Initial beam alignment method, device, storage medium and program product

Abstract

The present invention discloses an initial beam alignment method, device, storage medium and program product, which relate to the field of communications and are used to achieve rapid beam alignment. The present invention selects a corresponding beam alignment method based on the phased array state to scan the satellite side beam to detect the target beam; sets the beam pointing according to the target beam, sends an access request carrying the beam information of the target beam to the satellite; receives the access request response of the satellite to the access request, and completes the initial beam alignment. The present invention can achieve rapid and accurate beam alignment between the terminal and the satellite under the condition of no available ephemeris.

Description

Technical Field

[0001] The present invention relates to the field of communications, and in particular to an initial beam alignment method, device, storage medium and program product. Background Art

[0002] The coverage of terrestrial networks (TN) is limited by the terrain. In order to make up for the shortcomings of terrestrial networks, non-terrestrial networks (NTN) came into being. Among them, satellite communication networks are one of the most widely used communication networks in non-terrestrial networks.

[0003] Since satellite communication networks have the characteristics of long transmission distance, complex channel environment, and high satellite speed, the satellite and the end user need to align the beam with high directional gain to ensure a reliable satellite-to-ground communication link. Figure 1 As shown, in the 3GPP protocol, the initial beam alignment method is to determine the best target beam (transmit-receive beam pair) by transmitting / receiving beam scanning.

[0004] However, for known beam alignment methods, beam scanning is usually performed based on the satellite's ephemeris to obtain the target beam. In the case of no ephemeris or ephemeris failure due to long-term non-update (which is always the case of no available ephemeris), when the satellite signal search and demodulation capabilities are limited, it takes more time to download the ephemeris. For the case of no available ephemeris, a known method is to perform a full-space scan, but since this method uses a full-space scan method for beam search, it takes a long time for the terminal to access and the beam alignment efficiency is low. Summary of the invention

[0005] The object of the present invention is to provide an initial beam alignment method, device, storage medium and program product to achieve rapid beam alignment in order to solve all or part of the above problems.

[0006] The technical solution adopted by the present invention is as follows:

[0007] An initial beam alignment method, comprising:

[0008] Selecting a corresponding beam alignment method based on the phased array state to scan the satellite side beam to detect the target beam;

[0009] Setting a beam direction according to the target beam, and sending an access request carrying beam information of the target beam to the satellite;

[0010] An access request response from the satellite to the access request is received to complete initial beam alignment.

[0011] In order to solve the above problem, the present invention further provides a computer-readable storage medium storing computer instructions, which can execute the above initial beam alignment method when the computer instructions are run.

[0012] To solve the above problem, the present invention further provides a device, including a processor and a storage medium, wherein the storage medium stores a computer program, and when the processor executes the computer program, the above initial beam alignment method can be executed.

[0013] To solve the above problem, the present invention further provides a computer program product, including a computer program. When the computer program is executed by a processor, the above initial beam alignment method can be executed.

[0014] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0015] This patent application is aimed at the scenario where the terminal initially accesses the satellite communication network. In the absence of available ephemeris, according to the phased array state, a corresponding beam alignment method is selected to scan the satellite side beam, so that according to the influence of the phased array state on the terminal beam width and directional selectivity, the target beam can be scanned with a corresponding beam alignment method. This patent application is different from the prior art method of unconditionally performing full-airspace scanning without caring about the characteristics of the terminal beam. It implements a beam alignment method adapted to the terminal beam characteristics to minimize the time required for beam alignment and ensure the beam search accuracy as much as possible, thereby improving the efficiency and accuracy of beam alignment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will now be described by way of example with reference to the accompanying drawings, in which:

[0017] Figure 1 It is a flow chart of the beam alignment method in the 3GPP protocol.

[0018] Figure 2 This is a flowchart of an initial beam alignment method provided in an embodiment of the present application.

[0019] Figure 3 It is a flowchart of the first beam alignment method provided in an embodiment of the present application.

