CN115694592A

CN115694592A - Random access method, equipment and storage medium

Info

Publication number: CN115694592A
Application number: CN202110832641.3A
Authority: CN
Inventors: 丁勇; 云翔
Original assignee: Baicells Technologies Co Ltd
Current assignee: Baicells Technologies Co Ltd
Priority date: 2021-07-22
Filing date: 2021-07-22
Publication date: 2023-02-03

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

Random access method, equipment and storage medium

Technical Field

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

Background

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

The defects of the prior art are as follows: no scheme is provided for the user equipment to calculate the timing advance.

Disclosure of Invention

The invention provides a random access method, equipment and a storage medium, which are used for providing a scheme for calculating timing advance by user equipment.

The invention provides the following technical scheme:

a random access method, comprising:

the method comprises the steps that UE receives beam signals, wherein the beam signals carry beam coverage area numbers, 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;

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

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 agreed by the TA and the communication satellite.

In an implementation, the beam coverage area is formed by a group of wave positions, the wave positions are a plurality of wave positions which are divided by taking a sub-satellite point as a center in the whole ground coverage area of one communication satellite, and one beam covers one wave position at a certain moment.

In implementation, the position relationship is a mapping table of a reference line and a satellite-ground distance, wherein the reference line is a plurality of concentric circular lines planned by taking a sub-satellite point as a center in the whole ground coverage area of one communication satellite, and the satellite-ground distance is determined by the radius of the circular line and the earth center included angle.

In implementation, the wave bit groups are in one-to-one correspondence with the reference lines, wherein the geometric center of any one wave bit is closest to the reference line.

In an implementation, the method further comprises the following steps of planning the reference line and the wave position according to one or a combination of the following modes:

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

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.

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

PSS、SSS、PBCH。

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

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 the beam coverage area;

SIB is used to carry the beam coverage area number.

In implementation, when the UE is powered on or during the wave position reselection or the wave position group reselection, the beam coverage area number carried in the beam signal is detected.

In an implementation, the method further comprises the following steps:

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.

In an implementation, the method further comprises the following steps:

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.

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

and the UE initiates random access 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.

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

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.

In an implementation, the method further comprises the following steps:

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.

In an implementation, the method further comprises the following steps:

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.

A random access method, comprising:

the method comprises the steps that a communication satellite sends beam signals to UE, wherein the beam signals carry beam coverage area numbers, the beam coverage areas are areas covered on the ground by beams sent by the communication satellite, and the areas covered by the beams have respective preset numbers;

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

In an implementation, the beam coverage area is formed by a group of wave positions, the wave positions are a plurality of wave positions divided by taking a sub-satellite point as a center in the whole ground coverage area of a communication satellite, and a beam covers one wave position at a certain moment.

PSS、SSS、PBCH。

in an implementation, the beam signal carries a beam coverage area number by one or a combination of the following methods:

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

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

In an implementation, the method further comprises the following steps:

notifying the UE of TA _ margin, wherein the TA _ margin 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 protection margin of timing advance.

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

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.

In an implementation, the method further comprises the following steps:

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

In an implementation, the method further comprises the following steps:

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.

A user equipment, comprising:

a processor for reading the program in the memory and executing 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 of the UE according to the number of the beam coverage area;

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 agreed by the TA with the communication satellite;

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

In implementation, the position relationship is a mapping table of a reference line and a satellite-to-ground distance, where the reference line is a plurality of concentric circular lines planned within the entire ground coverage area of one communication satellite and centered on a sub-satellite point, and the satellite-to-ground distance is determined by the radius of the circular line and an included angle of a ground center.

In an implementation, the method further comprises the step of planning the reference line and the wave position according to one of the following modes or a combination of the following modes:

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

PSS、SSS、PBCH。

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

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

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

In an implementation, the method further comprises the following steps:

In implementation, initiating random access on the PRACH by using a Preamble according to the TA on the RO agreed with the communication satellite, including:

and initiating 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 RO Shift is appointed by the UE and the communication satellite.

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

DTA＝RTT_act-RTT_est+TA_margin

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

In an implementation, the method further comprises the following steps:

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

A user equipment, 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 on the ground by beams sent by a communication satellite, 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.

