CN111491363B

CN111491363B - Signal sending and processing method and device

Info

Publication number: CN111491363B
Application number: CN202010165824.XA
Authority: CN
Inventors: 王新玲; 李长庚; 李华栋; 高珂增; 杨芸霞; 鲁志兵
Original assignee: Hytera Communications Corp Ltd
Current assignee: Hytera Communications Corp Ltd
Priority date: 2020-03-11
Filing date: 2020-03-11
Publication date: 2022-05-17
Anticipated expiration: 2040-03-11
Also published as: WO2021179738A1; CN111491363A; CN113766627A; CN113766627B

Abstract

According to the signal sending and processing method and device, the terminal estimates the starting time of the downlink time sequence unit X in the downlink time sequence unit N, further estimates the starting time of the uplink time sequence unit X, and sends the uplink time sequence unit X at the starting time of the uplink time sequence unit X, or under the condition that the downlink time sequence unit X is received, the starting time of sending the uplink time sequence unit X is calculated according to the uplink receiving delay and the starting time of the downlink time sequence unit X, and the uplink time sequence unit X is sent at the starting time of sending the uplink time sequence unit X, so that the aim of aligning uplink time sequence with downlink time sequence is fulfilled.

Description

Signal sending and processing method and device

Technical Field

The present application relates to the field of electronic information, and in particular, to a method and an apparatus for transmitting and processing a signal.

Background

Fig. 1a illustrates a satellite communication system comprising a terminal 101, a base station 102, and a satellite 103. The satellite is used for communication relay between the terminal and the base station, that is, in uplink communication (as shown by a solid arrow in fig. 1 a), the terminal sends uplink data to the satellite, and after relay, sends the uplink data to the base station. In downlink communication (as shown by the dotted arrow in fig. 1 a), the base station transmits downlink data to the satellite, and after relaying, transmits the downlink data to the terminal. Thereby, data communication between the terminal and the base station is completed. The satellite relay long-distance transmission brings large RTT (Round-Trip time), and the RTT varies with the satellite movement.

Specifically, as shown in fig. 1b, the base station downlink timing is used for the base station to transmit downlink data. Base station uplink timing for base station uplink data (aligned with downlink timing). And the base station uplink receiving time sequence is used for the base station to receive the uplink data sent by the terminal. And the terminal uplink time sequence is used for the terminal to send uplink data. And the terminal downlink time sequence is used for the terminal to receive downlink data. In fig. 1b, the number is the number of a time series unit in each time series.

The distance between the satellite and the base station (d 0_ F shown in fig. 1 a) and the distance between the satellite and the terminal (d 0 shown in fig. 1 a) are long, so a large RTT is generated during the data communication. This may cause a delay RTT in data interaction between the base station and the terminal. As shown in fig. 1b, when the base station sends downlink data in the downlink time sequence unit with number K, the terminal receives the downlink data after time TX because RTT exists, where TX is downlink reception delay, and the terminal sends uplink data to the base station using the time sequence unit K, and the base station receives the uplink data after TY because RTT exists. Obviously, at this time, the timing unit of the uplink data received by the base station and the timing unit of the downlink data sent by the base station cannot be aligned, which increases the complexity of the uplink data demodulation of the base station.

Disclosure of Invention

The application provides a method and a device for sending and processing signals, aiming at realizing the alignment of an uplink time sequence and a downlink time sequence of a base station.

In order to achieve the above object, the present application provides the following technical solutions:

a signal sending method is applied to a terminal and comprises the following steps:

estimating the starting time of a downlink time sequence unit X of the terminal in a downlink time sequence unit N, wherein the downlink time sequence unit X is a downlink time sequence unit after the absolute time of the downlink time sequence unit N;

acquiring the starting time of an uplink time sequence unit X of the terminal based on the starting time of the downlink time sequence unit X;

and sending the uplink time sequence unit X at the starting time of the uplink time sequence unit X.

Optionally, the obtaining the starting time of the uplink timing unit X of the terminal based on the starting time of the downlink timing unit X includes:

acquiring a first time according to the starting time of the downlink time sequence unit X, wherein the first time is the time when a signal received by the terminal at the starting time of the downlink time sequence unit X is transmitted from a base station to a satellite;

acquiring a second moment according to the first moment, wherein the second moment is the moment when the base station receives the uplink time sequence unit X sent by the satellite;

acquiring a third time according to the second time, wherein the third time is the time when the uplink time sequence unit X sent by the terminal reaches the satellite;

and calculating the starting time of the uplink time sequence unit X of the terminal according to the third time.

