CN115694592A - A random access method, device and storage medium - Google Patents

Abstract

The invention discloses a random access method, equipment and a storage medium, comprising the following steps: the method comprises the steps that UE receives beam signals, wherein the beam signals carry beam coverage area numbers, the beam coverage areas are areas covered on the ground by beams sent by a communication satellite, and the areas covered by the beams have the preset numbers; the UE determines the area where the UE is located according to the number of the beam coverage area; the UE determines a TA according to the position relation between the area and the communication satellite, wherein the position relation is acquired by the UE in advance; and the UE initiates random access on the PRACH by using the Preamble according to the RO appointed by the TA and the communication satellite. By adopting the invention, the UE can acquire the position, the TA can be determined through the position relation between the area and the communication satellite acquired in advance, such as the satellite-to-ground distance and the like, and random access is initiated according to the TA.

Description

A random access method, device and storage medium

technical field

The present invention relates to the field of communication technology, in particular to a random access method, device and storage medium.

Background technique

In communication satellite communication, because the distance between the communication satellite and the user equipment is very large, there is a large communication delay in the communication process. If the communication delay cannot be pre-compensated, random access cannot be realized, and normal communication cannot be realized. communication process.

The disadvantage of the prior art is that there is no solution for advancing the calculation timing of the user equipment.

Contents of the invention

The present invention provides a random access method, device and storage medium, which are used to provide a scheme for advance calculation timing of user equipment.

The invention provides the following technical solutions:

A random access method, comprising:

The UE receives the beam signal, and the beam signal carries a beam coverage area number, the beam coverage area is the area covered by the beam sent by the communication satellite on the ground, and the area covered by each beam has its own preset number;

The UE determines the area where the UE is located according to the number of the beam coverage area;

The UE determines the TA according to the positional relationship between the area and the communication satellite, and the positional relationship is obtained by the UE in advance;

The UE uses the Preamble to initiate random access on the PRACH according to the RO agreed with the communication satellite by the TA.

In implementation, the beam coverage area is composed of a group of wave positions, and the wave positions are divided into multiple wave positions centered on the sub-satellite point within the entire ground coverage area of a communication satellite. Covers a wave position at a certain time.

In implementation, the positional relationship is a mapping table of the reference line and the distance between the satellite and the ground, wherein the reference line is a plurality of concentric satellite points planned within the entire ground coverage area of a communication satellite. Circular line, through the radius of the circular line, the angle between the center of the earth determines the distance between the star and the ground.

In practice, there is a one-to-one correspondence between wave position groups and reference lines, wherein the geometric center of any wave position is closest to the reference line.

During implementation, it further includes planning reference lines and wave positions in one of the following ways or a combination thereof:

The number of reference lines is determined according to the RTT and frequency offset estimation error threshold requirements;

Avoid a wave level crossing two or more circular reference lines;

The sum of the distances from the geometric center of gravity of all waves in the wave group to the reference line is the smallest.

In an implementation, the beam signal is one of the following signals or part of a combination of them:

PSS, SSS, PBCH.

In an implementation, the beam signal carries the beam coverage area number in one of the following ways or a combination thereof:

The part of the CID transmitted in the PSS or SSS carries the beam coverage area number;

The part that transmits the SSB index in the PBCH carries the beam coverage area number;

The part that transmits additional bits in the PBCH carries the beam coverage area number;

Carry the beam coverage area number in the information bit part of the MIB;

Use the SIB to carry the beam coverage area number.

In implementation, when the UE is turned on or when the beam position is reselected or the beam position group is reselected, the number of the beam coverage area carried in the beam signal is detected.

In implementation, it further includes:

When at least two beam coverage area numbers are detected, the beam coverage area number carried by the beam signal with the best signal quality is used as the beam coverage area number.

In implementation, it further includes:

Set TA=RTT_est-TA_margin, where RTT_est is the RTT determined according to the reference line, TA_margin is the protection margin for timing advance, and TA_margin is half of the detection window length, or the network notifies the UE in advance.

In the implementation, the UE uses Preamble to initiate random access on the PRACH according to the RO agreed with the communication satellite by the TA, including:

Based on the time when the UE receives the number of the beam coverage area, the UE initiates random access after a time interval RO Shift-TA, wherein the RO Shift is agreed between the UE and the communication satellite.

During implementation, when the Preamble arrives at the communication satellite, the deviation from the standard timing of the base station (communication satellite) is:

DTA=RTT_act-RTT_est+TA_margin

Among them, RTT_act represents the real RTT of the UE, RTT_est is the RTT determined according to the reference line, and TA_margin is the protection margin for timing advance.

In implementation, it further includes:

Adjust the guide line and wave pack planning pattern so that the guide line is close to the inside of the wave pack to make RTT_est smaller.

In implementation, it further includes:

After receiving the timing offset fed back by the communication satellite, the timing offset is used as an adjustment amount for the timing advance of the UE's subsequent uplink transmission.

A random access method, comprising:

The communication satellite sends a beam signal to the UE, the beam signal carries a beam coverage area number, the beam coverage area is the area covered by the beam sent by the communication satellite on the ground, and each beam coverage area has its own preset number;

The communication satellite receives the random access initiated by the UE using the Preamble on the PRACH in the RO agreed with the communication satellite.

In implementation, the beam coverage area is composed of a group of wave positions, and the wave positions are divided into multiple wave positions centered on the sub-satellite point within the entire ground coverage area of a communication satellite. Covers a wave position at a certain time.

In an implementation, the beam signal is one of the following signals or part of a combination of them:

PSS, SSS, PBCH.

In an implementation, the beam signal carries the beam coverage area number in one of the following ways or a combination thereof:

The part of the CID transmitted in the PSS or SSS carries the beam coverage area number;

The part that transmits the SSB index in the PBCH carries the beam coverage area number;

The part that transmits additional bits in the PBCH carries the beam coverage area number;

Carry the beam coverage area number in the information bit part of the MIB;

Use the SIB to carry the beam coverage area number.

In implementation, it further includes:

Inform the UE of TA_margin, the TA_margin is used to set TA=RTT_est-TA_margin, where RTT_est is the RTT determined according to the reference line, and TA_margin is the protection margin for timing advance.

In the implementation, the receiving UE uses the random access initiated by Preamble on the PRACH in the RO agreed with the communication satellite, including:

Receiving the random access initiated by the UE after the time interval RO Shift-TA has elapsed based on the time when the UE receives the number of the beam coverage area, wherein the RO Shift is agreed between the UE and the communication satellite.

In implementation, it further includes:

advance the timing of the PRACH detection window by a margin TA_margin; and/or,

Adjust the guide line and wave pack planning pattern so that the guide line is close to the inside of the wave pack to make RTT_est smaller.

In implementation, it further includes:

After the timing deviation of the arrival of the Preamble is detected, the timing deviation is fed back to the UE, and the timing deviation is used as an adjustment amount for the timing advance of the UE's subsequent uplink transmission.

A user equipment, comprising:

The processor, which reads the program in the memory, performs the following processes:

receiving the beam signal, the beam signal carries the number of the beam coverage area, the beam coverage area is the area covered by the beam sent by the communication satellite on the ground, and the area covered by each beam has its own preset number;

Determine the area where the UE is located according to the number of the beam coverage area;

Determine the TA according to the positional relationship between the area and the communication satellite, the positional relationship is pre-acquired by the UE;

Use Preamble to initiate random access on PRACH according to the RO agreed with the communication satellite by TA;

Transceiver, used to receive and transmit data under the control of the processor.

