Dynamic propagation spatial correlation by changing position of HAPS-equipped antenna in HAPS multi-feeder links

Patent metadata

Field	Value
Publication number	US-12445190-B2
Application number	US-202118016464-A
Country	US
Kind code	B2
Filing date	Jul 7, 2021
Priority date	Jul 22, 2020
Publication date	Oct 14, 2025
Grant date	Oct 14, 2025

Abstract

It is to prevent a deterioration of communication quality due to an instantaneous increase in a propagation spatial correlation between plural feeder links between plural antennas for feeder link (FL antennas) incorporated in an aerial-floating type communication relay apparatus (HAPS) and plural gateway (GW) stations. The aerial-staying type communication relay apparatus (HAPS) comprises a feeder-link communication section that transmits and receives relay signals different from each other at a same frequency in the feeder links between the communication relay apparatus and plural GW stations that are time-synchronized with each other, an interference suppression section that suppresses interferences between the plural feeder links formed between the communication relay apparatus and the plural GW stations, means for obtaining correlation index values (SINRs, singular values or eigenvalues) indicating respective degrees of propagation spatial correlation of the plural feeder links, and means for changing a mutual positional relationship between the plural antennas for feeder link, based on a comparison result between the correlation index values and a predetermined threshold value.

First claim

The invention claimed is:

1. An aerial-staying type communication relay apparatus having a relay communication station for relaying a radio communication of a terminal apparatus and plural antennas for feeder link, comprising:
a feeder-link communication section for transmitting and receiving relay signals different from each other at a same frequency in feeder links to and from plural gateway stations that are time-synchronized with each other;
an interference suppression section for suppressing interference between plural feeder links formed between the relay communication station and the plural gateway stations;
means for obtaining a correlation index value indicating a degree of propagation spatial correlation of the plural feeder links; and
means for changing a mutual positional relationship between the plural antennas for feeder link, based on a comparison result between the correlation index value and a predetermined threshold value.

2. The communication relay apparatus according to claim 1 ,
wherein the communication relay apparatus changes at least one of plural placement distances between a virtual reference point of the communication relay apparatus and the plural antennas for feeder link.

3. The communication relay apparatus according to claim 1 , wherein the communication relay apparatus changes at least one placement angle of plural placement angles between the plural antennas for feeder link with respect to a virtual reference direction based on a virtual reference point of the communication relay apparatus.

4. The communication relay apparatus according to claim 1 ,
wherein the communication relay apparatus:
comprises the plural antennas for feeder link and one or more spare antennas for feeder link that are located at respective positions different from each other on a virtual circle centered on a virtual reference point of the communication relay apparatus; and
switches at least one of the plural antennas for feeder link to the spare antenna for feeder link.

5. The communication relay apparatus according to claim 1 ,
wherein the communication relay apparatus:
comprises the plural antennas for feeder link and one or more spare antennas for feeder link that are respectively located on plural virtual circles having radii different from each other centered on a virtual reference point of the communication relay apparatus; and
switches at least one of the plural antennas for feeder link to the spare antenna for feeder link.

6. The communication relay apparatus according to claim 1 ,
wherein the communication relay apparatus:
comprises the plural antennas for feeder link and one or more spare antennas for feeder link so that positions on an outer peripheral surface of a columnar or prismatic support member having a central axis passing through a virtual reference point of the communication relay apparatus in at least one of the axial direction and the circumferential direction are different from each other; and
switches at least one of the plural antennas for feeder link to the spare antenna for feeder link.

7. The communication relay apparatus according to claim 1 ,
wherein the correlation index values are plural SINRs of signals received from the plural gateway stations by the plural antennas for feeder link.

8. The communication relay apparatus according to claim 1 ,
wherein the correlation index values are plural eigenvalues in a propagation path response between the plural antennas for feeder link and the plural gateway stations estimated based on reception results of plural pilot signals transmitted and received between the plural antennas for feeder link and the plural gateway stations.

9. The communication relay apparatus according to claim 1 ,
wherein the correlation index values are FB ratios (forward gain/rear gain of a directional beam) of the plural directional beams when the plural antennas for feeder link are respectively beamformed in the direction to the plural gateway stations.

10. The communication relay apparatus according to claim 1 ,
wherein the correlation index value indicates a degree of propagation spatial correlation in plural forward links that respectively transmit relay signals from the plural gateway stations to the relay communication station, and
wherein the communication relay apparatus changes a mutual positional relationship between the plural antennas for feeder link when performing respective communications of the plural forward links.

11. The communication relay apparatus according to claim 1 ,
wherein the correlation index value indicates a degree of propagation spatial correlation in plural reverse links that respectively transmit relay signals from the relay communication station to the plural gateway stations, and
wherein the communication relay apparatus changes a mutual positional relationship between the plural antennas for feeder link when performing respective communications of the plural reverse links.

12. A system comprising:
the communication relay apparatus according to claim 1 ; and
plural gateway stations that are time-synchronized with each other and transmit and receive relay signals different from each other at a same frequency in the feeder links between respective gateway stations and the relay communication station of the aerial-staying type communication relay apparatus.

13. An interference suppression method of feeder links between a relay communication station and plural gateway stations, the relay communication station being incorporated in an aerial-staying type communication relay apparatus and relaying a radio communication of a terminal apparatus, and the gateway stations being time-synchronized with each other and transmitting and receiving relay signals different from each other at a same frequency, the interference suppression method comprising:
transmitting and receiving relay signals different from each other at the same frequency in the feeder links between the relay communication station and the plural gateway stations that are time-synchronized with each other;
suppressing interferences between the plural feeder links formed between the relay communication station and the plural gateway stations;
obtaining a correlation index value indicating a degree of propagation spatial correlation of the plural feeder links; and
changing a mutual positional relationship between the plural antennas for feeder link, based on a comparison result between the correlation index values and a predetermined threshold value.

14. A non-transitory computer readable storage medium containing a software application that is executed by a computer or processor provided in an aerial-staying type communication relay apparatus having a relay communication station that relays a radio communication of a terminal apparatus and plural antennas for feeder link, the software application comprising:
executable code that transmits and receives relay signals different from each other at a same frequency in feeder links between the relay communication station and plural gateway stations that are time-synchronized with each other;
executable code that suppresses interferences between the plural feeder links formed between the relay communication station and the plural gateway stations;
executable code that obtains a correlation index value indicating a degree of propagation spatial correlation of the plural feeder links; and
executable code that changes a mutual positional relationship between the plural antennas for feeder link, based on a comparison result between the correlation index value and a predetermined threshold value.

Assignees

• Softbank Corp

Inventors

• Fujii Takafumi

Classifications

• H04B7/18563

  Arrangements for interconnecting multiple systems (data switching networks H04L12/00) · CPC title

• H04B7/18539

  Arrangements for managing radio, resources, i.e. for establishing or releasing a connection · CPC title

• H04B17/336

  Signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR] · CPC title

• H04B7/18504 Primary

  Aircraft used as relay or high altitude atmospheric platform · CPC title