. A computer program product, characterized in that, It includes a computer program or instructions that, when executed by a processor, cause the method of any one of claims 1-6 to be implemented; or cause the method of any one of claims 7-12 to be implemented; or cause the method of any one of claims 13-17 to be implemented; or cause the method of any one of claims 18-22 to be implemented.

26. A computer-readable storage medium, characterized in that, The storage medium stores a computer program or instructions that, when executed by a processor, cause the method as described in any one of claims 1-6 to be implemented; or cause the method as described in any one of claims 7-12 to be implemented; or cause the method as described in any one of claims 13-17 to be implemented; or cause the method as described in any one of claims 18-22 to be implemented.

27. A communication system, characterized in that, include: Terminals and network equipment; The terminal is configured to perform the method as described in any one of claims 1-6; The network device is configured to perform the method as described in any one of claims 7-12; or... The terminal is configured to perform the method as described in any one of claims 13-17; the network device is configured to perform the method as described in any one of claims 18-22.

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