In implementation, the beam coverage area is composed of a group of wave positions, and the wave positions are divided into multiple wave positions centered on the sub-satellite point within the entire ground coverage area of a communication satellite. Covers a wave position at a certain time.

In implementation, the positional relationship is a mapping table of the reference line and the distance between the satellite and the ground, wherein the reference line is a plurality of concentric satellite points planned within the entire ground coverage area of a communication satellite. Circular line, through the radius of the circular line, the angle between the center of the earth determines the distance between the star and the ground.

In practice, there is a one-to-one correspondence between wave position groups and reference lines, wherein the geometric center of any wave position is closest to the reference line.

During implementation, it further includes planning reference lines and wave positions in one of the following ways or a combination thereof:

The number of reference lines is determined according to the RTT and frequency offset estimation error threshold requirements;

Avoid a wave level crossing two or more circular reference lines;

The sum of the distances from the geometric center of gravity of all waves in the wave group to the reference line is the smallest.

In an implementation, the beam signal is one of the following signals or part of a combination of them:

PSS, SSS, PBCH.

In an implementation, the beam signal carries the beam coverage area number in one of the following ways or a combination thereof:

The part of the CID transmitted in the PSS or SSS carries the beam coverage area number;

The part that transmits the SSB index in the PBCH carries the beam coverage area number;

The part that transmits additional bits in the PBCH carries the beam coverage area number;

Carry the beam coverage area number in the information bit part of the MIB;

Use the SIB to carry the beam coverage area number.

In implementation, when the UE is turned on or when the beam position is reselected or the beam position group is reselected, the number of the beam coverage area carried in the beam signal is detected.

In implementation, it further includes:

When at least two beam coverage area numbers are detected, the beam coverage area number carried by the beam signal with the best signal quality is used as the beam coverage area number.

In implementation, it further includes:

Set TA=RTT_est-TA_margin, where RTT_est is the RTT determined according to the reference line, TA_margin is the protection margin for timing advance, and TA_margin is half of the detection window length, or the network notifies the UE in advance.

In the implementation, according to the RO agreed with the communication satellite by the TA, the Preamble is used to initiate random access on the PRACH, including:

Taking the time when the number of the beam coverage area is received as a reference, a random access is initiated after a time interval RO Shift-TA, wherein the RO Shift is agreed between the UE and the communication satellite.

During implementation, when the Preamble arrives at the communication satellite, the deviation from the standard timing of the base station (communication satellite) is:

DTA=RTT_act-RTT_est+TA_margin

Among them, RTT_act represents the real RTT of the UE, RTT_est is the RTT determined according to the reference line, and TA_margin is the protection margin for timing advance.

In implementation, it further includes:

Adjust the guide line and wave pack planning pattern so that the guide line is close to the inside of the wave pack to make RTT_est smaller.

In implementation, it further includes:

After receiving the timing offset fed back by the communication satellite, the timing offset is used as an adjustment amount for the timing advance of the UE's subsequent uplink transmission.

A user equipment, comprising:

The UE receiving module is used to receive the beam signal, the beam signal carries the number of the beam coverage area, the beam coverage area is the area covered by the beam sent by the communication satellite on the ground, and the area covered by each beam has its own preset number ;

A UE area module, configured to determine the area where the UE is located according to the beam coverage area number;

a UE TA module, configured to determine the TA according to the positional relationship between the area and the communication satellite, the positional relationship is acquired by the UE in advance;

The UE access module is configured to use the Preamble to initiate random access on the PRACH according to the RO agreed with the communication satellite by the TA.

In implementation, it further includes:

The area planning module is used to plan an area, wherein the beam coverage area is composed of a group of wave positions, and the wave positions are divided within the entire ground coverage area of a communication satellite with the sub-satellite point as the center Multiple wave positions, one beam covers one wave position at a certain moment.

In implementation, the area planning module is further used to plan the positional relationship, wherein the positional relationship is a mapping table of the reference line and the distance between the satellite and the ground, wherein the reference line is within the entire ground coverage area of a communication satellite, with With the sub-satellite point as the center, multiple concentric circular lines are planned, and the distance between the star and the ground is determined by the radius of the circular line and the angle between the center of the earth.

During implementation, the area planning module is further used to plan a one-to-one correspondence between wave position groups and reference lines, wherein the geometric center of any wave position is closest to the reference line.

During implementation, the area planning module is further used to plan reference lines and wave positions in one of the following ways or a combination thereof:

The number of reference lines is determined according to the RTT and frequency offset estimation error threshold requirements;

Avoid a wave level crossing two or more circular reference lines;

The sum of the distances from the geometric center of gravity of all waves in the wave group to the reference line is the smallest.

In an implementation, the UE receiving module is further configured to receive the beam signal of one of the following signals or a part of a combination thereof:

PSS, SSS, PBCH.

In implementation, the UE receiving module is further configured to receive the beam signal carrying the beam coverage area number in one of the following ways or a combination thereof:

The part of the CID transmitted in the PSS or SSS carries the beam coverage area number;

The part that transmits the SSB index in the PBCH carries the beam coverage area number;

The part that transmits additional bits in the PBCH carries the beam coverage area number;

Carry the beam coverage area number in the information bit part of the MIB;

Use the SIB to carry the beam coverage area number.

During implementation, the UE receiving module is further configured to detect the beam coverage area number carried in the beam signal when the UE is turned on or when the beam position reselection or beam position group reselection is performed.

In an implementation, the UE receiving module is further configured to use the beam coverage area number carried by the beam signal with the best signal quality as the beam coverage area number when at least two beam coverage area numbers are detected.

In implementation, the UE TA module is further used to set TA=RTT_est-TA_margin, where RTT_est is the RTT determined according to the reference line, TA_margin is the protection margin for timing advance, and TA_margin is half of the detection window length, or the network notifies the UE in advance .

During implementation, the UE access module is further used to initiate random access on the PRACH using Preamble according to the RO agreed upon by the TA with the communication satellite, including:

Based on the time when the UE receives the number of the beam coverage area, the UE initiates random access after a time interval RO Shift-TA, wherein the RO Shift is agreed between the UE and the communication satellite.

During implementation, the UE access module is further used to determine that when the Preamble arrives at the communication satellite, the deviation from the standard timing of the communication satellite is:

DTA=RTT_act-RTT_est+TA_margin

Among them, RTT_act represents the real RTT of the UE, RTT_est is the RTT determined according to the reference line, and TA_margin is the protection margin for timing advance.

During implementation, the area planning module is further used to adjust the reference line and the wave set planning pattern, so that the reference line is close to the inside of the wave set, so as to reduce the RTT_est.

During implementation, the UE receiving module is further configured to receive the timing offset fed back by the communication satellite, and use the timing offset as an adjustment amount for the timing advance of the UE's subsequent uplink transmission.

A communications satellite comprising:

The processor, which reads the program in the memory, performs the following processes:

Sending a beam signal to the UE, the beam signal carrying the number of the beam coverage area, the beam coverage area is the area covered by the beam sent by the communication satellite on the ground, and the area covered by each beam has its own preset number;

Receive the random access initiated by the UE on the PRACH using Preamble on the RO agreed with the communication satellite;

Transceiver, used to receive and transmit data under the control of the processor.

In implementation, the beam coverage area is composed of a group of wave positions, and the wave positions are divided into multiple wave positions centered on the sub-satellite point within the entire ground coverage area of a communication satellite. Covers a wave position at a certain time.

