Fixed cell communication system with reduced interference

• US 7,369,847 B1
• Filed: 09/14/2000
• Issued: 05/06/2008
• 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: Ramanujam, Parthasarathy, Rosen, Harold, Feria, Ying
• Primary Examiner(s): Ly; Nghi H.
• Application Number:
  US09/661,986
• Time in Patent Office: 2,791 Days
• Field of Search: 455/429, 455/430, 455/427, 455/447, 455/12.1, 455/63, 455/67.1, 455/3.02, 455/13.2, 455/98, 455/63.1, 455/67.11, 342/5, 342/356, 342/155, 342/352, 342/26.A, 342/358
• 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. Preferably, cells having the same resource are 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 method of preventing interference in a communication system comprising the steps of:

generating a fixed reuse pattern in a service area from a high altitude communications device, said pattern having a plurality of first resource cells and a second resource cell having a resource different than the plurality of first resource cells;

selectively suppressing a side lobe of a first beam having a first resource by selectively reshaping an antenna surface at interference locations and maintaining a shape of the antenna in non-interference locations to form a suppressed portion and a non-suppressed portion so that said non-suppressed portion aligns with said second resource cell and a side lobe suppressed portion of the first beam aligns with other beams having the first resource.

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

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

4. A method as recited in claim 1 wherein said first resource and said second resource comprise an orthogonal code.

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

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