Spread spectrum system with random code retransmission

• US 5,084,900 A
• Filed: 12/21/1989
• Issued: 01/28/1992
• Est. Priority Date: 12/21/1989
• Status: Expired due to Term

• Current Assignee: Gilat Satellite Networks Limited
• Original Assignee: GTE Spacenet Corporation
• Inventors: Taylor, Desmond P.
• Primary Examiner(s): Gregory, Bernarr E.
• Application Number:
  US07/454,345
• Time in Patent Office: 768 Days
• Field of Search: 370/18, 370/60, 370/93, 370/94.1, 370/94.2, 370/94.3, 370/104.1, 455/12, 455/13, 375/1
• US Class Current: 370/320
• CPC Class Codes: H04B 7/216 Code division or spread-spectrum multiple access [CDMA, SSMA]
• CPC Class Codes: H04L 1/18 Automatic repetition systems, e.g. Van Duuren systems

Abstract

A communication system includes a hub station and a plurality of terminal stations. An inbound satellite communication link from each of the terminal stations to the hub station sends digital data packets encoded with a CDMA code for code division multiple access during synchronized time slots on a contention channel. Each of the digital data packets is encoded with the same CDMA code during a first transmission, but each packet is encoded with an alternate CDMA code during any subsequent transmission.

Claims

1. A communication system comprises of:

A hub station; and

a plurality of terminal stations, said terminal stations adapted to provide an inbound communication link from each of said terminal stations to said hub station for sending digital data packets encoded with a CDMA code for code division multiple access during synchronized time slots on a contention channel, each of said digital data packets encoded with the same CDMA code during a first transmission, said terminal stations provided with CDMA code means for pseudorandomly selecting from a pool of alternative CDMA codes for encoding each packet with an alternate CDMA code during any subsequent transmission.