Optionally, the obtaining a first time according to the starting time of the downlink timing unit X includes:

estimating a first position according to ephemeris information of a satellite, wherein the first position is the position of the satellite at the starting time of a downlink time sequence unit X of the terminal;

calculating a first time length, wherein the first time length is the time length of a signal transmitted from the first position to the position of the terminal;

and calculating the difference between the starting time of the downlink time sequence unit X and the first duration to obtain the first time.

Optionally, after obtaining the first time, the method further includes:

correcting the first time by the following iterative process:

and calculating the difference between the initial time of the downlink timing sequence unit X and the corrected first time to obtain the corrected first time.

Optionally, the obtaining a second time according to the first time includes:

estimating the position of the satellite at the first moment according to ephemeris information of the satellite;

calculating a second time length according to the position of the satellite at the first moment and the position of the base station, wherein the second time length is the time length from the transmission of the signal from the base station to the position of the satellite at the first moment;

taking the difference between the first time and the second time as the time when the base station sends the downlink time sequence unit X to the satellite;

and taking the time when the base station transmits the downlink time sequence unit X to the satellite as the second time.

Optionally, the obtaining a third time according to the second time includes:

and acquiring a third moment according to the second moment, and correcting the third moment.

Optionally, the calculating a starting time of the uplink timing unit X of the terminal according to the third time includes:

estimating the position of the satellite at the third moment according to the ephemeris information of the satellite;

calculating a third time length according to the position of the satellite at the third moment and the position of the terminal, wherein the third time length is the time length from the transmission of the signal from the position of the terminal to the position of the satellite at the third moment;

and taking the difference between the third time and the third duration as the starting time of the uplink timing unit X of the terminal.

Optionally, estimating, in the downlink timing unit N, a starting time of the downlink timing unit X of the terminal includes:

and delaying the starting time of the downlink time sequence unit N by a first target time length to obtain the starting time of the downlink time sequence unit X, wherein the first target time length is determined according to the interval time length between the downlink time sequence unit X and the downlink time sequence unit N and the CRS time delay change rate of the downlink time sequence unit N.

Optionally, a difference between X and N is greater than or equal to m, where m is a ratio of a preset duration to a length of a time sequence unit, and is a value obtained by rounding up.

Optionally, receiving downlink scheduling data PDSCH data in a downlink timing unit X;

the method further comprises the following steps: transmitting PUCCH feedback data in an uplink timing unit X + K1, the K1 satisfying: k1 Tslot > RTTm + K1 Tslot, where RTTm is the maximum time delay of the system, Tslot is a time sequence unit, and K1 is the number of time sequence units occupied by the terminal processing time length;

alternatively, the first and second electrodes may be,

receiving uplink scheduling data PDCCH data in the downlink time sequence unit X;

the method further comprises the following steps:

transmitting PUSCH data in an uplink timing unit X + K2, the K2 satisfying: k2 Tslot > RTTm + K2 Tslot, K2 is the number of time sequence units occupied by the terminal processing time length.

Optionally, the K1 and the K2 are sent to the terminal by a base station.

acquiring uplink receiving delay, wherein the uplink receiving delay is Z times of the length of a time sequence unit, Z is greater than or equal to a preset numerical value, and the preset numerical value is determined according to the maximum transmission round trip RRTm of a system and the processing capacity of the terminal;

under the condition of receiving a downlink time sequence unit X, calculating the starting time of sending the uplink time sequence unit X according to the uplink receiving delay and the starting time of the downlink time sequence unit X;

and transmitting the uplink timing unit X at the starting time of transmitting the uplink timing unit X.

Optionally, the calculating the starting time of sending the uplink timing unit X according to the uplink receiving delay and the starting time of the downlink timing unit X includes:

acquiring a first moment according to the starting moment of the terminal in the downlink time sequence unit X, wherein the first moment is the moment when a signal received by the terminal at the starting moment of the downlink time sequence unit X is transmitted from a base station to a satellite;

acquiring a second moment according to the first moment, wherein the second moment is the moment when the base station sends the downlink time sequence unit X to the satellite;

taking the sum of the second time and the uplink receiving delay as a third time, wherein the third time is the time when the base station receives the uplink time sequence unit X sent by the satellite;

acquiring a fourth time according to the third time, wherein the fourth time is the time when the uplink time sequence unit X sent by the terminal reaches the satellite;

and acquiring the starting time of the uplink time sequence unit X according to the fourth time.

