CN116210289A

CN116210289A - Method, device, equipment and storage medium for determining uplink advance timing

Info

Publication number: CN116210289A
Application number: CN202080104679.2A
Authority: CN
Inventors: 胡奕; 李海涛; 徐伟杰
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2020-08-07
Filing date: 2020-08-07
Publication date: 2023-06-02
Also published as: WO2022027628A1

Abstract

The embodiment of the application discloses a method, a device, equipment and a storage medium for determining uplink Timing Advance (TA), and relates to the technical field of wireless communication. The method comprises the following steps: and determining a first TA according to the TA offset value and the TA predicted value, wherein the TA offset value is used for indicating the offset condition of the signal propagation round trip delay between the terminal and the serving cell base station, and the TA predicted value is the signal propagation round trip delay between the terminal and the serving cell satellite estimated by the terminal based on the positioning capability. By introducing the TA offset value in the process of determining the uplink TA by the terminal, the situation that the TA is overcompensated by the terminal due to the error of positioning accuracy is avoided, so that interference is not caused to the uplink signal of the previous symbol received by the network side or the downlink signal transmitted by the network side, and the signal receiving performance of the network side is ensured.

Description

Method, device, equipment and storage medium for determining uplink advance timing

Technical Field

The present invention relates to the field of wireless communications technologies, and in particular, to a method, an apparatus, a device, and a storage medium for determining an uplink Timing Advance (TA).

Background

In an NR (New Radio) system, in order to ensure orthogonality of uplink transmission, to avoid interference between uplink transmissions from different terminals in the same cell, the NR system supports an uplink timing advance mechanism, i.e. alignment of time when uplink transmissions from terminals in the same time slot but different frequency domain resources reach a network side. In a conventional NR terrestrial cellular network, the terminal transmits an uplink message during random access and does not perform TA compensation when transmitting an uplink transmission in an RRC (Radio Resource Control ) connected state.

In NTN (Non Terrestrial Network, non-terrestrial communication network), a mechanism is introduced in which a terminal itself compensates for a TA to send an uplink message and uplink transmission, and the terminal can directly use the TA estimated based on positioning capability to send the uplink message and uplink transmission.

However, due to the error of positioning accuracy, the TA estimated by the terminal may be greater than or less than the actual TA of the terminal, and when the TA estimated by the terminal is too large, the time from the uplink message or uplink transmission sent by the terminal to the network side may be advanced, so that interference is caused to the uplink signal reception or downlink signal transmission of the previous symbol on the network side, and the receiving performance of the network side is affected.

Disclosure of Invention

The embodiment of the application provides a method, a device, equipment and a storage medium for determining uplink TA, which can effectively avoid the situation that a terminal overcompensates TA, so that interference is not caused to the uplink signal or the downlink signal of a previous symbol received by a network side, and the signal receiving performance of the network side is ensured. The technical scheme is as follows:

in one aspect, a method for determining an uplink timing advance TA is provided, which is applied to a terminal, and the method includes:

and determining a first TA according to a TA offset value and a TA pre-estimated value, wherein the TA offset value is used for indicating the offset condition of signal propagation round trip delay between the terminal and a serving cell base station, and the TA pre-estimated value is estimated by the terminal based on positioning capability and is used for signal propagation round trip delay between the terminal and a serving cell satellite.

In another aspect, a method for determining an uplink timing advance TA is provided, which is applied to a serving cell base station, and the method includes:

and sending a TA offset value to a terminal, wherein the TA offset value is used for indicating the terminal to determine a first TA according to the TA offset value.

In another aspect, a device for determining an uplink timing advance TA is provided, where the device includes:

And the determining module is used for determining a first TA according to a TA offset value and a TA predicted value, wherein the TA offset value is used for indicating the offset condition of signal propagation round trip delay between the terminal and the serving cell base station, and the TA predicted value is estimated by the terminal based on positioning capability and is used for signal propagation round trip delay between the terminal and the serving cell satellite.

and the sending module is used for sending a TA offset value to the terminal, wherein the TA offset value is used for indicating the terminal to determine a first TA according to the TA offset value.

In another aspect, a terminal is provided, where the terminal device includes a processor and a memory, where the memory stores at least one instruction, and the at least one instruction is configured to be executed by the processor to implement the method for determining an uplink TA according to any one of the foregoing aspects.

In another aspect, a network device, which may be a serving cell base station, is provided, where the network device includes a processor and a memory, where the memory stores at least one instruction, and the at least one instruction is configured to be executed by the processor to implement the method for determining an uplink TA according to any one of the foregoing aspects.

In another aspect, a computer readable storage medium is provided, where instructions are stored, where the instructions, when executed by a processor, implement the method for determining an upstream TA according to any one of the above aspects.

In another aspect, a computer program product is provided comprising instructions which, when run on a computer, cause the computer to perform the method of determining an upstream TA as described in any of the above aspects.

The beneficial effects that technical scheme that this application embodiment provided include at least:

the TA offset value is introduced in the process of determining the uplink TA by the terminal, so that the situation that the TA is overcompensated by the error of the positioning accuracy of the terminal is avoided, interference is not caused to the uplink signal of the previous symbol received by the network side or the downlink signal transmitted by the network side, and the signal receiving performance of the network side is ensured.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic diagram of an NTN scenario based on a transparent load provided in an exemplary embodiment of the present application;

fig. 2 is a schematic diagram of an NTN scenario based on regenerative loading provided in an exemplary embodiment of the present application;

FIG. 3 is a schematic diagram of timing advance provided by an exemplary embodiment of the present application;

fig. 4 is a flowchart of a random access procedure provided in an exemplary embodiment of the present application;

FIG. 5 is a schematic diagram of a signal propagation round trip delay provided by an exemplary embodiment of the present application;

FIG. 6 is a schematic diagram of timing advance adjustment provided by an exemplary embodiment of the present application;

fig. 7 is a flowchart of a method for determining an uplink TA according to an exemplary embodiment of the present application;

fig. 8 is a flowchart of a communication method based on a first TA according to an exemplary embodiment of the present application;

fig. 9 is a schematic diagram of adjustment of a first TA based on a four-step random access procedure according to an exemplary embodiment of the present application;

fig. 10 is a schematic diagram of adjustment of a first TA based on a two-step random access procedure according to an exemplary embodiment of the present application;

fig. 11 is a flowchart of a communication method based on a first TA according to another exemplary embodiment of the present application;

Fig. 12 is a schematic structural diagram of an uplink TA determining device according to an exemplary embodiment of the present application;

fig. 13 is a schematic structural diagram of an uplink TA determining device according to another exemplary embodiment of the present application;

fig. 14 is a schematic structural diagram of a communication device according to an exemplary embodiment of the present application.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present application more apparent, the embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

Before describing the method for determining the uplink TA provided in the embodiments of the present application in detail, related terms and implementation environments related to the embodiments of the present application will be briefly described.