In an implementation, the beam signal is one of the following signals or part of a combination of them:

PSS, SSS, PBCH.

In an implementation, the beam signal carries the beam coverage area number in one of the following ways or a combination thereof:

The part of the CID transmitted in the PSS or SSS carries the beam coverage area number;

The part that transmits the SSB index in the PBCH carries the beam coverage area number;

The part that transmits additional bits in the PBCH carries the beam coverage area number;

Carry the beam coverage area number in the information bit part of the MIB;

Use the SIB to carry the beam coverage area number.

In implementation, it further includes:

Inform the UE of TA_margin, the TA_margin is used to set TA=RTT_est-TA_margin, where RTT_est is the RTT determined according to the reference line, and TA_margin is the protection margin for timing advance.

In the implementation, the receiving UE uses the random access initiated by Preamble on the PRACH in the RO agreed with the communication satellite, including:

Receiving the random access initiated by the UE after the time interval RO Shift-TA has elapsed based on the time when the UE receives the number of the beam coverage area, wherein the RO Shift is agreed between the UE and the communication satellite.

In implementation, it further includes:

advance the timing of the PRACH detection window by a margin TA_margin; and/or,

Adjust the guide line and wave pack planning pattern so that the guide line is close to the inside of the wave pack to make RTT_est smaller.

In implementation, it further includes:

After the timing deviation of the arrival of the Preamble is detected, the timing deviation is fed back to the UE, and the timing deviation is used as an adjustment amount for the timing advance of the UE's subsequent uplink transmission.

A communications satellite comprising:

The satellite sending module is used to send a beam signal to the UE. The beam signal carries the number of the beam coverage area. The beam coverage area is the area covered by the beam sent by the communication satellite on the ground. The area covered by each beam has its own preset number of

The satellite receiving module is used to receive the random access initiated by the UE on the PRACH using the Preamble on the RO agreed with the communication satellite.

During implementation, the area planning module is further used to plan the beam coverage area, the beam coverage area is composed of a group of wave positions, and the wave positions are within the entire ground coverage area of a communication satellite, with sub-satellite point As the center, divided into multiple wave positions, one beam covers one wave position at a certain moment.

In implementation, the satellite sending module is further used to send the beam signal of one of the following signals or a part of a combination of the signals:

PSS, SSS, PBCH.

In implementation, the satellite sending module is further used to carry the beam signal with the beam coverage area number in one of the following ways or a combination thereof:

The part of the CID transmitted in the PSS or SSS carries the beam coverage area number;

The part that transmits the SSB index in the PBCH carries the beam coverage area number;

The part that transmits additional bits in the PBCH carries the beam coverage area number;

Carry the beam coverage area number in the information bit part of the MIB;

Use the SIB to carry the beam coverage area number.

In implementation, the satellite sending module is further used to notify the UE of TA_margin, and the TA_margin is used to set TA=RTT_est-TA_margin, where RTT_est is the RTT determined according to the reference line, and TA_margin is the protection margin for timing advance.

In the implementation, the satellite receiving module is further used to receive the random access initiated by the UE on the PRACH using the Preamble on the RO agreed with the communication satellite, including:

Receiving the random access initiated by the UE after the time interval RO Shift-TA has elapsed based on the time when the UE receives the number of the beam coverage area, wherein the RO Shift is agreed between the UE and the communication satellite.

In implementation, the satellite receiving module is further used to advance the timing of the PRACH detection window by a margin TA_margin; and/or,

Adjust the guide line and wave pack planning pattern so that the guide line is close to the inside of the wave pack to make RTT_est smaller.

During implementation, the satellite receiving module is further used to detect the timing deviation of the Preamble arrival, feed back the timing deviation to the UE, and use the timing deviation as an adjustment amount for the timing advance of the UE's subsequent uplink transmission.

A computer-readable storage medium storing a computer program for executing the above random access method.

The beneficial effects of the present invention are as follows:

In the technical solution provided by the embodiment of the present invention, since the beam signal sent by the communication satellite carries the number of the beam coverage area, the UE can know its location through the pre-acquired position relationship between the area and the communication satellite, such as the distance between the satellite and the ground, etc. , the TA can be determined, and random access is initiated according to the TA.

Description of drawings

The accompanying drawings described here are used to provide a further understanding of the present invention, and constitute a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention, and do not constitute improper limitations to the present invention. In the attached picture:

FIG. 1 is a schematic diagram of an implementation flow of a random access method on the UE side in an embodiment of the present invention;

FIG. 2 is a schematic diagram of an implementation flow of a random access method on the communication satellite side in an embodiment of the present invention;

Fig. 3 is a schematic diagram of the relationship between satellites and wave positions in an embodiment of the present invention;

4 is a schematic diagram of circular reference line planning in an embodiment of the present invention;

FIG. 5 is a schematic diagram of wave position group planning in an embodiment of the present invention;

FIG. 6 is a schematic diagram of the protection margin relationship of timing advance in an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a UE in an embodiment of the present invention;

FIG. 8 is a schematic diagram of the structure of a communication satellite in an embodiment of the present invention.

Detailed ways

Specific embodiments of the present invention will be described below in conjunction with the accompanying drawings.

In the description process, the implementation of the UE and the communication satellite base station will be described separately, and then an example of the cooperation between the two will be given to better understand the implementation of the solution given in the embodiment of the present invention. Such an explanation does not mean that the two must be implemented together or must be implemented separately. In fact, when the UE and the communication satellite are implemented separately, they also solve the problems on the UE side and the communication satellite base station side respectively, and the two are used in combination. , better technical results will be obtained.

Figure 1 is a schematic diagram of the implementation process of the random access method on the UE side, as shown in the figure, including:

Step 101, the UE receives a beam signal, the beam signal carries a beam coverage area number, the beam coverage area is the area covered by the beam sent by the communication satellite on the ground, and the area covered by each beam has its own preset number;

Step 102, the UE determines the area where the UE is located according to the number of the beam coverage area;

Step 103, the UE determines the TA according to the positional relationship between the area and the communication satellite, the positional relationship is obtained by the UE in advance;

Step 104 , the UE initiates random access on the PRACH using the Preamble according to the RO agreed with the communication satellite by the TA.

Figure 2 is a schematic diagram of the implementation process of the random access method on the communication satellite side, as shown in the figure, including:

Step 201. The communication satellite sends a beam signal to the UE. The beam signal carries the number of the beam coverage area. The beam coverage area is the area covered by the beam sent by the communication satellite on the ground. The area covered by each beam has its own preset serial number;

Step 202 , the communication satellite receives the random access initiated by the UE using the Preamble on the PRACH in the RO agreed with the communication satellite.

The implementation of the wave position planning scheme of communication satellite communication and the time synchronization pre-compensation scheme based on wave position groups will be described below.

The beam coverage area will be specifically described by beam position and beam position group. Correspondingly, the number of the beam coverage area will be described by the wave position group number GID in the embodiment.

1. Beam.

A communications satellite sends its signal using multiple beams, covering its entire service area. These beams can work at the same time, or work in time-sharing by scanning.

The wireless propagation distance of communication satellite communication is long, the path loss is large, and the requirement for transmission power is high, and because the power consumption is directly related to the overall cost of communication satellite design, production and launch, the transmission power is limited. The advantage of using multiple beams is: the narrower the beam, the higher the beam gain, which can overcome the problem of insufficient signal power at the receiving end caused by the limited transmission power and the large link loss. One of the important technical means.