[0020] Figure 4 This is a flowchart of terminal beam subset division provided in an embodiment of the present application.

[0021] Figure 5 It is a flow chart of a phased array controllable beam alignment method provided in an embodiment of the present application.

[0022] Figure 6 It is a flowchart of the second beam alignment method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0023] All features disclosed in this specification, or steps in all methods or processes disclosed, except mutually exclusive features and / or steps, can be combined in any manner.

[0024] Any feature disclosed in this specification (including any additional claims and abstract), unless otherwise stated, may be replaced by other alternative features that are equivalent or have similar purposes. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

[0025] According to the guidance method for beam alignment in the 3GPP protocol, the existing technology generally adopts two methods when performing initial beam alignment. One is to perform satellite side beam scanning based on the satellite's ephemeris to obtain the target beam; the other is to scan the satellite side beam in the entire space without considering the satellite ephemeris, and to scan the target beam by traversing the terminal beam in the entire space. By judging whether there is a satellite signal in the scanning range during the search process, the target beam is scanned and beam alignment is then achieved.

[0026] In view of the problem that the first type of method in the prior art is not suitable for initial beam alignment when there is no available ephemeris, and the second type of method has low efficiency in beam alignment because it takes a lot of time to traverse the terminal beam in the entire spatial range, the embodiments of the present application provide an initial beam alignment method, device, storage medium and program product to improve the speed of initial beam alignment when there is no available ephemeris.

[0027] In some embodiments, Figure 2 As shown, the initial beam alignment method provided by the present application includes the following process:

[0028] S1. Select a corresponding beam alignment method based on the phased array state to scan the satellite side beam to detect the target beam.

[0029] Taking the configuration of the initial beam alignment method of the embodiment of the present application in the terminal as an example, when the terminal performs initial beam alignment (that is, when preparing to send an access request to the satellite), the state of the phased array is determined. In the embodiment of the present application, the phased array state is divided into two types: controllable phased array and uncontrollable phased array. When the phased array is controllable, the width and direction of the terminal beam can be arbitrarily controlled, that is, when the phased array is controllable, the terminal beam of corresponding width and direction can be selected as needed, so that higher precision beam alignment can be achieved; when the phased array is uncontrollable, the width and direction of the terminal beam cannot be adjusted, that is, the terminal beam cannot be arbitrarily selected to scan the satellite side beam. Therefore, for the situation where the phased array is uncontrollable, the method of performing full space range scanning in the prior art is not applicable.

[0030] As an optional implementation, step S1 includes:

[0031] S11, when the phased array state is uncontrollable, selecting a first beam alignment method to scan the satellite side beam to detect the target beam, the first beam alignment method using a sequential scanning method to scan the satellite side beam;

[0032] S12. When the phased array state is controllable, select a second beam alignment method to scan the satellite side beam to detect the target beam, wherein the second beam alignment method scans the satellite side beam based on an estimation of the satellite signal arrival direction.

[0033] When the phased array state is uncontrollable, the terminal beam cannot be selected arbitrarily. In the embodiment of the present application, the satellite side beam is scanned in a sequential scanning manner to cover the entire spatial range with a sparse angular resolution, so that the entire spatial range is covered with as few terminal beams as possible. This reduces the number of scanning beams on the one hand, and prevents the omission of scanning directions on the other hand, thereby ensuring the scanning accuracy while simplifying the calculation amount of beam alignment and improving the beam alignment speed.

[0034] As an optional implementation, Figure 3 As shown, selecting the first beam alignment method to scan the satellite side beam to detect the target beam includes the following process:

[0035] S111. Select multiple terminal beams from the terminal beam set generated by the phased array to scan the satellite side beams, and the multiple terminal beams cover the entire space with a sparse angular resolution.

