Position determination method, communication device, communication system, storage medium and chip system

Abstract

The invention discloses a position determination method, a communication device, a communication system, a storage medium and a chip system, and belongs to the technical field of communication. The method comprises the steps that terminal equipment determines first position information based on an LEO positioning algorithm under the condition that a GNSS fails, obtains second position information based on a position prediction algorithm, and then fuses the first position information and the second position information to obtain target position information. According to the invention, the positioning precision after fusion is higher than the positioning precision of the LEO positioning algorithm and the positioning precision of the position prediction algorithm, so that the terminal equipment can obtain the target position information with high accuracy when the GNSS fails, thereby facilitating the normal operation of communication.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a location determination method, a communication device, a communication system, a storage medium, and a chip system. Background Technology

[0002] In non-terrestrial network (NTN) communication systems, terminal devices typically rely on their Global Navigation Satellite System (GNSS) location information for uplink time and frequency pre-compensation. However, in actual deployments, GNSS failures often occur due to signal obstruction, interference, or hardware limitations, preventing the terminal devices from obtaining usable GNSS location information and consequently affecting communication. Summary of the Invention

[0003] This application provides a location determination method, a communication device, a communication system, a storage medium, and a chip system, which facilitate normal communication. The technical solution is as follows: Firstly, a location determination method is provided. This method can be executed by a terminal device, or by a component (such as a circuit, chip, or chip system) configured in the terminal device, or by a logic module or software capable of implementing all or part of the functions of the terminal device. This application does not limit the scope of this method. The following description uses a terminal device as an example.

[0004] In the event of GNSS failure, the terminal device obtains its first location information based on the LEO positioning algorithm and its second location information based on the location prediction algorithm; and determines the target location information of the terminal device based on the first and second location information.

[0005] In this application, when GNSS fails, the terminal device can determine first location information based on the LEO positioning algorithm, obtain second location information based on the location prediction algorithm, and then fuse the first and second location information to obtain the target location information. The positioning accuracy after fusion is higher than the individual positioning accuracy of the LEO positioning algorithm and the location prediction algorithm. Thus, the terminal device can obtain highly accurate target location information even when GNSS fails, thereby facilitating normal communication.

[0006] In one possible approach, a first GNSS status message is sent to the serving satellite in the event of GNSS failure; a second GNSS status message is sent to the serving satellite in the event of GNSS availability. This allows the serving satellite to promptly obtain the GNSS status of the terminal device and make corresponding resource adjustments accordingly.

[0007] In one possible approach, the operation of the terminal device to obtain the first location information of the terminal device based on the LEO positioning algorithm can be as follows: determine multiple satellites for positioning; determine the first location information based on the TOA of the PRS sent by each of the multiple satellites and the location information of each satellite.

[0008] In this application, the terminal device can combine the TOA of the PRS transmitted by each of the multiple satellites used for positioning with the position information of each satellite to perform positioning, thereby improving the accuracy of the obtained first position information.

[0009] In one possible approach, before determining the first location information based on the TOA of the PRS transmitted by each of the plurality of satellites and the location information of each satellite, the terminal device may also determine a first PRS cycle level. The first PRS cycle level is used to indicate the cycle length of transmitting PRS. The first PRS cycle level is one of n PRS cycle levels, where n is an integer greater than or equal to 2. A positioning service request message is sent to the serving satellite. The positioning service request message includes the first PRS cycle level and a set of satellite identifiers to indicate that each of the plurality of satellites transmits PRS based on the first PRS cycle level. Upon receiving a positioning service confirmation message from the serving satellite, the terminal device receives the PRS transmitted by each of the plurality of satellites based on the first PRS cycle level.

[0010] In this application, the terminal device can request the satellite to transmit PRS according to a corresponding period length based on its own needs. This flexible period adjustment mechanism can effectively ensure the positioning needs of the terminal device in different scenarios, while improving the system's resource utilization.

[0011] In one possible approach, the operation of the terminal device determining the first PRS cycle level can be: determining the first PRS cycle level based on the moving speed of the terminal device.

[0012] In this application, when the terminal device moves at a high speed, a PRS period level corresponding to a shorter period length can be selected as the first PRS period level. This allows for a shorter PRS transmission period when the terminal device moves at high speed, increasing the update frequency of the positioning signal and effectively counteracting rapid channel changes caused by high-speed movement, thus maintaining high-precision positioning. Conversely, when the terminal device moves at a low speed, a PRS period level corresponding to a longer period length can be selected as the first PRS period level. This allows for a longer PRS transmission period when the terminal device moves at low speed, significantly reducing the power consumption of the terminal device while meeting basic positioning requirements.

[0013] In one possible approach, n-1 of the n PRS cycle levels correspond one-to-one with the preset n-1 cycle lengths, and one of the n PRS cycle levels other than the n-1 PRS cycle levels is used to indicate the default cycle length on the network side.

[0014] In this application, one PRS period level is reserved to point to the network-side default period length, which allows terminal devices to directly indicate the use of the default value, simplifying scheduling and management. Furthermore, the remaining n-1 PRS period levels are pre-configured with different period lengths to accommodate diverse business needs.

[0015] In one possible approach, the length of the first PRS period level in the location service request message is L bits. This can save signaling overhead and improve communication efficiency.

[0016] In one possible approach, the operation of the terminal device to obtain the second location information of the terminal device based on the location prediction algorithm can be as follows: training a model based on multiple first motion state information in the historical motion state information set to obtain a location prediction model, wherein the first motion state information includes time information and location information; and obtaining the second location information based on the target time information and the location prediction model.

[0017] In this application, the terminal device can train a model based on the motion state information of the terminal device over a recent period of time to obtain a location prediction model. This location prediction model can learn and adapt to the unique motion patterns of the terminal device in the recent period, thereby obtaining relatively accurate second location information through the location prediction model.

[0018] In one possible approach, the first motion state information may also include one or more of velocity and acceleration information. In this way, the first motion state information can more accurately reflect the historical motion state of the terminal device, thereby helping to more accurately predict the current position of the terminal device subsequently.

[0019] In one possible approach, the terminal device trains a model based on multiple first motion state information from a historical motion state information set to obtain a location prediction model. This process can be as follows: replacing the time information in each first motion state information from the historical motion state information set with the corresponding time increment, and replacing the position information in each first motion state information with the corresponding position increment, to obtain multiple second motion state information; normalizing the multiple second motion state information to obtain a sample dataset; and training the model based on the sample dataset to obtain a location prediction model.

[0020] In this application, the first motion state information in the historical motion state information set is preprocessed. Specifically, the time information is replaced with the corresponding time increment, and the position information is replaced with the corresponding position increment. Then, normalization is performed to eliminate significant differences in numerical range and units between different data points, thereby helping to reflect their essential motion patterns. This improves the stability and accuracy of subsequent model training and accelerates model convergence. Furthermore, the trained position prediction model can more easily capture the real patterns of recent motion of the terminal device, thus making more accurate predictions.

[0021] In one possible approach, the terminal device can set a target time interval based on the terminal device's moving speed; and update the historical motion state information set based on the target time interval.

[0022] In this application, when the moving speed of the terminal device is low, the target time interval can be set to a larger value, thereby reducing the location update frequency when the location changes slowly, so as to reduce power consumption while meeting positioning requirements; when the moving speed of the terminal device is high, the target time interval can be set to a smaller value, thereby increasing the location update frequency when the location changes rapidly, so as to ensure the real-time and continuity of location information.

[0023] In one possible approach, the terminal device can generate first motion state information based on GNSS location information when GNSS is available, or generate first motion state information based on second location information when GNSS is unavailable or LEO positioning fails, or generate first motion state information based on target location information when LEO positioning is successful; and add the newly generated first motion state information to the historical motion state information set.

[0024] In this application, location information can be obtained to update the historical motion state information set regardless of whether GNSS is valid. The maintained historical motion state information set is real-time, continuous, and well-organized, and can accurately reflect the recent motion patterns of the terminal equipment, which provides a guarantee for making accurate short-term future predictions.

[0025] In one possible approach, the operation of the terminal device to determine the target location information of the terminal device based on the first location information and the second location information can be: to perform a weighted average of the first location information and the second location information based on the first weight corresponding to the first location information and the second weight corresponding to the second location information to obtain the target location information.

[0026] In this application, the first and second location information can be quickly fused by a simple weighted average calculation, thereby reducing the computational burden and improving the real-time performance of the location information.

[0027] In one possible approach, before determining the target location information of the terminal device based on the first location information and the second location information, the terminal device may also determine a first weight based on the variance of the positioning error of the LEO positioning algorithm and the variance of the positioning error of the location prediction algorithm. For example, the terminal device may determine the first weight based on the variance of the positioning error of the LEO positioning algorithm and the variance of the positioning error of the location prediction algorithm using the following formula:

[0028] As the first weight, Let V be the variance of the positioning error of the LEO positioning algorithm. This represents the variance of the positioning error in the location prediction algorithm.

[0029] In this application, the variance of the positioning error after the fusion of the LEO positioning algorithm and the location prediction algorithm is smaller than the variance of the positioning error of each of the two schemes, thereby obtaining target location information with higher accuracy.

[0030] Secondly, a communication device is provided, comprising a processing module and a communication module. The processing module is used to, in the event of GNSS failure, acquire first location information of a terminal device based on a LEO positioning algorithm, acquire second location information of the terminal device based on a location prediction algorithm, and determine target location information of the terminal device based on the first and second location information.

