Predicting Signal Quality in a Rotating Beam Platform

• US 20170302368A1
• Filed: 04/13/2016
• Published: 10/19/2017
• Est. Priority Date: 04/13/2016
• Status: Abandoned Application

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Trott, Mitchell
• Application Number:
  US15/097,599
• Publication Number:
  US 20170302368A1
• Time in Patent Office: Days
• CPC Class Codes: H04B 7/18502 Airborne stations
• CPC Class Codes: H04B 7/18504 Aircraft used as relay or high altitude atmospheric platform
• CPC Class Codes: H04B 7/18506 Communications with or from aircraft, i.e. aeronautical mobile service
• CPC Class Codes: H04B 7/2041 Spot beam multiple access

Abstract

A method of receiving a target position and a target orientation of an airborne base station; predicting a target signal quality of the airborne base station at the target position and the target orientation based on at least one previous signal quality of the airborne base station corresponding to at least one previous position and at least one previous orientation of the airborne base station relative to the ground reference. Each previous signal quality of the airborne base station is measured by one or more terrestrial terminals located in corresponding one or more communication beams of the airborne base station. The method further includes selecting a target communication beam among the communication beams of the airborne base station for a communication link.

Claims

1. A method comprising:

receiving, at data processing hardware, a target position and a target orientation of an airborne base station relative to a ground reference;

predicting, by the data processing hardware, a target signal quality of the airborne base station at the target position and the target orientation based on at least one previous signal quality of the airborne base station corresponding to at least one previous position and at least one previous orientation of the airborne base station relative to the ground reference, each previous signal quality of the airborne base station measured by one or more terrestrial terminals located in corresponding one or more cells of the airborne base station, and each cell corresponding to a different communication beam of the airborne base station, the airborne base station having a plurality of communication beams; and

selecting, by the data processing hardware, a target communication beam among the communication beams of the airborne base station for a communication link between a target terrestrial terminal and the airborne base station, the communication link existing for a period of time relative to a current position and a current orientation of the airborne base station.

2. The method of claim 1, wherein the at least one previous signal quality comprises a reference signal receive power measurement.

3. The method of claim 1, further comprising transmitting, by the data processing hardware, data using the target communication beam.

4. The method of claim 3, further comprising delaying, by the data processing hardware, transmission of the data using the target communication beam until the target signal quality satisfies a threshold signal quality.

5. The method of claim 1, further comprising:

when the target signal quality of the target communication beam fails to satisfy a threshold signal quality;

selecting, by the data processing hardware, an alternative communication beam among the communication beams of the airborne base station for the communication link between the target terrestrial terminal and the airborne base station, the alternative communication beam different from the target communication beam; and

transmitting, by the data processing hardware, data using the alternative communication beam.

6. The method of claim 1, wherein the target position comprises a current position or a future position of the airborne base station.

7. The method of claim 1, wherein predicting the target signal quality is based at least in part on a Fourier series expansion using multiples of a base period.

8. The method of claim 1, further comprising estimating the target signal quality based on a sounding reference signal.

9. The method of claim 1, wherein the airborne base station maintains a flight path within a majority of a line of sight of the target terrestrial terminal.

10. The method of claim 1, wherein the airborne base station maintains a flight path having a diameter that is approximately at or less than a diameter of earth.

11. A method comprising:

receiving, at data processing hardware, a first collection of signal quality measurements of a plurality of communication beams of an airborne base station at a first position and a first orientation relative to a ground reference;

receiving, at data processing hardware, a second collection of signal quality measurements of the plurality of communication beams of the airborne base station at a second position and a second orientation relative to the ground reference;

predicting, by the data processing hardware, a target signal quality of multiple communication beams of the airborne base station at a target position and a target orientation relative to the ground reference based on the first and second collections of signal quality measurements; and

selecting, by the data processing hardware, a target communication beam among the plurality of communication beams of the airborne base station that satisfies a threshold signal quality for communicating with a target terrestrial terminal during a period of time relative to the target position and the target orientation of the airborne base station.

12. The method of claim 11, wherein each signal quality measurement comprises a reference signal receive power measurement.