[0036] In some feasible implementations, it is assumed that the phased array of the terminal generates ( is a positive integer) terminal beams, beam represents beam, UE (User Equipment) represents user terminal, The terminal beams constitute the above terminal beam set. N (N is a positive integer) terminal beams are selected from the terminal beams to scan the satellite side beams. The N terminal beams cover the entire space with sparse angular resolution. The so-called covering the entire space with sparse angular resolution means that the coverage angle ranges of the N terminal beams are different. The N terminal beams achieve coverage of a 360-degree space range, and N is much smaller than 360. As a feasible implementation method, among the N terminal beams, the i indivual( ) Coverage angle of terminal beam for: .

[0037] S112 : Determine a coarse alignment beam based on a reference signal receiving power (RSRP) value of a terminal-satellite beam pair scanned by each selected terminal beam.

[0038] Continuing with the example of selecting N terminal beams to scan the satellite side beams, the N terminal beams are scanned against the satellite side beams, and the RSRP of the terminal-satellite beam pairs obtained by scanning each terminal beam is measured respectively. Based on the RSRP corresponding to each terminal beam, a predetermined number of coarse alignment beams with the highest RSRP are selected, and the predetermined number is represented by K (K is a positive integer). The value of K is set as required. As one of the best selection methods, the value of K needs to meet the requirements of beam alignment accuracy and minimize the terminal beam search time.

[0039] S113. Scan the satellite side beam using a terminal beam subset spatially related to the coarse alignment beam.

[0040] Since the terminal beams covering adjacent azimuth / elevation angles have high spatial correlation, selecting other terminal beams that are spatially correlated with the coarse alignment beam for secondary scanning can further improve the accuracy of beam alignment.

[0041] The spatial correlation between terminal beams can be calculated according to the following formula:

[0042] Formula 1: .

[0043] In the formula, and They represent the antenna weight vectors of two different terminal beams, express The conjugate transpose of Express Take the absolute value.

[0044] As an optional implementation, the terminal beam set is divided into N terminal beam subsets according to the spatial correlation between the selected N terminal beams, and the N terminal beams correspond to the N terminal beam subsets one by one. In this way, it is convenient to quickly find other terminal beams spatially correlated with the K terminal beams in the second scanning stage, thereby improving the scanning speed.

[0045] In some possible implementations, such as Figure 4 As shown, the method for dividing a terminal beam set into a terminal beam subset includes:

[0046] Selecting the above-mentioned N terminal beams from the terminal beam set;

[0047] Constructing N terminal beam subsets corresponding to the N terminal beams one by one;

[0048] Each remaining terminal beam in the terminal beam set is divided into the same terminal beam subset as the terminal beam with the highest spatial correlation among the N terminal beams.

[0049] Still taking N terminal beams covering the entire space as an example, N terminal beams covering the entire space with sparse angular resolution are randomly selected from the terminal beam set, and accordingly, N terminal beam subsets are constructed. For each remaining terminal beam in the terminal beam set, the spatial correlation with the N terminal beams is calculated according to Formula 1, and the terminal beam subset corresponding to the terminal beam with the highest spatial correlation is selected as the division result to which the current terminal beam belongs according to the order of the spatial correlation with the N terminal beams from high to low.

[0050] On the basis of dividing the terminal beam set into multiple terminal beam subsets according to the spatial correlation between the terminal beams, taking the selection of K coarse alignment beams from N terminal beams as an example, in some feasible implementation modes, the other terminal beams in the terminal beam subset corresponding to the K coarse alignment beams perform a second stage of scanning on the satellite side beams to obtain the RSRP of the corresponding terminal-satellite beam pairs respectively.

[0051] S114. Determine a target beam based on RSRP of the terminal-satellite beam pair scanned by the terminal beam subset.

[0052] In the second stage, the terminal beam with the highest RSRP and the corresponding scanned satellite side beam are determined as the target beam from the RSRP obtained by scanning the satellite side beam using the terminal beam, that is, a transmit-receive beam pair is obtained.

[0053] When the phased array is controllable, the width and direction of the terminal beam can be arbitrarily controlled. Therefore, the corresponding terminal beam can be selected for scanning based on the estimation of the direction of arrival of the satellite-side signal, thereby achieving fast and high-precision beam alignment.