[0031] The second aspect is the implementation on the device side, which corresponds to the first aspect. The explanations, supplements, and descriptions of the beneficial effects of the first aspect also apply to the second aspect, and will not be repeated here.

[0032] Thirdly, a communication device is provided, including a processor. The processor is coupled to a memory and can be used to execute instructions or data in the memory to implement the methods in any possible implementation of any of the above aspects. Optionally, the communication device further includes a memory. Optionally, the communication device further includes a communication interface, and the processor is coupled to the communication interface.

[0033] In one implementation, the communication interface can be a transceiver, or an input / output interface.

[0034] In another implementation, the communication device is a chip configured in the terminal device. When the communication device is a chip configured in the terminal device, the communication interface can be an input / output interface.

[0035] Fourthly, a computer program product is provided, comprising: a computer program (also referred to as code or instructions) that, when run, causes a computer to perform the method in any possible implementation of any of the above aspects.

[0036] Fifthly, a computer-readable storage medium is provided that stores a computer program (also referred to as code or instructions) that, when run on a computer, causes the computer to perform the methods in any possible implementation of any of the above aspects.

[0037] Sixthly, embodiments of this application provide a chip system including one or more processors for calling and executing instructions stored in memory, causing the methods in any of the possible implementations of the above aspects to be executed. The chip system may be composed of chips or may include chips and other discrete devices.

[0038] The chip system may include input circuits or interfaces for transmitting information or data, and output circuits or interfaces for receiving information or data.

[0039] In a seventh aspect, a communication system is provided, including the aforementioned terminal device. Optionally, the communication system may further include other devices that communicate with the terminal device. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of a communication system provided in an embodiment of this application.

[0041] Figure 2 This is a flowchart of a location determination method provided in an embodiment of this application.

[0042] Figure 3 This is a flowchart of another location determination method provided in the embodiments of this application.

[0043] Figure 4 This is a schematic diagram showing the location of a satellite and terminal equipment provided in an embodiment of this application.

[0044] Figure 5 This is a schematic diagram of a PRS periodic level coding provided in an embodiment of this application.

[0045] Figure 6 This is a flowchart of another location determination method provided in the embodiments of this application.

[0046] Figure 7 This is a schematic diagram of a historical motion state information set provided in an embodiment of this application.

[0047] Figure 8This is a flowchart of another location determination method provided in the embodiments of this application.

[0048] Figure 9 This is a schematic block diagram of a communication device provided in an embodiment of this application.

[0049] Figure 10 This is a schematic block diagram of another communication device provided in the embodiments of this application. Detailed Implementation

[0050] In the following description, specific details such as particular system architectures and technologies are set forth for illustrative purposes and not for limiting purposes, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details.

[0051] It should be understood that, when used in this specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or collections thereof. The terms "comprising," "including," "having," and variations thereof all mean "including but not limited to," unless otherwise specifically emphasized.

[0052] It should be understood that "one or more" as used in this application refers to one, two, or more, and "multiple" as used in this application refers to two or more. In the description of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B. "And / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone.

[0053] To facilitate a clear description of the technical solutions of this application, the terms "first" and "second" are used to distinguish identical or similar items with essentially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and that the terms "first" and "second" do not necessarily imply that they are different.

[0054] The terms "one embodiment" or "some embodiments" used in this application mean that one or more embodiments of this application include the specific features, structures, or characteristics described in that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in other embodiments," etc., appearing in different parts of this application do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized.

[0055] The embodiments of this application can be applied to various communication systems. For example, Global System for Mobile Communications (GSM), General Packet Radio Service (GPRS) systems, Wireless Local Area Network (WLAN) systems (such as Wireless Fidelity (Wi-Fi) systems), Long Term Evolution (LTE) systems, LTE Frequency Division Duplex (FDD) systems, LTE Time Division Duplex (TDD) systems, sidelink communication systems, Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication systems, NTN communication systems, 4th generation (4G) mobile communication systems, 5th generation (5G) mobile communication systems, or new radio access technology (NR) systems, 6th generation (6G) mobile communication systems, etc. The 5G mobile communication system may include non-standalone (NSA) and / or standalone (SA) networking. It is understood that the embodiments of this application can also be applied to future communication systems, and the embodiments of this application do not limit this application.

[0056] Figure 1 This is a schematic diagram of a communication system 100 provided in an embodiment of this application. The communication system 100 may include network (NW) devices, such as... Figure 1The network device 110 shown. The communication system 100 may also include terminal devices, such as... Figure 1 The terminal device 120 shown can communicate with the network device via a wireless link. Figure 1 An exemplary network device 110 and a terminal device 120 are shown. Optionally, the communication system 100 may also include multiple network devices and / or multiple terminal devices. Additionally, Figure 1 The example described uses network device 110 as a satellite only, and the embodiments of this application do not limit the type of network device 110.

[0057] The network device in this application embodiment can be a network-side device such as an access network device or a core network device. The access network device is sometimes also called an access node. The access network device has wireless transceiver capabilities and can communicate with terminal devices. For example, the access network device can be a base station, an evolved NodeB (eNodeB), a transmission reception point (TRP), a next-generation radio access network (NG-RAN) device in a 5G mobile communication system (such as a next-generation NodeB (gNB)), an access network device or a module of an access network device in an open RAN (ORAN) system, or a satellite in an NTN communication system (such as...). Figure 1 The network devices in the communication system 100 include network devices 110, base stations in future mobile communication systems, and access points (APs) in Wi-Fi systems. Access network devices can also be modules or units capable of performing some functions of a base station, such as macro base stations, micro base stations, indoor stations, relay nodes, or donor nodes, or wireless controllers in cloud radio access network (CRAN) scenarios. Multiple access network devices in the communication system 100 can be of the same type or different types. This application does not limit the specific technologies or device forms used in the access network devices.

[0058] In this application embodiment, the apparatus for implementing the functions of a network device can be a network device itself, or an apparatus capable of supporting the network device in implementing those functions, such as a processor, circuit, chip, or chip system. This apparatus can be installed in the network device or connected to and used with the network device. In this application embodiment, taking a network device as an example to illustrate the technical solution provided by this application, we will describe it accordingly.

[0059] The terminal device in this application embodiment can be a wireless terminal device capable of receiving network device scheduling and instructions. The wireless terminal device can be a device providing voice and / or data connectivity to a user, a handheld device with wireless connectivity, or other processing devices connected to a wireless modem. For example, the terminal device can communicate with one or more core networks or the Internet via a radio access network (RAN). The terminal device can also be referred to as a terminal, user equipment (UE), mobile terminal (MT), mobile station (MS), mobile unit (MU), radio unit, remote unit, user agent, mobile client, etc. Terminal devices can be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IoT), ultra-reliable low-latency communication (URLLC), virtual reality (VR), augmented reality (AR), industrial control, self-driving, remote medical surgery, smart grid, smart furniture, smart office, smart wearables, smart transportation, smart cities, or satellite communication. Terminal devices can be mobile phones, tablets, computers with wireless transceiver capabilities, wearable devices, vehicles, aircraft (such as drones, helicopters, and airplanes), hot air balloons, ships, robots, robotic arms, or smart home devices. This application does not limit the form of the terminal device.

[0060] In this application embodiment, the device for implementing the functions of the terminal device can be the terminal device itself, or any device capable of supporting the terminal device in implementing the functions, such as a processor, circuit, chip, or chip system. This device can be installed in the terminal device or connected to and used with the terminal device. In this application embodiment, taking the terminal device as an example to illustrate the technical solution provided by this application, we will describe it accordingly.

[0061] Network devices and / or terminal devices can be fixed or mobile. They can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; on water; or in the air, such as on airplanes, balloons, or satellites. This application does not limit the application scenarios of the network devices and terminal devices. They can be deployed in the same or different scenarios. For example, network devices and terminal devices can be deployed simultaneously on land; or, network devices can be deployed on land and terminal devices on water; or, network devices can be deployed in the air and terminal devices on land, etc., and so on.

[0062] To facilitate understanding of the embodiments of this application, the terminology involved in the embodiments of this application will be briefly explained first. Optionally, the explanation of some terms can also refer to the explanation in the 3rd Generation Partnership Project (3GPP) standard protocol.

[0063] 1. GNSS GNSS is a satellite-based radio navigation technology that provides all-weather, high-precision positioning, navigation, and timing services to global users through the coordinated efforts of multiple constellations (such as the Global Positioning System (GPS), BeiDou Navigation Satellite System, GLONASS, and Galileo). Its applications cover a wide range of fields, including transportation, surveying and mapping, agriculture, communications, consumer electronics, and smart cities.

[0064] Currently, terminal devices can enable GNSS functionality to obtain their own location information. In this application embodiment, the location information obtained in this way is referred to as GNSS-based location information, or simply GNSS location information.

[0065] However, in practical applications, terminal devices do not always obtain usable GNSS location information. This may manifest as an inability to obtain GNSS location information, or the obtained GNSS location information being of low accuracy or poor timeliness. The main causes of this problem include: Signal obstruction and attenuation: When the terminal device is indoors, underground, in urban canyons (between tall buildings), in dense forests, or in tunnels, satellite signals may be severely obstructed or completely blocked, leading to inability to locate or a sharp decrease in accuracy. Multipath effect: In complex environments such as cities, satellite signals may be reflected by buildings, ground surfaces, etc., before reaching the receiver, causing path delays and positioning errors. Electromagnetic interference: Strong electromagnetic radiation sources nearby (such as high-voltage lines, radar stations, communication base stations, or malicious jamming equipment) can interfere with the receiver's normal reception and interpretation of satellite signals. Intentional interference and deception: Deliberately implemented suppression interference or deceptive interference simulating legitimate signals can cause the receiver to malfunction or output an incorrect location.