Optionally, the obtaining a first time according to the starting time of the terminal in the downlink timing unit X includes:

calculating a first position according to ephemeris information of a satellite, wherein the first position is the position of the satellite at the starting moment of the downlink time sequence unit X;

calculating a first time length according to the first position and the position of the terminal, wherein the first time length is the time length of a signal transmitted from the first position to the position of the terminal;

and calculating the difference between the starting time of the downlink timing unit X and the first duration to obtain the first time.

Optionally, after obtaining the first time, the method further includes:

correcting the first time by the following iterative process:

and calculating the difference between the starting time of the downlink timing sequence unit X and the corrected first time to obtain the corrected first time.

Optionally, the obtaining a fourth time according to the third time includes:

and acquiring the fourth moment according to the third moment, and correcting the fourth moment.

Optionally, the obtaining the starting time of sending the uplink timing unit X according to the fourth time includes:

calculating the position of the satellite at the fourth moment according to the ephemeris information of the satellite;

calculating a second time length according to the position of the satellite at the fourth moment and the position of the terminal, wherein the second time length is the time length from the transmission of the signal from the position of the terminal to the position of the satellite at the fourth moment;

and calculating the difference between the fourth time and the second time length to obtain the starting time of the uplink timing unit X.

A signal processing method is applied to a base station and comprises the following steps:

and after the downlink time sequence unit X is sent, delaying uplink receiving delay, and receiving the uplink time sequence unit X, wherein the uplink receiving delay is Z times of the length of the time sequence unit, Z is greater than or equal to a preset numerical value, and the preset numerical value is determined according to the maximum transmission round trip RRTm of the system and the processing capacity of the terminal.

A terminal, comprising:

a processor and a memory;

the memory is used for storing an application program, and the processor is used for running the application program so as to realize the signal transmission method.

A terminal, comprising:

a processor and a memory;

A base station, comprising:

a processor and a memory;

the memory is used for storing an application program, and the processor is used for running the application program so as to realize the signal processing method.

According to the technical scheme, the terminal estimates the starting time of a downlink time sequence unit X in a downlink time sequence unit N, further estimates the starting time of an uplink time sequence unit X, and sends the uplink time sequence unit X at the starting time of the uplink time sequence unit X, or calculates the starting time of sending the uplink time sequence unit X according to an uplink receiving delay and the starting time of the downlink time sequence unit X under the condition of receiving the downlink time sequence unit X, and sends the uplink time sequence unit X at the starting time of sending the uplink time sequence unit X, so that the aim of aligning uplink time sequence and downlink time sequence is fulfilled.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1a is an exemplary diagram of a satellite communication system;

FIG. 1b is an exemplary diagram of a timing sequence for a satellite communication system;

fig. 2 is a flowchart of a signal transmission method disclosed in an embodiment of the present application;

fig. 3 is a schematic diagram illustrating a principle that a terminal acquires a start time of an uplink timing unit X according to an embodiment of the present application;

fig. 4 is an exemplary diagram illustrating an advantageous effect of a signal transmission method disclosed in an embodiment of the present application;

fig. 5 is a diagram illustrating still another example of the advantageous effects of the signal transmission method disclosed in the embodiment of the present application;

fig. 6 is a diagram illustrating still another example of the advantageous effects of the signal transmission method disclosed in the embodiment of the present application;

fig. 7 is a flowchart of another signal transmission method disclosed in an embodiment of the present application;

fig. 8 is a flowchart of another signal transmission method disclosed in the embodiment of the present application;

fig. 9 is a diagram illustrating still another example of the advantageous effects of the signal transmission method disclosed in the embodiment of the present application;

fig. 10 is a schematic structural diagram of an apparatus disclosed in an embodiment of the present application.