In an implementation, the method further comprises the following steps:

the area planning module is used for planning an area, wherein the wave beam coverage area is formed by a group of wave positions, the wave positions are a plurality of wave positions which are divided by taking a sub-satellite point as a center in the whole ground coverage area of one communication satellite, and one wave beam covers one wave position at a certain moment.

In an implementation, the area planning module is further configured to plan a location relationship, where the location relationship is a mapping table of a reference line and a satellite-to-ground distance, where the reference line is a plurality of concentric circular lines planned within an entire ground coverage area of one communication satellite and centered on a sub-satellite point, and the satellite-to-ground distance is determined by a radius of the circular line and an included angle between a ground center and the circular line.

In an implementation, the region planning module is further configured to plan a one-to-one correspondence between the wave position groups and the reference lines, where a geometric center of any one wave position is closest to the reference line.

In an implementation, the area planning module is further configured to perform reference line and wave position planning in one or a combination of the following manners:

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

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

PSS、SSS、PBCH。

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

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

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

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

In an implementation, the UE receiving module is further configured to detect a beam coverage area number carried in the beam signal when the UE is powered on or during a wave position reselection or a wave position group reselection.

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

In an implementation, the UE TA module is further configured to set 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 a half of a detection window length, or the UE is notified by a network in advance.

In an implementation, the UE access module is further configured to initiate random access on the PRACH using the Preamble according to the TA on the RO agreed with the communication satellite, including:

In implementation, the UE access module is further configured 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

In an implementation, the region planning module is further configured to adjust the reference line and the waveform group planning pattern to make the reference line close to the inner side of the waveform group, so as to reduce RTT _ est.

In an implementation, the UE receiving module is further configured to, after receiving the timing offset fed back by the communication satellite, use the timing offset as an adjustment amount of a timing advance of a subsequent uplink transmission of the UE.

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 on the ground by a beam sent by a communication satellite, and the area covered by each beam has a preset number;

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

PSS、SSS、PBCH。

the part transmitting CID in PSS or SSS 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.

In an implementation, the method further comprises the following steps:

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.

In implementation, the receiving UE receives a random access initiated by the UE on the PRACH by using a Preamble agreed with a communication satellite, including:

In an implementation, the method further comprises the following steps:

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

In an implementation, the method further comprises the following steps:

A communications 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.

In an implementation, the area planning module is further configured to plan the beam coverage area, where the beam coverage area is formed by a group of wave positions, the wave positions are a plurality of wave positions divided by taking a sub-satellite point as a center in an entire ground coverage area of one communication satellite, and one beam covers one wave position at a time.

In an implementation, the satellite transmission module is further configured to transmit the beam signal of a portion of one or a combination of the following signals:

PSS、SSS、PBCH。

in an implementation, the satellite transmission module is further configured to carry the beam signal with the beam coverage area number by one of the following manners or a combination thereof:

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

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

In an implementation, the satellite sending module is further configured to notify the UE of TA _ margin, where TA _ margin is used to set TA = RTT _ est-TA _ margin, where RTT _ est is RTT determined according to a reference line, and TA _ margin is a guard margin of timing advance.

In an implementation, the satellite receiving module is further configured to receive a random access initiated by the UE on the PRACH by using the Preamble on the RO agreed with the communication satellite, and includes:

In implementation, the satellite receiving module is further configured to advance the timing of the PRACH detection window by a margin TA _ margin; and/or the presence of a gas in the atmosphere,

In implementation, the satellite receiving module is further configured to, after detecting a timing offset at which the Preamble arrives, feed back the timing offset to the UE, and use the timing offset as an adjustment amount of a timing advance for subsequent uplink transmission by the UE.