First, related terms related to the present application will be briefly described.

1、NTN

Currently 3GPP (Third Generation Partnership Project ) is researching NTN technology, which generally provides communication services to terrestrial users by way of satellite communications. Satellite communications have many unique advantages over terrestrial cellular communications. First, satellite communications are not limited by the user region, for example, general land communications cannot cover areas where communication devices cannot be installed, such as oceans, mountains, deserts, etc., or communication coverage is not performed due to rarity of population, while for satellite communications, since one satellite can cover a larger ground, and the satellite can orbit around the earth, theoretically every corner on the earth can be covered by satellite communications. And secondly, satellite communication has great social value. Satellite communication can be covered in remote mountain areas, poor and backward countries or regions with lower cost, so that people in the regions enjoy advanced voice communication and mobile internet technology, and the digital gap between developed regions is reduced, and the development of the regions is promoted. Again, the satellite communication distance is far, and the cost of communication is not obviously increased when the communication distance is increased; and finally, the satellite communication has high stability and is not limited by natural disasters.

Communication satellites are classified into LEO (Low-Earth Orbit) satellites, MEO (Medium-Earth Orbit) satellites, GEO (Geostationary Earth Orbit, geosynchronous Orbit) satellites, HEO (High Elliptical Orbit ) satellites, and the like according to the difference in Orbit heights. LEO and GEO are the main studies at the present stage.

(1)LEO

The low orbit satellite has a height ranging from 500km to 1500km and a corresponding orbit period of about 1.5 hours to 2 hours. The signal propagation delay for single hop communications between users is typically less than 20ms. The maximum satellite visibility time is 20 minutes. The signal propagation distance is short, the link loss is less, and the requirement on the transmitting power of the user terminal is not high.

(2)GEO

Geosynchronous orbit satellites have an orbit height of 35786km and a period of 24 hours around the earth. The signal propagation delay for single hop communications between users is typically 250ms.

In order to ensure the coverage of the satellite and improve the system capacity of the whole satellite communication system, the satellite adopts multiple beams to cover the ground, and one satellite can form tens or hundreds of beams to cover the ground; a satellite beam may cover a ground area of several tens to hundreds of kilometers in diameter.

Currently, there are at least two NTN scenarios: NTN scenes based on transmission load and NTN scenes based on regeneration load. Fig. 1 shows a schematic diagram of an NTN scenario based on a transmission load, and fig. 2 shows a schematic diagram of an NTN scenario based on a regeneration load.

The NTN network consists of the following network elements:

1 or more gateways for connecting satellites and a terrestrial public network.

Feeder Link: links for communication between gateway and satellite

Service Link: link for communication between a terminal and a satellite

Satellite: the functions provided by the system can be divided into transmission forwarding and regeneration forwarding.

Transparent load-only provides the functions of radio frequency filtering, frequency conversion and amplification-only provides transparent forwarding of signals without changing the waveform signals it forwards.

Regeneration payload-in addition to providing the functions of radio frequency filtering, frequency conversion and amplification, demodulation/decoding, routing/conversion, encoding/modulation may also be provided. Which has some or all of the functionality of the base station.

ISL (Inter-satellite links): exist in the NTN scenario of regenerative forwarding.

2. Upload timing advance

An important feature of uplink transmission is that different terminals are orthogonally multiple access in time-frequency, i.e. uplink transmissions from different terminals in the same cell do not interfere with each other.

In order to ensure orthogonality of uplink transmissions, and avoid interference between uplink transmissions from different terminals in the same cell, network devices (e.g., base stations) require substantial alignment of the times at which uplink transmissions from terminals in the same time slot but different frequency domain resources arrive at the network device. Since the network device can correctly decode the uplink transmission sent by the terminal as long as the network device receives the uplink transmission sent by the terminal within the CP (Cyclic Prefix) range, the network device requires that the time when the uplink transmission from the terminal with the same time slot but different frequency domain resources arrives at the network device falls within the CP.

To ensure time synchronization of network devices, the NR supports a mechanism for upstream timing advance. For a terminal, a TA is essentially a slot offset value between receiving a downlink transmission and sending an uplink transmission. The network device can control the time at which the uplink transmissions from the different terminals arrive at the network device by appropriately controlling the TA slot offset value of each terminal. For terminals farther from the network device, the uplink transmission is sent earlier than for terminals nearer to the network device due to the larger signal propagation round trip delay.

Fig. 3 shows a schematic diagram of timing advance, as shown in (a) in fig. 3, when the terminal does not perform uplink timing advance, the time difference of uplink transmission from the terminal of the same time slot but different frequency domain resources reaching the network device is large. And as shown in fig. 3 (b), when the terminal performs uplink timing advance, the times when uplink transmissions from terminals of the same time slot but different frequency domain resources arrive at the network device are substantially aligned.

It should be noted that, as shown in (b) in fig. 3, the uplink clock and the downlink clock of the network device are aligned, and there is an offset between the uplink clock and the downlink clock of the terminal, and the timing advance of different terminals may be different.

The network device may determine the TA value of the terminal by measuring the uplink transmission of the terminal, for example. Further, the network device transmits the TA command to the terminal in the following two ways.

First kind: acquisition of initial TA

In the random access procedure, the network device may determine the TA value of the terminal by measuring the received preamble and transmit it to the terminal through a TAC (Timing Advance Command ) field in the RAR (Random Access Response, random access response).