[0066] In this embodiment of the application, the GNSS status of the terminal device exists in two states: GNSS active and GNSS inactive. These two states are described below: GNSS validity means that the terminal device can obtain usable GNSS location information. Usable means that the GNSS location information is accurate, or that the GNSS location information is accurate and not expired. Optionally, "GNSS location information not expired" can also be expressed in some cases as "GNSS location information is not in its expiration period" or "GNSS location information has not exceeded its validity period."

[0067] GNSS failure refers to the terminal device failing to obtain usable GNSS location information; that is, the terminal device cannot obtain GNSS location information, or the GNSS location information obtained by the terminal device is unusable. Unusable means that the GNSS location information is inaccurate or expired. Optionally, expired GNSS location information can also be described in some cases as the GNSS location information being in a period of expiration or exceeding its validity period.

[0068] In some implementations, the terms "failure" and "invalidity" used in the embodiments of this application can be used interchangeably. Nouns or verbs related to failure in the embodiments of this application can be replaced with nouns or verbs related to invalidity. For example, "GNSS failure" in the embodiments of this application can also be called "GNSS invalidity," and "failure period" can also be called "invalidity period." Other similar nouns or verbs can be replaced in this way, and will not be described in detail here.

[0069] 2. Low Earth Orbit (LEO) Positioning Algorithm LEO typically refers to satellite orbits with altitudes between 160 and 2000 kilometers. Compared to traditional GNSS satellites (orbital altitudes of approximately 20,000 to 36,000 kilometers), the biggest advantages of LEO satellites are their high signal strength and low-latency communication capabilities. This offers new possibilities for solving the pain points of traditional GNSS (such as weak signals indoors and in urban canyons).

[0070] The LEO positioning algorithm refers to an algorithm that uses LEO satellites for positioning. Its core principle is to calculate the terminal device's own position based on the transmission delay differences between the terminal device and multiple LEO satellites with known locations. In the embodiments of this application, the terminal device can measure the time of arrival (TOA) of the positioning reference signals (PRS) broadcast by multiple LEO satellites, and combine the time difference of arrival (TDOA) between the PRS broadcast by each LEO satellite with the position of each LEO satellite to achieve positioning.

[0071] 3. Location prediction algorithm Location prediction algorithms refer to algorithms that use historical locations to predict the current location. Their core principle is to infer the most likely location a terminal device will appear in the near future based on its past location, speed, direction, and other information. In this embodiment, the terminal device can predict its current location using an artificial intelligence (AI) model based on multiple historical motion state information (including time, location, speed, acceleration, etc.). For example, this AI model can be a long short-term memory (LSTM) network model, a self-attention model (such as a transformer model), a convolutional neural network (CNN) model, a graph neural network (GNN) model, or a recurrent neural network (RNN) model (including but not limited to gated recurrent unit (GRU) models), etc. This embodiment does not limit the specific model used.

[0072] It should be understood that the terminology used in the embodiments of this application is for illustrative purposes only and not as limiting. As technology evolves, the terminology may also change, and other terms should also be applicable to the embodiments of this application if the technical meaning remains the same.

[0073] The application scenarios involved in the embodiments of this application are described below.

[0074] Traditional terrestrial networks rely on fixed base stations, making it difficult to achieve seamless coverage in vast or remote areas such as oceans, deserts, and the air. NTN, as a key development direction for future wireless communication, can effectively compensate for this deficiency. NTN refers to a three-dimensional network that utilizes non-terrestrial equipment such as satellites and high-altitude platforms as air nodes, working in conjunction with terrestrial networks. Among these, NTN using satellites as air platforms is currently the mainstream, with its core characteristics being: wide-area coverage: a single satellite beam covers an extremely wide area, overcoming complex geographical obstacles and providing communication possibilities between any two points; high reliability: communication links are not easily affected by ground disasters (such as earthquakes and floods), possessing inherent network resilience. As a key supplement and extension to terrestrial networks, the main value of NTN (especially satellite NTN) lies in: coverage extension: providing reliable communication services to areas that cannot be covered by terrestrial networks or where the cost of coverage is extremely high; emergency support: enabling the rapid establishment of emergency communication links when terrestrial infrastructure is damaged; industry empowerment: providing continuous global services for aviation, shipping, IoT, and other industries, and reducing end-to-end latency and optimizing business paths through technologies such as on-board processing; and global connectivity: serving as the foundation for achieving seamless global coverage and the 6G "air-ground-sea integration" vision.

[0075] In NTN communication systems, terminal devices typically rely on their GNSS location information for uplink time and frequency pre-compensation. GNSS availability is crucial for NTN services. However, this deep dependence on GNSS reduces the resilience of NTN communication systems. In practical deployments, terminal devices often experience GNSS failures due to signal obstruction, interference, or hardware limitations, leading to NTN service interruptions and significantly impacting service robustness. Therefore, current research focuses on reducing the dependence of NTN communication systems on GNSS, enabling the system to operate efficiently even in GNSS failure situations. To this end, this application proposes a method for determining the location of terminal devices in the event of GNSS failure, enabling a relatively accurate location of the terminal devices even with GNSS failure. This allows for uplink time and frequency pre-compensation, achieving uplink synchronization and ensuring normal communication.

[0076] Specifically, in the location determination method provided in this application embodiment, when GNSS fails, the terminal device can be located based on the LEO positioning algorithm to obtain first location information, and the location of the terminal device can be predicted based on the location prediction algorithm to obtain second location information. Then, the first and second location information can be fused to obtain highly accurate target location information, and uplink synchronization can be achieved based on the target location information. Optionally, the location determination method provided in this application embodiment can be executed by the terminal device in a connected state.

[0077] In some implementations, the location information and location coordinates described in the embodiments of this application can be used interchangeably. Nouns or verbs related to location information in the embodiments of this application can be replaced with nouns or verbs related to location coordinates. For example, "GNSS location information" in the embodiments of this application can also be called "GNSS location coordinates," "first location information" can also be called "first location coordinates," "second location information" can also be called "second location coordinates," "target location information" can also be called "target location coordinates," "terminal device location information" can also be called "terminal device location coordinates," and "satellite location information" can also be called "satellite location coordinates." Other similar nouns or verbs can be replaced in this way, and will not be described one by one.

[0078] The location determination method provided in this application embodiment will be described in detail below with reference to the corresponding flowcharts. It is understood that the illustrative flowcharts provided in this application embodiment mainly use different devices (such as network devices and terminal devices) as examples of the execution subjects of the interaction to illustrate the location determination method, but this application embodiment does not limit the execution subject of the interaction. For example, the device (such as a network device or terminal device) in the illustrative flowchart can also be a chip, chip system, or processor that supports the device in implementing the location determination method, or it can be a logic module or software that can implement all or part of the functions of the device.

[0079] As a general statement, the message or signaling interactions involved in the interaction process of this application embodiment can be standard messages or signaling or newly introduced messages or signaling. This application embodiment does not limit this.

[0080] Understandable, the following text Figures 2 to 8 The network device described in the implementation method can be the one mentioned above. Figure 1 Any of the network devices described in the embodiments can also be devices within a network device (such as processors, chips, or chip systems). (The following...) Figures 2 to 8 The terminal device described in the implementation method can be as described above. Figure 1 Any of the terminal devices described in the embodiments can also be devices within the terminal device (such as processors, chips, or chip systems).

[0081] It should be noted that in this embodiment, the terminal device can periodically acquire its own location information to perform uplink time-frequency pre-compensation. Typically, the terminal device can periodically acquire GNSS location information. Each time it attempts to acquire GNSS location information, if it successfully acquires usable GNSS location information, it can determine that GNSS is valid and use this GNSS location information for uplink time-frequency pre-compensation. However, if it fails to acquire usable GNSS location information (i.e., GNSS location information cannot be obtained or the acquired GNSS location information is unavailable), it can determine that GNSS is invalid. In this case, the terminal device can proceed as follows: Figure 2 The implementation method acquires the target location information of the terminal device. In this way, regardless of whether GNSS is disabled, the terminal device can obtain highly accurate location information for uplink synchronization, thereby ensuring normal communication.

[0082] The periodic length of when a terminal device periodically acquires its own location information can be called the target time interval, which is the update interval for the terminal device's location information. Optionally, this update interval can also be called the sampling interval or epoch interval. The target time interval can be set based on one or more factors such as the scenario, positioning accuracy requirements, and resource overhead. Generally, a smaller target time interval can be set in high-precision positioning scenarios, while a larger target time interval can be set in low-power scenarios.

[0083] In one possible approach, the terminal device can set the target time interval based on its own movement speed.

[0084] For example, when the terminal device moves at a low speed, the target time interval can be set larger, thus reducing the location update frequency when location changes slowly, thereby reducing power consumption while meeting positioning requirements. Conversely, when the terminal device moves at a high speed, the target time interval can be set smaller, thus increasing the location update frequency when location changes rapidly, ensuring the real-time nature and continuity of location information. For instance, the target time interval corresponding to walking speed could be set to tens of seconds, while the target time interval corresponding to car speed could be set to a few seconds. In this way, adjusting the location update frequency based on the terminal device's moving speed makes the positioning service more aligned with actual needs.

[0085] Figure 2 This is a flowchart of a location determination method provided in an embodiment of this application. See also... Figure 2 The method may include the following steps: Step 201: In the event of GNSS failure, the terminal device obtains its first location information based on the LEO positioning algorithm.