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

The invention has the following beneficial effects:

in the technical scheme provided by the embodiment of the invention, because the beam signal sent by the communication satellite carries the beam coverage area number, the UE can acquire the position, the TA can be determined according to the position relation between the area and the communication satellite acquired in advance, such as the satellite-to-ground distance, and the random access can be initiated according to the TA.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic flow chart of a random access method implemented by a UE side in an embodiment of the present invention;

fig. 2 is a schematic flow chart of an implementation of a random access method at a communication satellite side according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a relationship between a satellite and a wave position according to an embodiment of the present invention;

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

FIG. 5 is a schematic diagram of a byte plan according to an embodiment of the present invention;

FIG. 6 is a diagram illustrating a relationship between timing advance protection margins according to an embodiment of the present invention;

FIG. 7 is a diagram illustrating a UE structure according to an embodiment of the present invention;

fig. 8 is a schematic structural diagram of a communication satellite according to an embodiment of the present invention.

Detailed Description

The following describes embodiments of the present invention with reference to the drawings.

In the description process, the implementation of the UE and the communication satellite base station side will be described separately, and then an example of the implementation of the UE and the communication satellite base station side 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 in cooperation or separately, and actually, when the UE and the communication satellite are implemented separately, the UE and the communication satellite respectively solve the problems on the UE side and the communication satellite base station side, and when the UE and the communication satellite are used in combination, a better technical effect is obtained.

Fig. 1 is a schematic flow chart of an implementation of a random access method on a UE side, as shown in the figure, the method includes:

step 101, receiving a beam signal by 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;

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

and step 104, the UE uses Preamble on PRACH according to RO appointed by the TA and the communication satellite to initiate random access.

Fig. 2 is a schematic flow chart of an implementation of a random access method at a communication satellite side, as shown in the figure, including:

step 201, a communication satellite sends a beam signal to a 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 each beam coverage area has a preset number;

step 202, the communication satellite receives the random access initiated by the UE on the PRACH by using the Preamble on the RO appointed by the communication satellite.

The following description will be made of the implementation of the wave position planning scheme and the time synchronization pre-compensation scheme based on the wave position group for communication of the communication satellite.

The beam coverage area will be specifically described by the wave bits, wave bit groups, and accordingly, the beam coverage area number will be described by the wave bit group number GID in the embodiment.

1. The beam.

A communication satellite transmits its signals using multiple beams, covering its entire service area. The beams can work simultaneously or in a time-sharing mode in a scanning mode.

The communication satellite has long communication radio propagation distance, large path loss and high requirement on transmission power, and the transmission power is limited because the power consumption is directly related to the total cost of design, production and transmission of the communication satellite. The advantages of using multiple beams are: the narrower the wave beam, the higher the wave beam gain, and can overcome the problem of insufficient signal power at the receiving end caused by limited transmitting power and large link loss, which is one of the important technical means of communication satellite communication, especially low-orbit small communication satellite.

2. Wave position.

Specifically, fig. 3 is a schematic diagram of a relationship between a satellite and wave positions, and as shown in the figure, a plurality of wave positions are divided by taking a sub-satellite point as a center in the entire ground coverage area of one communication satellite. The corresponding relation between the wave position and the wave beam is as follows: one beam covers one wave bit at a time. The size and shape of the individual wave bits need not be the same.

3. Reference line.

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

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

And the earth center included angle of C (i) is marked as AC (i) and represents the included angle between any point on C (i) and the point under the star relative to the earth center.

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

Once established, the plan for the reference line remains stable (unchanged prior to replanning).

The UE (User Equipment) knows in advance from the network the mapping table DC (i), i =1,2. This mapping table does not need to be updated frequently due to the stability of the reference line and wave bit group plans.

By way of example, circular reference lines C (i) are numbered sequentially from smaller to larger radii RC (i).

4. A group of wavelets.

In an implementation, the wave bit groups are in one-to-one correspondence with the reference lines, wherein the geometric center of any one wave bit is closest to the reference line.

Fig. 5 is a schematic diagram of the wave-bit group planning, in which the number marked in each wave bit is the wave-bit group number, and as shown in the figure, all the wave bits are divided into N wave-bit groups, which are denoted as G (i), i =1, 2.

The wave bit group G (i) contains the number of wave bits Ki, and the number of wave bits in different wave bit groups is not necessarily equal. The kth wave position in the wave position group G (i) is denoted as B (i, k), i =1, 2.