Second kind: adjustment of RRC connected state TA

Although the terminal and the network device acquire uplink synchronization during the random access procedure, the time when the uplink transmission arrives at the network device may vary. For example, for a terminal in high speed movement, the signal propagation round trip delay between the terminal and the network device may change continuously. Therefore, the terminal needs to continuously update its TA value to maintain uplink synchronization with the network device.

As an example, the network device may use a closed loop mechanism to adjust the TA value. I.e. the network device may determine the TA value of the terminal by measuring its uplink transmission. Thus, the network device can be used to estimate the TA value whenever the terminal has an uplink transmission. In theory, any signal transmitted by the terminal may be used for the network device to measure the TA value, for example, SRS (Sounding Reference Signal ), DMRS (Demodulation Reference Signal, demodulation reference signal), CQI (Channel Quality Indication ), ACK (acknowledgement)/NACK (Non-acknowledgement), PUSCH (Physical Uplink Control Channel, physical uplink shared channel), and the like, which may be used for the network device to measure the TA value.

If the TA value of a certain terminal needs to be corrected, the network device sends a TAC to the terminal, and the terminal is required to adjust the TA value. The TAC may be sent to the terminal through a MAC (Media Access Control ) CE (Control Element).

3. Random access procedure

Referring to fig. 4, the random access procedure may generally include the following four-step procedure.

The first step: the terminal sends an Msg1 to the network device, the Msg1 being a random access preamble sequence (i.e. preamble).

The terminal sends Msg1 to the network device to inform the network device of a random access request, and at the same time, the network device can estimate the transmission delay between itself and the terminal, and calibrate the uplink time according to the transmission delay.

As an example, the information of the resources transmitting Msg1 may be obtained through the resource configuration of RACH (Random Access Channel ). In the Rel-15NR technology, RACH resource configuration information configured for terminal access is defined, including 256 kinds, and a cell may indicate RACH resource configuration information used by itself to a terminal in a system message. Each RACH resource configuration information includes a preamble format, a period, a radio frame offset, a subframe number within a radio frame, a starting symbol within a subframe, a number of PRACH slots within a subframe, a number of PRACH occasions within a PRACH slot, and a PRACH occasion duration. The time, frequency and code information of the PRACH resource can be determined through the information, so that the terminal can send Msg1 on the corresponding PRACH resource according to the RACH resource configuration information indicated by the network equipment.

And a second step of: after detecting the Msg1 sent by the terminal, the network device sends an RAR (Msg 2) to the terminal to inform the terminal of uplink resource information that can be used when sending the next message (Msg 3).

The RAR may include response messages to a plurality of terminals sending the preamble, and the response message to each terminal includes the random access preamble identification field rapid, the resource allocation information of Msg3, the TA information, and the like adopted by each terminal.

Of course, other operations may be performed by the network device in addition to this, such as allocating a temporary RNTI (Radio Network Temporary Identity ) to the terminal, etc., which are not described here too much.

And a third step of: and the terminal receives the RAR and sends the Msg3 to the network equipment on the uplink resource indicated by the RAR.

In some embodiments, the terminal may monitor the PDCCH (Physical Downlink Control Channel ) in a search space within one RAR time window corresponding to the RAR to receive the RAR. The RAR time window may be configured by a higher layer parameter, and configuration information of a search space of the PDCCH may be indicated by a system message.

If the terminal does not receive the RAR sent by the network equipment in the RAR time window, the random access process is considered to be failed. If the terminal receives an RAR and the preamble index in the RAR is the same as the preamble index sent by the terminal, the terminal considers that the RAR is successfully received, and can stop monitoring the RAR at this time, and the terminal sends Msg3 to the network device.

As an example, the Msg3 may carry a terminal specific temporary identity information or a terminal identity from the core network, e.g. the terminal identity may be S-TMSI (Serving-Temporary Mobile Subscriber Identity) or a random number.

Fourth step: after receiving the Msg3, the network device sends an Msg4 to the terminal.

As an example, the Msg4 includes a contention resolution message and includes information of uplink transmission resources allocated to the terminal, and the network device may, for example, carry a unique flag in the Msg4 in the contention resolution mechanism to indicate the terminal that wins the contention. When the terminal receives the Msg4 sent by the base station, it can detect whether the temporary identification information sent by the terminal in the Msg3 is contained in the contention resolution message sent by the network device, if so, it indicates that the random access process of the terminal is successful, otherwise, the random process is considered to be failed, and the terminal needs to initiate the random access process from the first step again.

4. Determination of initial TA in NTN

In NTN, the terminals have positioning capability, and the NTN will support two types of terminals, one is a terminal without initial TA compensation capability, i.e. the terminal does not perform TA compensation when transmitting Msg1 in the random access procedure, and the other is a terminal with initial TA compensation capability, i.e. the terminal uses its own estimated TA to transmit Msg1 in the random access procedure.

The determination method of TA is different for both types of terminals.

First, for terminals that do not have initial TA compensation capability, the network device will broadcast 1 common TA based on the signal propagation round trip delay between the terrestrial reference point and the satellite. When the terminal sends the Msg1, the public TA broadcasted by the network is used for TA compensation, and then the network equipment indicates an exclusive TA value to the terminal in the RAR, so that the terminal can accumulate the broadcasted public TA and the exclusive TA indicated to the terminal in the RAR, and the TA used when the Msg3 is sent is obtained.

As shown in fig. 5, for the NTN scenario of the regenerated load, as shown in (a) of fig. 5, the common ta=2×d0/c, where d0 refers to the distance between the ground reference point and the satellite, and c refers to the light velocity.

For the NTN scenario of the transparent load, as shown in (b) of fig. 5, ta=2 x (d0+d0_f)/c, where d0 refers to the distance between the ground reference point and the satellite, c refers to the speed of light, and d0_f refers to the distance between the satellite and the ground base station.

Next, for a terminal with initial TA compensation capability, its random access procedure is shown in fig. 6.

Specifically, the terminal estimates its own TA based on its own positioning capability, and transmits Msg1 using its own estimated TA.

Further, the network device determines the TA adjustment value of the terminal after receiving the Msg1, and indicates the TA adjustment value to the terminal through the Msg 2. Since the network device does not know the actual signal propagation round trip delay with the terminal at this time, the network device can schedule the Msg3 resource of the terminal according to the maximum uplink scheduling delay.

