Satellite communication system and method with asymmetric feeder and service frequency bands

• US 7,869,759 B2
• Filed: 12/12/2007
• Issued: 01/11/2011
• Est. Priority Date: 12/14/2006
• Status: Active Grant

• Current Assignee: ViaSat Incorporated
• Original Assignee: ViaSat Incorporated
• Inventors: Pateros, Charles N., Dankberg, Mark D.
• Primary Examiner(s): LEE, JOHN J
• Application Number:
  US11/954,654
• Publication Number:
  US 20080146145A1
• Time in Patent Office: 1,126 Days
• Field of Search: 455/12.1, 455/7, 455/9, 455/3.02, 455/427, 455/3.04, 455/430, 455/447, 455/446, 455/452.1, 455/452.2, 455/13.2, 455/13.3, 455/13.4, 370/316, 370/318, 370/319, 370/321
• US Class Current: 455/12.1
• CPC Class Codes: H04B 7/18515 Transmission equipment in satellites or space-based relays
• CPC Class Codes: H04B 7/1858 Arrangements for data transmission on the physical system, i.e. for data bit transmission between network components

Abstract

System and method for communicating data in a multibeam satellite system having feeder beams associated with a plurality of gateways and a plurality of service beams associated with a plurality of user subscriber terminals utilizing frequency re-use by service beams between a satellite and a plurality of subscriber terminals, wherein the service beams are transmitted to and from the satellite by re-using at least one common frequency channel of the service beam, such that the beam allocation is asymmetric among available frequency channels. The result is a potential for reduction of transponder resources.

Claims

1. In a satellite communication system, a method for communicating between a central source and a plurality of user terminals via feeder frequency bands and service frequency bands, said method comprising:

causing the generating of uplink feeder beams and downlink feeder beams, said uplink feeder beams and downlink feeder beams being associated with a plurality of gateways via a translator satellite having a different number of receivers than transmitters, said uplink feeder beams and said downlink feeder beams being characterized by a selection of feeder signals of first frequencies and first polarization slots, and each said feeder signal corresponding with a different color in a first selection of colors in a color map, each color being characterized by a unique frequency band and unique signal polarization; and

causing the generating of a plurality of uplink service beams and downlink service beams, said uplink service beams and downlink service beams being associated with a plurality of user subscriber terminals via the satellite, said service beams being characterized by a selection of second frequencies and second polarization slots, the number of said second frequencies and second polarizations being less than the number of said first frequencies and said first polarizations and each said feeder signal corresponding with a different color in a second selection of colors in said color map, said second color selection being less in number than said first color selection, such that the feeder frequency bands and the service frequency bands are asymmetric among available frequency channels for communicating with enhanced efficiency between a central source and a plurality of user terminals via feeder frequency bands and service frequency bands.

2. The method according to claim 1, further including the step of:

causing the reusing frequencies in the feeder beams between said satellite and said plurality of gateways, wherein the gateway beams transmit transmitting to and from the satellite re-using at least one common frequency channel of the feeder beams, such that allocation of frequency and polarization slots of the feeder beams is asymmetric.

3. In a satellite communication system having a method for communicating between a central source and a plurality of user terminals via feeder frequency bands and service frequency bands, the improvement in the method comprising:

modifying a four-color reuse pattern for assigning spot coverage areas so that the ratio of a select group of the four colors in the pattern is not equal, thereby allowing for asymmetric service frequency usage on service downlinks and thereby requiring fewer than conventional numbers of types of frequency translators;

wherein uplink service links being caused to employ three identical frequency bandwidths, each with two orthogonal polarizations, and downlink feeder links employ two frequency bandwidths, each with two orthogonal polarizations, and wherein the frequency bandwidths between the uplink feeder links and the downlink feeder links are being caused to be reused asymmetrically to reduce the required number of separate and unique elements on a satellite.

4. In a satellite communication system having a method for communicating between a central source and a plurality of user terminals via feeder frequency bands and se ice frequency bands, the improvement in the method comprising:

modifying a four-color reuse pattern for assigning spot coverage areas so that the ratio of a select group of the four colors in the pattern is not equal, thereby allowing for asymmetric service frequency usage on service downlinks and thereby requiring fewer than conventional numbers of types of frequency translators;

wherein at least one uplink feeder beam comprises comprising six carriers, wherein the beam comprises comprising three frequency channels, each of the three frequency channels being operatively separated by right hand circular polarization (RHCP) and left hand circular polarization (LHCP), to form six unique combinations of frequency and polarization (colors), and wherein each of the six carriers is being caused to transmitted transmit using only one of the six unique combinations of frequency and polarization.