Detailed Description

The application can be applied in the application scenario illustrated in fig. 1 a. In the following embodiments of the present application, a terminal and a base station transmit and receive data according to a timing sequence, where a timing sequence unit may be a slot (slot) or a subframe, and a timing sequence is a plurality of sequentially arranged timing sequence units. The time series unit number may be expressed by a natural number: 1. 2, …, K, … K + 1. The time sequence unit number can also be expressed in a traditional 5G cyclic number manner, that is, the cyclic number includes three levels of system frame, subframe and time slot, each system frame is 10ms, the number range of the system frame is 0-1024, one system frame includes 10 subframes, the number range of the subframe is 0-9, the number of the time slot included in one subframe depends on the subcarrier spacing, as shown in table 1, it is assumed that the subcarrier spacing is 120KHz, and the number range of the time slot is 0-79. The addition and subtraction of the time sequence unit number also adopts a cyclic numbering mode, for example, the time sequence unit N is: system frame 1023 slot 79, then timing unit N +1 is: system frame 0 time slot 0, timing unit N-1 is: system frame 1023 slots 78 and so on. The number of the time-series unit described in the following example may be any of the above.

TABLE 1

Subcarrier spacing	Number of time slots/system frame	Number of slots/subframe	Duration/time slot
				15KHz	10	1	1ms
30KHz	20	2	0.5ms
				60KHz	40	4	0.25ms
120KHz	80	8	0.125ms
				240KHz	160	16	0.625ms

It should be noted that the terminal in the embodiment of the present application may be a mobile phone or other communication devices.

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Fig. 2 is a flowchart of a signal sending method according to an embodiment of the present application, which may specifically include the following steps:

s201: the terminal estimates the start time T1 of the downlink timing unit X of the terminal in the downlink timing unit N.

The downlink timing unit X is a downlink timing unit after the absolute time of the downlink timing unit N.

Specifically, the starting time of the downlink timing unit X is obtained by delaying the starting time of the downlink timing unit N by the first target duration.

Further, the terminal determines the first target time duration according to an interval time duration of the downlink timing unit X and the downlink timing unit N and a CRS (cell reference signal) delay change rate of the downlink timing unit N.

As shown in equation 1:

the start time T1 of the downlink sequence X is the start time of the downlink sequence unit N + (X-N) × Tslot (1+ amrs) (1)

The terminal measures a downlink signal sent by the base station to obtain the starting time of a downlink time sequence unit N; tslot is the length of the timing unit, (X-N) × Tslot is the interval duration of the downlink timing unit X and the downlink timing unit N, and amcrs is the CRS delay variation rate of the downlink timing unit N. The aCRS estimation method includes the following three methods:

1) when the inspiration time of the downlink timing X is roughly estimated, the effect of CRS, that is, CRS is 0.

2) And calculating a first difference value, wherein the first difference value is the difference value between the downlink time sequence unit N and the starting time of the adjacent downlink time sequence unit. And calculating a second difference value, wherein the second difference value is the difference value between the first difference value and the unit length of the time sequence. And calculating the quotient of the second difference value and the length of the time sequence unit to obtain aCRS.

3) The avrs may be an average value of CRS delay variation rates within a preset duration range before the timing unit N.

S202: and the terminal acquires the starting time of the uplink time sequence unit X based on the starting time of the downlink time sequence unit X of the terminal.

In this embodiment, considering that the main reason for generating RTT is the distance between the terminal and the satellite and the distance between the satellite and the base station, the principle of the step of acquiring the start time of the uplink timing unit X by the terminal can be seen in fig. 3, D _ X represents a downlink timing unit X, and U _ X represents an uplink timing unit X.

The specific calculation flow is as follows:

a1, the time when the signal received by the computing terminal at time T1 is transmitted from the base station to the satellite is denoted as T1.

Specifically, since the start time T1 of the downlink timing unit X is already obtained in S201, the position of the satellite (referred to as the T1 position) at the start time T1 of the downlink timing unit X of the terminal can be estimated from the ephemeris information of the satellite. The distance between the position of T1 and the position of the terminal is calculated, and this distance is divided by the speed of light, i.e. the length of time that the signal travels from the position of T1 to the position of the terminal, and is denoted as S1. The time T1 is obtained by calculating T1-S1, and the time T1 is the time when the signal received by the terminal at time T1 is transmitted from the base station to the satellite.

Optionally, t1 may be further iteratively modified:

1) the position of the satellite at the latest (i.e., the last calculation) time t1 (referred to as the updated t1 position) is calculated based on the ephemeris information of the satellite.