And then, the terminal adjusts the TA based on the received RAR instruction and sends the Msg3 on the uplink resource scheduled by the network equipment.

Further, after the network device receives the Msg3 of the terminal, the actual signal propagation round trip delay with the terminal can be determined.

It should be noted that, in the random access process, whether the terminal has the initial TA compensation capability or not, the RAR sent by the network device includes a UL grant field for indicating the uplink resource of Msg3. The terminal transmits Msg3 on PUSCH resources indicated by UL grant of the RAR.

Next, an implementation environment related to the embodiments of the present application will be briefly described.

In a conventional NR terrestrial cellular network, a terminal does not estimate TA by itself to perform TA compensation when transmitting a preamble during random access. In NTN, since a mechanism that the terminal compensates for the TA to send the preamble is introduced, if the terminal directly uses the TA estimated based on the positioning capability to send the preamble, the TA estimated by the terminal may be greater or less than the actual TA of the terminal due to the error of the positioning accuracy. If the TA estimated by the terminal is too large, the time when the preamble sent by the terminal reaches the network side is advanced, so that interference is caused to the uplink signal receiving or the downlink signal sending of the previous symbol of the network side, and the receiving performance of the network side is affected.

Also, in the NR system, the TA of the terminal is completely determined and controlled by the network side. In NTN, if the terminal compensates the TA, when the TA estimated by the terminal is too large, the time for the uplink transmission of the terminal to reach the network side will be advanced, so as to interfere the uplink signal reception or downlink signal transmission of the previous symbol at the network side, and affect the receiving performance at the network side.

Therefore, based on the above two cases, in the embodiments of the present application, by introducing the TA offset value, interference caused by the signal sent by the terminal on the signal of the last symbol due to overcompensation of the TA is avoided.

After describing related terms and implementation environments related to the embodiments of the present application, a detailed description will be given below of a method for determining uplink TA according to the embodiments of the present application with reference to the attached drawings.

Fig. 7 is a flowchart of a method for determining an uplink TA according to an exemplary embodiment of the present application, where the method may be applied to a terminal in the NTN scenario shown in fig. 1 or fig. 2, and the method for determining an uplink TA may include at least some of the following:

step 710: and determining a first TA according to the TA offset value and the TA predicted value, wherein the TA offset value is used for indicating the offset condition of signal propagation round trip delay between the terminal and the serving cell base station, and the TA predicted value is estimated by the terminal based on positioning capability.

Wherein, the TA offset value is any one of the following:

(1) Common TA offset value

The common TA offset value is a TA offset value configured by the serving cell base station for a terminal in the serving cell according to a first positioning capability, wherein the first positioning capability is a positioning capability of at least one terminal in the serving cell.

As one example, the serving cell base station may determine the common TA offset value for the serving cell based on the positioning capabilities of any terminal within the serving cell. All terminals in the serving cell then use the common TA offset value in determining that the first TA is. Alternatively, the serving cell base station may determine the common TA offset value for the serving cell based on the positioning capability of the terminal with the lowest positioning capability in the serving cell.

As another example, the serving cell base station determines an average value of the positioning capabilities based on the positioning capabilities of the plurality of terminals within the serving cell, and determines a common TA offset value for the serving cell from the average value. All terminals in the serving cell then use the common TA offset value in determining the first TA.

It should be noted that, the serving cell base station is configured with a common TA offset value for all cells within its coverage area. The common TA offset values configured by different cells may be the same or different, which is not limited in the embodiments of the present application.

In one possible implementation, the TA offset value is sent to the terminal in broadcast form by the serving cell base station. That is, the terminals in the serving cell acquire the common TA offset value through cell broadcast, and the TA offset value used by each terminal in the serving cell when it determines the first TA may be the above-mentioned common TA offset value.

(2) Predefined TA offset value

Wherein the predefined TA offset value is a TA offset value pre-determined from a second positioning capability, the second positioning capability being a positioning capability of the at least one terminal.

The pre-defined TA offset values may be the same or different for terminals with different positioning capabilities. The TA offset value is determined based on the positioning capabilities of the at least one terminal.

As an example, one TA offset value common to all terminals may be predefined based on the positioning capability of a certain terminal or the positioning capability of the terminal with the lowest positioning capability. That is, the TA offset value predefined for each terminal is the same.

As another example, different TA offset values may be defined for terminals with different positioning capabilities according to different positioning capabilities corresponding to the plurality of terminals, that is, the TA offset values predefined for at least one terminal with the same positioning capability are the same.

(3) A proprietary TA offset value.

The dedicated TA offset value is a TA offset value configured by the serving cell base station for the terminal according to a third positioning capability, where the third positioning capability is a positioning capability of the terminal. For each terminal, the serving cell base station configures a TA offset value for each terminal that is most appropriate for the terminal.

In one possible implementation manner, when the terminal sends the preamble in the random access process, the terminal reports its own positioning capability, and the serving cell base station determines the offset condition of signal propagation round trip delay between the terminal and itself based on the positioning capability, so as to determine the special TA offset value of the terminal.

In another possible implementation, the serving cell base station may determine the positioning capability of the terminal by measuring any uplink transmission of the terminal, and determine the terminal-specific TA offset value based on the positioning capability.

It should be understood that the foregoing is for illustrative purposes only and is not intended to be limiting, as the serving cell base station may configure the terminal-specific TA offset value for terminals having different positioning capabilities.

In addition, based on the TA offset value shown above, the serving cell base station may also adjust the TA offset value at any time, and notify the terminal of the adjusted TA offset value.

It should be noted that, the above-mentioned proprietary TA offset value may send the determined TA offset value to the terminal through the TAC field in the RAR during the random access process; or in RRC connection state, transmitting TAC to the terminal through MAC CE to inform the terminal of the determined TA offset value; the terminal may also be informed by other proprietary signaling, broadcasting, etc., which embodiments of the present application do not limit.

The TA estimated value is estimated by the terminal according to the current position of the terminal and first ephemeris information, wherein the first ephemeris information is the ephemeris information of a satellite in a service cell.

Generally, ephemeris information includes information such as a moving track and a moving speed of a satellite, and a position of the satellite at each time can be determined based on the ephemeris information.