[0054] As an optional implementation, when the phased array is controllable, the ESPRIT (Estimation of Signal Parameters via Rotational Invariance Techniques) method based on rotational invariance is used to estimate the satellite signal arrival direction, and then the satellite side beam is scanned based on the estimated satellite signal arrival direction to detect the target beam. When the phased array is controllable, ESPRIT is used to estimate the satellite signal arrival direction, which takes advantage of the low complexity of the ESPRIT algorithm, so that faster arrival direction estimation can be achieved to improve the beam alignment speed. According to the estimated arrival direction, the azimuth of the terminal beam is adjusted to the corresponding angle to scan the satellite side beam, which can achieve high-precision transmission beam scanning.

[0055] Simply put, if Figure 5 As shown in the figure, after estimating the direction of arrival of the satellite signal, the azimuth and elevation angles of the terminal beam are determined according to the estimated direction of arrival. The terminal phased array generates a terminal beam in a specified direction by adjusting the phase of each antenna unit, and uses the terminal beam to scan the satellite side beam. The RSRP of the corresponding terminal-satellite beam pair is measured. The terminal-satellite beam pair with the maximum RSRP is used as the target beam.

[0056] As an optional implementation, Figure 6 As shown, selecting a second beam alignment method to scan the satellite side beam to detect the target beam includes:

[0057] S121. Split the entire scanning space into several sub-scanning areas.

[0058] S122: Estimate the direction of arrival of satellite signals in each sub-scanning area to estimate the best terminal beam in the sub-scanning area.

[0059] S123. Perform spatial expansion based on each optimal terminal beam, and construct a number of beam search subspaces accordingly.

[0060] S124: Scan the satellite side beams again in each beam search subspace to obtain a target beam, that is, use the scanned terminal-satellite beam pair with the maximum RSRP as the target beam.

[0061] The ESPRIT algorithm can also be used to estimate the direction of arrival of satellite signals in each sub-scanning area. This method can reduce the space for satellite side beam scanning on the basis of full-space scanning, reduce the complexity of beam scanning, and further improve the beam alignment speed.

[0062] S2. Set the beam direction according to the target beam, and send an access request carrying the beam information of the target beam to the satellite.

[0063] According to the target beam obtained in step S1, the beam pointing of the terminal beam is set, an access request is sent to the satellite, and at the same time, the transmission beam information in the target beam is reported to the satellite.

[0064] S3. Receive the access request response from the satellite to the access request, and complete the initial beam alignment.

[0065] After receiving the access request from the terminal, the satellite will send down a beam carrying downlink data services as an access request response to the access request based on the reported transmission beam information. After the terminal receives the access request response, the initial beam alignment is completed, and then data services can be provided through the target beam.

[0066] The initial beam alignment method provided in the present application is different from the existing beam alignment method with ephemeris and the full airspace scanning method without ephemeris. Instead, it adopts a corresponding beam alignment method according to the phased array state to perform satellite side beam scanning. While ensuring the accuracy of beam alignment, the fastest method can be used to complete beam alignment and enable the terminal to quickly access the satellite communication network. Although the initial beam alignment method provided in the present application is based on the initial beam alignment between the terminal and the satellite when there is no available ephemeris, it is suitable for NTN communication networks such as UAV (Unmanned Aerial Vehicle), LEO (Low Earth Orbit), MEO (Medium Earth Orbit), and GEO (Geosynchronous Orbit), but the possibility of being applied to TN communication networks is not excluded.

[0067] The initial beam alignment method of the above embodiment is configured on a satellite communication terminal, for example, configured in the memory of the satellite communication terminal, and called and executed by its processor, so as to obtain a satellite communication terminal suitable for accessing a satellite communication network without available ephemeris.

[0068] According to the concept of the present application, in some embodiments, the computer-readable storage medium provided by the present application stores computer instructions, and when the computer instructions are run, the initial beam alignment method of the above embodiment can be executed.