2. Wave position.

In implementation, the beam coverage area is composed of a group of wave positions, and the wave positions are divided into multiple wave positions centered on the sub-satellite point within the entire ground coverage area of a communication satellite. Covers a wave position at a certain time.

Specifically, FIG. 3 is a schematic diagram of the relationship between satellites and wave positions. As shown in the figure, in the entire ground coverage area of a communication satellite, multiple wave positions are divided with the sub-satellite point as the center. The corresponding relationship between wave positions and beams is: a beam covers a wave position at a certain moment. The individual waves do not have to be the same size and shape.

3. Reference line.

In implementation, the positional relationship is a mapping table of the reference line and the distance between the satellite and the ground, wherein the reference line is a plurality of concentric satellite points planned within the entire ground coverage area of a communication satellite. Circular line, through the radius of the circular line, the angle between the center of the earth determines the distance between the star and the ground.

Figure 4 is a schematic diagram of circular reference line planning. As shown in the figure, in the entire ground coverage area of a communication satellite, with the sub-satellite point as the center, N concentric circular reference lines are planned, denoted as C(i ), i=1,2,...,N.

The radius of C(i) is denoted as RC(i).

The angle between the center of the earth of C(i) is denoted as AC(i), which means the angle between any point on C(i) and the sub-satellite point relative to the center of the earth.

The satellite-ground distance of C(i) is denoted as DC(i), which means the distance between any point on C(i) and the communication satellite.

Once the planning of the reference line is established, it remains stable (unchanged until re-planning).

The UE (User Equipment, User Equipment) obtains the mapping table DC(i) of the reference line and the distance between the satellite and the ground from the network in advance, where i=1, 2, . . . , N. Due to the stability of the reference line and wave group planning, this mapping table does not require frequent updates.

As an example, the circular reference lines C(i) are numbered in descending order according to their radii RC(i).

4. Wave group.

In practice, there is a one-to-one correspondence between wave position groups and reference lines, wherein the geometric center of any wave position is closest to the reference line.

Figure 5 is a schematic diagram of wave position group planning, in which the number marked in each wave position is its wave position group number. As shown in the figure, all wave positions are divided into N wave position groups, which are denoted as G(i), i=1,2,...,N.

The number of wave positions contained in the wave position group G(i) is Ki, and the number of wave positions in different wave position groups does not have to be equal. The kth wave position in the wave position group G(i) is denoted as B(i,k), i=1,2,...,N, k=1,2,...,Ki.

The position of the geometric center of gravity of B(i,k) is denoted as P(i,k). The distance between P(i,k) and the sub-satellite point is recorded as RP(i,k). The distance between P(i,k) and the circular reference line C(j) is recorded as DP(i,k,j),

DP(i,k,j)=abs[RP(i,k)-RC(j)]

Wherein, i=1,2,...,N, k=1,2,...,Ki, j=1,2,...,N, and abs is to calculate the absolute value.

The planning method of wave group can be:

The reference line C(i) of wave position group G(i) corresponds one to one, and the geometric center of any wave position is the closest to the reference line C(i), that is:

DP(i,k,i)=min{DP(i,k,j),j=1,2,...N}, k=1,2,...,Ki

After wave position group planning, each wave position in a communication satellite coverage area is roughly divided into multiple ring-shaped areas centered on a circular reference line.

It further includes planning reference lines and wave positions in one of the following ways or a combination thereof:

The number of reference lines is determined according to the RTT and frequency offset estimation error threshold requirements;

Avoid a wave level crossing two or more circular reference lines;

The sum of the distances from the geometric center of gravity of all waves in the wave group to the reference line is the smallest.

Specifically, as an optimization principle for reference line and wave position planning, it can be implemented as follows:

(1) The number of reference lines is determined according to the RTT and frequency offset estimation error threshold requirements;

The circular reference line should not be too sparse, otherwise some wave positions will be too far away from its circular reference line, resulting in excessive errors in RTT (Round Trip Time) and frequency offset estimation.

(2) Avoid a wave position crossing two or more circular reference lines;

If it is not necessary, avoid one wave spanning two or more circular reference lines, otherwise it means that the circular reference lines are too dense, the number of wave groups is too large, and the utilization efficiency of wave group numbers is low.

(3) The sum of the distances from the geometric center of gravity of all wave positions to the reference line in the wave position group is the smallest.

If each wave position group has been basically determined and the position of the circular reference line needs to be further optimized, then an optimization scheme is: the sum of the distances from the geometric center of gravity of all wave positions in the wave position group to its reference line is the smallest.

Once the wave group plan is established, it remains stable, that is, it remains unchanged until it is re-planned. For GEO (Geostationary Earth Orbit), the communication satellite is stationary relative to the ground, and the wave pattern is static and stable relative to the ground. For MEO (medium earth orbit (communication satellite), Medium Earth Orbit) and LEO (low orbit (communication satellite), Low Earth Orbit), the wave position moves with the communication satellite to the ground, but the wave position group planning pattern has a certain stability.

5. Transmission of wave group number.

In an implementation, the beam signal is one of the following signals or part of a combination of them:

PSS, SSS, PBCH.

Specifically, the communication satellite may send the beam group number GID to the UE through a beam signal.

When the beam points to the wave position B(i,k), i=1,2,...,N, k=1,2,...,Ki, the beam signal carries the wave group number information of the wave position GID=i.

Beam signal, for 3gpp's NTN (Non-Terrestrial Networks), or based on 4G LTE (4th Generation Mobile Communication System-Long Term Evolution Technology, 4th Generation Long Term Evolution) or 5GNR (5th Generation Mobile Communication System- Long-term evolution-new air interface technology, other communication systems derived from 5th Generation New Radio), which can be PSS (Primary Synchronization Signal), SSS (Secondary Synchronization Signal, Secondary Synchronization Signal), PBCH (Physical Broadcast Channel, Physical BroadcastChannel )a part of.

In a specific implementation, the beam signal carries the beam coverage area number in one of the following ways or a combination thereof:

The part of the CID transmitted in the PSS or SSS carries the beam coverage area number;

The part that transmits the SSB index in the PBCH carries the beam coverage area number;

The part that transmits additional bits in the PBCH carries the beam coverage area number;

Carry the beam coverage area number in the information bit part of the MIB;

Use the SIB to carry the beam coverage area number.

Described below.

Method 1:

The part of the CID transmitted in the PSS or SSS carries the beam coverage area number;

Redistribute information bits that originally transmit CID (Physical layer cell identity) in the PSS and SSS, or first expand and then redistribute, one part is allocated to the CID, and the other part is allocated to the GID. A proportional trade-off can be made between the demand for CID for inter-cell interference avoidance and the demand for GID by the planned number of wave positions.

Method 2:

The part that transmits the SSB index in the PBCH carries the beam coverage area number;

Redistribute the information bits originally transmitted in the SSB index (SSB index; SSB: synchronization signal/physical broadcast channel signal block (or synchronization signal block), Synchronization Signal and PBCH block) in the PBCH, or first expand and then redistribute, All or part of the assignment to the GID.

It should be noted that in 5G NR, in one SSB period, each SSB beam carries a different SSBindex when transmitting. The difference in this solution is that different beams of the same wavebit group carry the same GID.