2) The distance between the position t1 and the position of the terminal is calculated, and the distance is divided by the speed of light, i.e. the time duration for the signal to travel from the position t1 to the position of the terminal, and is denoted as S1'.

3) T1-S1' are calculated, and the time when the signal received by the terminal at T1 is transmitted from the base station to the satellite is recorded as the latest T1.

1) -3) are repeated until the accuracy of t1 meets the requirement of uplink receiving synchronization of the base station. In practice, the number of iterations may be preset according to the requirements.

A2, time t0 when the base station transmits downlink timing unit X to the satellite and time t3 when the base station receives uplink timing unit X transmitted by the satellite are calculated.

Specifically, the position of the satellite at time t1 (referred to as t1 position for short) is determined according to the ephemeris information of the satellite, and the distance between the position of the base station and the t1 position, which is divided by the speed of light, is the time duration for the signal to be transmitted from the base station to the t1 position, and is denoted as S2. t1-S2 is t 0.

Since the aim is to achieve alignment of the uplink timing and the downlink timing of the base station, t3 is equal to t 0.

A3, calculating the time t2 when the uplink sequence unit X transmitted by the terminal reaches the satellite.

Specifically, the position of the satellite at t3 (referred to as t3 position) is estimated based on the ephemeris information. And calculating the distance ss1 between the t3 position and the position of the base station, dividing ss1 by the speed of light to obtain the time length S2 of the signal transmitted from the t3 position of the satellite to the base station, and calculating t3-S2 to obtain t 2.

Optionally, t2 may be further iteratively modified:

1) based on the ephemeris information, the position of the satellite at the latest time t2 (referred to simply as the t2 position) is calculated.

2) Calculating the distance ss1 between the t2 position and the position of the base station^’The distance is divided by the speed of light, which is the time duration for the signal to travel from the t3 position to the satellite position, and is denoted as S2^’。

3) Calculation of t3-S2^’And the latest t2 is obtained.

1) -3) are repeated until the accuracy of t2 meets the requirement of uplink receiving synchronization of the base station.

A4, the time T2 of the uplink sequence X is sent to the satellite by the computing terminal.

Specifically, the distance ss2 between the position T2 of the satellite and the position of the terminal is calculated, ss2 is divided by the speed of light, the time length S3 of the signal transmitted from the position of the terminal to the position T2 is obtained, and T2-S3 is calculated, and T2 is obtained.

T2 is the starting time of uplink timing X of the terminal. As can be seen from a1-a4, according to the generation principle of RTT, in this embodiment, communication delays between the uplink base station and the downlink base station and between the satellite and the terminal are calculated, respectively, and the starting time of the uplink timing unit X is obtained. The RTT obtained in this way is highly accurate in the case of constantly changing positions of the satellites.

S203: the terminal transmits the uplink timing unit X at time T2.

As can be seen from the flow shown in fig. 2, after the terminal estimates the start time of the downlink timing unit X, the terminal further estimates the start time of the uplink timing unit X, and sends the uplink timing unit X at the estimated start time of the uplink timing unit X, thereby achieving the purpose of aligning the uplink timing with the downlink timing.

As shown in fig. 4, when X is K, the terminal transmits the uplink timing unit K by an RTT before the downlink timing unit K, so that the base station receives the uplink timing unit K at the start time of transmitting the downlink timing unit K, and alignment of uplink and downlink timing is achieved.

It should be noted that the procedure shown in fig. 2 is applicable to the case where RTT increases or decreases, as shown in fig. 5, when RTT increases, a time between downlink timing K and K +1 of the terminal is greater than a fixed timing Tslot, assuming that Tslot + TA, uplink timing K needs to advance TB on the basis of downlink timing K, uplink timing K +1 needs to advance TC on the basis of K +1, because TB and TC calculate a change of an actual RTT is considered, uplink K and uplink K +1 of the base station are respectively aligned with downlink K and K +1, and fixed timing Tslot is maintained between uplink K and uplink K +1 of the base station, it can be seen that, using the procedure shown in fig. 2, uplink and downlink timing of the base station can still be aligned.

