WO2025223415A1 - Timing advance determination method, device, and system - Google Patents

Abstract

The present application relates to the technical field of communications. Disclosed are a timing advance determination method, a device, and a system. At the moment when a terminal device performs switching between new ephemeris information and old ephemeris information, by means of the acquired new ephemeris information and the old ephemeris information, and a timing deviation which is measured by means of a physical channel at the moment when ephemeris information switching is performed, a timing advance corresponding to a communication system when the terminal device performs switching between the new ephemeris information and the old ephemeris information is calculated. In this way, the problem that when a terminal device switches from old ephemeris information to new ephemeris information, a timing deviation of a communication system to which the terminal device belongs undergoes a sudden change can be avoided, thereby improving the stability and transmission performance of the communication system.

Description

A method, device and system for determining timing advance

This application claims priority to Chinese Patent Application No. 202410518937.1, filed with the State Intellectual Property Office of China on April 26, 2024, entitled “A method, apparatus and system for determining timing advance”, the entire contents of which are incorporated herein by reference.

Technical Field

This application relates to the field of communication technology, and in particular to a method, device and system for determining timing advance.

Background Technology

Non-terrestrial network (NTN) communication boasts advantages such as wide coverage, long communication distance, high reliability, high flexibility, and high throughput, and is unaffected by geographical environment, climate conditions, and natural disasters. Satellite communication, for example, has been widely applied in fields such as aviation, maritime, and military communications. In satellite communication systems, because satellites are subject to various perturbations, terminal equipment needs to periodically update ephemeris information to ensure communication performance. However, after updating the ephemeris information, the timing deviation determined based on the new ephemeris information will abruptly change compared to the timing deviation determined based on the old ephemeris information. This abrupt change in timing deviation will affect the system performance of the communication system.

Summary of the Invention

This application provides a method, device, and system for determining timing advance. When the terminal device switches ephemeris information, it determines the corresponding timing advance based on the ephemeris information and timing deviation, thereby avoiding sudden changes in timing deviation caused by ephemeris switching and improving the stability of the communication system.

To achieve the above objectives, this application adopts the following technical solution:

Firstly, this application provides a timing advance determination method applied to a terminal device. The method may include: receiving first ephemeris information, which is different from second ephemeris information, where the second ephemeris information is the ephemeris information currently used by the terminal device; when performing ephemeris switching based on the first ephemeris information, determining the timing advance of the communication system to which the terminal device belongs based on the first ephemeris information, the second ephemeris information, and a timing deviation, wherein the timing deviation is used to characterize the delay error corresponding to the first ephemeris information measured through a physical channel. Based on this, the terminal device switches from using the second ephemeris information to using the first ephemeris information when performing ephemeris switching, wherein the first ephemeris information is the new ephemeris information, and the second ephemeris information is the old ephemeris information.

The solution provided in the first aspect above allows the terminal device to calculate the timing advance when switching between new and old ephemeris information by acquiring the new and old ephemeris information and the timing deviation measured through the physical channel at the time of the ephemeris information switch. This can avoid sudden changes in the timing deviation of the communication system when switching between new and old ephemeris information, thereby improving the stability of the communication system.

As one possible implementation, determining the timing advance of the communication system to which the terminal device belongs based on the first ephemeris information, the second ephemeris information, and the timing deviation may include: determining a first compensation delay corresponding to the first ephemeris information based on the first ephemeris information and the second ephemeris information; and determining the timing advance based on the first ephemeris information and the first compensation delay. Based on this, the terminal device can determine the first compensation delay during ephemeris switching using the first ephemeris information and the second ephemeris information. The first compensation delay is used to compensate and correct the first delay calculated according to the first ephemeris information at the time of ephemeris information switching. Then, the timing advance of the communication system is calculated using the first compensation delay and the first ephemeris information, thereby preventing abrupt changes in timing deviation and improving the stable communication performance of the communication system.

As one possible implementation, determining the first compensation delay corresponding to the first ephemeris information based on the first ephemeris information and the second ephemeris information may include: calculating the first delay and the second delay respectively based on the first ephemeris information and the second ephemeris information; and determining the first compensation delay based on the first delay, the second delay, the second compensation delay corresponding to the second ephemeris information, and the timing deviation. Based on this, when determining the first compensation delay, the terminal device calculates the first delay and the second delay according to the first ephemeris information and the second ephemeris information, respectively. The first delay represents the propagation delay calculated from the old delay information, and the second delay represents the propagation delay calculated from the new delay information. The terminal device can determine the first compensation delay based on the first delay, the second delay, the second compensation delay corresponding to the second ephemeris information, and the timing deviation. When the terminal device uses the old ephemeris information, the second compensation delay corresponding to the second ephemeris information is used to compensate and correct the propagation delay calculated based on the old ephemeris information. When switching between the new and old ephemeris information, it is used to combine the first delay, the second delay, and the timing deviation to determine the first compensation delay at the time of ephemeris information switching, so as to prevent sudden changes in timing deviation during ephemeris switching and improve the stable communication performance of the communication system.

As one possible implementation, determining the first compensation delay based on the first delay, the second delay, the second compensation delay corresponding to the second ephemeris information, and the timing deviation may include: calculating a first value by subtracting the first delay and the second delay; and determining the first compensation delay based on the first value, the second compensation delay, and the timing deviation. Based on this, in determining the first compensation delay, the terminal device first determines the difference between the propagation delay determined by the new ephemeris information and the propagation delay determined by the old ephemeris information, i.e., the absolute value of the change in propagation delay when switching between the new and old ephemeris information, based on the first delay and the second delay. Then, it determines the first compensation delay when switching between the new and old ephemeris information based on the calculated difference between the first delay and the second delay, the second compensation delay, and the timing deviation, to help determine the timing advance of the communication system and improve the stability and transmission performance of the communication system.