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 intersatellite point is denoted as RP (i, k). The distance between P (i, k) and the circular reference line C (j) is designated as DP (i, k, j),

DP(i,k,j)＝abs[RP(i,k)-RC(j)]

wherein i =1,2,.. Ang, N, k =1,2,. Ang, ki, j =1,2,. Ang, N, abs are absolute values.

The way of planning the wave bit group may be:

the reference line C (i) of the wave bit group G (i) corresponds to one, and the geometric center of any one wave bit is nearest to the reference line C (i), namely:

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

through the wave position group planning, each wave position in a communication satellite coverage area is roughly divided into a plurality of annular areas taking a circular reference line as a center.

Further comprising performing reference line and wave position planning in one or a combination of the following ways:

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

Specifically, as an optimization principle of the reference line and wave position planning, the following method can be implemented:

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

the circular reference line should not be too sparse, otherwise, some wave bits are too far away from the circular reference line, resulting in too large RTT (Round Trip Time) and frequency offset estimation error.

(2) Avoiding one wave position crossing two or more circular reference lines;

if not necessary, one wave bit is prevented from crossing two or more circular reference lines, otherwise the wave bit means that the circular reference lines are too dense, the number of wave bit groups is too large, and the utilization efficiency of the wave bit group number is low.

(3) 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.

If the groups of wave bits have been substantially determined and further optimization of the position of the circular reference line is required, one optimization scheme is: the sum of the distances from the geometric barycenter of all wave bits in the wave bit group to the reference line thereof is the smallest.

The byte-group plan, once established, remains stable, i.e., unchanged prior to re-planning. For GEO (Geostationary Orbit) the communications satellite is stationary with respect to the ground and the wave-bit pattern is static and stable with respect to the ground. For MEO (Medium Earth Orbit) and LEO (Low Earth Orbit) the wave bits move to Earth following the communication satellite, but the wave bit group planning pattern has stability with respect to the communication satellite.

5. Transmission of the byte number.

PSS、SSS、PBCH。

specifically, the communication satellite may transmit the tuple number GID to the UE through the beam signal.

When a beam points to a wave position B (i, k), i =1,2,.. Ang, N, k =1,2,.. Ang, ki, then the wave position group number information GID = i of the wave position is carried in the beam signal.

The beam Signal may be a part of PSS (Primary Synchronization Signal), SSS (Secondary Synchronization Signal), PBCH (Physical Broadcast Channel), for 3gpp NTN (Non-Terrestrial Networks), or other communication systems derived based on 4G LTE (4 th Generation Long Term Evolution technology) or 5G NR (5 th Generation New Radio) or 4G LTE (4 th Generation mobile communication system — Long Term Evolution technology).

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

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

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

The following description is made.

Mode 1:

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

the information bits of the original transport CID (Physical cell identity) in the PSS and SSS are reallocated, or are expanded and then reallocated, one part is allocated to the CID and the other part is allocated to the GID. The requirement of inter-cell interference avoidance on CID and the requirement of planning number of wave bit groups on GID can be considered to be subjected to proportional compromise distribution.

Mode 2:

the information bits originally transmitted by the SSB index (SSB: synchronization Signal/physical broadcast channel Signal block (or Synchronization Signal block), synchronization Signal and PBCH block) in the PBCH are reallocated, or are expanded and reallocated, and are fully or partially allocated to the GID.

It should be noted that in the 5G NR, each SSB beam carries a different SSB index when transmitting in one SSB period, and the difference of the scheme is that different beams of the same set of beams carry the same GID.

Mode 3:

the original Information bits of the PBCH that transmit additional bits (additional timing-related PBCH payload bits)) and/or MIB (Master Information Block) are reallocated, or reallocated after being expanded, to achieve the purpose of carrying GID.

Mode 4:

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

The GID is transmitted using an SIB (System Information Block) or other resource.

6. Time synchronization pre-compensation based on the set of wavelets.

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

Specifically, when a UE is powered on or during a wave position reselection or a wave position group reselection, GIDs in a received signal are detected within a period of time, such as a wave position scanning period, and if only one GID is detected, the GID is taken as the GID of the UE and is denoted as UE _ GID. And if a plurality of GIDs are detected successively, the GID carried in the beam signal with the optimal signal quality is taken as the UE _ GID.