[0086] The LEO positioning algorithm refers to an algorithm that uses LEO satellites for positioning. The process of obtaining the initial location information of a terminal device based on the LEO positioning algorithm will be discussed below. Figure 3 The implementation methods are described in detail, but will not be elaborated here.

[0087] Step 202: In the event of GNSS failure, the terminal device obtains its second location information based on a location prediction algorithm.

[0088] Location prediction algorithms are algorithms that use historical locations to predict the current location. The process of obtaining the second location information of a terminal device based on location prediction algorithms will be discussed below. Figure 6 The implementation methods are described in detail, but will not be elaborated here.

[0089] It should be noted that there is no strict order in which steps 201 and 202 are executed. That is, step 201 can be executed first and then step 202, or step 202 can be executed first and then step 201, or steps 201 and 202 can be executed simultaneously. This application embodiment does not limit the execution order of steps 201 and 202.

[0090] Step 203: The terminal device determines the target location information of the terminal device based on the first location information and the second location information.

[0091] The target location information can be used as the current location information of the terminal device, such as for uplink time-frequency pre-compensation based on the target location information. This application does not limit this.

[0092] In this embodiment, when GNSS fails, the terminal device can determine first location information based on the LEO positioning algorithm, obtain second location information based on the location prediction algorithm, and then fuse the first and second location information to obtain the target location information. The positioning accuracy after fusion is higher than the individual positioning accuracy of the LEO positioning algorithm and the location prediction algorithm. Thus, the terminal device can obtain highly accurate target location information even when GNSS fails, thereby facilitating normal communication.

[0093] In some implementations, step 203 can be performed by the terminal device taking a weighted average of the first location information and the second location information based on the first weight corresponding to the first location information and the second weight corresponding to the second location information, to obtain the target location information.

[0094] The sum of the first weight and the second weight is 1. The first weight and the second weight can be preset.

[0095] In this embodiment of the application, the first location information and the second location information can be quickly fused by a simple weighted average calculation, thereby reducing the computational burden and improving the real-time performance of the location information.

[0096] For example, prior to step 203, the terminal device may determine a first weight based on the variance of the positioning error of the LEO positioning algorithm and the variance of the positioning error of the location prediction algorithm. For instance, the first weight may be determined using the following formula (1): (1) in, As the first weight, Let V be the variance of the positioning error of the LEO positioning algorithm. This represents the variance of the positioning error in the location prediction algorithm.

[0097] Therefore, the variance of the positioning error after fusing the LEO positioning algorithm and the location prediction algorithm will be smaller than the variance of the positioning error of each of the two schemes individually, thus obtaining more accurate target location information. This will be analyzed below: The above weighted average process can be represented by the following formula (2): (2) in, For target location information, As the first weight, As the second weight, This is the first location information. This is the second location information.

[0098] The positioning errors of both the LEO positioning algorithm and the location prediction algorithm follow a Gaussian distribution. The positioning error of the LEO positioning algorithm can be expressed as... The positioning error of the location prediction algorithm can be expressed as: ,in, Therefore, the above formula (2) can be derived into the following formula (3): (3). Among them, This refers to the actual location information of the terminal device.

[0099] Target location information obtained by fusing the first and second location information Positioning error It also follows a Gaussian distribution. Therefore, the positioning error can be derived from the above formula (3). variance As shown in the following formula (4): (4) From the above formula (4), it can be seen that when At that time, positioning error variance Take the minimum value, at this time .because Therefore, the variance of the positioning error after the fusion of the LEO positioning algorithm and the location prediction algorithm is smaller than the variance of the positioning error of each of the two schemes, that is, the positioning result after the fusion of the two schemes is better.

[0100] In some implementations, when GNSS is unavailable, the terminal device can send a first GNSS status message to the serving satellite, indicating that GNSS is unavailable. The serving satellite is the satellite with which the terminal device has established a communication connection. Alternatively, when GNSS is available, the terminal device can send a second GNSS status message to the serving satellite, indicating that GNSS is available. This allows the serving satellite to promptly obtain the GNSS status of the terminal device and make corresponding resource adjustments accordingly.

[0101] It should be noted that the terminal device can periodically acquire GNSS location information. If it fails to acquire usable GNSS location information in a certain period but acquired usable GNSS location information in the previous period, the terminal device can determine that the GNSS status has changed from GNSS valid to GNSS invalid. At this time, it can send a first GNSS status message to the serving satellite. Conversely, if it acquires usable GNSS location information in a certain period but failed to acquire usable GNSS location information in the previous period, the terminal device can determine that the GNSS status has changed from GNSS invalid to GNSS valid. At this time, it can send a second GNSS status message to the serving satellite.

[0102] For example, both the first GNSS status message and the second GNSS status message can be radio resource control (RRC) messages. Of course, they can also be other message types, and this application embodiment does not limit them.

[0103] The following is combined with Figure 3 The operation of obtaining the first location information of the terminal device based on the LEO positioning algorithm is described. It should be noted that, in the embodiments of this application, only the following text... Figure 3 The LEO positioning algorithm is illustrated by example in the implementation method. In practical applications, the LEO positioning algorithm may also have other implementation methods, which are not limited in this application.

[0104] Figure 3 This is a flowchart of a location determination method provided in an embodiment of this application. See also... Figure 3The method may include the following steps: Step 301: The terminal device identifies multiple satellites used for positioning. These multiple satellites are all LEO satellites.

[0105] The terminal device can periodically acquire its own location information. Based on the previously acquired location information (hereinafter referred to as third location information), the terminal device can determine multiple satellites for this positioning. For example, the third location information can be the previously acquired GNSS location information, the previously acquired second location information, or the previously acquired target location information. For instance, the third location information can be as follows: Figure 6 The location information in the latest added first motion state information in the historical motion state information set described in the implementation method.

[0106] In one possible approach, the terminal device can identify multiple visible satellites based on third-party location information and stored satellite ephemeris data, and then select multiple satellites from these visible satellites for positioning.

[0107] The satellite ephemeris data includes the ephemeris data for each of multiple satellites. A satellite's ephemeris data is a set of orbital model parameters used to calculate the satellite's precise position at any given time. Satellites continuously broadcast their ephemeris data. For example, a satellite can broadcast its ephemeris data by including it in system information block (SIB) messages (including but not limited to SIB19). Terminal devices can receive and update the ephemeris data broadcast by satellites for use when needed. For example, a terminal device can determine the position of a satellite at any given time based on its ephemeris data.

[0108] Visible satellites refer to satellites that are theoretically visible to the terminal device when it is at the location corresponding to the third location information. For example, the operation of the terminal device determining multiple visible satellites based on the third location information and stored satellite ephemeris data can be as follows: determining the position information of each satellite at the current time based on the stored satellite ephemeris data; determining the elevation angle of each satellite relative to the terminal device based on the position information of each satellite and the third location information; and eliminating all satellites with elevation angles lower than a preset masking angle, leaving the remaining satellites as visible satellites. Of course, this is not the only method; the terminal device can also determine multiple visible satellites through other means based on the third location information and stored satellite ephemeris data, and this application embodiment does not limit this method.

[0109] The multiple satellites used for positioning are those with better geometric configurations among the multiple visible satellites, which can bring higher positioning accuracy. For example, the operation of the terminal device to determine the multiple satellites for positioning from the multiple visible satellites can be as follows: determine multiple combinations from the multiple visible satellites, each combination including at least three satellites; for each combination, determine the geometry dilution of precision (GDOP) value of the geometry formed by all satellites in the combination based on third location information and the location information of each satellite in the combination; and determine all satellites in the combination with the smallest GDOP value as the satellites used for positioning. Of course, this is not a limitation; the terminal device can also determine the multiple satellites for positioning from the multiple visible satellites in other ways, and this application embodiment does not limit this.

[0110] Alternatively, the satellite used for positioning may also be called an auxiliary satellite, an auxiliary positioning satellite, or a positioning auxiliary satellite, and this application embodiment does not limit this.

[0111] Step 302: The terminal device determines the first location information based on the TOA of the PRS transmitted by each of the multiple satellites and the location information of each of the multiple satellites.

[0112] In this embodiment, downlink time difference of arrival (DL-TDOA) can be used to complete LEO-based assisted positioning. Each of the multiple satellites can periodically broadcast a Positioning Reference (PRS). After the terminal device captures the PRS broadcast by each satellite, it measures the Time of Arrival (TOA) of each satellite's broadcast PRS (hereinafter referred to as the satellite-specific TOA) and calculates the TDOA between any two satellite broadcast PRS (hereinafter referred to as the two-satellite-specific TDOA). Then, the terminal device determines the first position information based on the position information of each satellite and the TDOA of every two satellites.

[0113] For example, such as Figure 4 As shown, given the position of each of the multiple satellites and the corresponding TOA, the position of the terminal device can be calculated.

[0114] Assuming the first location information of the terminal device is The position information of the i-th satellite among these multiple satellites is: Then the first position information can be determined by the following formula (5): (5) In the above formula (5), This represents the TOA (Time of Arrival) for a satellite. This indicates the TOA corresponding to another satellite. This indicates the TDOA corresponding to these two satellites. This represents the speed of light. Based on the position information of each satellite and its corresponding TOA (Time of Arrival), multiple equations can be established as shown in formula (5). Solving this system of equations will yield the first position information. .

[0115] In some implementations, the broadcast period of the PRS can be a standardized, configurable parameter rather than a fixed value, and its specific value can be dynamically adjusted based on factors such as the scenario, positioning accuracy requirements, and resource consumption. Generally, high-precision positioning scenarios typically require a shorter period to improve measurement accuracy, while low-power scenarios can choose a longer period to reduce resource consumption.