As one possible implementation, determining the first compensation delay based on the first value, the second compensation delay, and the timing deviation may include: summing the first value, the second compensation delay, and the timing deviation to obtain the first compensation delay. Based on this, when the terminal device determines the first compensation delay based on the difference between the first delay and the second delay, i.e., the first value, the second compensation delay, and the timing deviation, it can sum the first value, the second compensation delay, and the timing deviation, and simultaneously accumulate the impact of the first value, the second compensation delay, and the timing deviation on the first compensation delay, further determining the timing advance of the communication system to prevent sudden changes in timing deviation during ephemeris switching and improve the stable communication performance of the communication system.

As one possible implementation, determining the timing advance based on the first ephemeris information and the first compensation delay may include: determining the timing advance based on the first delay and the first compensation delay. Based on this, when determining the timing advance of the communication system based on the first ephemeris information and the first compensation delay, the terminal device first determines the first delay corresponding to the new ephemeris information based on the first ephemeris information, and then determines the timing advance when switching between the old and new ephemeris information based on the first delay and the first compensation delay, thereby improving the stability and transmission performance of the communication system.

As one possible implementation, determining the timing advance based on the first delay and the first compensated delay may include: summing the first delay and the first compensated delay to obtain the timing advance. Based on this, when determining the timing advance based on the first delay and the first compensated delay, the terminal device sums the first delay and the first compensated delay, and simultaneously accumulates the impact of the first delay and the first compensated delay on the timing advance, to determine the timing advance when switching between old and new ephemeris information, thereby improving the stability and transmission performance of the communication system.

As one possible implementation, the method may further include: when the first ephemeris information is valid, determining the timing advance of the communication system to which the terminal device belongs based on the first ephemeris information and the timing deviation. Therefore, after the first ephemeris information is successfully switched and is still valid, the terminal device determines the timing advance of the communication system using the first ephemeris information and the timing deviation to improve the transmission performance of the communication system.

As one possible implementation, determining the timing advance of the communication system to which the terminal device belongs based on the first ephemeris information and the timing deviation may include: calculating the first delay based on the first ephemeris information; determining the third compensation delay based on the timing deviation and the first compensation delay; and determining the timing advance based on the first delay and the third compensation delay. Based on this, when the terminal device determines the timing advance of the communication system based on the first ephemeris information and the timing deviation, it first calculates the corresponding first delay based on the first ephemeris information, determines the third compensation delay corresponding to the current time based on the timing deviation and the first compensation information, and then determines the timing advance corresponding to the current time based on the first delay and the third compensation delay, thereby improving the transmission performance of the communication system.

As one possible implementation, determining the third compensation delay based on the timing deviation and the first compensation delay may include: summing the timing deviation and the first compensation delay to obtain the third compensation delay. Based on this, when determining the third compensation delay based on the timing deviation and the first compensation delay, the terminal device can sum the first compensation delay and the timing deviation, simultaneously accumulating the impact of the first compensation delay and the timing deviation on the third compensation delay, in order to obtain a reasonable timing advance and improve the transmission performance of the communication system.

As one possible implementation, determining the timing advance based on the first delay and the third compensated delay may include: summing the first delay and the third compensated delay to obtain the timing advance. Based on this, the terminal device can determine the timing advance within the first ephemeris validity period by summing the first delay and the third compensated delay to obtain the timing advance, thereby improving the transmission performance of the communication system.

As one possible implementation, determining the timing advance of the communication system to which the terminal device belongs based on the first ephemeris information, the second ephemeris information, and the timing deviation may include: calculating a first delay and a second delay based on the first ephemeris information and the second ephemeris information, respectively; and using a filtering model to filter the first delay and the sum of the second delay and the second timing deviation to obtain the timing advance. Based on this, at the moment of switching between new and old ephemeris information, the terminal device first calculates the first delay based on the first ephemeris information, calculates the second delay based on the second ephemeris information, and then filters the first and second delays using a filtering model. This avoids abrupt changes in the timing deviation of the communication system during the switch between new and old ephemeris information, thereby improving the stability of the communication system.

As one possible implementation, the filtering model uses filtering parameters greater than 0 and less than 1, which are positively correlated with the difference between the first delay and the second delay. Based on this, when the terminal device filters the first delay and the second delay, the filtering parameters can be between 0 and 1. Specifically, parameter 1 corresponding to the first delay, parameter 2 corresponding to the sum of the second delay and the second timing deviation, equals 1. That is, parameter 2 corresponding to the sum of the second delay and the second timing deviation equals 1 minus parameter 1 corresponding to the first delay. Furthermore, the greater the difference between the first delay and the second delay, the larger the value of parameter 1, to avoid abrupt changes in the timing deviation of the communication system when switching between new and old ephemeris information, thereby improving the stability of the communication system.

As one possible implementation, the filtering model includes an alpha filter. Based on this, the terminal device can use an alpha filter to filter the first and second time delays to avoid abrupt changes in the timing deviation of the communication system when switching between new and old ephemeris information, thereby improving the stability of the communication system.

Secondly, this application provides a terminal device, which includes: a transceiver for transmitting and receiving signals; a memory for storing computer program instructions; and a processor for executing the computer program instructions to support the terminal device in implementing the method as described in any one of the first aspects.

Thirdly, this application provides a computer-readable storage medium storing computer program instructions that, when executed by a processing circuit, implement the method as described in any one of the first aspects.

Fourthly, this application provides a computer program product containing instructions that, when run on a computer, cause the computer to perform the method as described in any one of the first aspects.

Fifthly, this application provides a chip system, the chip system including a processing circuit and a storage medium, the storage medium storing computer program instructions; when the computer program instructions are executed by the processing circuit, they implement the method as described in any one of the first aspects.

Attached Figure Description

Figure 1 is a schematic diagram showing the change of ephemeris information error over time;

Figure 2 is a flowchart illustrating a method for determining timing advance provided in an embodiment of this application;

Figure 3 is a flowchart illustrating a timing advance determination method provided in an embodiment of this application at different times;

Figure 4 is a flowchart illustrating a filter-based timing advance determination method provided in an embodiment of this application.

