Digital beamforming acquisition system

• US 6,697,619 B1
• Filed: 12/10/1999
• Issued: 02/24/2004
• Est. Priority Date: 12/10/1999
• Status: Expired due to Term

• Current Assignee: CDC Propriete Intellectuelle
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Hogberg, Shawn Wesley, Gross, Jonathon Henry, Davieau, Gerald Joseph
• Primary Examiner(s): APPIAH, CHARLES NANA
• Application Number:
  US09/459,295
• Time in Patent Office: 1,537 Days
• Field of Search: 455/427, 455/428, 455/429, 455/430, 455/431, 455/12.1, 455/13.1, 455/13.2, 455/13.3, 342/352, 342/354, 342/356, 342/359, 342/360, 342/368, 342/371, 370/325
• US Class Current: 455/429
• CPC Class Codes: H04B 7/2041 Spot beam multiple access

Abstract

A satellite communications system (10) provides for digital beamforming acquisition. The communications system (10) has an antenna configuration (20) for maintaining communications links with satellite networking equipment, and a signal processing system (30) for processing signals resulting from the communications links. A beamforming subsystem (40) dynamically forms traffic beams and overhead beams, wherein the overhead beams scan overhead areas of the satellite footprint. Overhead areas are defined by areas of the satellite footprint without active traffic channels. The beamforming subsystem (40) includes a channel database configuration (50) containing traffic channel input data and overhead channel input data. A beamforming processor (60) converts the input data contained in the channel database configuration (50) into traffic beams schedules and overhead beam schedules. An antenna management system (70) dynamically forms traffic beams and overhead beams based on the beam schedules.

Claims

1. A method for providing satellite communication channels within a satellite footprint, the method comprising the steps of:

producing a set of traffic beams in traffic areas of the satellite footprint;

forming an overhead beam structure; and

scanning the overhead beam structure in overhead areas of the satellite footprint, the overhead areas defined by areas of the satellite footprint outside the traffic areas.

2. The method of claim 1 wherein the traffic beams contain traffic channels.

3. The method of claim 2 wherein the traffic beams contain overhead channels.

4. The method of claim 3 wherein the overhead channels include broadcast channels.

5. The method of claim 3 wherein the overhead channels include acquisition channels.

6. The method of claim 1 wherein the overhead beam structure includes an array of overhead beams.

7. The method of claim 6 wherein the overhead beams contain overhead channels.

8. The method of claim 7 wherein the overhead channels include broadcast channels.

9. The method of claim 7 wherein the overhead channels include acquisition channels.

10. The method of claim 6 further including the step of producing an overhead beam in every region of the overhead areas at a predetermined rate.

11. A satellite communications system comprising:

an antenna configuration for maintaining communications links with satellite networking equipment;

a signal processing system for processing signals resulting from the communications links; and

a beamforming subsystem for dynamically forming traffic beams and overhead beams based on the signals processed by the signal processing system, the overhead beams scanning overhead areas of a satellite footprint, the overhead areas defined by areas of the satellite footprint without active traffic channels.

12. The communications system of claim 11 wherein the antenna configuration includes:

a feederlink antenna for maintaining feederlinks with ground stations;

a crosslink antenna for maintaining crosslinks with satellite vehicles; and

a subscriber antenna configuration for maintaining subscriber links with subscriber devices.

13. The communications system of claim 12 wherein the subscriber antenna configuration includes:

a subscriber transmit antenna for transmitting subscriber link beams to subscriber devices; and

a subscriber receive antenna for receiving subscriber link signals from subscriber devices.

14. The communications system of claim 11 wherein the signal processing system includes:

a communication electronics subsystem for performing communication functions in the communications system; and

a processor subsystem for performing management and control functions in the communications system, the processor subsystem updating a channel database configuration with traffic channel input data and overhead channel input data.

15. The communications system of claim 14 wherein the communication electronics subsystem performs frequency conversion, switching, and modem functions.

16. The communications system of claim 14 wherein the processor subsystem performs channel management, satellite resource management and satellite control functions.

17. The communications system of claim 11 wherein the beamforming subsystem includes:

a channel database configuration containing traffic channel input data and overhead channel input data;

a beamforming processor for converting the input data contained in the channel database configuration into traffic beam coefficient schedules and overhead beam coefficient schedules; and

an antenna management system for dynamically forming traffic beams and overhead beams based on the beam coefficient schedules.

18. A beamforming subsystem for a satellite communications system, the beamforming subsystem comprising:

a channel database configuration containing traffic channel input data and overhead channel input data;

a beamforming processor for converting the input data contained in the channel database configuration into traffic beam coefficient schedules and overhead beam coefficient schedules; and

an antenna management system for dynamically forming traffic beams and overhead beams based on the beam coefficient schedules, the overhead beams scanning overhead areas of a satellite footprint, the overhead areas defined by areas of the satellite footprint without active traffic channels.

19. The beamforming subsystem of claim 18 wherein the channel database configuration includes a traffic channel database containing current traffic channel requirements, and an overhead channel database containing current overhead channel requirements.

20. The beamforming subsystem of claim 18 wherein the beamforming processor includes:

a beam location system for updating beam locations based on the input data contained in the channel database configuration;

a beam shape system for updating beam shapes based on the input data contained in the channel database configuration and the updated beam locations;

a beamform coefficient processor for calculating antenna coefficients based on the updated beam locations, the updated beam shapes, and physical configuration data; and

a beam scheduling system for generating beam coefficient schedules based on the calculated antenna coefficients and the input data contained in the channel database configuration.

21. The beamforming subsystem of claim 20 the beam location system includes:

a traffic beam location module for updating traffic beam locations; and

an overhead beam location module for updating overhead beam locations.

22. The beamforming subsystem of claim 20 wherein the beam shape system includes:

a traffic beam shape module for updating traffic beam shapes; and

an overhead beam shape module for updating overhead beam shapes.

23. The beamforming subsystem of claim 20 wherein the beamform coefficient processor calculates transmit antenna coefficients and receive antenna coefficients.

24. The beamforming subsystem of claim 20 wherein the beam scheduling system includes:

a traffic beam scheduler for generating traffic beam coefficient schedules; and

an overhead beam scheduler for generating overhead beam coefficient schedules.

25. The beamforming subsystem of claim 18 wherein the antenna management system includes:

a transmit antenna manager for dynamically forming beams for a subscriber transmit antenna; and

a receive antenna manager for dynamically forming beams for a subscriber receive antenna.

26. The beamforming subsystem of claim 18 further including:

a hardware constraint module for providing the beamforming processor with satellite hardware constraint data; and

a satellite position and attitude module for providing the beamforming processor with satellite position and attitude data.