The UE _ GID is used to indicate the wave bit group to which the wave bit of the UE currently belongs, and since the wave bit group has a one-to-one correspondence relationship with the circular reference line, and each wave bit group surrounds one circular reference line, the UE _ GID also indicates the reference line, i.e., C (UE _ GID), to which the wave bit of the UE is closest.

DC (UE _ GID) is used as an estimate of the UE's range to satellite, so that an estimate of the UE's RTT can be calculated as follows:

where c represents the speed of light and is a constant, approximately 3E8 meters per second.

In an implementation, the method may further include:

Fig. 6 is a schematic diagram of a protection margin relationship of Timing Advance, as shown in the figure, the UE sets a value GTA (Timing Advance) of the Timing Advance to:

GTA＝RTT_est-TA_margin

the TA _ margin is a guard margin (TA _ margin ≧ 0) for timing advance, and may be set to half the length of the detection window, or take another value and be notified to the UE by the network in advance.

In implementation, for the UE side, there are: the UE initiates random access on the PRACH by using a Preamble according to the RO agreed by the TA with the communication satellite, and the method comprises the following steps:

Accordingly, for the communication satellite side there are: receiving random access initiated by UE on PRACH by using Preamble at RO agreed with communication satellite, including:

Specifically, after a base station (communication satellite) transmits a signal carrying a GID, an Access timing RO is set after a time interval RO Shift (RO offset; RO: access timing, RACH Opportunity; RACH: random Access Channel).

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

The UE transmits a Physical Random Access Channel (PRACH) after a time interval RO Shift-GTA with reference to the time when the GID is received.

It should be noted that, corresponding to the GID, there may be a plurality of ROs and their RO shifts, and only one of the available ROs and their RO shifts is selected for description herein. By available, it is meant that the condition RO Shift-GTA-Tother ≧ 0 is satisfied, where Tother (the other) includes reception and processing time, and the like.

DTA＝RTT_act-RTT_est+TA_margin

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

the RTT _ act represents a true (accurate) RTT of the UE, and the RTT _ act-RTT _ est may be a positive number or a negative number, and after the TA _ margin is added, it may be guaranteed that the DTA is a positive number or is guaranteed with a relatively high probability, so that when a Preamble ((random access channel) Preamble sequence, (RACH) Preamble) arrives at a base station (communication satellite), a starting point of the Preamble falls within a detection window.

In specific implementation, for the UE side, there are: the method can further comprise the following steps:

Accordingly, for the communication satellite side there are: 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.

Specifically, after detecting a timing offset (equal to DTA) of PRACH arrival, the base station (communication satellite) feeds back the value to the UE as an adjustment amount of timing advance for subsequent uplink transmission by the UE, thereby implementing further uplink synchronization adjustment.

In an implementation, the method may further include:

Other modes of implementing the protection margin 1:

as shown in fig. 6, in order to realize the function of the guard margin TA _ margin, the following manner may be adopted.

The base station (communication satellite) advances the timing of the PRACH detection window by a margin TA _ margin, e.g. half the length of the detection window. The TA precompensation value of the UE is set as:

GTA＝RTT_est

the PRACH arrives at the base station (communication satellite) with a standard timing deviation from the base station (communication satellite) of:

DTA＝RTT_act-RTT_est

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

The benefit of this scheme is that TA _ margin does not require the network to inform the UE.

Other modes of implementing the protection margin 2:

in order to realize the function of the protection margin TA _ margin, the following scheme may be adopted.

As shown in fig. 5, where the circular reference line C (1) converges to the sub-satellite point. And adjusting the circular reference line and the waveform group planning pattern to enable the circular reference line to be close to the inner side of the waveform group, so that RTT _ est is reduced, and setting GTA = RTT _ est, wherein DTA = RTT _ act-RTT _ est and DTA is a positive number or a positive number with a larger probability.

Based on the same inventive concept, the embodiment of the invention also provides a communication satellite, user equipment and a computer readable storage medium, and because the principle of solving the problems of the equipment is similar to the random access method, the implementation of the equipment can refer to the implementation of the method, and repeated parts are not described again.