[0116] In this embodiment, the terminal device can set the broadcast period of the PRS according to its own needs. Specifically, the terminal device can be configured with n PRS period levels, each of which indicates the period length of the transmitted PRS. For example, the n PRS period levels can be 0, 1, 2, ..., n-2, n-1.

[0117] As an example, the n PRS cycle levels correspond one-to-one with the n cycle lengths. These n cycle lengths can be preset. For example, they can be agreed upon through a protocol, set by the terminal device, set by the network device (e.g., via RRC messages), or negotiated between the communicating parties.

[0118] For example, the PRS cycle levels “0”, “1”, “2”, ..., “n-2”, “n-1” are used to indicate the preset length of n cycles.

[0119] As another example, among the n PRS period levels, n-1 PRS period levels correspond one-to-one with n-1 period lengths. One of the n PRS period levels, excluding the n-1 PRS period levels, is used to indicate the default period length on the network side. This n-1 period length can be preset. For example, it can be agreed upon through a protocol, set by the terminal device, set by the network device (e.g., through RRC messages), or negotiated between the communicating parties.

[0120] For example, PRS cycle level "0" indicates the default cycle length on the network side. PRS cycle levels "1", "2", ..., "n-2", "n-1" are used to indicate the preset n-1 cycle lengths.

[0121] In this embodiment, one PRS period level is reserved to point to the network-side default period length, which facilitates the terminal device to directly indicate the use of the default value, simplifying scheduling and management. Furthermore, the remaining n-1 PRS period levels are pre-configured with different period lengths to adapt to diverse service requirements (such as high-precision positioning, regular positioning, energy-saving mode, etc.).

[0122] In some implementations, prior to step 302, the terminal device may select one of the n PRS periodic levels as the first PRS periodic level based on its own needs, and instruct the multiple satellites used for positioning to transmit PRS based on the first PRS periodic level.

[0123] Terminal devices can determine the first PRS cycle level based on one or more factors such as scenario, positioning accuracy requirements, and resource overhead. Generally, in high-precision positioning scenarios, a PRS cycle level corresponding to a smaller cycle length can be selected as the first PRS cycle level, while in low-power scenarios, a PRS cycle level corresponding to a larger cycle length can be selected as the first PRS cycle level.

[0124] In one possible approach, the terminal device can determine the first PRS cycle level based on its own movement speed.

[0125] For example, when the terminal device moves at a high speed, a PRS period level corresponding to a shorter period length can be selected as the first PRS period level. This allows for a shorter PRS transmission period when the terminal device moves at high speed, increasing the update frequency of the positioning signal and effectively counteracting the rapid channel changes caused by high-speed movement, thus maintaining high-precision positioning. Conversely, when the terminal device moves at a low speed, a PRS period level corresponding to a longer period length can be selected as the first PRS period level. This allows for a longer PRS transmission period when the terminal device moves at low speed, significantly reducing the terminal device's power consumption while meeting basic positioning requirements.

[0126] After the terminal device determines the first PRS cycle level, it may also perform the following steps A to B before step 302: Step A: The terminal device sends a positioning service request message to the serving satellite. The positioning service request message includes the first PRS period level and the satellite identifier set.

[0127] This location service request message is used to request location services, specifically to request a satellite to send a PRS (Positioning Service Request). For example, this location service request message can be an RRC (Redirect Receipt / Redirection) message; of course, it can also be other message types, and this embodiment of the application does not limit this.

[0128] It should be noted that the multiple satellites used for positioning may or may not include service satellites. The satellite identifier set may include the identifier of each of the multiple satellites used for positioning.

[0129] In some cases, it can be used The PRS period levels are encoded using 11 bits. Specifically, these n PRS period levels can be encoded sequentially using 00…0 (L bits), 00…1 (L bits), ..., 11…0 (L bits), 11…1 (L bits). This compact encoding method saves signaling overhead and improves communication efficiency. Furthermore, this encoding method is backward compatible. If a new PRS period level needs to be added in the future (i.e., n increases), only one encoding bit (L+1) needs to be added, and the existing encoding and correspondence remain completely unaffected.

[0130] For example, such as Figure 5 As shown, the PRS period level corresponding to the default period length on the network side can be encoded using 00…0, and the n-1 PRS period levels corresponding to the preset n-1 period lengths can be encoded using 00…1, …, 11…0, 11…1 in ascending order of period length.

[0131] Based on this encoding method, the length of the first PRS period level in the location service request message is L bits, that is, the location service request message includes the bit encoding of the first PRS period level.

[0132] Step B: After receiving the positioning service request message, the serving satellite instructs each of the multiple satellites used for positioning to send a PRS based on the first PRS period level, according to the satellite identifier set.

[0133] In some cases, after receiving the positioning service request message, if the satellite identifier set includes the identifier of the serving satellite, the serving satellite periodically transmits PRS according to the period length indicated by the first PRS period level, and transmits the first PRS period level to the satellites identified by each satellite identifier in the satellite identifier set other than the identifier of the serving satellite, to instruct each satellite to periodically transmit PRS according to the period length indicated by the first PRS period level; if the satellite identifier set does not include the identifier of the serving satellite, the serving satellite transmits the first PRS period level to the satellites identified by each satellite identifier in the satellite identifier set, to instruct each satellite to periodically transmit PRS according to the period length indicated by the first PRS period level.

[0134] In other cases, after receiving the positioning service request message, the serving satellite may, for various reasons, refuse to send PRS based on the first PRS periodicity level and instead choose to send PRS based on the second PRS periodicity level. The second PRS periodicity level may be sent by other terminal devices or may be determined autonomously by the serving satellite; this embodiment does not limit this. In this case, if the satellite identifier set includes the serving satellite's identifier, the serving satellite periodically sends PRS according to the period length indicated by the second PRS periodicity level, and sends the second PRS periodicity level to each satellite identified by each satellite identifier in the satellite identifier set other than the serving satellite's identifier, to instruct each satellite to periodically send PRS according to the period length indicated by the second PRS periodicity level; if the satellite identifier set does not include the serving satellite's identifier, the serving satellite sends the second PRS periodicity level to each satellite identified by each satellite identifier in the satellite identifier set, to instruct each satellite to periodically send PRS according to the period length indicated by the second PRS periodicity level.

[0135] For example, the serving satellite can communicate with other satellites via inter-satellite links. Of course, the serving satellite can also communicate with other satellites in other ways, and this application does not limit this.

[0136] Step C: The serving satellite sends a location service confirmation message to the terminal device.

[0137] This location service confirmation message is used to indicate that the location service has been enabled, that is, to indicate that the satellite has started transmitting PRS.

[0138] When multiple satellites transmit PRS based on the first PRS cycle level, the positioning service confirmation message may not include the PRS cycle level; when multiple satellites transmit PRS based on the second PRS cycle level, the positioning service confirmation message may include the second PRS cycle level.

[0139] Step D: After receiving the location service confirmation message, the terminal device receives the PRS sent by each of the multiple satellites.

[0140] In some cases, if the location service confirmation message does not include the PRS periodicity level, the terminal device, after receiving the location service confirmation message, can receive the PRS sent by each of the multiple satellites based on the first PRS periodicity level. That is, it can periodically receive the PRS sent by each satellite according to the period length indicated by the first PRS periodicity level.

[0141] In other cases, if the location service confirmation message includes a second PRS periodicity level, the terminal device, after receiving the location service confirmation message, can receive the PRS sent by each of the multiple satellites based on the second PRS periodicity level. That is, it can periodically receive the PRS sent by each satellite according to the periodic length indicated by the second PRS periodicity level.

[0142] In this embodiment, the terminal device can actively select and request a suitable PRS transmission period based on its own needs. The serving satellite can coordinate all satellites used for positioning to transmit PRS using the same period based on the terminal device's request. This avoids interference or inefficiency caused by inconsistent parameters among multiple satellites, achieving efficient collaborative positioning.

[0143] In some implementations, the above... Figure 3 The variance of the positioning error of the LEO positioning algorithm provided in the implementation method It can be determined based on the TDOA observation error and the GDOP values ​​of multiple satellites used for positioning, as shown in the following formula (6): (6) in, TDOA observation error is a constant value determined by factors such as clock drift and receiver noise. The GDOP value is determined by the spatial distribution of satellites, with two core influencing factors: 1. Number of satellites: Under the premise of meeting the minimum positioning requirements, the more satellites involved in positioning, the lower the GDOP value and the higher the positioning accuracy; 2. Satellite spatial distribution: The more evenly the satellites are distributed in the sky, the lower the GDOP value and the higher the positioning accuracy. For example, the GDOP value of multiple satellites used for positioning can be calculated by the following formula (7): (7) in, , Let be the elevation angle of the i-th satellite among multiple satellites used for positioning. Let be the azimuth angle of the i-th satellite.

[0144] In this embodiment, the terminal device can be positioned based on the LEO positioning algorithm. Specifically, positioning can be achieved by combining the TOA (Time of Arrival) of the PRS (Presentation Status Response) transmitted by each of the multiple satellites used for positioning with the position information of each satellite, thereby improving the accuracy of the obtained first position information.

[0145] Furthermore, during this positioning process, the terminal device can request the satellite to send PRS (Positioning Report) at appropriate intervals based on its own needs. This flexible interval adjustment mechanism effectively ensures the positioning requirements of the terminal device in different scenarios while improving the system's resource utilization. For example, in scenarios requiring high-precision or high-frequency positioning, the terminal device can request PRS transmissions with shorter intervals to obtain more positioning information in a timely manner. Conversely, in scenarios where high-precision or high-frequency positioning is not required, the terminal device can request PRS transmissions with longer intervals, thereby saving energy and computing resources.