It should be noted that, the terminal has positioning capability, and can determine the position of the terminal itself, and in addition, after the terminal establishes a connection with the serving cell base station through the serving cell satellite, the terminal can store the first ephemeris information of the serving cell satellite.

In one possible implementation manner, the implementation process of estimating the TA estimated value according to the current location of the terminal and the first ephemeris information is: the terminal determines the position of the satellite in the service cell according to the first ephemeris information, further determines the first distance between the satellite in the service cell and the position of the satellite in the service cell, and uses the ratio between the first distance and the signal transmission rate as the signal propagation delay between the terminal and the satellite in the service cell.

For a terminal, a TA is essentially a slot offset value between receiving a downlink transmission and sending an uplink transmission. Thus, the TA estimate should reflect the signal propagation round trip delay between the terminal and the serving cell satellite.

For example, the TA estimated value can be determined by the following formula (1).

Wherein TA_SL is the signal propagation round trip delay of the terminal and the satellite in the service cell on the service link, d1 is the first distance between the satellite in the service cell and the current position of the terminal, and v is the signal transmission rate.

As an example, v may also be replaced by the light velocity c.

Based on the above-described embodiment of fig. 7, the first TA is determined according to the TA offset value and the TA pre-estimated value, including the following ways:

mode one: in an NTN scenario based on a regenerative load, a first difference between a TA-predicted value and a TA-offset value is determined, and the first difference is taken as a first TA.

For example, the first TA may be determined by the following equation (2).

TA1＝TA_SL-TA_offset (2)

Wherein TA1 is a first TA, ta_sl is a round trip delay of signal propagation of the terminal and the serving cell satellite on the serving link, and ta_offset is a TA offset value.

Mode two: and in the NTN scene based on the transparent load, when the terminal can obtain a second TA on the feeder link between the serving cell satellite and the serving cell base station, determining the first TA according to the TA predicted value, the TA offset value and the second TA.

In one possible implementation, the implementation procedure for determining the first TA is: and determining a third TA according to the TA predicted value and the second TA, wherein the third TA is the signal propagation round trip delay between the terminal estimated based on the positioning capability and the serving cell base station, and then determining a second difference value between the third TA and the TA offset value, and taking the second difference value as the first TA. .

For example, the first TA may be determined by the following equation (3).

TA1＝TA_SL+TA2-TA_offset (3)

Wherein TA1 is a first TA, ta_sl is a signal propagation round trip delay of the terminal and the serving cell satellite on the serving link, TA2 is a signal propagation round trip delay of the serving cell satellite and the serving cell base station on the feeder link, ta_sl+ta2 represents the third TA, and ta_offset is a TA offset value.

Similarly, the terminal determines the position of the satellite in the service cell according to the first ephemeris information, and further determines a second distance between the satellite in the service cell and the base station in the service cell, wherein the ratio between the second distance and the signal transmission rate is the signal transmission delay between the base station in the service cell and the satellite in the service cell.

For example, TA2 can be determined by the following formula (4).

Wherein ta_fl is the signal propagation round trip delay of the serving cell base station and the serving cell satellite on the feeder link, that is, TA2, d2 is the second distance between the serving cell satellite and the serving cell base station, and v is the signal transmission rate.

As an example, v may also be replaced by the light velocity c.

Mode three: in an NTN scene based on a transparent load, if a terminal cannot obtain a second TA on a feeder link between a serving cell satellite and a serving cell base station, determining a first difference value between a TA predicted value and a TA offset value, and taking the first difference value as the first TA.

For example, the first TA may be determined by the above equation (2).

In summary, in the embodiment of the present application, the TA offset value is introduced in the process of determining the uplink TA by the terminal, so that the situation that the terminal overcompensates the TA due to the error of the positioning accuracy can be avoided, so that interference is not caused to the network side in receiving the uplink signal of the previous symbol or transmitting the downlink signal, and the signal receiving performance of the network side is ensured.

Based on the embodiment shown in fig. 7, after determining the first TA, the terminal may use the first TA to communicate with the serving cell base station.

As an example, please refer to fig. 8, fig. 8 is a flowchart illustrating an uplink communication method based on the first TA according to an exemplary embodiment of the present application, the method may be applied in the NTN scenario, and the uplink communication method may include at least some of the following:

Step 810: and the terminal determines a first TA according to the TA offset value and the TA predicted value.

The TA offset value is used for indicating the offset condition of signal propagation round trip delay between the terminal and the serving cell base station, and the TA estimated value is estimated by the terminal based on positioning capability.

The TA offset value may be a predefined TA offset value, or may be a public TA offset value or a proprietary TA offset value that is sent by the serving cell base station to the terminal, which is not limited in this embodiment of the present application.

Step 820: and the terminal uses the first TA to send an uplink message to the serving cell base station, wherein the uplink message comprises a first message Msg1 or MsgA in a random access process.

Step 830: the serving cell base station receives an uplink message sent by the terminal by using the first TA.

Next, the foregoing steps 820, 830 and the subsequent random access procedure will be further explained with reference to the drawings of the embodiments of the present application.

In the four-step random access scenario, the terminal uses the first TA to send Msg1 to the serving cell base station, and the procedure of adjusting the first TA is shown in fig. 9.

After determining a first TA according to the TA offset value and the TA predicted value, the terminal uses the first TA to send Msg1 to the serving cell base station so as to inform the serving cell base station of a random access request, and simultaneously enables the serving cell base station to estimate the transmission delay between the base station and the terminal and calibrate the first TA.

After receiving the Msg1 sent by the terminal, the serving cell base station sends an RAR (Msg 2) to the terminal to inform the terminal of uplink resource information that can be used when sending the next message (Msg 3), and meanwhile, the adjustment amount of the first TA is carried in the RAR.

It should be noted that, if the times of uplink transmissions from terminals of the same time slot but different frequency domain resources reaching the serving cell base station are all substantially aligned, the adjustment amount of the first TA may be 0. If there is a deviation in the time of uplink transmission from the terminal of the same time slot but different frequency domain resources to the serving cell base station, the adjustment amount of the first TA of the terminal is informed in the Msg 2.

And the terminal receives the RAR and uses the adjusted uplink TA to send the Msg3 to the serving cell base station on the uplink resource indicated by the RAR.

