Channel quality feedback in satellite communication systems

1. A method of operating a user terminal in a satellite communication system, the method comprising:

detecting an occurrence of an inter-beam handover for switching communications with a controller of the satellite communication system from a first beam to a second beam;

measuring a channel quality of the second beam in response to detecting the occurrence of the inter-beam handover, wherein a timing of the channel quality measurement depends on a timing of the inter-beam handover;

sending the channel quality measurement to the controller via a reverse-link communication, wherein the channel quality measurement is sent to the controller via the second beam within a threshold period after completing the inter-beam handover and prior to receiving forward-link communications on the second beam; and

receiving forward-link communications on the second beam, after the inter-beam handover, in accordance with a modulation and coding scheme (MCS) that is based at least in part on the channel quality measurement.

2. The method of claim 1 , wherein the detection is based on beam transition information.

3. The method of claim 1 , wherein the detection is based on a trigger signal received from the controller.

4. The method of claim 1 , wherein the measuring comprises:

receiving one or more pilot signals on the second beam; and

determining the channel quality of the second beam based at least in part on the received pilot signals.

5. The method of claim 1 , wherein the measuring is performed prior to initiating the inter-beam handover.

6. The method of claim 1 , wherein the first beam and the second beam are provided by a first satellite.

7. The method of claim 1 , wherein the first beam is provided by a first satellite and the second beam is provided by a second satellite.

8. A user terminal, comprising:

one or more processors; and

a memory configured to store instructions that, when executed by the one or more processors, cause the user terminal to:

detect an occurrence of an inter-beam handover for switching communications with a controller of a satellite communication system from a first beam to a second beam;

measure a channel quality of the second beam in response to detecting the occurrence of the inter-beam handover, wherein a timing of the channel quality measurement depends on a timing of the inter-beam handover;

send the channel quality measurement to the controller via a reverse-link communication, wherein the channel quality measurement is sent to the controller via the second beam within a threshold period after completing the inter-beam handover and prior to receiving forward-link communications on the second beam; and

receive forward-link communications on the second beam, after the inter-beam handover, in accordance with a modulation and coding scheme (MCS) that is based at least in part on the channel quality measurement.

9. The user terminal of claim 8 , wherein the detection is based on beam transition information.

10. The user terminal of claim 8 , wherein the detection is based on a trigger signal received from the controller.

11. The user terminal of claim 8 , wherein execution of the instructions to measure the channel quality of the second beam causes the user terminal to:

receive one or more pilot signals on the second beam; and

determine the channel quality of the second beam based at least in part on the received pilot signals.

12. The user terminal of claim 8 , wherein the measuring is performed prior to initiating the inter-beam handover.

13. The user terminal of claim 8 , wherein the first beam and the second beam are provided by a first satellite.

14. The user terminal of claim 8 , wherein the first beam is provided by a first satellite and the second beam is provided by a second satellite.

15. A user terminal, comprising:

means for detecting an occurrence of an inter-beam handover for switching communications with a controller of a satellite communication system from a first beam to a second beam;

means for measuring a channel quality of the second beam in response to detecting the occurrence of the inter-beam handover, wherein a timing of the channel quality measurement depends on a timing of the inter-beam handover;

means for sending the channel quality measurement to the controller via a reverse-link communication, wherein the channel quality measurement is sent to the controller via the second beam within a threshold period after completing the inter-beam handover and prior to receiving forward-link communications on the second beam; and

means for receiving forward-link communications on the second beam, after the inter-beam handover, in accordance with a modulation and coding scheme (MCS) that is based at least in part on the channel quality measurement.

16. The user terminal of claim 15 , wherein the detection is based on at least one of beam transition information or a trigger signal received from the controller.

17. The user terminal of claim 15 , wherein the means for measuring the channel quality of the second beam is to:

receive one or more pilot signals on the second beam; and

determine the channel quality of the second beam based at least in part on the received pilot signals.

18. The user terminal of claim 15 , wherein the measuring is performed prior to initiating the inter-beam handover.

19. The user terminal of claim 15 , wherein the first beam and the second beam are provided by a first satellite.

20. The user terminal of claim 15 , wherein the first beam is provided by a first satellite and the second beam is provided by a second satellite.

21. A non-transitory computer-readable medium storing instructions that, when executed by one or more processors of a user terminal, cause the user terminal to perform operations comprising:

detecting an occurrence of an inter-beam handover for switching communications with a controller of a satellite communication system from a first beam to a second beam;

measuring a channel quality of the second beam in response to detecting the occurrence of the inter-beam handover, wherein a timing of the channel quality measurement depends on a timing of the inter-beam handover;

sending the channel quality measurement to the controller via a reverse-link communication, wherein the channel quality measurement is sent to the controller via the second beam within a threshold period after completing the inter-beam handover and prior to receiving forward-link communications on the second beam; and

receiving forward-link communications on the second beam, after the inter-beam handover, in accordance with a modulation and coding scheme (MCS) that is based at least in part on the channel quality measurement.

22. The non-transitory computer-readable medium of claim 21 , wherein the detection is based on at least one of beam transition information or a trigger signal received from the controller.

23. The non-transitory computer-readable medium of claim 21 , wherein execution of the instructions for measuring the channel quality of the second beam causes the user terminal to perform operations further comprising:

receiving one or more pilot signals on the second beam; and

determining the channel quality of the second beam based at least in part on the received pilot signals.

24. The non-transitory computer-readable medium of claim 21 , wherein the measuring is performed prior to initiating the inter-beam handover.

25. The non-transitory computer-readable medium of claim 21 , wherein the first beam and the second beam are provided by a first satellite.

26. The non-transitory computer-readable medium of claim 21 , wherein the first beam is provided by a first satellite and the second beam is provided by a second satellite.