[0069] In some embodiments, the apparatus provided in the present application includes a processor and a storage medium, wherein the storage medium stores a computer program. When the processor executes the computer program, the initial beam alignment method of the above embodiment can be executed.

[0070] In some embodiments, the computer program product provided by the present application includes a computer program, and when the computer program is executed by a processor, the initial beam alignment method of the above embodiment can be executed.

[0071] The present invention is not limited to the above-mentioned specific embodiments, but extends to any new features or any new combination disclosed in this specification, as well as any new method or process steps or any new combination disclosed.

Claims

1. An initial beam alignment method, characterized in that: include: Selecting a corresponding beam alignment method based on a phased array state to scan a satellite side beam to detect a target beam includes: when the phased array state is uncontrollable, selecting a first beam alignment method to scan a satellite side beam to detect a target beam, wherein the first beam alignment method scans the satellite side beam in a sequential scanning manner; when the phased array state is controllable, selecting a second beam alignment method to scan a satellite side beam to detect a target beam, wherein the second beam alignment method scans the satellite side beam based on an estimation of a satellite signal arrival direction; Setting a beam direction according to the target beam, and sending an access request carrying beam information of the target beam to the satellite; An access request response from the satellite to the access request is received to complete initial beam alignment.

2. The initial beam alignment method according to claim 1, characterized in that: The method of selecting a first beam alignment to scan a satellite side beam to detect a target beam comprises: Selecting a plurality of terminal beams from a terminal beam set generated by a phased array to scan a satellite side beam, wherein the plurality of terminal beams cover the entire space with a sparse angular resolution; Determining a coarse alignment beam based on reference signal received power values ​​of terminal-satellite beam pairs scanned by each selected terminal beam; Scanning the satellite side beams using a subset of terminal beams spatially associated with the coarse alignment beam; A target beam is determined based on reference signal received power values ​​of terminal-satellite beam pairs scanned by the terminal beam subset.

3. The initial beam alignment method according to claim 2, characterized in that: The terminal beam set is divided into a plurality of terminal beam subsets according to spatial correlations between the plurality of terminal beams, and the plurality of terminal beams correspond to the plurality of terminal beam subsets one by one.

4. The initial beam alignment method according to claim 3, characterized in that: The method for dividing the terminal beam set into terminal beam subsets comprises: selecting the plurality of terminal beams from the terminal beam set; Constructing a plurality of terminal beam subsets in one-to-one correspondence with the plurality of terminal beams; Each remaining terminal beam in the terminal beam set is divided into the same terminal beam subset as the terminal beam with the highest spatial correlation among the multiple terminal beams.

5. The initial beam alignment method according to claim 3 or 4, characterized in that: Scanning the satellite side beams using a subset of terminal beams spatially associated with the coarse alignment beam includes: The satellite side beam is scanned using a terminal beam in the same terminal beam subset as the coarse aiming beam.

6. The initial beam alignment method according to claim 1, characterized in that: The second beam alignment method is selected to scan the satellite side beam to detect the target beam, comprising: The entire scanning space is divided into multiple sub-scanning areas; for each sub-scanning area, there are: Estimate the direction of arrival of satellite signals in the sub-scanning area to obtain the best terminal beam; Performing spatial expansion on the optimal terminal beam to construct a beam search subspace; The satellite side beam is scanned in each of the beam search subspaces to obtain a target beam.

7. The initial beam alignment method according to claim 1 or 6, characterized in that: Estimates of satellite signal direction of arrival, including: The satellite signal arrival direction is estimated using ESPRIT, a parameter estimation method based on rotation invariance.

8. A computer-readable storage medium storing computer instructions, characterized in that: When the computer instructions are executed, the initial beam alignment method as described in any one of claims 1 to 7 can be executed.

9. An initial beam alignment device, comprising a processor and a storage medium, wherein the storage medium stores a computer program, characterized in that: When the processor executes the computer program, it can execute the initial beam alignment method as described in any one of claims 1-7.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the initial beam alignment method according to any one of claims 1 to 7 can be executed.

Images