When the adjustment amount of the first TA is 0, the adjusted uplink TA is the same as the first TA. And when the adjustment amount of the first TA is not 0, determining the adjusted uplink TA according to the first TA and the adjustment amount of the first TA.

As an example, the adjusted upstream TA may be determined according to the following equation (5).

TA＝TA1+Δ (5)

Wherein, TA is the adjusted uplink TA, TA1 is the first TA determined by the terminal, and Δ is the adjustment amount of the first TA.

After receiving the Msg3, the serving cell base station knows the adjusted uplink TA of the terminal and sends the Msg4 to the terminal. After the random access is successful, the serving cell base station receives any uplink transmission sent by the terminal by using the adjusted uplink TA.

In the two-step random access scenario, the terminal uses the first TA to send MsgA to the serving cell base station, and the procedure of adjusting the first TA is shown in fig. 10.

After determining a first TA according to the TA offset value and the TA predicted value, the terminal uses the first TA to send an MsgA to the serving cell base station so as to inform the serving cell base station of a random access request, and simultaneously enables the serving cell base station to estimate the transmission delay between the base station and the terminal and calibrate the first TA.

After receiving the MsgA sent by the terminal, the serving cell base station sends an MsgB to the terminal to inform the terminal of uplink resource information that can be used after the random access is successful, and meanwhile, the MsgB carries the adjustment amount of the first TA.

It should be noted that, if the times of uplink transmissions from terminals of the same time slot but different frequency domain resources reaching the serving cell base station are all substantially aligned, the adjustment amount of the first TA may be 0. If there is a deviation in the time when the uplink transmission from the terminal of the same time slot but different frequency domain resources arrives at the serving cell base station, the adjustment amount of the first TA of the terminal is informed in the MsgB.

And the terminal receives the MsgB and adjusts the first TA based on the adjustment amount of the first TA carried by the MsgB.

In summary, in the embodiment of the present application, the terminal determines the first TA for sending the uplink message according to the introduced TA offset value, so as to avoid the situation that the terminal overcompensates the TA due to the error of the positioning accuracy. In addition, after the random access is completed, the terminal may calibrate the first TA according to the indication of the serving cell base station. The terminal determines the first TA and recalibrates the serving cell base station, so that the terminal can not interfere with the uplink signal or the downlink signal of the previous symbol received by the network side when transmitting the uplink message by using the first TA, and the signal receiving performance of the network side is ensured.

Fig. 11 is a flowchart illustrating a first TA-based communication method according to another exemplary embodiment of the present application, where the method may be applied in an NTN scenario, and the uplink communication method may include at least some of the following:

step 1110: and the terminal determines a first TA according to the TA offset value and the TA predicted value.

Step 1120: in the RRC connected state, the terminal transmits uplink transmission to the serving cell base station using the first TA.

Wherein, the uplink transmission includes at least one of PUSCH (Physical Uplink Shared Channel ), PUCCH (Physical Uplink Control Channel, physical uplink control channel) and SR (Scheduling Request ).

Step 1130: the serving cell base station receives the uplink transmission sent by the terminal by using the first TA.

The service cell base station monitors uplink transmission from a terminal side in real time, and obtains a first TA used by a certain terminal by receiving any uplink transmission of the terminal. In addition, the serving cell base station may further determine an adjustment value for the first TA of the terminal according to the first TA. The embodiments of the present application are not limited in this regard.

In summary, in the embodiment of the present application, the TA offset value is introduced in the process of determining the uplink TA by the terminal, so that the situation that the terminal overcompensates the TA due to the error of positioning accuracy is avoided, and therefore, interference is not caused to the uplink signal or the downlink signal sent by the network side when the network side receives the previous symbol, and the signal receiving performance of the network side is ensured.

Fig. 12 is a schematic structural diagram of an uplink TA determining apparatus according to an exemplary embodiment, where the apparatus 1200 may be configured in a terminal, and the apparatus 1200 includes:

a determining module 1210 is configured to determine a first TA according to a TA offset value and a TA pre-determined value, where the TA offset value is used to indicate an offset condition of a signal propagation round trip delay between the device and a serving cell base station, and the TA pre-determined value is a signal propagation round trip delay between the device and a serving cell satellite estimated by the device based on a positioning capability.

Optionally, the TA offset value is any one of the following:

a public TA offset value, wherein the public TA offset value is configured by a serving cell base station for a serving cell where the device is located according to a first positioning capability, and the first positioning capability is the positioning capability of at least one terminal in the serving cell;

a predefined TA offset value, the predefined TA offset value being a TA offset value pre-configured for the device according to a second positioning capability, the second positioning capability being a positioning capability of the at least one terminal;

and the special TA offset value is configured by the serving cell base station for the device according to a third positioning capability, wherein the third positioning capability is the positioning capability of the device.

Optionally, the TA pre-estimate is estimated by the device based on the current location of the device and the first ephemeris information;

wherein the first ephemeris information is ephemeris information of a serving cell satellite.

Optionally, in a case where the apparatus is in a non-terrestrial communication network NTN scenario based on regenerative loading, or in a case where the apparatus is in a NTN scenario based on transparent loading, and a second TA cannot be acquired, the second TA is a TA on a feeder link between a serving cell satellite and a serving cell base station;

a determining module 1210 for:

a first difference between the TA pre-estimate and the TA offset value is determined, and the first difference is determined to be the first TA.

Optionally, in the case that the apparatus is in an NTN scenario based on a transparent load;

the determining module 1210 further includes:

an acquisition sub-module 1211 for acquiring a second TA on the feeder link between the serving cell satellite and the serving cell base station;

a determining submodule 1212 is configured to determine a first TA according to the TA pre-estimate, the TA offset value, and the second TA.

Optionally, determining sub-module 1212 includes:

a first determining subunit, configured to determine a third TA according to the TA predicted value and the second TA, where the third TA is a signal propagation round trip delay between the apparatus and the serving cell base station estimated by the apparatus based on the positioning capability;

And the second determining subunit is used for determining a second difference value between the third TA and the TA offset value, and taking the second difference value as the first TA.

Optionally, the apparatus 1200 further includes:

and the sending module is used for sending an uplink message by using the first TA, wherein the uplink message comprises Msg1 or MsgA in the random access process.