Method 3:

The part that transmits additional bits in the PBCH carries the beam coverage area number;

Carry the beam coverage area number in the information bit part of the MIB;

Redistribute the information bits originally transmitted in the PBCH (additional timing related PBCH payload bits (additional timing related PBCH payload bits)) and/or MIB (Master Information Block), or after expansion Redistribute to achieve the purpose of carrying GID.

Method 4:

Use the SIB to carry the beam coverage area number.

The GID is transmitted using a SIB (System Information Block, System Information Block) or other resources.

6. Time synchronization pre-compensation based on wave groups.

In implementation, when the UE is turned on or when the beam position is reselected or the beam position group is reselected, the number of the beam coverage area carried in the beam signal is detected.

In a specific implementation, when at least two beam coverage area numbers are detected, the beam coverage area number carried by the beam signal with the best signal quality is used as the beam coverage area number.

Specifically, when a UE is turned on or when wave position reselection or wave position group reselection is performed, within a period of time, such as a wave position scanning period, it detects the GID in the received signal. If only one GID is detected, the This GID is used as the GID of the UE, and is recorded as UE_GID. If multiple GIDs are detected successively, the GID carried in the beam signal with the best signal quality is used as the UE_GID.

The function of UE_GID is to indicate the wave group to which the current wave position of the UE belongs, because the wave group has a one-to-one correspondence with the circular reference line, and each wave group surrounds a circular reference line, so UE_GID simultaneously It also indicates the closest reference line at the wave position of the UE, that is, C(UE_GID).

Using DC(UE_GID) as the estimated value of the UE's satellite-ground distance, the estimated value of the UE's RTT can be calculated, as follows:

Where c represents the speed of light, which is a constant, about 3E8 meters per second.

In implementation, it may further include:

Set TA=RTT_est-TA_margin, where RTT_est is the RTT determined according to the reference line, TA_margin is the protection margin for timing advance, and TA_margin is half of the detection window length, or the network notifies the UE in advance.

Figure 6 is a schematic diagram of the protection margin relationship of timing advance. As shown in the figure, the UE sets its timing advance value GTA (timing advance, Timing Advance) as:

GTA=RTT_est-TA_margin

Among them, TA_margin (TA edge) is the protection margin of timing advance (TA_margin≥0), which can be set to half of the detection window length, or take other values and notify the UE in advance by the network.

In the implementation, for the UE side: the UE uses Preamble to initiate random access on the PRACH according to the RO agreed with the communication satellite by the TA, including:

Based on the time when the UE receives the number of the beam coverage area, the UE initiates random access after a time interval RO Shift-TA, wherein the RO Shift is agreed between the UE and the communication satellite.

Correspondingly, for the communication satellite side, there are: the receiving UE uses the random access initiated by the Preamble on the PRACH in the RO agreed with the communication satellite, including:

Receiving the random access initiated by the UE after the time interval RO Shift-TA has elapsed based on the time when the UE receives the number of the beam coverage area, wherein the RO Shift is agreed between the UE and the communication satellite.

Specifically, after the base station (communication satellite) sends a signal carrying a GID, after a time interval RO Shift (RO Shift; RO: Access Opportunity, RACH Opportunity; RACH: Random Access Channel, Random Access Channel), an access channel is set. Entry time RO.

The time interval RO Shift is agreed upon by the network side and the UE through an agreement.

Based on the time when the GID is received, the UE sends a physical random access channel PRACH (Physical Random Access Channel, Physical Random Access Channel) after a time interval RO Shift-GTA.

It should be noted that, corresponding to the GID, there may be multiple ROs and their RO Shifts, and here only one of the available ROs and its RO Shifts is selected for description. The so-called availability includes satisfying the condition RO Shift-GTA-Tother≥0, where Tother (another) includes receiving and processing time and so on.

During implementation, when the Preamble arrives at the communication satellite, the deviation from the standard timing of the base station (communication satellite) is:

DTA=RTT_act-RTT_est+TA_margin

Among them, RTT_act represents the real RTT of the UE, RTT_est is the RTT determined according to the reference line, and TA_margin is the protection margin for timing advance.

Specifically, when the PRACH arrives at the base station (communication satellite), the deviation from the standard timing of the base station (communication satellite) is:

DTA=RTT_act-RTT_est+TA_margin

Among them, RTT_act represents the real (accurate) RTT of the UE. RTT_act-RTT_est may be a positive number or a negative number. After adding TA_margin, DTA can be guaranteed or guaranteed to be a positive number with a high probability, so that Preamble((random access channel ) preamble sequence, (RACH) Preamble) when it arrives at the base station (communication satellite), its starting point falls within the detection window.

In the specific implementation, for the UE side: it may further include:

After receiving the timing offset fed back by the communication satellite, the timing offset is used as an adjustment amount for the timing advance of the UE's subsequent uplink transmission.

Correspondingly, for the communication satellite side, after detecting the timing deviation of the arrival of the Preamble, the timing deviation is fed back to the UE, and the timing deviation is used as an adjustment amount for the timing advance of the UE's subsequent uplink transmission.

Specifically, after the base station (communication satellite) detects the timing deviation (equal to DTA) of the PRACH arrival, it feeds back this value to the UE as an adjustment amount for the timing advance of the UE's subsequent uplink transmission to achieve further uplink synchronization adjustment.

In implementation, it may further include:

advance the timing of the PRACH detection window by a margin TA_margin; and/or,

Adjust the guide line and wave pack planning pattern so that the guide line is close to the inside of the wave pack to make RTT_est smaller.

Other ways to achieve protection margin1:

As shown in FIG. 6 , in order to realize the function of the protection margin TA_margin, the following manner may also be adopted.

The base station (communication satellite) advances the timing of the PRACH detection window by a margin TA_margin, such as half the length of the detection window. The UE's TA precompensation value is set to:

GTA=RTT_est

Then when the PRACH arrives at the base station (communication satellite), the deviation from the standard timing of the base station (communication satellite) is:

DTA=RTT_act-RTT_est

DTA can be positive or negative, and can fall into the detection window.

The advantage of this solution is that TA_margin does not require the network to notify the UE.

Other ways to achieve protection margin2:

In order to realize the function of the protection margin TA_margin, the following solution may also be adopted.

As shown in Figure 5, the circular reference line C(1) shrinks to the sub-satellite point. Adjust the circular reference line and the wave group planning pattern so that the circular reference line is close to the inner side of the wave group, so that RTT_est is reduced. Set GTA=RTT_est, then DTA=RTT_act-RTT_est, DTA is a positive number, or a larger value Probability is positive.

Based on the same inventive concept, an embodiment of the present invention also provides a communication satellite, user equipment, and a computer-readable storage medium. Since the problem-solving principle of these equipment is similar to that of the random access method, the implementation of these equipment can be found in the method The implementation of this method will not be repeated here.

When implementing the technical solution provided by the embodiment of the present invention, it can be implemented in the following manner.

FIG. 7 is a schematic diagram of a UE structure. As shown in the figure, the user equipment includes:

The processor 700 is used to read the program in the memory 720 and execute the following processes:

receiving the beam signal, the beam signal carries the number of the beam coverage area, the beam coverage area is the area covered by the beam sent by the communication satellite on the ground, and the area covered by each beam has its own preset number;

Determine the area where the UE is located according to the number of the beam coverage area;

Determine the TA according to the positional relationship between the area and the communication satellite, the positional relationship is pre-acquired by the UE;

Use Preamble to initiate random access on PRACH according to the RO agreed with the communication satellite by TA;

The transceiver 710 is used for receiving and sending data under the control of the processor 700 .

