Multi-spot-beam satellite system with broadcast and surge capacity capability

• US 6,704,544 B1
• Filed: 06/28/2000
• Issued: 03/09/2004
• Est. Priority Date: 06/25/1997
• Status: Expired due to Term

• Current Assignee: Hughes Electronics Corporation (Rtx Corporation)
• Original Assignee: Hughes Electronics Corporation (Rtx Corporation)
• Inventors: Fitzpatrick, Edward J., Glaser-Weiner, Michelle J., Justiss, James E., Sarraf, Jamal, Martin, Remberto
• Primary Examiner(s): APPIAH, CHARLES NANA
• Application Number:
  US09/605,775
• Time in Patent Office: 1,350 Days
• Field of Search: 455/12.1, 455/13.1, 455/13.2, 455/13.3, 455/13.4, 455/15, 455/3.2, 455/17, 455/20, 455/22, 455/427, 455/428, 455/429, 455/430, 370/319, 370/437, 370/352, 370/353, 370/318
• US Class Current: 455/13.1
• 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
• CPC Class Codes: H04B 7/2041 Spot beam multiple access

Abstract

A payload design for a multi-spot-beam satellite communication system includes a plurality of uplink spot beam receivers and downlink spot beam transmitters, and a broadcast transmitting subsystem capable of transmitting a broadcast beam to an entire system geographical service area. An input filter-switch-matrix (IFSM) controllably selects input IF signal bands for routing to an on-board digital signal processor-router (DSPR). The DSPR subsequently routes all received point-to-point and broadcast data packets to the appropriate downlink spot or broadcast transmitting subsystems for transmission thereof. The broadcast downlink allows broadcast transmissions to occur at the highest efficiency possible, while also allowing for flexible provision of surge capacity for point-to-point transmissions on previously exhausted spot beams by selective use of the broadcast beam for such point-to-point transmissions.

Claims

1. A method of configuring a satellite payload for use in a multi-spot-beam communication system comprising the steps of:

providing a plurality of spot-beam uplinks each of which receives signals transmitted from a particular section of a total service area to be serviced by the communication system;

providing a plurality of spot-beam downlinks each of which transmits signals to a particular section of the total service area;

providing a broadcast downlink which transmits a single wide-area beam to the total service area;

routing point-to-point transmissions received by said plurality of uplinks to a particular one of said plurality of downlinks; and

routing broadcast transmissions received by said plurality of uplinks to said broadcast downlink in a non-blocking manner with said point-to-point transmissions.

2. The method of claim 1 wherein transmitted signals comprise one of two opposite polarizations, and the step of routing point-to-point transmissions comprises routing one of the two polarizations as point-to-point transmissions, and the step of routing broadcast transmissions comprises routing transmissions having the other polarization as broadcast transmissions.

3. The method of claim 2 wherein the polarization for broadcast transmissions has a primary frequency spectrum assignable in minimum resolution blocks.

4. A satellite system comprising:

a satellite having a payload generating a wide-area downlink broadcast beam to a predetermined area on the earth, and generating a plurality of downlink spot beams over the predetermined area;

a plurality of user terminals generating uplink point-to-point signals and uplink broadcast signals;

said payload routing the uplink broadcast signals and the uplink point-to-point signals to respective ones of the downlink broadcast beam and downlink spot beams in a non-blocking manner, wherein said Payload comprises an on-board digital signal processor-router for processing the uplink point-to-point signals and uplink broadcast signals.

5. A satellite system, comprising:

a satellite having a payload generating a downlink broadcast beam to a predetermined area on the earth, and generating a plurality of downlink spot beams over the predetermined area for point-to-point transmissions;

a plurality of user terminals generating uplink point-to-point signals and uplink broadcast signals;

said payload routing the uplink broadcast signals and the uplink point-to-point signals to respective ones of the downlink broadcast beam and downlink spot beams in a non-blocking manner,

wherein said payload comprises;

at least one uplink receiver subsystem each arranged to receive the uplink point-to-point signals over an entire primary frequency bandwidth of the satellite system;

an on-board digital signal processor-router for processing the uplink point-to-point and the uplink broadcast signals;

a reconfigurable input-filter-switch-matrix connected to said at least one uplink receiver subsystem and said onboard digital signal processor-router;

a broadcast downlink antenna transmitting a downlink broadcast signal;

an output-filter multiplexer supplying the downlink broadcast signal to said broadcast downlink antenna, and

at least one broadcast transmitter amplifier subsystem connected to said on-board digital signal processor-router for transmitting the downlink broadcast signal.

6. A satellite system as recited in claim 5, wherein said reconfigurable input-filter-switch-matrix selectively routes all uplink signals received with a particular one of two opposite polarizations to said on-board digital signal processor-router for routing to said broadcast transmitter amplifier subsystem.

7. A satellite system as recited in claim 6, further comprising a command decoder connected to said reconfigurable input-filter-switch-matrix, said command decoder being responsive to a system ground controller for selecting signals for routing to said broadcast transmitter amplifier subsystem.

8. A method for communicating through a satellite having a repeater comprising the steps of:

generating a broadcast wide area downlink beam from a satellite over a service area;

generating a plurality of point-to-point uplink signals within the service area;

generating a plurality of point-to-point downlink beams within the service area;

uplinking a broadcast signal as data packets from a user terminal;

uplinking point-to-point signals as data packets from a user terminal;

processing the data packets in an on-board digital signal processor-router for subsequent downlink transmission as point-to-point and broadcast signals; and

routing a broadcast wide area downlink signal and a plurality of point-to-point downlink signals to respective ones of the broadcast wide area downlink beam and plurality of point-to-point downlink beams in a non-blocking manner.

9. A method as recited in claim 8 further comprising the step of overlapping the broadcast wide area downlink beam and the plurality of point-to-point downlink beams.