[0146] It should be noted that LEO positioning may fail in some situations. For example, if multiple satellites used for positioning cannot be identified in step 301, or if the TOA based on the PRS transmitted by the satellites and the satellite's position information fails to determine the first location information in step 302, the predicted second location information can be used as the current location information of the terminal device.

[0147] The following is combined with Figure 6 The operation of obtaining the second location information of the terminal device based on the location prediction algorithm is described. It should be noted that the embodiments in this application only illustrate... Figure 6 The location prediction algorithm is illustrated by taking the implementation method as an example. In actual applications, the location prediction algorithm may also have other implementation methods, which are not limited in this application.

[0148] Figure 6 This is a flowchart of a location determination method provided in an embodiment of this application. See also... Figure 6 The method may include the following steps: Step 601: The terminal device trains a model based on multiple first motion state information from the historical motion state information set to obtain a position prediction model.

[0149] This location prediction model is an AI model used to predict the location of terminal devices.

[0150] The first motion state information is information used to indicate the motion state of the terminal device. The first motion state information may include time information (such as a timestamp) and location information. Optionally, the first motion state information may also include one or more of the following: velocity information, acceleration information, etc. In this way, the first motion state information can more accurately reflect the historical motion state of the terminal device, thereby helping to more accurately predict the current position of the terminal device subsequently.

[0151] The multiple first motion state information entries in the historical motion state information set represent motion state information from the most recent period. For example, such as... Figure 7As shown, the historical motion state information set can be a first-in-first-out queue of length N, where N is an integer greater than or equal to 2, and N can be preset. When the time... motion state information When stored in this queue, time The motion status information was deleted. The period length for a terminal device to periodically acquire its own location information is the aforementioned target time interval.

[0152] For example, the format of the first motion state information can be shown in the following formula (8): (8) in, This is the first motion state information. For time information, For location information, For speed information, This is acceleration information.

[0153] For any first motion state information in the historical motion state information set, the position information in this first motion state information may be GNSS position information, second position information, or target position information obtained by fusing the first and second position information. Specifically, if GNSS is valid, the position information stored is the GNSS position information; if GNSS is invalid, if LEO positioning fails, the position information stored is the second position information; if LEO positioning is successful, the position information stored is the target position information.

[0154] Specifically, the terminal device can update the historical motion state information set based on a target time interval. Each time the terminal device needs to update the historical motion state information set, if GNSS is active, it generates first motion state information based on GNSS location information. Specifically, this can be generated based on GNSS location information and one or more of the terminal device's current time, velocity, and acceleration information. If GNSS fails and LEO positioning fails, it generates first motion state information based on second location information. Specifically, this can be generated based on second location information and one or more of the terminal device's current time, velocity, and acceleration information. If GNSS fails but LEO positioning is successful, it generates first motion state information based on target location information. Specifically, this can be generated based on target location information and one or more of the terminal device's current time, velocity, and acceleration information. Afterwards, the terminal device deletes the oldest first motion state information from the historical motion state information set and adds the newly generated first motion state information to the historical motion state information set, ensuring that the number of first motion state information items in the historical motion state information set is always maintained at N.

[0155] In this embodiment, location information can be obtained to update the historical motion state information set regardless of whether GNSS is active. The maintained historical motion state information set is real-time, continuous, and well-organized, and can accurately reflect the recent motion patterns of the terminal device, thus providing a guarantee for making accurate short-term future predictions.

[0156] In one possible approach, step 601 can be performed as follows: replacing the time information in each first motion state information in the historical motion state information set with the corresponding time increment, and replacing the position information in each first motion state information with the corresponding position increment, to obtain multiple second motion state information; normalizing the multiple second motion state information to obtain a sample dataset; and training the model based on the sample dataset to obtain a position prediction model.

[0157] This time increment is used to indicate the change in time information in a first motion state compared to the time information in the previous first motion state. Here, this time increment is the aforementioned target time interval.

[0158] The position increment is used to indicate the change in position information in a first motion state compared to the position information in the previous first motion state.

[0159] For example, the format of the second motion state information can be shown in the following formula (9): (9) in, This is the second motion state information. For time increments, This is the position increment.

[0160] In this embodiment, the multiple first motion state information are preprocessed. Specifically, the time information is replaced with the corresponding time increment, and the position information is replaced with the corresponding position increment. Then, normalization is performed to eliminate the large differences in numerical range and units between different data (such as time, position, velocity, and acceleration), thereby helping to reflect their essential motion laws. This improves the stability and accuracy of subsequent model training and accelerates model convergence. Furthermore, it makes the trained position prediction model more likely to capture the real patterns of recent motion of the terminal device, thus making more accurate predictions.

[0161] In some implementations, when a terminal device trains a model based on the sample dataset, it can first divide the dataset into a training set, a validation set, and a test set according to a certain ratio. The training set is used to train the model, that is, to let the model learn the patterns and regularities in the data. The validation set is used to fine-tune the model, that is, to evaluate the model's performance during training, help select the optimal network structure and / or hyperparameters, and prevent the model from overfitting on the training set. The test set is used for final evaluation, that is, after the model is completely determined, test data is used to objectively evaluate its generalization ability and final performance.

[0162] Next, a suitable AI model is selected, and the network structure, such as the number of model layers and neurons, is set, as well as hyperparameters such as batch size and number of training rounds. The sliding window step size is set to M. The sliding window step size of M means that the next position information is predicted based on M consecutive motion state information during model training. Then, the model is trained using the training set, and the model is fine-tuned using the validation set periodically during the training process. After obtaining the trained position prediction model using the training set and validation set, the performance index of the position prediction model is evaluated using the test set. For example, the performance index can be the root mean square error (RMSE) between the predicted value and the true value, which can be expressed as shown in the following formula (10): (10) in, This represents the number of times the prediction model makes a prediction at this location on the test set. Let i be the predicted value output by the prediction model at this location during the i-th prediction. For predicted values The corresponding actual value.

[0163] Step 602: The terminal device obtains its second location information based on the target time information and the location prediction model.

[0164] The target time information is the time information corresponding to the current location information that needs to be acquired. The target time information can be obtained by superimposing the time information from the latest added first motion state information in the historical motion state information set with the target time interval.

[0165] The terminal device can input the target time information into the location prediction model to obtain the output data of the location prediction model. Then, the terminal device can perform the inverse transformation of the preprocessing described in step 601 on the output data to obtain the second location information.

[0166] For example, the terminal device can perform inverse normalization on the output data to obtain the predicted position increment value, and then superimpose the predicted position increment value on the position information in the latest first motion state information added to the historical motion state information set to obtain the second position information.

[0167] In some implementations, the above... Figure 6 The variance of the positioning error of the location prediction algorithm provided in the implementation method It can be the RMSE mentioned above.

[0168] In this embodiment, the terminal device can predict its current location based on a location prediction algorithm. Specifically, a location prediction model can be obtained by training a model based on the terminal device's recent motion state information. This location prediction model can learn and adapt to the terminal device's recent unique motion patterns, thereby obtaining relatively accurate second location information.

[0169] The following example, using a vehicle traveling on a highway, illustrates the location determination process of a terminal device when GNSS fails in a tunnel scenario.

[0170] 1. Application Scenarios The terminal device was traveling at a speed of 100 km / h (approximately 27.77 m / s) on the highway when it entered a tunnel, triggering a GNSS failure state.

[0171] 2. Basic parameter configuration (1) The queue length of the historical motion status information set is N=60, and the update interval of the terminal device's location information is 2 seconds.

[0172] (2) The PRS periodic level is set at 5 levels, using The bits are encoded using PRS periodic level encoding, and the encoding results are shown in Table 1 below: Table 1 PRS Periodic Level coding Period length Default 000 1280 milliseconds 1 001 40 milliseconds 2 010 160 milliseconds 3 011 320 milliseconds 4 100 640 milliseconds The embodiments of this application are merely illustrative examples of PRS periodic level coding using Table 1 above, and Table 1 above does not constitute a limitation on the embodiments of this application.

[0173] (3) Location prediction model The location prediction model selected is the GRU model.

[0174] For example, the network structure parameters of the GRU model can be: sliding window length = 10; input layer vector dimension = 10, expressed as follows: Number of hidden layer units = 64, number of hidden layers = 2, dropout rate = 0.1; output layer vector dimension = 3, represented as... The network structure parameters are shown in Table 2 below: Table 2

[0175] The embodiments of this application are merely illustrative examples of network structure parameters using Table 2 above, and Table 2 above does not constitute a limitation on the embodiments of this application.

[0176] For example, the network training parameters of the GRU model can be shown in Table 3 below: Table 3 parameter Value Dataset split ratio Training set:Validation set:Test set = 7:2:1 Batch size 32 Number of training epochs 200 Optimizer Adam Loss function Mean squared error (MSE) The embodiments of this application are merely illustrative examples of network training parameters using Table 3 above, and Table 3 above does not constitute a limitation on the embodiments of this application.

[0177] 3. Implementation steps Figure 8 This is a flowchart of a location determination method provided in an embodiment of this application. See also... Figure 8 The method may include the following steps: Step 801: In the event of GNSS failure, the terminal device sends a first GNSS status message to the serving satellite. The first GNSS status message is used to indicate GNSS failure.