5. In a satellite communication system having a method for communicating between a central source and a plurality of user terminals via feeder frequency bands and service frequency bands, the improvement in the method comprising:

modifying a four-color reuse pattern for assigning spot coverage areas so that the ratio of a select group of the four colors in the pattern is not equal, thereby allowing for asymmetric service frequency usage on service downlinks and thereby requiring fewer than conventional numbers of types of frequency translators;

wherein the downlink service beams include including one of four carriers, wherein the carriers are being chosen from two frequency bands, each of the two frequency bands being capable of being separated by right hand circular polarization (RHCP) and left hand circular polarization (LHCP), to form four unique combinations of frequency and polarization (colors), and wherein each of the four carriers is transmitted using one of the four unique combinations of frequency and polarization to spot beam cells according to the four color pattern.

6. A satellite communication system for communicating between a central source gateway and a plurality of user terminals via feeder frequency bands and service frequency bands, said system comprising:

a gateway ground station configured for generating uplink feeder beams and downlink feeder beams via a bent-pipe transponder satellite, said uplink feeder beams and said downlink feeder beams being characterized by a selection of feeder signals of first frequencies and first polarization slots, and each said feeder signal corresponding with a different color in a first selection of colors in a color map, each color being characterized by a unique frequency band and unique signal polarization; and

a plurality of user subscriber terminals remote from the gateway configured for generating a plurality of uplink service beams and downlink service beams, said uplink service beams and said downlink service beams being characterized by a selection of second frequencies and second polarization slots, and each said feeder signal corresponding with a different color in a second selection of colors in said color map, said second color selection being less in number than said first color selection;

such that the feeder frequency bands and the service frequency bands are asymmetric among available frequency channels.

7. The system according to claim 6, further comprising:

a controller configured for reusing frequencies in the feeder beams between said satellite and said plurality of gateways, wherein the gateway beams being configured to transmit to and from the satellite re-using at least one common frequency channel of the feeder beams, such that allocation of frequency and polarization slots of the feeder beams is asymmetric in accordance with a four-color color reuse pattern employed for assigning spot coverage areas.

8. The system according to claim 7, wherein uplink service links being caused to employ three identical frequency bandwidths, each with two orthogonal polarizations, and downlink feeder links being caused to employ two frequency bandwidths, each with two orthogonal polarizations, and wherein the frequency bandwidths between the uplink feeder links and the downlink feeder links are being caused to be reused asymmetrically to reduce the required number of separate and unique elements on a satellite.

9. The system according to claim 7, wherein at least one uplink feeder beam comprises comprising six carriers, wherein the beam comprises each with three potential frequency channels, each of the three frequency channels being operatively separated by right hand circular polarization (RHCP) and left hand circular polarization (LHCP), to form six unique possible combinations of frequency and polarization (colors), and wherein each of the six carriers is transmitted being caused to transmit using only one of the six unique possible combinations of frequency and polarization.

10. The system according to claim 7, wherein the downlink service beams being caused to include one of four carriers, wherein the carriers are chosen from two frequency bands, each of the two frequency bands being capable of being separated by right hand circular polarization (RHCP) and left hand circular polarization (LHCP), to form four unique combinations of frequency and polarization (colors), and wherein each of the four carriers is being caused to be transmitted using one of the four unique combinations of frequency and polarization to spot beam cells according to the four color pattern.

11. A method for communicating via a satellite communication system, the method comprising:

communicating a plurality of uplink feeder beams from a gateway to a satellite, each of the plurality of uplink feeder beams being associated with a different uplink color in a first selection of colors in a uplink color map, each of the different uplink colors being characterized by one of a set of unique uplink frequency bands and unique uplink signal polarizations; and

causing the communicating of a plurality of downlink service beams from the satellite to a plurality of user terminals each of the plurality of downlink service beams being associated with a different downlink color in a second selection of colors in a downlink color map, each of the different downlink colors being characterized by one of a set of unique downlink frequency bands and unique signal downlink polarizations the second selection of colors being less in number than the first selection of colors.

12. A satellite communication system comprising:

a gateway configured to communicate a plurality of uplink feeder beams to a satellite, each of the plurality of uplink feeder beams associated with a different uplink color in a first selection of colors in an uplink color map, each of the different uplink colors being characterized by one of a set of uplink unique frequency bands and unique uplink signal polarizations; and

a plurality of user terminals configured to receive a plurality of downlink service beams from the satellite, each of the plurality of downlink service beams associated with a different downlink color in a second selection of colors in a downlink color map, each of the different downlink colors being characterized by one of a set of unique downlink frequency bands and unique downlink signal polarizations, the first selection of colors being more in number than the second selection of colors.

13. A satellite communication system, comprising:

means for communicating a plurality of uplink feeder beams from a gateway to a satellite, each of the plurality of uplink feeder beams being associated with a different uplink color in a first selection of colors in an uplink color map, each of the different uplink colors being characterized by one of a set of unique uplink frequency bands and unique uplink signal polarizations; and

means for communicating a plurality of downlink service beams from the satellite to a plurality of user terminals, each of the plurality of downlink service beam being associated with a different downlink color in a second selection of colors in a downlink color map, each of the different downlink colors being characterized by one of a set of unique downlink frequency bands and unique downlink signal polarizations, the first selection of colors being more in number than the second selection of colors.