As shown in fig. 6, under the condition that RTT is reduced, the time between terminal downlink timing K and K +1 is smaller than fixed timing Tslot, assuming Tslot-TD, uplink timing K needs to advance TE on the basis of downlink timing K, uplink timing K +1 needs to advance TF on the basis of K +1, because the actual RTT variation is considered in the calculation process of T2 and T5, uplink K and uplink K +1 of the base station are respectively aligned with downlink K and K +1, and fixed timing Tslot is maintained between uplink K and uplink K +1 of the base station, it can be seen that, using the flow shown in fig. 2, the uplink and downlink timing of the base station can still be aligned.

Fig. 7 is a flowchart of another signal transmission method disclosed in the embodiment of the present application, and the method of specifying X by N, the transmission timing of the feedback data of the downlink data, and the transmission timing of the PUSCH data in the uplink scheduling will be described with greater emphasis on the flowchart shown in fig. 2.

Fig. 7 includes the following steps:

s701: the terminal determines the number X of the target downlink timing unit to be estimated in the downlink timing unit N.

Specifically, the difference between X and N is greater than or equal to m, where m is a ratio of a preset time duration (for example, a sum of a maximum transmission round trip delay RTTm of the system and a processing delay of the terminal) to a length of the time sequence unit, and is a value obtained by rounding up.

It should be noted that, in a specific embodiment, in a communication system, the terminal estimates a target downlink timing unit number X in the downlink timing unit N according to a fixed difference between X and N. For example, the calculated value of m is 5, and assuming that the difference between X and N is equal to m, then at time unit 0, time unit 5 needs to be estimated, at time unit 1, time unit 6 … … needs to be estimated, and so on.

In a specific embodiment, in a communication system, at least one target downlink timing unit number X is estimated in timing unit N, for example, m is calculated to have a value of 5, and assuming that the difference between X and N is equal to m, timing unit 5 and/or 6 needs to be estimated in timing unit 0, timing unit 7 and/or 8 needs to be estimated in timing unit 2, and so on.

In another embodiment, the difference between X and N may be the same or different for different terminals in a communication system.

S702: the terminal acquires the start time T2 of the uplink timing unit X.

The obtaining method is as A1-A4, and is not described in detail here.

S703: if the terminal receives downlink scheduling data PDSCH data in downlink timing unit X, PUCCH feedback data is transmitted in uplink timing unit X + K1.

Wherein K1 is the number of time sequence units, and satisfies: k1 Tslot > -RTTm + K1 Tslot, RTTm being the maximum RTT of the system, Tslot being the time duration in time units, and K1 being the number of time units occupied by the terminal processing time duration. It can be seen that the uplink timing unit X + K1 is after the downlink timing unit X, and the absolute time is also after the absolute time of the downlink timing unit X.

And if the terminal receives the uplink scheduling data PDCCH data in the downlink timing unit X, the terminal transmits the PUSCH data in the uplink timing unit X + K2.

Wherein K2 is the number of time sequence units, and satisfies: k2 Tslot > -RTTm + K2 Tslot, K2 being the number of time-series units of the processing time of the terminal. It can be seen that the uplink timing unit X + K2 is after the downlink timing unit X, and the absolute time is also after the absolute time of the downlink timing unit X.

As can be seen from the flow shown in fig. 7, when the base station schedules uplink data, the maximum RTT of the system and the processing delay of the terminal are considered, and in addition, in consideration of the timing relationship between uplink data and downlink data, such as X + K1 or X + K2, sufficient processing time needs to be ensured, so that the start time of the uplink timing unit X + K1 is estimated in a certain downlink timing unit M after the downlink timing unit X, and the start time of the uplink timing unit X + K2 is estimated in a certain downlink timing unit W, where the relationship between M and X + K1 and the relationship between W and X + K2 are the same as the relationship between N and X, see step S701, and the start times of the uplink timing units X + K1 and X + K2 are calculated in steps S201 to S203, which are not described herein again. The two points can ensure the accuracy of communication under the condition of ensuring the alignment of the uplink and downlink time sequences of the base station.

Fig. 8 is a flowchart of another signal sending method disclosed in an embodiment of the present application, and compared with the flowchart shown in fig. 2 or fig. 7, the "quasi-alignment" is implemented by reducing the alignment standard, so as to achieve the purpose of easier implementation.

Fig. 8 includes the following steps:

s801: the terminal obtains an uplink receiving delay Z Tslope, wherein the delay is an integral multiple of Tslope, and Tslope is the length of a time sequence unit.