Figure 5 is a schematic diagram of the composition structure of a terminal device provided in an embodiment of this application;

Figure 6 is a schematic diagram of the hardware structure of a terminal device provided in an embodiment of this application.

Detailed Implementation

The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. In the description of the embodiments of this application, unless otherwise stated, "/" means "or," for example, A/B can mean A or B; "and/or" in this text 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. Furthermore, in the description of the embodiments of this application, "multiple" refers to two or more than two.

In the following text, the terms "first," "second," etc., are used only to distinguish different descriptive objects and do not limit the position, order, priority, quantity, or content of the described objects. For example, if the described object is a "field," then the ordinal numbers before "field" in "first field" and "second field" do not limit the position or order of the "fields." "First" and "second" do not limit whether the "fields" they modify are in the same message, nor do they restrict the order of "first field" and "second field." Similarly, if the described object is a "level," then the ordinal numbers before "level" in "first level" and "second level" do not limit the priority of the "levels." Furthermore, the quantity of described objects is not limited by ordinal numbers and can be one or more; for example, in "first device," the number of "devices" can be one or more. In addition, objects modified by different prefixes can be the same or different. For example, if the described object is "device," then "first device" and "second device" can be devices of the same type or different types. Similarly, if the described object is "information," then "first information" and "second information" can be information with the same content or information with different content. In summary, the use of ordinal numbers and other prefixes used to distinguish the described objects in the embodiments of this application does not constitute a limitation on the described objects. The description of the described objects is given in the claims or the context of the embodiments, and the use of such prefixes should not constitute an unnecessary limitation.

Furthermore, in the embodiments of this application, "connection" can be a direct connection or an indirect connection; in addition, it can refer to an electrical connection or a communication connection; for example, the connection of two electrical components A and B can refer to A and B being directly connected, or it can refer to A and B being indirectly connected through other electrical components or connection media, or it can refer to A and B being indirectly connected through other communication devices or communication media, as long as it enables communication between A and B.

Currently, satellite communication systems use ephemeris information to calculate satellite position and velocity information, and then use this information to address issues such as timing offset, Doppler frequency shift, and beam direction. The ephemeris information measured and transmitted by the satellite in the current NTN communication system represents a single instant. However, in reality, satellites are affected by various perturbations, causing their trajectories to deviate from the ideal two-body motion assumption. Therefore, over time, the actual ephemeris information deviates significantly from the transmitted ephemeris information.

Referring to Figure 1, which illustrates the change in ephemeris information error over time, as shown in Figure 1, based on the relationship between the ephemeris information error (m) and the time (t) since the ephemeris generation time, it can be seen that as time progresses, the error of the ephemeris information broadcast by the satellite to the terminal device will increase, and the rate of increase in the error will also accelerate. To prevent the error from accumulating beyond the system's tolerance, the communication protocol defines a maximum validity period for the ephemeris information. When the time for transmitting the ephemeris information exceeds the validity period, the terminal will update the ephemeris information, and the error of the new ephemeris information is smaller. However, after the terminal device updates the ephemeris information, the error of the new ephemeris information will change abruptly compared to the old ephemeris information. But the loop adjustments previously completed based on the old ephemeris information cannot be updated synchronously. Therefore, after updating the ephemeris information, the timing deviation of the communication system will suddenly increase, reaching up to twice the maximum ephemeris error, seriously affecting system performance.

In some embodiments, the timing deviation of ephemeris information accumulates over time. By shortening the usage time of ephemeris information, the amount of accumulated error can be reduced. Therefore, in order to avoid a sudden increase in the timing deviation of the communication system, the communication system reduces the accumulated error when switching ephemeris information by shortening the validity period of the ephemeris information. The sudden change in timing deviation of the terminal device when switching ephemeris information can also be greatly reduced. However, ephemeris information is carried through the system information block (SIB). After the validity period of the ephemeris information expires, the frequency of the terminal parsing the SIB increases. However, frequent parsing of the SIB will increase the power consumption of the terminal device.

In some embodiments, the principle of error adjustment based on ephemeris information in a satellite communication system includes: first, the terminal device calculates the spatial coordinates of the satellite based on the ephemeris, obtains the spatial coordinates of the terminal device based on the Global Navigation Satellite System (GNSS) information, then calculates the straight-line distance between the satellite and the terminal device and divides it by the speed of light to obtain the one-way propagation delay between the satellite and the terminal device. Since both the ephemeris information and the GNSS information have errors, a loop adjustment mechanism is also needed, i.e., the measurement of the physical channel, to measure and compensate for the residual timing deviation.

In some embodiments, the timing advance of the satellite communication system is determined based on the aforementioned error adjustment principle of the satellite communication system. For example, when determining the timing advance of the satellite communication system, the timing advance is calculated by summing the propagation delay calculated based on ephemeris/GNSS information and the timing deviation obtained by physical channel measurement. In the NR/LTE system, the timing advance is equal to the two-way propagation delay, that is, twice the sum of the propagation delay and the timing deviation. For example, the timing advance TA in the satellite communication system can be calculated by formula (1):
TA = _Tc + _Tm (1)

Where T _{_c} is the propagation delay calculated based on ephemeris/GNSS information; and T_{_m is the timing deviation (i.e., the error in ephemeris/GNSS information calculation) obtained by measuring through the physical channel after timing adjustment based on T_c}.

When a terminal device switches from old ephemeris information to new ephemeris information, the timing deviation of the satellite communication system will experience a large abrupt change. At this time, the actual timing advance TA is determined by the sum of the delay calculated from the old ephemeris information and the timing deviation. For example, the timing advance TA in the satellite communication system can be calculated using formula (2):
TA = T _{c - old} + T _m (2)

Where Tc _-old is the propagation delay calculated based on old ephemeris information.

