Multi-user detection in satellite return link

• US 8,159,993 B2
• Filed: 03/26/2009
• Issued: 04/17/2012
• Est. Priority Date: 09/26/2006
• Status: Active Grant

• Current Assignee: ViaSat Incorporated
• Original Assignee: ViaSat Incorporated
• Inventors: Jaska, Kristi Ann, Dankberg, Mark D.
• Primary Examiner(s): Phan, Tri H
• Application Number:
  US12/411,694
• Publication Number:
  US 20090290535A1
• Time in Patent Office: 1,118 Days
• Field of Search: 370315-326, 370445-447, 370461-462, 375/222, 375240-241, 455 7- 25
• US Class Current: 370/316
• CPC Class Codes: H04B 7/18582 Arrangements for data linking, i.e. for data framing, for error recovery, for multiple access

Abstract

Use of multi-user detection (MUD) with a frequency-multiplexed satellite return link (scheduling algorithms, etc) is described. The satellite return link may utilize multi-frequency time division multiple access (MF-TDMA). The satellite return link may include a plurality of return sub-channels, wherein one or more of the return sub-channels may operate in a contention mode during some time periods and a non-contention mode at different time periods.

Claims

1. A satellite modem comprising:

a communication interface configured to communicate wirelessly with a satellite; and

a processor communicatively coupled to the communication interface and configured to cause the communication interface to communicate wirelessly with the satellite using a first return sub-channel at a first frequency and a second return sub-channel at a second frequency such that the first return sub-channel will operate in a non-contention mode at a first time, and will operate in a contention mode at a second time different from the first time.

2. The satellite modem according to claim 1, wherein the processor is configured to switch from the non-contention mode to the contention mode after a determination that bandwidth is below a predetermined threshold.

3. The satellite modem according to claim 1, wherein the processor is configured to switch from the non-contention mode to the contention mode after a determination that latency is above a predetermined threshold.

4. The satellite modem according to claim 1, wherein the processor is configured to cause the communication interface to use the first return sub-channel in the contention mode at the second time.

5. A method for multi-user detection in a satellite return link utilizing multi-frequency time division multiple access (MF-TDMA), the method comprising:

wirelessly coupling a satellite via a first return sub-channel at a first frequency to a plurality of satellite modems;

wirelessly coupling a satellite via a second return sub-channel at a second frequency to the plurality of satellite modems;

wirelessly coupling a satellite via a third return sub-channel at a third frequency to the plurality of satellite modems;

operating at least one of the first return sub-channel, the second return sub-channel, or the third sub-channel in a non-contention mode at a first time;

instructing a subset of the plurality of satellite modems to use the at least one of the first return sub-channel, the second return sub-channel, or the third sub-channel in a contention mode at a second time different from the first time;

in response to the instructions, operating the at least one of the first return sub-channel, the second return sub-channel, or the third sub-channel in the contention mode at the second time; and

affecting a multi-user detection (MUD) algorithm in the satellite return link in accordance with the subset.

6. The method for multi-user detection in the satellite return link utilizing MF-TDMA according to claim 5, further comprising:

determining if bandwidth is below a predetermined threshold; and

switching the at least one of the first return sub-channel, the second return sub-channel, or the third sub-channel from the non-contention mode to the contention mode if the determining step determines that the bandwidth is below the predetermined threshold.

7. The method for multi-user detection in the satellite return link utilizing MF-TDMA according to claim 5, further comprising:

determining if latency is above a predetermined threshold; and

switching the at least one of the first return sub-channel, the second return sub-channel, or the third sub-channel from the non-contention mode to the contention mode if the determining step determines that the latency is above the predetermined threshold.

8. The method for multi-user detection in the satellite return link utilizing MF-TDMA according to claim 5, further comprising:

instructing a subset of the plurality of satellite modems to use the at least one of the first return sub-channel, the second return sub-channel, or the third sub-channel in the contention mode at the second time.

9. A satellite modem comprising:

means for wirelessly communicating with a broadband communication satellite over a return link comprising a plurality of sub-channels; and

means for controlling the satellite modem to communicate with the broadband communication satellite via one of the return sub-channels using a non-contention mode at a first time and using a contention mode at a second time different from the first time.

10. The satellite modem according to claim 9, wherein the controlling means is configured to cause a switch from the non-contention mode to the contention mode in response to bandwidth being below a predetermined threshold.

11. The satellite modem according to claim 9, wherein the controlling means is configured to cause a switch from the non-contention mode to the contention mode in response to latency being above a predetermined threshold.

12. The satellite modem according to claim 9, wherein the controlling means is configured to cause the satellite modem to use the first return sub-channel in the contention mode at the second time.

13. A method for multi-user detection in a satellite return link utilizing multi-frequency time division multiple access (MF-TDMA), the method comprising:

wirelessly coupling a plurality of return sub-channels having respective frequencies to a plurality of satellite modems;

operating at least one of the return sub-channels in a non-contention mode at a first time;

instructing a subset of the plurality of satellite modems to use the at least one of the return sub-channels in a contention mode at a second time different from the first time

operating at least one of the return sub-channels in the contention mode at the second time and

affecting a multi-user detection (MUD) algorithm in the satellite return link in accordance with the subset.

14. The method for multi-user detection in the satellite return link utilizing MF-TDMA according to claim 13, further comprising:

switching the at least one of the return sub-channels from the non-contention mode to the contention mode if bandwidth is below a predetermined bandwidth threshold.

15. The method for multi-user detection in the satellite return link utilizing MF-TDMA according to claim 13, further comprising:

switching the at least one of the return sub-channels from the non-contention mode to the contention mode if latency is above a predetermined latency threshold.

16. The method for multi-user detection in the satellite return link utilizing MF-TDMA according to claim 13, further comprising:

instructing a subset of the plurality of satellite modems to use the at least one of the return sub-channels in the contention mode at the second time.