Z is greater than or equal to a preset value, which is determined according to the maximum transmission round trip RRTm of the system and the processing capability of the terminal, for example, Z satisfies:

and K is the number of time sequence units occupied by the processing time length of the terminal.

The terminal may obtain Z Tslot in a manner of receiving a broadcast from the base station, or a value manually input by the user.

S802: and under the condition that the terminal receives the downlink time sequence unit X, calculating the starting time of the uplink time sequence unit X according to the uplink receiving delay and the starting time of the downlink time sequence unit X.

The time when all terminal uplink timing unit X in the cell reaches the base station needs to be aligned to the same time, and the terminals at different positions in the cell need to separately calculate the uplink X sending time of the terminal due to different transmission RTTs, so as to achieve the purpose of base station uplink receiving alignment. The principle of calculating the starting time of the uplink timing unit X is shown in fig. 8, and the specific steps are as follows:

b1, calculating the time T4 when the signal received by the terminal at the starting time T3 of the downlink timing unit X is transmitted from the base station to the satellite.

Specifically, since the downlink timing unit X has been received in S803, the position of the satellite at the start time T3 of the downlink timing unit X of the terminal (referred to as the T3 position for short) can be estimated from the ephemeris information of the satellite. The distance between the position of T3 and the position of the terminal is calculated, and this distance is divided by the speed of light, i.e. the length of time that the signal travels from the position of T3 to the position of the terminal, and is denoted as S1. And calculating T3-S1 to obtain the time T4 of the signal received by the terminal at the time T3 and transmitting the signal from the base station to the satellite.

Optionally, t4 may be further iteratively modified:

1) from the ephemeris information, the position of the satellite at time t4 (referred to as the t4 position for short) is calculated.

2) The distance between the position t4 and the position of the terminal is calculated, and the distance is divided by the speed of light, i.e. the time duration for the signal to travel from the position t4 to the position of the terminal, and is denoted as S1'.

3) And calculating T3-S1' to obtain the time of the signal received by the terminal at the time of T3, and recording the time of the signal transmitted from the base station to the satellite as the latest T4.

1) -3) are repeated until the accuracy of t4 meets the requirement of uplink receiving synchronization of the base station.

B2, time t5 at which the base station transmits downlink time series unit X to the satellite and time t6 at which the base station receives uplink time series unit X transmitted from the satellite are calculated.

Specifically, the position of the satellite at time t4 (referred to as t4 position for short) is determined according to the ephemeris information of the satellite, and the distance between the base station position and the t4 position, which is divided by the speed of light, is the time duration for the signal to be transmitted from the base station to the t4 position, and is denoted as S2. t4-S2 is t 5.

Since the objective is to achieve a fixed delay Z Tslot for the uplink timing of the bs relative to the downlink timing, t6 is equal to t5+ Z Tslot.

B3, calculating the time t7 when the uplink sequence unit X transmitted by the terminal reaches the satellite.

Specifically, the position of the satellite at t6 (referred to as t6 position) is estimated based on the ephemeris information. And calculating the distance ss1 between the t6 position and the position of the base station, dividing ss1 by the speed of light to obtain the time length S2 of the signal transmitted from the t6 position of the satellite to the base station, and calculating t6-S2 to obtain t 7.

Optionally, t7 may be further iteratively modified:

1) and ephemeris information, calculating the position of the satellite at t7 (referred to as the t7 position).

2) The distance ss1 'between the t7 position and the position of the base station is calculated, and this distance is divided by the speed of light, which is the duration of the signal transmitted from the t7 position to the satellite position, denoted as S2'.

3) And calculating t 6-S2' to obtain the latest t 7.

1) -3) are repeated until the accuracy of t7 meets the requirement of uplink receiving synchronization of the base station.

B4, the computing terminal sends the starting time T4 of the uplink sequence X to the satellite.

Specifically, the distance ss2 between the position T7 of the satellite and the position of the terminal is calculated, ss2 is divided by the speed of light, the time length S3 of the signal transmitted from the position of the terminal to the position T7 is obtained, and T7-S3 is calculated, and T4 is obtained.

As can be seen from B1-B4, in this embodiment, the communication time delays between the uplink base station and the downlink base station, and between the downlink base station and the satellite, and between the satellite and the terminal are calculated, respectively, to obtain the starting time of the uplink timing sequence X. The up-link synchronization accuracy of T4 achieved in this way is high under the condition that the position of the satellite is constantly changed.