Optionally, the sending module is further configured to:

and sending uplink transmission by using the first TA, wherein the uplink transmission comprises at least one of a physical uplink control channel (PUSCH), a Physical Uplink Control Channel (PUCCH) and a Scheduling Request (SR).

In the embodiment of the application, the accuracy of determining the uplink TA by the terminal is improved by introducing the TA offset value, so that the situation that the terminal overcompensates the TA due to the error of the positioning accuracy can be avoided, interference can not be caused to the uplink signal or the downlink signal of the previous symbol received by the network side, and the signal receiving performance of the network side is ensured.

Fig. 13 is a schematic structural diagram of an uplink TA determining apparatus according to another exemplary embodiment, where the apparatus 1300 may be configured in a network device (such as a serving cell base station), and the apparatus 1300 includes:

and a sending module 1310, configured to send a TA offset value to the terminal, where the TA offset value is used to instruct the terminal to determine the first TA according to the TA offset value.

Optionally, the sending module 1310 is further configured to:

transmitting a public TA offset value to the terminal, wherein the public TA offset value is configured for a service cell where the terminal is located according to a first positioning capability, and the first positioning capability is the positioning capability of at least one terminal in the service cell;

or alternatively, the process may be performed,

and sending a proprietary TA offset value to the terminal, wherein the proprietary TA offset value is configured for the terminal according to a third positioning capability, and the third positioning capability is the positioning capability of the terminal.

Optionally, the apparatus 1300 further includes:

and the receiving module is used for receiving an uplink message sent by the terminal by using the first TA, wherein the uplink message comprises a first message Msg1 or MsgA in a random access process.

Optionally, the receiving module is further configured to:

the receiving terminal uses the first TA to send uplink transmission, wherein the uplink transmission comprises at least one of a physical uplink control channel PUSCH, a physical uplink control channel PUCCH and a scheduling request SR.

In the embodiment of the application, the service cell base station configures the TA offset value for the terminal, so that the situation that the terminal overcompensates the TA due to the error of positioning precision is avoided, interference is not caused to the service cell base station in receiving the uplink signal of the previous symbol or transmitting the downlink signal, and the signal receiving performance of the service cell base station is ensured.

Fig. 14 shows a schematic structural diagram of a communication device provided in an exemplary embodiment of the present application, where the communication device may be a terminal and a serving cell base station in the embodiment of the present application. The terminal comprises: processor 1401, receiver 1402, transmitter 1403, memory 1404 and bus 1405.

The processor 1401 includes one or more processing cores, and the processor 1401 executes various functional applications and information processing by running software programs and modules.

The receiver 1402 and the transmitter 1403 may be implemented as one communication component, which may be a communication chip.

The memory 1404 is connected to the processor 1401 by a bus 1405.

The memory 1404 may be used to store at least one instruction that the processor 1401 is configured to execute to implement the various steps performed by the terminal and serving cell base station in the various method embodiments described above.

Further, memory 1404 may be implemented by any type or combination of volatile or nonvolatile storage devices including, but not limited to: magnetic or optical disks, EEPROMs (Electrically Erasable Programmable Read Only Memory ), EPROMs (Erasable Programmable Read-Only Memory, erasable programmable Read Only Memory), SRAMs (Static Random Access Memory ), ROMs (Read Only Memory), magnetic Memory, flash Memory, PROM (Programmable Read-Only Memory, programmable Read Only Memory).

The application provides a computer readable storage medium, wherein at least one instruction is stored in the storage medium, and the at least one instruction is loaded and executed by the processor to implement the method for determining the uplink TA provided by each method embodiment.

The present application also provides a computer program product, which when run on a computer, causes the computer to execute the method for determining an uplink TA provided by the above method embodiments.

Those skilled in the art will appreciate that in one or more of the examples described above, the functions described in the embodiments of the present application may be implemented in hardware, software, firmware, or any combination thereof. When implemented in software, these functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a general purpose or special purpose computer.

The foregoing description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, since it is intended that all modifications, equivalents, improvements, etc. that fall within the spirit and scope of the invention.

Claims

The method for determining the uplink timing advance TA is characterized by being applied to a terminal, and comprises the following steps:

and determining a first TA according to a TA offset value and a TA pre-estimated value, wherein the TA offset value is used for indicating the offset condition of signal propagation round trip delay between the terminal and a serving cell base station, and the TA pre-estimated value is estimated by the terminal based on positioning capability and is used for signal propagation round trip delay between the terminal and a serving cell satellite.
The method of claim 1, wherein the TA offset value is any one of:

a public TA offset value, wherein the public TA offset value is configured by the serving cell base station for a serving cell where the terminal is located according to a first positioning capability, and the first positioning capability is the positioning capability of at least one terminal in the serving cell;

a predefined TA offset value, the predefined TA offset value being a TA offset value pre-configured for the terminal according to a second positioning capability, the second positioning capability being a positioning capability of at least one terminal;

and the special TA offset value is configured for the terminal according to a third positioning capability by the serving cell base station, wherein the third positioning capability is the positioning capability of the terminal.
The method of claim 1, wherein the TA pre-estimate is estimated by the terminal based on a current location of the terminal and first ephemeris information;

wherein the first ephemeris information is ephemeris information of the serving cell satellite.
The method of claim 1, wherein the terminal is in a non-terrestrial communication network NTN scenario based on regenerative loading, or wherein the terminal is in a NTN scenario based on transparent loading and is unable to acquire a second TA on a feeder link between the serving cell satellite and the serving cell base station;

the determining the first TA according to the TA offset value and the TA pre-estimated value includes:

and determining a first difference value between the TA predicted value and the TA offset value, and taking the first difference value as the first TA.
The method of claim 1, wherein the terminal is located in a transparent load based NTN scenario;

the determining the first TA according to the TA offset value and the TA pre-estimated value further includes:

acquiring a second TA on a feeder link between the serving cell satellite and the serving cell base station;

and determining the first TA according to the TA predicted value, the TA offset value and the second TA.
The method of claim 5, wherein the determining a first TA based on the TA pre-estimate, the TA offset value, and the second TA comprises:

determining a third TA according to the TA predicted value and the second TA, wherein the third TA is signal propagation round trip delay between the terminal estimated by the terminal based on positioning capability and the serving cell base station;