However, after the terminal equipment switches to the nova ephemeris information, the timing advance TA in the satellite communication system suddenly changes to be calculated using formula (3):
TA = T _{c - new} + T _m (3)

Where _Tc-new is the propagation delay calculated based on the nova ephemeris information.

Because the timing advance (TA) in a satellite communication system can change abruptly at the moment of switching between new and old ephemeris information, meaning that the timing advance used to determine the moment of switching between new and old ephemeris information solely through new or old ephemeris information can be subject to such abrupt changes, this can affect uplink synchronization in the communication system. This can lead to packet errors or even loss of synchronization during uplink synchronization, thus impacting the transmission performance of the satellite communication system.

Based on this, embodiments of this application provide a timing advance determination method, device, and system. In this application, when a terminal device switches between old and new ephemeris information, it calculates the timing advance corresponding to the communication system when the terminal device switches between old and new ephemeris information by acquiring the new and old ephemeris information and the timing deviation measured through the physical channel at the time of the ephemeris information switch. In this way, the timing deviation abrupt change during the ephemeris switch can be reduced without shortening the ephemeris validity period. This can avoid the timing deviation of the communication system to which the terminal device belongs abruptly when the terminal device switches from old ephemeris information to new ephemeris information, thereby improving the stability and transmission performance of the communication system.

In some embodiments, the terminal device can simultaneously calculate _Tc-old and _Tc-new to obtain the deviation T_delta between _Tc-old and _Tc-new , which serves as one of the factors for determining the timing advance of the communication system. Compensation is then applied to the deviation to achieve the purpose of preventing sudden timing changes between the old and new systems. On the other hand, the terminal device can filter Tc _-old and _Tc-new to prevent sudden timing deviations in the communication system.

The network elements involved in this application include satellite base stations in LTE/NR systems and terminal equipment that conducts satellite communication through satellite base stations. Based on the same principle, this application can also be applied to other communication systems that require transmission delay adjustment.

Terminal devices can also be referred to as user equipment (UE), mobile stations, mobile terminal devices, 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), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, smart transportation, smart cities, etc. Terminal devices can be mobile phones, tablets, computers with wireless transceiver capabilities, wearable devices, vehicles, drones, helicopters, airplanes, ships, robots, robotic arms, smart home devices, roadside units (RSUs), sensors, etc. The embodiments of this application do not limit the specific technologies or device forms used in the terminal devices.

The aforementioned terminal devices can establish connections with the operator's network through interfaces provided by the operator's network (such as N1), and use data and/or voice services provided by the operator's network. The terminal devices can also access the Domain Name System (DNS) through the operator's network, and use operator services deployed on the DNS, and/or services provided by third parties. These third parties can be service providers outside of the operator's network and the terminal devices, and can provide other data and/or voice services to the terminal devices. The specific form of these third parties can be determined based on the actual application scenario and is not limited here.

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

The terminal device can be fixed or mobile. It can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; it can also be deployed on water; and it can be deployed in the air on aircraft, balloons, and satellites. The embodiments of this application do not limit the application scenarios of the terminal device.

The uplink scheduling method provided in the embodiments of this application will be described in detail below with reference to the accompanying drawings.

Referring to Figure 2 in some embodiments, a flowchart illustrating a timing advance determination method provided by an embodiment of this application is shown. As shown in Figure 2, the method is applied to a terminal device and may include steps S201-S202:

S201: The terminal device receives the first ephemeris information, which is different from the second ephemeris information. The second ephemeris information is the ephemeris information currently used by the terminal device.

For example, the second ephemeris information is the old ephemeris information, and the first ephemeris information is the new ephemeris information.

S202: When the terminal device performs ephemeris switching based on the first ephemeris information, it determines the timing advance of the communication system to which the terminal device belongs based on the first ephemeris information, the second ephemeris information, and the timing deviation. The timing deviation is used to characterize the delay error corresponding to the first ephemeris information measured through the physical channel.

In some embodiments, the terminal device may switch ephemeris information immediately after receiving the first ephemeris information, i.e., switch from the second ephemeris information to the first ephemeris information, or it may switch ephemeris information at other times as needed after receiving the first ephemeris information.

When a terminal device performs an ephemeris switch, it switches from using the second ephemeris information to using the first ephemeris information. The first ephemeris information is the new ephemeris information, and the second ephemeris information is the old ephemeris information. The terminal device switches ephemeris information based on the first ephemeris information, that is, the terminal device switches from the old ephemeris information to the new ephemeris information.

In some embodiments, when switching ephemeris information, the terminal device can calculate the timing advance for switching between the new and old ephemeris information based on the new ephemeris information, the old ephemeris information, and the timing deviation measured through the physical channel at the time of the ephemeris information switch. Based on this, abrupt changes in the timing deviation of the communication system can be avoided when switching between the new and old ephemeris information, thus improving the stability of the communication system.

In some embodiments, the terminal device may first determine the first compensation delay corresponding to the first ephemeris information based on the first ephemeris information and the second ephemeris information, wherein the first compensation delay is used to compensate and correct the first delay calculated according to the first ephemeris information at the time when the terminal device switches the ephemeris information; and then determine the timing advance based on the first ephemeris information and the first compensation delay.

In some embodiments, the terminal device may first calculate a first delay and a second delay based on the first ephemeris information and the second ephemeris information, respectively, and then determine the first compensated delay based on the first delay, the second delay, the second compensated delay corresponding to the second ephemeris information, and the timing deviation. The first delay represents the propagation delay calculated from the old delay information, and the second delay represents the propagation delay calculated from the new delay information. The second compensated delay corresponding to the second ephemeris information is used to compensate and correct the propagation delay calculated based on the old ephemeris information when the terminal device uses the old ephemeris information. When switching between the new and old ephemeris information, it is used to combine the first delay, the second delay, and the timing deviation to determine the first ephemeris information at the time of ephemeris information switching.

