Satellite communication system using linear cell tracking

• US 7,171,158 B2
• Filed: 06/14/2002
• Issued: 01/30/2007
• Est. Priority Date: 08/23/1999
• Status: Expired due to Fees

• Current Assignee: The DIRECTV Group, Inc. (AT&T, Inc.)
• Original Assignee: The DIRECTV Group, Inc. (AT&T, Inc.)
• Inventors: Rosen, Harold A., Vaughan, Robert E., Lane, Steven O.
• Primary Examiner(s): Anderson; Matthew D.
• Assistant Examiner(s): Pan; Yuwen
• Application Number:
  US10/172,260
• Publication Number:
  US 20020151274A1
• Time in Patent Office: 1,691 Days
• Field of Search: 455/13.1, 455/13.3, 455/12.1, 455/427, 455/428, 455/446, 370/316
• US Class Current: 455/12.1
• CPC Class Codes: H04B 7/1851 Systems using a satellite or space-based relay H04B7/18508, H04B7/18521 take precedence; providing specific services H04B7/18523 - H04B7/18576

Abstract

An improved satellite communication device and system are provided. The satellite communication device uses yaw or roll-yaw steering to linearize angular track of uplink cells; one-dimensional linear “ratcheting” in an uplink antenna to maintain resource allocation of uplink cells along antenna columns; phased-array downlink antennas which can track earth-fixed downlink cells while compensating for the yaw (or roll-yaw) satellite steering; and variable rate TDMA service among downlink cells in a footprint. As a result, system overhead for performing new resource allocations between satellite handovers is minimized, thereby reducing resource management and increasing system capacity. Flexible bandwidth/capacity assignment of both uplink and downlink resources to earth locations via linear cell ratcheting, uplink RF peaking switch, and data-driven variable-TDMA downlink phased-arrays, is provided.

Claims

1. A communication device for use in conjunction with a plurality of communication devices in a communications network, comprising:

a receiving antenna coupled to a circuit, employing one-dimensional linear ratcheting of rows to maintain resource allocation of uplink cells along antenna coupled to a circuit columns for capturing a first receive signal comprised of a plurality of received data packets.

2. A communication device as recited in claim 1 further comprising a first transmitting antenna capable of generating a first independently steerable transmit beam comprised of a plurality of transmitted data packets.

3. A communication device as recited in claim 1 further comprising an interdevice receiver for receiving a first plurality of interdevice data packets from another communication device in the plurality of communication devices.

4. A communication device as recited in claim 1 further comprising an interdevice transmitter for transmitting a second plurality of interdevice data packets to a communication device in the plurality of communication devices.

5. A communication device as recited in claim 1 further comprising a routing switch for routing data packets from the receiving antenna to a transmitting antenna, from the receiving antenna to an interdevice transmitter, from an interdevice receiver to the transmitting antenna, and from the interdevice receiver to the interdevice transmitter.

6. A communication system comprising:

a first communication device generating a first footprint comprising a first plurality of beams arranged in a first plurality of rows and first plurality of columns;

a second communication device generating a second footprint comprising a second plurality of beams comprising a second plurality of rows and a second plurality of columns so that one of said first plurality of rows overlaps one of said second plurality of rows; and

a beam forming network within said first communication device linearly ratcheting said first plurality of rows so that each of said first plurality of rows is successively included within the second footprint.

7. A communication system as recited in claim 6 wherein said first communication device comprises a satellite.

8. A communication system as recited in claim 6 wherein said second communication device comprises a satellite.

9. A method of operating a communication system comprising:

generating a first footprint comprising a first plurality of beams arranged in a first plurality of rows and first plurality of columns;

generating a second footprint comprising a second plurality of beams comprising a second plurality of rows and a second plurality of columns so that one of said first plurality of rows overlaps one of said second plurality of rows; and

linearly ratcheting said first plurality of rows so that each of said first plurality of rows is successively included within the second footprint.

10. A method as recited in claim 9 wherein ratcheting is performed in response to a movement of a first communication device in a first direction.

11. A method as recited in claim 10 wherein ratcheting is performed in a second direction opposite the first direction.

12. A method as recited in claim 9 wherein ratcheting is performed while maintaining relative column positions.

13. A method of operating a communication system comprising:

forming a first beam footprint and a second beam footprint, said first beam footprint comprised of a plurality of cells, said cells arranged in a first plurality of rows and a first plurality of columns;

overlapping at least one of said first plurality of rows and one of said second plurality of rows;

ratcheting said first plurality of rows linearly downward.

14. A method as recited in claim 13 wherein ratcheting comprises controlling a motion of a communications device using yaw steering.

15. A method as recited in claim 13 wherein ratcheting comprises controlling a motion of a communications device using yaw-roll steering.

16. A method of operating a communication system having a first and second communication device comprising:

dividing a footprint of the first communication device into discrete cells;

moving the first communication device in a travel direction relative to said cells;

grouping the discrete cells into columns in the travel direction and rows in a direction perpendicular to the travel direction;

linearly ratcheting the discrete cells along the columns so that the cells maintain their respective columns and channel resources until handing over; and

handing over one of the rows of cells to the second communication device.

17. A method as recited in claim 16 wherein prior to handing over, sharing a row of discrete cells with the second communication device.

18. A method as recited in claim 16 wherein moving the first communication device comprises moving the first communication device in a yaw direction.

19. A method as recited in claim 16 wherein moving the first communication device comprises moving the first communication device in a yaw and roll direction.

20. A method of operating a communication system comprising:

generating a footprint comprising a plurality of beams arranged in a plurality of rows and plurality of columns;

assigning users to respective rows and allocating respective beam ports thereto; and

simultaneously commanding an RF matrix to change said beam ports through linear ratcheting to maintain the users within respective columns and in a different row while maintaining a resource allocation.