In implementation, the beam coverage area is composed of a group of wave positions, and the wave positions are divided into multiple wave positions centered on the sub-satellite point within the entire ground coverage area of a communication satellite. Covers a wave position at a certain time.

In implementation, the positional relationship is a mapping table of the reference line and the distance between the satellite and the ground, wherein the reference line is a plurality of concentric satellite points planned within the entire ground coverage area of a communication satellite. Circular line, through the radius of the circular line, the angle between the center of the earth determines the distance between the star and the ground.

In practice, there is a one-to-one correspondence between wave position groups and reference lines, wherein the geometric center of any wave position is closest to the reference line.

During implementation, it further includes planning reference lines and wave positions in one of the following ways or a combination thereof:

The number of reference lines is determined according to the RTT and frequency offset estimation error threshold requirements;

Avoid a wave level crossing two or more circular reference lines;

The sum of the distances from the geometric center of gravity of all waves in the wave group to the reference line is the smallest.

In an implementation, the beam signal is one of the following signals or part of a combination of them:

PSS, SSS, PBCH.

In an implementation, the beam signal carries the beam coverage area number in one of the following ways or a combination thereof:

The part of the CID transmitted in the PSS or SSS carries the beam coverage area number;

The part that transmits the SSB index in the PBCH carries the beam coverage area number;

The part that transmits additional bits in the PBCH carries the beam coverage area number;

Carry the beam coverage area number in the information bit part of the MIB;

Use the SIB to carry the beam coverage area number.

In implementation, when the UE is turned on or when the beam position is reselected or the beam position group is reselected, the number of the beam coverage area carried in the beam signal is detected.

In implementation, it further includes:

When at least two beam coverage area numbers are detected, the beam coverage area number carried by the beam signal with the best signal quality is used as the beam coverage area number.

In implementation, it further includes:

Set TA=RTT_est-TA_margin, where RTT_est is the RTT determined according to the reference line, TA_margin is the protection margin for timing advance, and TA_margin is half of the detection window length, or the network notifies the UE in advance.

In the implementation, according to the RO agreed with the communication satellite by the TA, the Preamble is used to initiate random access on the PRACH, including:

Taking the time when the number of the beam coverage area is received as a reference, a random access is initiated after a time interval RO Shift-TA, wherein the RO Shift is agreed between the UE and the communication satellite.

During implementation, when the Preamble arrives at the communication satellite, the deviation from the standard timing of the base station (communication satellite) is:

DTA=RTT_act-RTT_est+TA_margin

Among them, RTT_act represents the real RTT of the UE, RTT_est is the RTT determined according to the reference line, and TA_margin is the protection margin for timing advance.

In implementation, it further includes:

Adjust the guide line and wave pack planning pattern so that the guide line is close to the inside of the wave pack to make RTT_est smaller.

In implementation, it further includes:

After receiving the timing offset fed back by the communication satellite, the timing offset is used as an adjustment amount for the timing advance of the UE's subsequent uplink transmission.

Wherein, in FIG. 7 , the bus architecture may include any number of interconnected buses and bridges, specifically one or more processors represented by the processor 700 and various circuits of the memory represented by the memory 720 are linked together. The bus architecture can also link together various other circuits, such as peripherals, voltage regulators, and power management circuits, etc., which are well known in the art and therefore will not be further described herein. The bus interface provides the interface. Transceiver 710 may be a plurality of elements, including a transmitter and a receiver, providing a means for communicating with various other devices over transmission media. For different user equipments, the user interface 730 may also be an interface capable of connecting externally and internally to required equipment, and the connected equipment includes but not limited to a keypad, a display, a speaker, a microphone, a joystick, and the like.

The processor 700 is responsible for managing the bus architecture and general processing, and the memory 720 can store data used by the processor 700 when performing operations.

An embodiment of the present invention also provides a user equipment, including:

The UE receiving module is used to receive the beam signal, the beam signal carries the number of the beam coverage area, the beam coverage area is the area covered by the beam sent by the communication satellite on the ground, and the area covered by each beam has its own preset number ;

A UE area module, configured to determine the area where the UE is located according to the beam coverage area number;

a UE TA module, configured to determine the TA according to the positional relationship between the area and the communication satellite, the positional relationship is acquired by the UE in advance;

The UE access module is configured to use the Preamble to initiate random access on the PRACH according to the RO agreed with the communication satellite by the TA.

In implementation, it further includes:

The area planning module is used to plan an area, wherein the beam coverage area is composed of a group of wave positions, and the wave positions are divided within the entire ground coverage area of a communication satellite with the sub-satellite point as the center Multiple wave positions, one beam covers one wave position at a certain moment.

In implementation, the area planning module is further used to plan the positional relationship, wherein the positional relationship is a mapping table of the reference line and the distance between the satellite and the ground, wherein the reference line is within the entire ground coverage area of a communication satellite, with With the sub-satellite point as the center, multiple concentric circular lines are planned, and the distance between the star and the ground is determined by the radius of the circular line and the angle between the center of the earth.

During implementation, the area planning module is further used to plan a one-to-one correspondence between wave position groups and reference lines, wherein the geometric center of any wave position is closest to the reference line.

During implementation, the area planning module is further used to plan reference lines and wave positions in one of the following ways or a combination thereof:

The number of reference lines is determined according to the RTT and frequency offset estimation error threshold requirements;

Avoid a wave level crossing two or more circular reference lines;

The sum of the distances from the geometric center of gravity of all waves in the wave group to the reference line is the smallest.

In an implementation, the UE receiving module is further configured to receive the beam signal of one of the following signals or a part of a combination thereof:

PSS, SSS, PBCH.

In implementation, the UE receiving module is further configured to receive the beam signal carrying the beam coverage area number in one of the following ways or a combination thereof:

The part of the CID transmitted in the PSS or SSS carries the beam coverage area number;

The part that transmits the SSB index in the PBCH carries the beam coverage area number;

The part that transmits additional bits in the PBCH carries the beam coverage area number;

Carry the beam coverage area number in the information bit part of the MIB;

Use the SIB to carry the beam coverage area number.

During implementation, the UE receiving module is further configured to detect the beam coverage area number carried in the beam signal when the UE is turned on or when the beam position reselection or beam position group reselection is performed.

In an implementation, the UE receiving module is further configured to use the beam coverage area number carried by the beam signal with the best signal quality as the beam coverage area number when at least two beam coverage area numbers are detected.

In implementation, the UE TA module is further used to set TA=RTT_est-TA_margin, where RTT_est is the RTT determined according to the reference line, TA_margin is the protection margin for timing advance, and TA_margin is half of the detection window length, or the network notifies the UE in advance .

During implementation, the UE access module is further used to initiate random access on the PRACH using Preamble according to the RO agreed upon by the TA with the communication satellite, including:

Based on the time when the UE receives the number of the beam coverage area, the UE initiates random access after a time interval RO Shift-TA, wherein the RO Shift is agreed between the UE and the communication satellite.

During implementation, the UE access module is further used to determine that when the Preamble arrives at the communication satellite, the deviation from the standard timing of the base station (communication satellite) is:

DTA=RTT_act-RTT_est+TA_margin

Among them, RTT_act represents the real RTT of the UE, RTT_est is the RTT determined according to the reference line, and TA_margin is the protection margin for timing advance.

During implementation, the area planning module is further used to adjust the reference line and the wave set planning pattern, so that the reference line is close to the inside of the wave set, so as to reduce the RTT_est.