In some embodiments, the terminal device may first calculate a first value by subtracting the first delay and the second delay, and then determine the first compensation delay based on the first value, the second compensation delay, and the timing deviation. For example, the terminal device may first determine the difference between the propagation delay determined by the new ephemeris information and the propagation delay determined by the old ephemeris information based on the first delay and the second delay, that is, the absolute value of the change in propagation delay when switching between the new ephemeris information and the old ephemeris information. Then, based on the calculated difference between the first delay and the second delay, the second compensation delay, and the timing deviation, the terminal device may determine the first compensation delay when switching between the new and old ephemeris information to help determine the timing advance of the communication system.

In some embodiments, the terminal device can sum the first value, the second compensated delay, and the timing deviation to obtain the first compensated delay. That is, when determining the first compensated delay based on the difference between the first delay and the second delay (i.e., the first value, the second compensated delay, and the timing deviation), the terminal device can sum the first value, the second compensated delay, and the timing deviation, and simultaneously accumulate the impact of the first value, the second compensated delay, and the timing deviation on the first compensated delay to further determine the timing advance of the communication system.

In some examples, the terminal device maintains a compensation variable T_comp (i.e., the first compensation delay in the aforementioned embodiments) to correct or compensate for the delay in ephemeris calculation. When the terminal device switches from old ephemeris information to new ephemeris information, in addition to the timing deviation of the channel measurement (i.e., Tm in the aforementioned embodiments), it also needs to add the difference T_delta (i.e., the first value in the aforementioned embodiments) between the first delay and the second delay calculated from the new ephemeris information and the old ephemeris information.

In some embodiments, the terminal device can determine the timing advance based on the first delay and the first compensated delay. For example, the terminal device can first determine the first delay corresponding to the new ephemeris information based on the first ephemeris information, and then determine the timing advance when switching between the old and new ephemeris information based on the first delay and the first compensated delay.

In some embodiments, the terminal device can sum the first delay and the first compensated delay to obtain the timing advance. For example, the terminal device can sum the first delay and the first compensated delay, and simultaneously accumulate the impact of the first delay and the first compensated delay on the timing advance, in order to determine the timing advance when switching between old and new ephemeris information.

In some examples, see Figure 3, which shows a flowchart of a timing advance determination method provided by an embodiment of this application at different times. As shown in Figure 3, at the time t0 when the terminal device switches from old ephemeris information to new ephemeris information, the transmission delay calculated by the terminal device based on the old ephemeris information is Tc_old(t0), the transmission delay calculated based on the new ephemeris information is Tc_new(t0), and the measurement feedback Tm(t0) of the previous time (i.e., the timing deviation in the aforementioned embodiment).

Based on formula (4), calculate T_delta according to Tc_old and Tc_new:
T_delta=Tc_old(t0)-Tc_new(t0) (4)

Based on formula (5), the first compensation delay T_comp(t0) at time t0 is calculated according to T_delta:
T_comp(t0)=T_comp(t1)+T_delta+Tm(t0)
(5)

Where T_comp(t1) is the T_comp calculated based on the old ephemeris information at time t1 before t0; Tm(t0) represents the timing deviation of the base station feedback at time t0.

In some examples, the timing deviation received by the terminal device can be at time t0 or earlier than time t0. The timing deviation at time Tm(t0) is obtained by measuring the uplink signal at a certain time before t0. Therefore, Tm(t0) represents the delay value at a certain time before t0.

Based on formula (6), the TA value at time t0 (i.e., the timing advance in the aforementioned embodiment) is calculated according to T_comp(t0) and Tc_new(t0):
TA(t0)=Tc-new(t0)+T-comp(t0) (6)

In some embodiments, the terminal device uses the aforementioned T_comp(t0) as a propagation delay compensation, which can prevent abrupt timing deviations when the terminal device switches from old ephemeris information to new ephemeris information, thus preventing system performance degradation during ephemeris switching. There are no abrupt timing changes during the switch between old and new ephemeris, allowing for a smooth transition.

In some embodiments, when the first ephemeris information is valid, the terminal device determines the timing advance of the communication system to which the terminal device belongs based on the first ephemeris information and the timing deviation. After the first ephemeris information is successfully switched and is still valid, the terminal device determines the timing advance of the communication system using the first ephemeris information and the timing deviation to improve the transmission performance of the communication system.

In some embodiments, the terminal device calculates the first delay based on the first ephemeris information; determines a third compensation delay based on the timing deviation and the first compensation delay; and determines the timing advance based on the first delay and the third compensation delay. When the terminal device determines the timing advance of the communication system based on the first ephemeris information and the timing deviation, it first calculates the corresponding first delay based on the first ephemeris information, determines the third compensation delay corresponding to the current time based on the timing deviation and the first compensation information, and then determines the timing advance corresponding to the current time based on the first delay and the third compensation delay to improve the transmission performance of the communication system.

In some embodiments, the terminal device sums the timing deviation and the first compensation delay to obtain the third compensation delay. When determining the third compensation delay based on the timing deviation and the first compensation delay, the terminal device can sum the first compensation delay and the timing deviation, and simultaneously accumulate the impact of the first compensation delay and the timing deviation on the third compensation delay, in order to obtain a reasonable timing advance and improve the transmission performance of the communication system.

In some embodiments, the terminal device sums the first delay and the third compensated delay to obtain the timing advance. The terminal device determines the timing advance within the first ephemeris validity period using the first delay and the third compensated delay, and can sum the first delay and the third compensated delay to obtain the timing advance, thereby improving the transmission performance of the communication system.

In some examples, the terminal device maintains a compensation variable T_comp (i.e., the first compensation delay in the aforementioned embodiments) to correct or compensate for the delay in ephemeris calculation. When the terminal device is not involved in switching from old ephemeris information to new ephemeris information and is within the validity period of the new ephemeris information, the compensation variable T_comp only needs to accumulate the timing deviation Tm of the channel measurement.