and determining a second difference value between the third TA and the TA offset value, and taking the second difference value as the first TA.
The method according to claim 1, wherein the method further comprises:

and sending an uplink message by using the first TA, wherein the uplink message comprises a first message Msg1 or MsgA in a random access process.
The method of claim 7, wherein the method further comprises:

and sending uplink transmission by using the first TA, wherein the uplink transmission comprises at least one of a physical uplink control channel (PUSCH), a Physical Uplink Control Channel (PUCCH) and a Scheduling Request (SR).
A method for determining an uplink timing advance TA, which is applied to a serving cell base station, the method comprising:

and sending a TA offset value to a terminal, wherein the TA offset value is used for indicating the terminal to determine a first TA according to the TA offset value.
The method of claim 9, wherein the sending the TA offset value to the terminal comprises:

transmitting a public TA offset value to the terminal, wherein the public TA offset value is configured by the serving cell base station for a serving cell where the terminal is located according to a first positioning capability, and the first positioning capability is the positioning capability of at least one terminal in the serving cell;

or alternatively, the process may be performed,

and sending a proprietary TA offset value to the terminal, wherein the proprietary TA offset value is configured by the serving cell base station for the terminal according to a third positioning capability, and the third positioning capability is the positioning capability of the terminal.
The method according to claim 9, wherein the method further comprises:

and receiving an uplink message sent by the terminal by using the first TA, wherein the uplink message comprises a first message Msg1 or MsgA in a random access process.
The method of claim 11, wherein the method further comprises:

and receiving the uplink transmission sent by the terminal by using the first TA, wherein the uplink transmission comprises at least one of a physical uplink control channel (PUSCH), a Physical Uplink Control Channel (PUCCH) and a Scheduling Request (SR).
An apparatus for determining an uplink timing advance TA, the apparatus comprising:

and the determining module is used for determining a first TA according to a TA offset value and a TA pre-estimated value, wherein the TA offset value is used for indicating the offset condition of signal propagation round trip delay between the device and the serving cell base station, and the TA pre-estimated value is the signal propagation round trip delay between the device and the serving cell satellite estimated by the device based on positioning capability.
The apparatus of claim 13, wherein the TA offset value is any one of:

a public TA offset value, wherein the public TA offset value is configured by the serving cell base station for a serving cell where the device is located according to a first positioning capability, and the first positioning capability is the positioning capability of at least one terminal in the serving cell;

a predefined TA offset value, the predefined TA offset value being a TA offset value pre-configured for the apparatus according to a second positioning capability, the second positioning capability being a positioning capability of at least one terminal;

and the special TA offset value is configured for the device according to a third positioning capability by the serving cell base station, wherein the third positioning capability is the positioning capability of the device.
The apparatus of claim 13 wherein the TA pre-estimate is estimated by the apparatus based on a current location of the apparatus and first ephemeris information;

wherein the first ephemeris information is ephemeris information of the serving cell satellite.
The apparatus of claim 13, wherein the apparatus is located in a non-terrestrial communication network, NTN, scenario based on regenerative loading, or wherein the apparatus is located in a NTN scenario based on transparent loading, and wherein a second TA is not available, the second TA being a TA on a feeder link between the serving cell satellite and the serving cell base station;

the determining module is used for:

and determining a difference value between the TA predicted value and the TA offset value, and taking the difference value as the first TA.
The apparatus of claim 13, wherein the apparatus is located in a payload-based NTN scenario;

the determining module further includes:

an acquisition sub-module, configured to acquire a second TA on a feeder link between the serving cell satellite and the serving cell base station;

and the determining submodule is used for determining a first TA according to the TA predicted value, the TA offset value and the second TA.
The apparatus of claim 17, wherein the determination submodule comprises:

a first determining subunit, configured to determine a third TA according to the TA pre-estimation value and the second TA, where the third TA is a signal propagation round trip delay between the apparatus and the serving cell base station estimated by the apparatus based on positioning capability;

and a second determining subunit, configured to determine a second difference between the third TA and the TA offset value, and take the second difference as the first TA.
The apparatus of claim 13, wherein the apparatus further comprises:

and the sending module is used for sending an uplink message by using the first TA, wherein the uplink message comprises a first message Msg1 or MsgA in a random access process.
The apparatus of claim 19, wherein the means for transmitting is further configured to:

and sending uplink transmission by using the first TA, wherein the uplink transmission comprises at least one of a physical uplink control channel (PUSCH), a Physical Uplink Control Channel (PUCCH) and a Scheduling Request (SR).
An apparatus for determining an uplink timing advance TA, the apparatus comprising:

and the sending module is used for sending a TA offset value to the terminal, wherein the TA offset value is used for indicating the terminal to determine a first TA according to the TA offset value.
The apparatus of claim 21, wherein the transmitting module is further configured to:

transmitting a public TA offset value to the terminal, wherein the public TA offset value is configured for a service cell where the terminal is located according to a first positioning capability, and the first positioning capability is the positioning capability of at least one terminal in the service cell;

or alternatively, the process may be performed,

and sending a proprietary TA offset value to the terminal, wherein the proprietary TA offset value is configured for the terminal according to a third positioning capability, and the third positioning capability is the positioning capability of the terminal.
The apparatus of claim 21, wherein the apparatus further comprises:

and the receiving module is used for receiving an uplink message sent by the terminal by using the first TA, wherein the uplink message comprises a first message Msg1 or MsgA in a random access process.
The apparatus of claim 23, wherein the receiving module is further configured to:

and receiving the uplink transmission sent by the terminal by using the first TA, wherein the uplink transmission comprises at least one of a physical uplink control channel (PUSCH), a Physical Uplink Control Channel (PUCCH) and a Scheduling Request (SR).
A terminal comprising a processor and a memory, the memory storing at least one instruction for execution by the processor to perform the steps of the method of any of claims 1-8.
A network device comprising a processor and a memory storing at least one instruction for execution by the processor to implement the steps of the method of any one of claims 9-12.
A computer readable storage medium having instructions stored thereon, which when executed by a processor, implement the steps of the method of any of claims 1-8.
A computer readable storage medium having instructions stored thereon, which when executed by a processor, implement the steps of the method of any of claims 9-12.