During implementation, the UE receiving module is further configured to receive the timing offset fed back by the communication satellite, and use the timing offset as an adjustment amount for the timing advance of the UE's subsequent uplink transmission.

For the convenience of description, each part of the device described above is divided into various modules or units by function and described separately. Of course, when implementing the present invention, the functions of each module or unit can be implemented in one or more pieces of software or hardware.

Figure 8 is a schematic diagram of the structure of a communication satellite. As shown in the figure, the communication satellite includes:

The processor 800 is used to read the program in the memory 820 and execute the following processes:

Sending a beam signal to the UE, the beam signal carrying the number of the beam coverage area, the beam coverage area is the area covered by the beam sent by the communication satellite on the ground, and the area covered by each beam has its own preset number;

Receive the random access initiated by the UE on the PRACH using Preamble on the RO agreed with the communication satellite;

The transceiver 810 is used for receiving and sending data under the control of the processor 800 .

In implementation, the beam coverage area is composed of a group of wave positions, and the wave positions are divided into multiple wave positions centered on the sub-satellite point within the entire ground coverage area of a communication satellite. Covers a wave position at a certain time.

In an implementation, the beam signal is one of the following signals or part of a combination of them:

PSS, SSS, PBCH.

In an implementation, the beam signal carries the beam coverage area number in one of the following ways or a combination thereof:

The part of the CID transmitted in the PSS or SSS carries the beam coverage area number;

The part that transmits the SSB index in the PBCH carries the beam coverage area number;

The part that transmits additional bits in the PBCH carries the beam coverage area number;

Carry the beam coverage area number in the information bit part of the MIB;

Use the SIB to carry the beam coverage area number.

In implementation, it further includes:

Inform the UE of TA_margin, the TA_margin is used to set TA=RTT_est-TA_margin, where RTT_est is the RTT determined according to the reference line, and TA_margin is the protection margin for timing advance.

In the implementation, the receiving UE uses the random access initiated by Preamble on the PRACH in the RO agreed with the communication satellite, including:

Receiving the random access initiated by the UE after the time interval RO Shift-TA has elapsed based on the time when the UE receives the number of the beam coverage area, wherein the RO Shift is agreed between the UE and the communication satellite.

In implementation, it further includes:

advance the timing of the PRACH detection window by a margin TA_margin; and/or,

Adjust the guide line and wave pack planning pattern so that the guide line is close to the inside of the wave pack to make RTT_est smaller.

In implementation, it further includes:

After the timing deviation of the arrival of the Preamble is detected, the timing deviation is fed back to the UE, and the timing deviation is used as an adjustment amount for the timing advance of the UE's subsequent uplink transmission.

Wherein, in FIG. 8 , the bus architecture may include any number of interconnected buses and bridges, specifically one or more processors represented by the processor 800 and various circuits of the memory represented by the memory 820 are linked together. The bus architecture can also link together various other circuits, such as peripherals, voltage regulators, and power management circuits, etc., which are well known in the art and therefore will not be further described herein. The bus interface provides the interface. Transceiver 810 may be a plurality of elements, including a transmitter and a receiver, providing a means for communicating with various other devices over transmission media. The processor 800 is responsible for managing the bus architecture and general processing, and the memory 820 can store data used by the processor 800 when performing operations.

A communication satellite is also provided in an embodiment of the present invention, including:

The satellite sending module is used to send a beam signal to the UE. The beam signal carries the number of the beam coverage area. The beam coverage area is the area covered by the beam sent by the communication satellite on the ground. The area covered by each beam has its own preset number of

The satellite receiving module is used to receive the random access initiated by the UE on the PRACH using the Preamble on the RO agreed with the communication satellite.

During implementation, the area planning module is further used to plan the beam coverage area, the beam coverage area is composed of a group of wave positions, and the wave positions are within the entire ground coverage area of a communication satellite, with sub-satellite point As the center, divided into multiple wave positions, one beam covers one wave position at a certain moment.

In implementation, the satellite sending module is further used to send the beam signal of one of the following signals or a part of a combination of the signals:

PSS, SSS, PBCH.

In implementation, the satellite sending module is further used to carry the beam signal with the beam coverage area number in one of the following ways or a combination thereof:

The part of the CID transmitted in the PSS or SSS carries the beam coverage area number;

The part that transmits the SSB index in the PBCH carries the beam coverage area number;

The part that transmits additional bits in the PBCH carries the beam coverage area number;

Carry the beam coverage area number in the information bit part of the MIB;

Use the SIB to carry the beam coverage area number.

In implementation, the satellite sending module is further used to notify the UE of TA_margin, and the TA_margin is used to set TA=RTT_est-TA_margin, where RTT_est is the RTT determined according to the reference line, and TA_margin is the protection margin for timing advance.

In the implementation, the satellite receiving module is further used to receive the random access initiated by the UE on the PRACH using the Preamble on the RO agreed with the communication satellite, including:

Receiving the random access initiated by the UE after the time interval RO Shift-TA has elapsed based on the time when the UE receives the number of the beam coverage area, wherein the RO Shift is agreed between the UE and the communication satellite.

In implementation, the satellite receiving module is further used to advance the timing of the PRACH detection window by a margin TA_margin; and/or,

Adjust the guide line and wave pack planning pattern so that the guide line is close to the inside of the wave pack to make RTT_est smaller.

During implementation, the satellite receiving module is further used to detect the timing deviation of the Preamble arrival, feed back the timing deviation to the UE, and use the timing deviation as an adjustment amount for the timing advance of the UE's subsequent uplink transmission.

For the convenience of description, each part of the device described above is divided into various modules or units by function and described separately. Of course, when implementing the present invention, the functions of each module or unit can be implemented in one or more pieces of software or hardware.

An embodiment of the present invention also provides a computer-readable storage medium, where the computer-readable storage medium stores a computer program for executing the above random access method.

For specific implementation, reference may be made to the implementation of the random access method on the UE side and/or the communication satellite side.

Those skilled in the art should understand that the embodiments of the present invention may be provided as methods, systems, or computer program products. Accordingly, the present invention can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each procedure and/or block in the flowchart and/or block diagram, and a combination of procedures and/or blocks in the flowchart and/or block diagram can be realized by computer program instructions. These computer program instructions may be provided to a general purpose computer, special purpose computer, embedded processor, or processor of other programmable data processing equipment to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing equipment produce a An apparatus for realizing the functions specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to operate in a specific manner, such that the instructions stored in the computer-readable memory produce an article of manufacture comprising instruction means, the instructions The device realizes the function specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions can also be loaded onto a computer or other programmable data processing device, causing a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process, thereby The instructions provide steps for implementing the functions specified in the flow chart or blocks of the flowchart and/or the block or blocks of the block diagrams.

Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims (27)

1. A random access method, comprising:

receiving a beam signal by User Equipment (UE), wherein the beam signal carries a beam coverage area number, the beam coverage area is an area covered on the ground by a beam sent by a communication satellite, and the area covered by each beam has a preset number;

the UE determines the area where the UE is located according to the beam coverage area number;

the UE determines a timing advance TA according to the position relation between the area and the communication satellite, wherein the position relation is acquired by the UE in advance;

and the UE initiates random access on a physical random access channel PRACH by using a Preamble sequence Preamble according to the TA at the access opportunity RO appointed by the communication satellite.

2. The method of claim 1, wherein the beam coverage area is formed by a plurality of wave bits divided around a sub-satellite point within an entire terrestrial coverage area of a communication satellite, a beam covering a wave bit at a time.