In some examples, as shown in Figure 3, at time t1 when the terminal device does not involve switching from old ephemeris information to new ephemeris information and is within the validity period of the old ephemeris information, the transmission delay calculated based on the old ephemeris information is Tc_old(t1). The measurement feedback Tm(t1) of the previous time (i.e., the timing deviation in the aforementioned embodiment) is obtained. Based on formula (7), the third compensation delay T_comp(t1) at time t1 is calculated according to Tm(t1) and T_comp(t2):
T_comp(t1)＝T_comp(t2)+Tm(t1) (7)

Where t2 is a time before t1, T_comp(t2) represents the T_comp value at time t2, and Tm(t1) represents the timing deviation of the base station feedback at time t1 (the terminal device may receive the timing deviation earlier than time t1).

In some examples, the transmission delay at time Tm(t1) is obtained by measuring the uplink signal at a time prior to t1, representing the delay value at that time. When t1 is the first frame, i.e., there is no historical value of T_comp, T_comp is considered 0. The adjustment amount of TA (i.e., the third compensation delay in the aforementioned embodiment) is Tc_old(t1) + T_comp(t1). Wherein, Tc_old(t1) is the TA value calculated based on ephemeris at time t1.

Based on formula (8), the TA value at time t1 (i.e., the timing advance in the aforementioned embodiment) is calculated according to T_comp(t1) and Tc_old(t1):
TA(t1)＝Tc-old(t1)+T-comp(t1) (8)

In some examples, as shown in Figure 3, at time t3 when the terminal device is within the validity period of the nova ephemeris information, the transmission delay calculated based on the nova ephemeris information is divided into Tc_new(t3). The measurement feedback Tm(t3) of the previous time (i.e., the timing deviation in the aforementioned embodiment) is obtained. Based on formula (9), the third compensation delay T_comp(t3) at time t1 is calculated according to Tm(t3) and T_comp(t0):
T_comp(t3)＝T_comp(t0)+Tm(t3) (9)

Where t0 is a time before t3, T_comp(t0) represents the T_comp value at time t0, and Tm(t3) represents the timing deviation of the base station feedback at time t3 (the terminal device may receive the timing deviation earlier than time t3).

In some examples, the transmission delay at time Tm(t3) is obtained by measuring the uplink signal at a time before t3, representing the delay value at that time before t3. The adjustment amount of TA (i.e., the third compensation delay in the aforementioned embodiment) is Tc-new(t3) + T-comp(t3). Wherein, Tc_old(t1) is the TA value calculated based on ephemeris at time t1.

Based on formula (10), the TA value at time t3 (i.e., the timing advance in the aforementioned embodiment) is calculated according to T_comp(t3) and Tc_new(t3):
TA(t3)＝Tc-new(t3)+T-comp(t3) (10)

In some embodiments, the terminal device can first calculate a first delay and a second delay based on the first ephemeris information and the second ephemeris information, respectively; then, using a filtering model, it performs filtering processing based on the sum of the second delay and the second timing deviation, as well as the first delay, to obtain the timing advance. At the moment of switching between new and old ephemeris information, the terminal device first calculates the first delay based on the first ephemeris information, calculates the second delay based on the second ephemeris information, and then filters the first and second delays using a filtering model. This avoids abrupt changes in the timing deviation of the communication system during the switching between new and old ephemeris information, thereby improving the stability of the communication system.

In some embodiments, the filtering parameters used in the filtering model are greater than 0 and less than 1, and the filtering parameters are positively correlated with the difference between the first delay and the second delay. When the terminal device filters the first delay and the second delay, the filtering parameters can be between 0 and 1. Specifically, parameter 1 corresponding to the first delay, parameter 2 corresponding to the sum of the second delay and the second timing deviation, equals 1. That is, parameter 2 corresponding to the sum of the second delay and the second timing deviation equals 1 minus parameter 1 corresponding to the first delay. Furthermore, the greater the difference between the first delay and the second delay, the larger the value of parameter 1, to avoid abrupt changes in the timing deviation of the communication system when switching between new and old ephemeris information, thereby improving the stability of the communication system.

In some embodiments, the filtering model may be an alpha filter. The terminal device can use an alpha filter to filter the first delay and the second delay to avoid abrupt changes in the timing deviation of the communication system when switching between new and old ephemeris information, thereby improving the stability of the communication system.

In some examples, see Figure 4, which illustrates a flowchart of a filter-based timing advance determination method provided in this application embodiment. As shown in Figure 4, at the moment when the terminal device switches from old ephemeris information to new ephemeris information, the transmission delay calculated by the terminal device based on the old ephemeris information is Tc_old(0), the transmission delay calculated based on the new ephemeris information is Tc_new(0), and the measurement feedback Tm(t0) of the previous moment (i.e., the timing deviation in the aforementioned embodiment) is also included. Then, an alpha filter is applied to Tc_new(0) and Tm+Tc_old(0), and the filter coefficient can be adjusted according to the system characteristics. The filter parameter is positively correlated with the difference between Tc_new and Tc_old.

In some examples, when the terminal device switches from old ephemeris information to new ephemeris information, the timing advance TA can be calculated using formula (11):
TA(t0)=alpha*(Tc_new(t0))+(1-alpha)*(Tm(t0)+Tc_old(t0))
(11)

Where Tc_new(0) is the transmission delay calculated based on the new ephemeris, Tc_old(0) is the transmission delay calculated based on the old ephemeris, and alpha generally takes the value range of (0, 1).

In this embodiment, when the terminal device switches between old and new ephemeris information, it can calculate the timing advance of the communication system at the time of the switch using the new ephemeris information, the old ephemeris information, and the timing deviation measured by the physical channel at the time of the ephemeris information switch. On the other hand, it can filter the propagation delay calculated from the new and old ephemeris information to avoid abrupt changes in the timing deviation of the communication system to which the terminal device belongs when switching from the old ephemeris information to the new ephemeris information, thereby improving the stability and transmission performance of the communication system.