[0178] For example, when a terminal device detects that the signal-to-noise ratio of a GNSS signal is lower than a threshold (such as 10 dB), it can determine that the GNSS is in failure and report the GNSS failure status to the serving satellite.

[0179] In the event of GNSS failure, the terminal device can perform LEO positioning by executing steps 802 to 807, and position prediction by executing step 808. Finally, step 809 can be executed to fuse the position information obtained from the two schemes to obtain target position information with higher accuracy.

[0180] Step 802: The terminal device identifies multiple satellites for positioning and determines the first PRS cycle level.

[0181] For example, the terminal device can calculate the positions of each satellite based on locally stored ephemeris data. Combined with the terminal device location at the last moment before GNSS failure Calculate satellite elevation angle If the angle of elevation If the GDOP value is the minimum, then this satellite is a visible satellite. Based on the principle of minimizing the GDOP value, three visible satellites with the optimal geometric configuration are selected as auxiliary satellites, and their identities (IDs) are recorded as S1, S2, and S3. Because the terminal device is in a high-speed moving state of 100 km / h, it is necessary to acquire PRS frequently to ensure positioning accuracy. Therefore, PRS period level 1 (40 milliseconds) is selected, and the corresponding code is 001.

[0182] Step 803: The terminal device sends a positioning service request message to the serving satellite. The positioning service request message includes the first PRS period level and the satellite identifier set.

[0183] The location service request message includes: satellite identifier set: [S1, S2, S3]; PRS period level code: 001.

[0184] Step 804: After receiving the positioning service request message, the serving satellite sends the first PRS periodic level to other auxiliary satellites based on the satellite identifier set.

[0185] Step 805: The serving satellite sends a location service confirmation message to the terminal device.

[0186] Step 806: Service satellites and other auxiliary satellites transmit PRS based on the first PRS cycle level.

[0187] The service satellite changed its PRS transmission period to 40 milliseconds, and other auxiliary satellites also changed their PRS transmission periods to 40 milliseconds. Both the service satellite and other auxiliary satellites periodically transmit PRS.

[0188] Step 807: After receiving the location service confirmation message, the terminal device receives the PRS sent by each of the multiple satellites based on the first PRS periodic level, and determines the first location information based on the TOA of the PRS sent by each of the multiple satellites and the location information of each satellite.

[0189] In this case, the terminal device can also determine the variance of the positioning error of the LEO positioning algorithm in this operation. .

[0190] Step 808: The terminal device predicts the second location information based on the historical motion state information set.

[0191] In this case, the terminal device can also determine the variance of the positioning error of the current location prediction algorithm. .

[0192] Step 809: The terminal device fuses the first location information and the second location information to obtain the target location information.

[0193] Terminal devices can use the variance of the positioning error from this LEO positioning algorithm as a basis. The variance of the positioning error of this location prediction algorithm The first weight corresponding to the first location information and the second weight corresponding to the second location information are determined, and the first location information and the second location information are weighted and averaged accordingly to obtain the target location information.

[0194] Step 810: When GNSS is restored (i.e., changes from invalid to valid), the terminal device sends a second GNSS status message to the serving satellite. The second GNSS status message is used to indicate that GNSS is valid.

[0195] In some cases, after receiving the second GNSS status message, the serving satellite can restore the PRS transmission period to the default period and instruct other auxiliary satellites to also restore the PRS transmission period to the default period.

[0196] Thus, when the terminal device is traveling on a highway, it can acquire GNSS location information normally before entering a tunnel. During the period after entering a tunnel when usable GNSS location information is unavailable, the location determination method provided in this application can obtain highly accurate target location information. After exiting the tunnel, it can continue to acquire GNSS location information normally. This ensures that the terminal device can continuously obtain highly accurate location information while traveling on a highway, guaranteeing normal communication.

[0197] It should be understood that Figures 1 to 8 The flowcharts or scene diagrams shown are for illustrative purposes only and are not intended to limit the embodiments of this application to the examples illustrated. In fact, those skilled in the art can interpret the embodiments based on... Figures 1 to 8 The examples in the document can be transformed into equivalent ways to obtain more implementations.

[0198] The above text combined Figures 1 to 8 This document describes in detail the location determination method provided in the embodiments of this application. The following will combine... Figures 9 to 10The device embodiments of this application are described in detail below. It should be understood that the communication device of this application embodiment can execute the various location determination methods described in the foregoing embodiments of this application. That is, the specific working processes of the various products below can be referred to the corresponding processes in the foregoing method embodiments.

[0199] In the embodiments described above, the network device may execute some or all of the steps in each embodiment; the terminal device may execute some or all of the steps in each embodiment. These steps or operations are merely examples, and other operations or variations thereof may also be performed in the embodiments of this application. Furthermore, the steps may be executed in different orders as presented in the embodiments, and it is not necessary to execute all the operations in the embodiments of this application. The sequence number of each step does not imply the order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0200] Figure 9 This is a schematic block diagram of a communication device provided in an embodiment of this application. Figure 9 As shown, the communication device 900 may include a communication module 920. The communication module 920 can implement corresponding communication functions, which can be internal communication functions of the communication device 900 or communication functions between the communication device 900 and other devices. Optionally, the communication module 920 may also be referred to as a communication interface or transceiver module. Optionally, the communication device 900 also includes a processing module 910. The processing module 910 can implement corresponding processing functions.

[0201] Optionally, the communication device 900 further includes a storage module, which can be used to store instructions and / or data; the processing module 910 can read the instructions and / or data in the storage module so that the communication device 900 can implement the aforementioned method embodiments.

[0202] In one possible design, the communication device 900 may correspond to the terminal device in the above method embodiments, or a component (such as a circuit, chip, or chip system) configured in the terminal device. The communication device 900 can be used to perform the steps or processes performed by the terminal device in any of the above method embodiments.

[0203] For example, the processing module 910 is used to: in the event of GNSS failure, obtain first location information of the terminal device based on the LEO positioning algorithm, obtain second location information of the terminal device based on the location prediction algorithm, and determine the target location information of the terminal device based on the first location information and the second location information.

[0204] For example, the communication module 920 is used to: send a first GNSS status message to the serving satellite in the event of GNSS failure; and send a second GNSS status message to the serving satellite in the event of GNSS availability.

[0205] For example, the processing module 910 is used to: determine multiple satellites for positioning; and determine first location information based on the TOA of the PRS transmitted by each of the multiple satellites and the location information of each satellite.

[0206] For example, processing module 910 is configured to: determine a first PRS period level, the first PRS period level indicating the period length of PRS transmission, the first PRS period level being one of n PRS period levels, where n is an integer greater than or equal to 2. Communication module 920 is configured to: send a positioning service request message to the serving satellite, the positioning service request message including the first PRS period level and a set of satellite identifiers, to instruct each of the plurality of satellites to transmit PRS based on the first PRS period level; and, upon receiving a positioning service confirmation message from the serving satellite, receive the PRS transmitted by each of the plurality of satellites based on the first PRS period level.

[0207] For example, the processing module 910 is used to: determine the first PRS cycle level based on the moving speed of the terminal device.

[0208] For example, n-1 of the n PRS cycle levels correspond one-to-one with the preset n-1 cycle lengths, and one of the n PRS cycle levels other than the n-1 PRS cycle levels is used to indicate the default cycle length on the network side.

[0209] For example, the length of the first PRS period level in the location service request message is L bits. .

[0210] For example, the processing module 910 is used to: train a model based on multiple first motion state information in the historical motion state information set to obtain a position prediction model, wherein the first motion state information includes time information and position information; and obtain second position information based on the target time information and the position prediction model.

[0211] For example, the first motion state information may also include one or more of velocity information and acceleration information.

[0212] For example, the processing module 910 is used to: replace the time information in each first motion state information in the historical motion state information set with the corresponding time increment, and replace the position information in each first motion state information with the corresponding position increment, to obtain multiple second motion state information; perform normalization processing on the multiple second motion state information to obtain a sample dataset; and perform model training based on the sample dataset to obtain a position prediction model.

[0213] For example, the processing module 910 is used to: set a target time interval based on the moving speed of the terminal device; and update the historical motion state information set based on the target time interval.

[0214] For example, the processing module 910 is used to: generate first motion state information based on GNSS location information when GNSS is valid, or generate first motion state information based on second location information when GNSS is invalid or LEO positioning fails, or generate first motion state information based on target location information when LEO positioning is successful; and add the newly generated first motion state information to the historical motion state information set.

[0215] For example, the processing module 910 is used to: perform a weighted average of the first location information and the second location information based on the first weight corresponding to the first location information and the second weight corresponding to the second location information to obtain the target location information.

[0216] For example, the processing module 910 is used to: determine a first weight based on the variance of the positioning error of the LEO positioning algorithm and the variance of the positioning error of the location prediction algorithm.

[0217] For example, the processing module 910 is used to determine a first weight based on the variance of the positioning error of the LEO positioning algorithm and the variance of the positioning error of the location prediction algorithm using the following formula:

[0218] As the first weight, Let V be the variance of the positioning error of the LEO positioning algorithm. This represents the variance of the positioning error in the location prediction algorithm.

[0219] The above are merely examples; for detailed steps or procedures, please refer to the descriptions in the foregoing embodiments.

[0220] Figure 10This is a schematic block diagram of a communication device 1000 provided in an embodiment of this application. The communication device 1000 may be a network device, a terminal device, or a circuit, chip, chip system, or processor for implementing the above methods. The communication device 1000 can be used to implement the methods described in the above method embodiments, and for details, please refer to the description in the above method embodiments.