When the technical scheme provided by the embodiment of the invention is implemented, the implementation can be carried out as follows.

Fig. 7 is a schematic structural diagram of a UE, and as shown in the figure, the UE includes:

the processor 700, which is used to read the program in the memory 720, executes the following processes:

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

a transceiver 710 for receiving and transmitting data under the control of the processor 700.

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

PSS、SSS、PBCH。

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

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

In implementation, when the UE is powered on or during wave position reselection or wave position group reselection, the beam coverage area number carried in the beam signal is detected.

In an implementation, the method further comprises the following steps:

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

DTA＝RTT_act-RTT_est+TA_margin

In an implementation, the method further comprises the following steps:

Where in fig. 7, the bus architecture may include any number of interconnected buses and bridges, with various circuits being linked together, particularly one or more processors represented by processor 700 and memory represented by memory 720. The bus architecture may also link together various other circuits such as peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further herein. The bus interface provides an interface. The transceiver 710 may be a plurality of elements including a transmitter and a receiver that provide a means for communicating with various other apparatus over a transmission medium. The user interface 730 may also be an interface capable of interfacing with a desired device for different user devices, including but not limited to a keypad, display, speaker, microphone, joystick, etc.

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

The embodiment of the invention also provides user equipment, which comprises:

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

In an implementation, the method further comprises the following steps:

In an implementation, the area planning module is further configured to plan a location relationship, where the location relationship is a mapping table of a reference line and a satellite-ground distance, where the reference line is a plurality of concentric circular lines planned within an entire ground coverage area of one communication satellite and centered on a sub-satellite point, and the satellite-ground distance is determined by a radius of the circular line and an included angle between a center of the earth.

In an implementation, the region planning module is further configured to plan the wave bit groups to correspond to the reference lines one to one, where a geometric center of any one wave bit is closest to the reference line.

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

PSS、SSS、PBCH。

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

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

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

In an implementation, the UE receiving module is further configured to detect a beam coverage area number carried in the beam signal when the UE is powered on or during wave position reselection or wave position group reselection.

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

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

DTA＝RTT_act-RTT_est+TA_margin

For convenience of description, each part of the above-described apparatus is separately described as being functionally divided into various modules or units. Of course, the functionality of the various modules or units may be implemented in the same one or more pieces of software or hardware in practicing the invention.

Fig. 8 is a schematic structural diagram of a communication satellite, as shown, the communication satellite includes:

the processor 800, which is used to read the program in the memory 820, executes 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;

a transceiver 810 for receiving and transmitting data under the control of the processor 800.

PSS、SSS、PBCH。

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

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

In an implementation, the method further comprises the following steps:

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

An embodiment of the present invention further provides a communication satellite, including:

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 by a beam transmitted by a communication satellite on the ground, and the area covered by each beam has a preset number;

In an implementation, the area planning module is further configured to plan the beam coverage area, where the beam coverage area is formed by a group of wave positions, the wave positions are a plurality of wave positions divided by using a sub-satellite point as a center in an entire ground coverage area of one communication satellite, and one beam covers one wave position at a certain time.

PSS、SSS、PBCH。

in an implementation, the satellite transmission module is further configured to carry the beam signal with a beam coverage area number by one or a combination of the following methods:

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

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

In an implementation, the satellite receiving module is further configured to receive a random access initiated by the UE on the PRACH by using a Preamble agreed with the communication satellite, and includes:

The embodiment of the invention also provides a computer readable storage medium, and the computer readable storage medium stores a computer program for executing the random access method.

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

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may 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, optical storage, and the like) having computer-usable program code embodied therein.

The present invention has been 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 will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

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 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;

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;

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:

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

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

13. The method of claim 12, further comprising:

14. The method of claim 1, further comprising:

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;

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

19. The method of claim 15, further comprising:

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:

21. The method of claim 15, further comprising:

22. The method of claim 15, further comprising:

23. A user device, comprising:

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

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;

25. A communications satellite, comprising:

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

26. A communication satellite, comprising:

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.