Based on the same inventive concept as the foregoing embodiments, referring to Figure 5, which shows a schematic diagram of the composition structure of a terminal device provided in an embodiment of this application. In one example, the terminal device can be used to implement any of the timing advance determination methods in the foregoing embodiments. Specifically, the terminal device may include:

The receiving unit 501 is configured to receive first ephemeris information, which is different from second ephemeris information, and the second ephemeris information is the ephemeris information currently used by the terminal device.

The processing unit 502 is configured to determine the timing advance of the communication system to which the terminal device belongs based on the first ephemeris information, the second ephemeris information, and the timing deviation when performing ephemeris switching based on the first ephemeris information. The timing deviation is used to characterize the delay error corresponding to the first ephemeris information measured through the physical channel.

In some embodiments, the processing unit 502 is specifically configured to determine a first compensation delay corresponding to the first ephemeris information based on the first ephemeris information and the second ephemeris information; and to determine the timing advance based on the first ephemeris information and the first compensation delay.

In some embodiments, the processing unit 502 is specifically configured to calculate a first delay and a second delay based on the first ephemeris information and the second ephemeris information, respectively; and to determine the first compensation delay based on the first delay, the second delay, the second ephemeris information, the second compensation delay corresponding to the second ephemeris information, and the timing deviation.

In some embodiments, the processing unit 502 is specifically configured to calculate a first value by performing a difference calculation on the first delay and the second delay; and to determine the first compensation delay based on the first value, the second compensation delay, and the timing deviation.

In some embodiments, the processing unit 502 is specifically configured to sum the first value, the second compensation delay, and the timing deviation to obtain the first compensation delay.

In some embodiments, the processing unit 502 is specifically configured to determine the timing advance based on the first delay and the first compensation delay.

In some embodiments, the processing unit 502 is specifically configured to sum the first delay and the first compensation delay to obtain the timing advance.

In some embodiments, the processing unit 502 is further configured to determine the timing advance of the communication system to which the terminal device belongs based on the first ephemeris information and the timing deviation when the first ephemeris information is valid.

In some embodiments, the processing unit 502 is specifically configured to calculate the first delay based on the first ephemeris information; determine a third compensation delay based on the timing deviation and the first compensation delay; and determine the timing advance based on the first delay and the third compensation delay.

In some embodiments, the processing unit 502 is specifically configured to sum the timing deviation and the first compensation delay to obtain the third compensation delay.

In some embodiments, the processing unit 502 is specifically configured to sum the first delay and the third compensation delay to obtain the timing advance.

In some embodiments, the processing unit 502 is specifically configured to calculate a first delay and a second delay based on the first ephemeris information and the second ephemeris information, respectively; and to use a filtering model to perform filtering processing based on the sum of the second delay and the second timing deviation, and the first delay, to obtain the timing advance.

In some embodiments, the filtering parameters used in the filtering model are greater than 0 and less than 1, and the filtering parameters are positively correlated with the difference between the first delay and the second delay.

In some embodiments, the filtering model includes an alpha filter.

Understandably, in this embodiment, a "unit" can be a portion of a circuit, a portion of a processor, a portion of a program or software, etc., and can also be a module or a non-modular component. Furthermore, the components in this embodiment can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional module.

If the integrated unit is implemented as a software functional module and is not sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this embodiment, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) or processor to execute all or part of the steps of the method provided in this embodiment. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

Therefore, this embodiment provides a computer storage medium storing a paging program that, when executed by at least one processor, implements the steps of the method described in any of the foregoing embodiments.

Based on the composition of the terminal device and the computer storage medium described above, referring to Figure 6, a schematic diagram of the composition structure of a terminal device provided in an embodiment of this application is shown. As shown in Figure 6, it may include a processor 601. Optionally, the terminal device may also include a memory 602 and/or a communication interface 603. The various components are coupled together through a communication line 604. It is understood that the communication line 604 is used to realize the connection and communication between these components. In addition to a data bus, the communication line 604 also includes a power bus, a control bus, and a status signal bus. However, for clarity, all buses are labeled as communication line 604 in Figure 6.

The processor 601 is configured to, when running the computer program, perform the following: receiving first ephemeris information, the first ephemeris information being different from second ephemeris information, the second ephemeris information being the ephemeris information currently used by the terminal device; and, when performing ephemeris switching based on the first ephemeris information, determining the timing advance of the communication system to which the terminal device belongs based on the first ephemeris information, the second ephemeris information, and a timing deviation, the timing deviation being used to characterize the delay error corresponding to the first ephemeris information measured through the physical channel.

In some embodiments, the processor 601 is configured to perform the steps of the method described in any of the foregoing embodiments when running the computer program.

The memory 602 is used to store computer programs that can run on the processor 601.

The communication interface 603 is used for receiving and sending signals during the process of sending and receiving information with other external network elements.

It is understood that the memory 602 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 DRAM (SDRAM), Double Data Rate SDRAM (DDRSDRAM), Enhanced Synchronous DRAM (ESDRAM), Synchronous Link DRAM (SLDRAM), and Direct Rambus RAM (DRRAM). The memory 602 of the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

The processor 601 may be an integrated circuit chip with signal processing capabilities. In implementation, each step of the above method can be completed by the integrated logic circuitry in the hardware of the processor 601 or by software instructions. The processor 601 may be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor may be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly embodied in the execution of a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules may reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. The storage medium is located in memory 602. Processor 601 reads the information in memory 602 and, in conjunction with its hardware, completes the steps of the above method.

It is understood that the embodiments described herein can be implemented in hardware, software, firmware, middleware, microcode, or a combination thereof. For hardware implementation, the processing unit can be implemented in one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), general-purpose processors, controllers, microcontrollers, microprocessors, other electronic units for performing the functions described herein, or combinations thereof.