13. The method of claim 11, further comprising transmitting, by the data processing hardware, data using the target communication beam.

14. The method of claim 13, further comprising delaying, by the data processing hardware, transmission of the data using the target communication beam until the target signal quality of the target communication beam satisfies the threshold signal quality.

15. The method of claim 11, further comprising:

when the target signal quality of the target communication beam fails to satisfy a threshold signal quality;

selecting, by the data processing hardware, an alternative communication beam among the plurality of communication beams of the airborne base for communicating between the target terrestrial terminal and the airborne base station, the alternative communication beam different from the target communication beam; and

transmitting, by the data processing hardware, data using the alternative communication beam.

16. The method of claim 11, wherein predicting the target signal quality of the multiple communication beams of the airborne base station at the target position and the target orientation relative to the ground reference is at least in part based on one or both of a target terrestrial area of the target terrestrial terminal or a target terrestrial position of the target terrestrial terminal.

17. The method of claim 11, wherein the target orientation comprises an azimuth, an elevation, and a roll.

18. The method of claim 11, wherein predicting the target signal quality of the multiple communication beams of the airborne base station at the target position and the target orientation relative to the ground reference is based on at least one of a channel quality indicator, a sounding reference signal, or a periodic measurement.

19. The method of claim 11, wherein predicting the target signal quality of the multiple communication beams of the airborne base station at the target position and the target orientation relative to the ground reference is based at least in part on a Fourier series expansion using multiples of a base period.

20. The method of claim 11, wherein predicating the target signal quality of the multiple communication beams of the airborne base station at the target position and the target orientation relative to the ground reference is based at least in part on a median signal quality value of over a base period.

21. The method of claim 11, wherein the airborne base station maintains a flight path within a majority of a line of sight of the target terrestrial terminal.

22. The method of claim 11, wherein airborne base station maintains a flight path with a diameter that is at or less than 25 miles.

23. The method of claim 11, wherein the airborne base station maintains a flight path having a diameter that is at or less than a diameter of earth.

24. A system comprising:

data processing hardware; and

memory hardware in communication with the data processing hardware, the memory hardware storing instructions that when executed on the data processing hardware cause the data processing hardware to perform operations comprising;

receiving a target position and a target orientation of an airborne base station relative to a ground reference;

predicting a target signal quality of the airborne base station at the target position and the target orientation based on at least one previous signal quality of the airborne base station corresponding to at least one previous position and at least one previous orientation of the airborne base station relative to the ground reference, each previous signal quality of the airborne base station measured by one or more terrestrial terminals located in corresponding one or more cells of the airborne base station, and each cell corresponding to a different communication beam of the airborne base station, the airborne base station having a plurality of communication beams; and

selecting a target communication beam among the communication beams of the airborne base station for a communication link between a target terrestrial terminal and the airborne base station, the communication link existing for a period of time relative to a current position and a current orientation of the airborne base station.

25. The system of claim 24, wherein the at least one previous signal quality comprises a reference signal receive power measurement.

26. The system of claim 24, wherein the operations further comprise transmitting data using the target communication beam.

27. The system of claim 26, wherein the operations further comprise delaying transmission of the data using the target communication beam until the target signal quality satisfies a threshold signal quality.

28. The system of claim 24, wherein the operations further comprise:

when the target signal quality of the target communication beam fails to satisfy a threshold signal quality;

selecting an alternative communication beam among the communication beams of the airborne base station for the communication link between the target terrestrial terminal and the airborne base station, the alternative communication beam different from the target communication beam; and

transmitting data using the alternative communication beam.

29. The system of claim 24, wherein the target position comprises a current position or a future position of the airborne base station.

30. The system of claim 24, wherein predicting the target signal quality is based at least in part on a Fourier series expansion using multiples of a base period.

31. The system of claim 24, wherein the operations further comprise estimating the target signal quality based on a sounding reference signal.

32. The system of claim 24, wherein the airborne base station maintains an flight path within a majority of a line of sight of the target terrestrial terminal or the flight path having a diameter that is approximately at or less than a diameter of earth.