[0221] like Figure 10 As shown, the communication device 1000 may include one or more processors 1010, which may also be referred to as processing units or processing modules, and can implement certain control functions. The processor 1010 may be a general-purpose processor or a dedicated processor, such as a baseband processor or a central processing unit. The baseband processor can be used to process communication protocols and communication data, while the central processing unit can be used to control the communication device 1000 (e.g., a base station, baseband chip, user equipment, user chip), execute software programs, and process data from the software programs.

[0222] In an alternative design, the processor 1010 may also store instructions and / or data that can be executed by the processor 1010 to cause the communication device 1000 to perform the methods described in the above method embodiments.

[0223] In another alternative design, the communication device 1000 may include a communication interface 1020 for implementing receiving and transmitting functions. For example, the communication interface 1020 may be a transceiver circuit, interface, interface circuit, or transceiver. The transceiver circuit, interface, interface circuit, or transceiver for implementing receiving and transmitting functions may be separate or integrated. The aforementioned transceiver circuit, interface, interface circuit, or transceiver may be used for reading and writing code / data, or it may be used for transmitting or relaying signals.

[0224] Optionally, the communication device 1000 may include one or more memories 1030, which may store instructions that can be executed on the processor 1010, causing the communication device 1000 to perform the methods described in the above method embodiments. Optionally, the memories 1030 may also store data. Optionally, the processor 1010 may also store instructions and / or data. The processor 1010 and the memories 1030 may be provided separately or integrated together.

[0225] It should be understood that, in one possible design, the steps in the method embodiments provided in this application can be implemented by integrated logic circuits in the processor's hardware or by instructions in software form. The steps of the methods disclosed in the embodiments of this application can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules in the processor. The software modules can reside in mature storage media in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, or registers. This storage medium is located in memory, and the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above method. To avoid repetition, detailed descriptions are not provided here.

[0226] In one implementation, the communication device 1000 may correspond to the network device in the above method embodiments and may be used to execute the various steps and / or processes executed by the network device in the above method embodiments. The processor 1010 may be used to execute instructions stored in the memory 1030, and when the processor 1010 executes the instructions stored in the memory, the processor 1010 is used to execute the various steps and / or processes of the above method embodiments corresponding to the network device.

[0227] In another implementation, the communication device 1000 may correspond to the terminal device in the above method embodiments, and may be used to execute the various steps and / or processes executed by the terminal device in the above method embodiments. The processor 1010 may be used to execute the instructions stored in the memory 1030, and when the processor 1010 executes the instructions stored in the memory, the processor 1010 is used to execute the various steps and / or processes of the above method embodiments corresponding to the terminal device.

[0228] It should be understood that the aforementioned processing device can be one or more chips. For example, the processing device can be a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), a system-on-chip (SoC), a central processor unit (CPU), a network processor (NP), a digital signal processor (DSP), a microcontroller unit (MCU), a programmable logic device (PLD), or other integrated chips.

[0229] It is understood that the memory in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM). It should be noted that the memory used in the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0230] According to the method provided in the embodiments of this application, this application also provides a chip system, which includes one or more processors for calling and executing instructions stored in memory, thereby causing the method described in the embodiments of this application to be executed. The chip system may be composed of chips or may include chips and other discrete devices.

[0231] The chip system may include input circuits or interfaces for transmitting information or data, and output circuits or interfaces for receiving information or data.

[0232] According to the method provided in the embodiments of this application, this application also provides a communication system, which includes the aforementioned network device and terminal device.

[0233] According to the method provided in the embodiments of this application, this application also provides a computer program product, which includes: computer program code, which, when run on a computer, causes the computer to execute the various steps or processes executed by the network device or terminal device in any of the foregoing method embodiments.

[0234] According to the method provided in the embodiments of this application, this application also provides a computer-readable storage medium storing program code, which, when run on a computer, causes the computer to execute the various steps or processes executed by the network device or terminal device in any of the foregoing method embodiments.

[0235] The computer-readable storage medium may be the aforementioned volatile memory or non-volatile memory, or it may include both volatile memory and non-volatile memory.

[0236] In the embodiments of this application, the terms and English abbreviations are exemplary examples given for ease of description and should not be construed as limiting the application in any way. This application does not preclude the possibility of defining other terms that can achieve the same or similar functions in existing or future agreements.

[0237] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions. When these computer instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated.

[0238] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0239] It should be understood that in the various embodiments of this application, the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0240] In summary, the above descriptions are merely optional embodiments of the technical solutions of this application and are not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for determining a location, characterized in that, Applied to a terminal device, the method includes: In the event of GNSS (Global Navigation Satellite System) failure, the terminal device's first location information is obtained based on a Low Earth Orbit (LEO) positioning algorithm, and its second location information is obtained based on a location prediction algorithm. The target location information of the terminal device is determined based on the first location information and the second location information.

2. The method as described in claim 1, characterized in that, The method further includes: In the event of GNSS failure, a first GNSS status message is sent to the serving satellite; If the GNSS is active, a second GNSS status message is sent to the serving satellite.

3. The method as described in claim 1, characterized in that, The acquisition of the first location information of the terminal device based on the Low Earth Orbit (LEO) positioning algorithm includes: Identify multiple satellites used for positioning; The first location information is determined based on the Time of Arrival (TOA) of the Positioning Reference Signal (PRS) transmitted by each of the plurality of satellites and the location information of each satellite.

4. The method as described in claim 3, characterized in that, Before determining the first location information based on the Time of Arrival (TOA) of the Positioning Reference Signal (PRS) transmitted by each of the plurality of satellites and the location information of each satellite, the method further includes: A first PRS cycle level is determined, which is used to indicate the cycle length of the transmitted PRS. The first PRS cycle level is one of n PRS cycle levels, where n is an integer greater than or equal to 2. Send a positioning service request message to the serving satellite, the positioning service request message including the first PRS periodic level and a satellite identifier set, to instruct each of the plurality of satellites to send PRS based on the first PRS periodic level; Upon receiving a positioning service confirmation message from the serving satellite, the PRS sent by each of the plurality of satellites is received based on the first PRS periodic level.

5. The method as described in claim 4, characterized in that, The determination of the first PRS cycle level includes: The first PRS cycle level is determined based on the moving speed of the terminal device.

6. The method as described in claim 4, characterized in that, The n-1 PRS cycle levels among the n PRS cycle levels correspond one-to-one with the preset n-1 cycle lengths. The PRS cycle level other than the n-1 PRS cycle levels among the n PRS cycle levels is used to indicate the default cycle length on the network side.

7. The method as described in any one of claims 4 to 6, characterized in that, The length of the first PRS period level in the location service request message is L bits. .

8. The method as described in claim 1, characterized in that, The method of obtaining the second location information of the terminal device based on the location prediction algorithm includes: A location prediction model is obtained by training the model based on multiple first motion state information in the historical motion state information set. The first motion state information includes time information and location information. The second location information is obtained based on the target time information and the location prediction model.

9. The method as described in claim 8, characterized in that, The first motion state information also includes one or more of velocity information and acceleration information.

10. The method as described in claim 8, characterized in that, The method of training a model based on multiple first motion state information from a historical motion state information set to obtain a position prediction model includes: The time information in each first motion state information in the historical motion state information set is replaced with the corresponding time increment, and the position information in each first motion state information is replaced with the corresponding position increment to obtain multiple second motion state information. The multiple second motion state information are normalized to obtain a sample dataset; The location prediction model is obtained by training the model based on the sample dataset.

11. The method as described in claim 8, characterized in that, The method further includes: Set the target time interval based on the moving speed of the terminal device; The historical motion state information set is updated based on the target time interval.

12. The method as described in any one of claims 8 to 11, characterized in that, The method further includes: If the GNSS is valid, the first motion state information is generated based on the GNSS location information; or, if the GNSS is invalid, the first motion state information is generated based on the second location information if the LEO positioning fails, and the first motion state information is generated based on the target location information if the LEO positioning is successful. The newly generated first motion state information is added to the historical motion state information set.

13. The method according to any one of claims 1 to 6, 8 to 11, characterized in that, Determining the target location information of the terminal device based on the first location information and the second location information includes: Based on the first weight corresponding to the first location information and the second weight corresponding to the second location information, a weighted average is performed on the first location information and the second location information to obtain the target location information.

14. The method as described in claim 13, characterized in that, Before determining the target location information of the terminal device based on the first location information and the second location information, the method further includes: The first weight is determined based on the variance of the positioning error of the LEO positioning algorithm and the variance of the positioning error of the location prediction algorithm.

15. The method as described in claim 14, characterized in that, The determination of the first weight based on the variance of the positioning error of the LEO positioning algorithm and the variance of the positioning error of the location prediction algorithm includes: Based on the variance of the positioning error of the LEO positioning algorithm and the variance of the positioning error of the location prediction algorithm, the first weight is determined by the following formula: The For the first weight, the The variance of the positioning error of the LEO positioning algorithm is given by the following: Let V be the variance of the positioning error of the location prediction algorithm.

16. A communication device, characterized in that, The communication device includes at least one processor coupled to a memory storing a program or instructions, the processor executing the program or instructions to cause the communication device to perform the method as described in any one of claims 1 to 15.

17. A communication system, characterized in that, The communication system includes the communication device as described in claim 16.

18. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program or instructions that, when executed, cause a computer to perform the method as described in any one of claims 1 to 15.

19. A chip system, characterized in that, The chip system includes one or more processors, which are configured to retrieve and execute instructions stored in a memory, such that the method as described in any one of claims 1 to 15 is performed.

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