For software implementation, the techniques described herein can be achieved through modules (e.g., procedures, functions, etc.) that perform the functions described herein. The software code can be stored in memory and executed by a processor. The memory can be implemented within the processor or externally.

Alternatively, as another embodiment, the processor 601 is further configured to perform the steps of the method described in any of the foregoing embodiments when running a computer program.

In some embodiments, based on the composition of the terminal device described above, this application provides another terminal device, which may include the terminal device described in any of the foregoing embodiments.

Optionally, the computer execution instructions in this application may also be referred to as application code, and this application does not specifically limit them.

In a specific implementation, as one example, processor 601 may include one or more CPUs, such as CPU0 and CPU1 in FIG6.

It should be noted that Figure 6 is only an example of a terminal device and does not limit the specific structure of the terminal device. For example, the terminal device or network device may also include other functional modules.

This application provides a computer program product containing instructions that, when run on a computer, cause the computer to perform any of the methods provided in the foregoing embodiments.

This application provides a chip system, which may include a processing circuit and a storage medium. The storage medium stores computer program instructions. When the computer program instructions are executed by the processing circuit, they implement the method provided in any of the foregoing embodiments.

It should be noted that, in this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

The methods disclosed in the several method embodiments provided in this application can be arbitrarily combined to obtain new method embodiments without conflict. The features disclosed in the several product embodiments provided in this application can be arbitrarily combined to obtain new product embodiments without conflict. The features disclosed in the several method or device embodiments provided in this application can be arbitrarily combined to obtain new method embodiments or device embodiments without conflict. The above descriptions are merely specific embodiments of this application, but the protection scope of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the protection scope of this application. Therefore, the protection scope of this application should be determined by the protection scope of the claims.

Claims (18)

A method for determining timing advance, characterized in that it is applied to a terminal device, the method comprising: Receive first ephemeris information, which is different from second ephemeris information, where the second ephemeris information is the ephemeris information currently used by the terminal device; When performing ephemeris switching based on the first ephemeris information, the timing advance of the communication system to which the terminal device belongs is determined based on the first ephemeris information, the second ephemeris information, and the timing deviation. The timing deviation is used to characterize the delay error corresponding to the first ephemeris information measured through the physical channel. According to the method of claim 1, the step of determining the timing advance of the communication system to which the terminal device belongs based on the first ephemeris information, the second ephemeris information, and the timing deviation includes: The first compensation delay corresponding to the first ephemeris information is determined based on the first ephemeris information and the second ephemeris information; The timing advance is determined based on the first ephemeris information and the first compensation delay. According to the method of claim 2, the step of determining the first compensation delay corresponding to the first ephemeris information based on the first ephemeris information and the second ephemeris information includes: The first delay and the second delay are calculated based on the first ephemeris information and the second ephemeris information, respectively. The first compensation delay is determined based on the first delay, the second delay, the second ephemeris information corresponding to the second compensation delay, and the timing deviation. According to the method of claim 3, the step of determining the first compensation delay based on the first delay, the second delay, the second ephemeris information corresponding to the second compensation delay, and the timing deviation includes: The first value is obtained by calculating the difference between the first delay and the second delay; The first compensation delay is determined based on the first value, the second compensation delay, and the timing deviation. The method according to claim 4, characterized in that, determining the first compensation delay based on the first value, the second compensation delay, and the timing deviation includes: The first compensation delay is obtained by summing the first value, the second compensation delay, and the timing deviation. The method according to any one of claims 3-5, characterized in that determining the timing advance based on the first ephemeris information and the first compensation delay includes: The timing advance is determined based on the first delay and the first compensation delay. The method according to claim 6, wherein determining the timing advance based on the first delay and the first compensation delay includes: The timing advance is obtained by summing the first delay and the first compensation delay. The method according to any one of claims 1-7, characterized in that the method further comprises: When the first ephemeris information is valid, the timing advance of the communication system to which the terminal device belongs is determined based on the first ephemeris information and the timing deviation. According to the method of claim 8, the step of determining the timing advance of the communication system to which the terminal device belongs based on the first ephemeris information and the timing deviation includes: The first delay is calculated based on the first ephemeris information; The third compensation delay is determined based on the timing deviation and the first compensation delay. The timing advance is determined based on the first delay and the third compensation delay. The method according to claim 9, characterized in that, determining the third compensation delay based on the timing deviation and the first compensation delay includes: The timing deviation and the first compensation delay are summed to obtain the third compensation delay. The method according to any one of claims 8-10, characterized in that determining the timing advance based on the first delay and the third compensation delay includes: The timing advance is obtained by summing the first delay and the third compensation delay. The method according to claim 1 or 2, characterized in that, determining the timing advance of the communication system to which the terminal device belongs based on the first ephemeris information, the second ephemeris information, and the timing deviation includes: The first delay and the second delay are calculated based on the first ephemeris information and the second ephemeris information, respectively. Using a filtering model, the timing advance is obtained by filtering the sum of the second delay and the second timing deviation, as well as the first delay. According to the method of claim 12, the filtering parameters used in the filtering model are greater than 0 and less than 1, and the filtering parameters are positively correlated with the difference between the first delay and the second delay. The method according to claim 13 is characterized in that the filtering model includes an alpha filter. A terminal device, characterized in that the terminal device comprises: A transceiver is used to send and receive signals. Memory is used to store computer program instructions; A processor for executing the computer program instructions to support the terminal device in implementing the method as described in any one of claims 1-14. A computer-readable storage medium, characterized in that the computer-readable storage medium stores computer program instructions, which, when executed by a processing circuit, implement the method as described in any one of claims 1-14. A computer program product comprising instructions, characterized in that, when the computer program product is run on a computer, it causes the computer to perform the method as described in any one of claims 1-14. A chip system, characterized in that the chip system includes a processing circuit and a storage medium, wherein the storage medium stores computer program instructions; when the computer program instructions are executed by the processing circuit, they implement the method as described in any one of claims 1-14.