S803: the terminal transmits the uplink timing unit X at time T4.

S804: and after the base station sends the downlink time sequence unit X, delaying Z × Tslope and receiving the uplink time sequence unit X.

The effect achieved by the flow shown in fig. 8 is shown in fig. 9: after the terminal receives a downlink timing unit, the terminal delays sending the uplink timing unit X, so that the starting positions of the uplink and downlink timing units are aligned at the base station side.

Fig. 10 is a schematic structural diagram of an apparatus provided in an embodiment of the present application, where the apparatus may include: at least one processor 1001, at least one communication interface 1002, at least one memory 1003 and at least one communication bus 1004. It should be noted that the device may be a terminal device or a base station device.

In the embodiment of the present application, the number of the processor 1001, the communication interface 1002, the memory 1003, and the communication bus 1004 is at least one, and the processor 1001, the communication interface 1002, and the memory 1003 complete communication with each other through the communication bus 1004;

the processor 1001 may be a central processing unit CPU, or an application Specific Integrated circuit asic, or one or more Integrated circuits configured to implement embodiments of the present invention, etc.;

the memory 1003 may include a high-speed RAM memory, and may further include a non-volatile memory (non-volatile memory) or the like, such as at least one disk memory;

the memory stores programs, and the processor can execute the programs stored in the memory, so as to realize the processes in the above embodiments.

The functions described in the method of the embodiment of the present application, if implemented in the form of software functional units and sold or used as independent products, may be stored in a storage medium readable by a computing device. Based on such understanding, part of the contribution to the prior art of the embodiments of the present application or part of the technical solution may be embodied in the form of a software product stored in a storage medium and including several instructions for causing a computing device (which may be a personal computer, a server, a mobile computing device or a network device) to execute all or part of the steps of the method described in the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.

The embodiments are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same or similar parts among the embodiments are referred to each other.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for transmitting a signal, applied to a terminal, includes:

at the starting time of the uplink time sequence unit X, sending the uplink time sequence unit X;

wherein the obtaining of the start time of the uplink timing unit X of the terminal based on the start time of the downlink timing unit X includes:

2. The method of claim 1, wherein the obtaining a first time according to a starting time of the downlink timing unit X comprises:

3. The method of claim 2, further comprising, after said obtaining said first time instant:

correcting the first time by the following iterative process:

4. The method of claim 1, wherein obtaining a second time based on the first time comprises:

estimating the position of the satellite at the first moment according to the ephemeris information of the satellite;

5. The method of claim 1, wherein obtaining a third time based on the second time comprises:

6. The method according to claim 1, wherein said calculating a starting time of an uplink timing unit X of the terminal according to the third time comprises:

7. The method of claim 1, wherein estimating a starting time of a downlink timing unit X of the terminal in a downlink timing unit N comprises:

8. The method according to claim 1 or 6, wherein the difference between X and N is greater than or equal to m, where m is a value obtained by rounding up a ratio of a preset duration to a length of a time sequence unit.

9. The method of claim 1, wherein downlink scheduling data PDSCH data is received in downlink timing unit X;

alternatively, the first and second electrodes may be,

the method further comprises the following steps:

10. The method of claim 9, wherein the K1 and the K2 are sent by a base station to the terminal.

11. A method for transmitting a signal, applied to a terminal, includes:

at the starting time of sending the uplink time sequence unit X, sending the uplink time sequence unit X;

wherein, the calculating the starting time of sending the uplink time sequence unit X according to the uplink receiving delay and the starting time of the downlink time sequence unit X includes:

12. The method of claim 11, wherein the obtaining a first time according to a starting time of the terminal in the downlink timing unit X comprises:

13. The method of claim 12, further comprising, after said obtaining said first time instant:

correcting the first time by the following iterative process:

14. The method of claim 11, wherein obtaining a fourth time according to the third time comprises:

15. The method according to claim 11, wherein the obtaining the starting time of the uplink timing unit X according to the fourth time comprises:

16. A terminal, comprising:

a processor and a memory;

the memory is used for storing an application program, and the processor is used for running the application program to realize the signal transmission method of any one of claims 1 to 10.

17. A terminal, comprising:

a processor and a memory;

the memory is used for storing an application program, and the processor is used for running the application program to realize the signal transmission method of any one of claims 11 to 15.