Fixed cell communication system with reduced interference

• US 8,103,270 B2
• Filed: 03/11/2008
• Issued: 01/24/2012
• Est. Priority Date: 09/14/2000
• Status: Expired due to Term

• Current Assignee: The DIRECTV Group, Inc. (AT&T, Inc.)
• Original Assignee: The DIRECTV Group, Inc. (AT&T, Inc.)
• Inventors: Rosen, Harold, Feria, Ying, Ramanujam, Parthasarathy
• Primary Examiner(s): LY, NGHI H
• Application Number:
  US12/046,271
• Publication Number:
  US 20080153481A1
• Time in Patent Office: 1,414 Days
• Field of Search: 455/429, 455/427, 455/447, 455/12.1, 455/63.1, 455/67.11, 455/3.02, 455/13.2, 455/98
• US Class Current: 455/429
• CPC Class Codes: H04B 7/18513 Transmission in a satellite or space-based system
• CPC Class Codes: H04B 7/18528 Satellite systems for providing two-way communications service to a network of fixed stations, i.e. fixed satellite service or very small aperture terminal [VSAT] system
• CPC Class Codes: H04B 7/2041 Spot beam multiple access

Abstract

A communication system has a high altitude communication device that has an antenna for directing beams to a fixed cell pattern with a polarity of cells. A specific pattern of cells having the same communication resource is provided. Cells having the same resource may be separated. The antenna is shaped to suppress interference with locations having the same resource. The areas not having the same resource are not suppressed to allow the system to have maximum capacity and allow a smaller antenna aperture.

Claims

1. A communication system comprising:

a high altitude communication device having an antenna for generating a first plurality of beams, each of said plurality of beams having a first frequency resource, a plurality of main lobes directed to one of a first plurality of cells and a plurality of side lobes and a second plurality of beams having a second resource directed to one of a second plurality of cells,

said antenna selectively shaped so that said side lobes of said first plurality of beams are selectively suppressed in directions of other beams of said first plurality of cells having said first resource and said side lobes are unsuppressed in the second plurality of cells.

2. A communication system as recited in claim 1 wherein said high altitude communication device comprises a satellite.

3. A communication system as recited in claim 1 wherein said high altitude communication device comprises a stratospheric platform.

4. A method as recited in claim 1 wherein said first resource and said second resource comprise a frequency.

5. A method as recited in claim 1 wherein said first resource and said second resource comprise polarization.

6. A method as recited in claim 1 wherein said first resource and said second resource comprise a code.

7. A method of forming a communication system comprising the steps of:

generating, with an antenna, a fixed reuse pattern having a maximum capacity having a first beam having a first resource and a first plurality of beams having the first resource;

generating, with the antenna, a second plurality of beams having a second resource different than the first resource;

identifying interference locations of said first beam relative to said plurality of second beams;

selectively reshaping an antenna to selectively suppress interference at the interference locations with the first plurality of beams and maintaining the shape of the antenna in non-interference locations, and

maintaining the antenna to not suppress interference at non-interference locations.

8. A method as recited in claim 7 wherein said interference locations correspond to a side lobe of said first beam.

9. A method as recited in claim 7 wherein said first resource and said second resource comprise a frequency.

10. A method as recited in claim 7 wherein said first resource and said second resource comprise polarization.

11. A method as recited in claim 7 wherein said first resource and said second resource comprise an orthogonal code.

12. In a fixed cell communication system generating a fixed reuse pattern using an antenna, a method of reducing interference between beams having side lobes, comprising:

selectively changing a shape of a reflector of the antenna so that side lobe suppression is performed only for beams using a same communication resource and maintaining the shape of the reflector of the antenna to not suppress interference for beams using a different communication resource.

13. A method as recited in claim 12, wherein generating a fixed reuse pattern comprises generating the fixed reuse pattern at a satellite.

14. A method as recited in claim 12, wherein generating a fixed reuse pattern comprises generating the fixed reuse pattern at a stratospheric platform.