3. The method of claim 2, wherein the position relationship is a mapping table of reference lines and satellite-to-ground distances, wherein the reference lines are a plurality of concentric circular lines planned by taking a sub-satellite point as a center within the whole ground coverage area of one communication satellite, and the satellite-to-ground distances are determined by the radius of the circular lines and the earth-center angle.

4. The method of claim 3, wherein the groups of wave bits are one-to-one mapped to reference lines, wherein the geometric center of any one wave bit is closest to the reference line.

5. The method of claim 4, further comprising reference line and wave position planning in one or a combination of the following ways:

the number of the reference lines is determined according to the requirements of the two-way transmission time delay RTT and the frequency offset estimation error threshold;

avoiding one wave position crossing two or more circular reference lines;

the sum of the distances from the geometric barycenter of all wave bits in the wave bit group to the reference line is the smallest.

6. The method of claim 1, wherein the beam signal is part of a signal that is one of, or a combination of:

primary synchronization signal PSS, secondary synchronization signal SSS, physical broadcast channel PBCH.

7. The method of claim 6, wherein the beam signals carry a beam coverage area number by one or a combination of:

transmitting part of physical cell identification CID in PSS or SSS to carry beam coverage area number;

transmitting a part of a synchronization signal block index SSB index in PBCH to carry a beam coverage area number;

transmitting the additional bits in the PBCH, the additional bits carrying the beam coverage area number;

the part of the information bits of the main system information block MIB carries the number of the beam coverage area;

the beam coverage area number is carried using the system information block SIB.

8. The method of claim 1, wherein the beam coverage area number carried in the beam signal is detected when the UE is powered on or at a wave position reselection or a wave position group reselection.

9. The method of claim 8, further comprising:

and when at least two beam coverage area numbers are detected, taking the beam coverage area number carried by the beam signal with the optimal signal quality as the beam coverage area number.

10. The method of any of claims 1 to 9, further comprising:

setting TA = RTT _ est-TA _ margin, where RTT _ est is RTT determined according to a reference line, TA _ margin is a guard margin of timing advance, and TA _ margin is half of a detection window length, or notifying the UE in advance by a network.

11. The method of claim 1, wherein the UE initiates random access using Preamble on PRACH at RO agreed with the communication satellite according to TA, comprising:

and the UE initiates random access after a time interval RO Shift-TA by taking the time of receiving the number of the beam coverage area as a reference, wherein the access opportunity Shift RO Shift is agreed by the UE and a communication satellite.

12. The method of claim 1, wherein the Preamble arrives at the communications satellite with a standard timing deviation from the communications satellite of:

DTA＝RTT_act-RTT_est+TA_margin

RTT _ act represents the real RTT of the UE, RTT _ est is the RTT determined according to the reference line, and TA _ margin is the protection margin of the timing advance.

13. The method of claim 12, further comprising:

the reference line and the waveform group planning pattern are adjusted to make the reference line close to the inner side of the waveform group so as to reduce RTT _ est.

14. The method of claim 1, further comprising:

and after receiving the timing deviation fed back by the communication satellite, taking the timing deviation as an adjustment quantity of the timing advance of the subsequent uplink transmission of the UE.

15. A random access method, comprising:

a communication satellite sends a beam signal to UE, wherein the beam signal carries a beam coverage area number, the beam coverage area is an area covered by a beam sent by the communication satellite on the ground, and the area covered by each beam has a preset number;

and the communication satellite receives the random access initiated by the UE on the PRACH by using the Preamble at the RO appointed by the communication satellite.

16. The method of claim 15, wherein the beam coverage area is formed by a plurality of wave bits divided around a sub-satellite point within an entire terrestrial coverage area of a communication satellite, and a beam covers one wave bit at a time.

17. The method of claim 15, wherein the beam signal is part of a signal that is one of, or a combination of:

PSS、SSS、PBCH。

18. the method of claim 17, wherein the beam signals carry a beam coverage area number by one or a combination of:

the part carrying CID in PSS or SSS carries the beam coverage area number;

transmitting the SSB index in PBCH, wherein the part of the SSB index carries the beam coverage area number;

the part of the additional bits transmitted in the PBCH carries the beam coverage area number;

the part of the information bits of the MIB carries the number of a beam coverage area;

the SIB is used to carry the beam coverage area number.

19. The method of claim 15, further comprising:

notifying the UE of TA _ margin, which is used for setting TA = RTT _ est-TA _ margin, wherein RTT _ est is RTT determined according to a reference line, and TA _ margin is a guard margin of timing advance.

20. The method of claim 15, wherein receiving a random access initiated by a UE using a Preamble on a PRACH at an RO agreed with a communication satellite, comprises:

and receiving the random access initiated by the UE after a time interval RO Shift-TA by taking the time of receiving the beam coverage area number as a reference, wherein the RO Shift is agreed by the UE and the communication satellite.

21. The method of claim 15, further comprising:

advancing the timing of a PRACH detection window by a margin TA _ margin; and/or the presence of a gas in the gas,

the reference line and the waveform group planning pattern are adjusted to make the reference line close to the inner side of the waveform group so as to reduce RTT _ est.

22. The method of claim 15, further comprising:

and after detecting the timing deviation of the Preamble, feeding the timing deviation back to the UE, and taking the timing deviation as the adjustment quantity of the timing advance sent by the UE in the subsequent uplink.

23. A user device, comprising:

a processor for reading the program in the memory, performing the following processes:

receiving a beam signal, wherein the beam signal carries a beam coverage area number, the beam coverage area is an area covered by a beam sent by a communication satellite on the ground, and the area covered by each beam has a preset number;

determining the area where the UE is located according to the beam coverage area number;

determining TA according to the position relation between the area and a communication satellite, wherein the position relation is acquired by UE in advance;

initiating random access on the PRACH by using a Preamble according to the RO appointed by the TA and the communication satellite;

a transceiver for receiving and transmitting data under the control of the processor.

24. A user device, comprising:

the UE receiving module is used for receiving beam signals, wherein the beam signals carry beam coverage area numbers, the beam coverage area is an area covered by beams sent by a communication satellite on the ground, and the area covered by each beam has a preset number;

the UE area module is used for determining the area where the UE is located according to the beam coverage area number;

a TA module of the UE, which is used for determining TA according to the position relation between the area and the communication satellite, wherein the position relation is acquired by the UE in advance;

and the UE access module is used for initiating random access on the PRACH by using a Preamble according to the RO agreed by the TA and the communication satellite.

25. A communications satellite, comprising:

a processor for reading the program in the memory, performing the following processes:

sending a beam signal to UE, wherein the beam signal carries a beam coverage area number, the beam coverage area is an area covered by a beam sent by a communication satellite on the ground, and each beam coverage area has a preset number;

receiving random access initiated by UE on PRACH by using Preamble on RO appointed by communication satellite;

a transceiver for receiving and transmitting data under the control of the processor.

26. A communication satellite, comprising:

the satellite transmission module is used for transmitting beam signals to the UE, wherein the beam signals carry beam coverage area numbers, the beam coverage area is an area covered on the ground by beams transmitted by a communication satellite, and the area covered by each beam has a preset number;

and the satellite receiving module is used for receiving the random access initiated by the UE on the PRACH by using the Preamble on the RO appointed by the communication satellite.

27. A computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program for executing the method of any one of claims 1 to 22.

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