Multiple access spread spectrum switching methodology

• US 7,417,965 B1
• Filed: 10/07/2005
• Issued: 08/26/2008
• Est. Priority Date: 12/02/1998
• Status: Expired due to Fees

• Current Assignee: AT&T Corporation (AT&T, Inc.)
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: Rudrapatna, Ashok N.
• Primary Examiner(s): Duong; Frank
• Application Number:
  US11/245,572
• Time in Patent Office: 1,054 Days
• Field of Search: None
• US Class Current: 370/323
• CPC Class Codes: H04B 7/18513 Transmission in a satellite or space-based system
• CPC Class Codes: H04B 7/18532 Arrangements for managing transmission, i.e. for transporting data or a signalling message
• CPC Class Codes: H04B 7/216 Code division or spread-spectrum multiple access [CDMA, SSMA]
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A low-cost, low-power, low-complexity, small, high-reliability, robust, seamless satellite communication network is described. The network performs encoding of a user signal at the customer premises to enable routing of the user signal to an appropriate destination beam at the satellite requiring low power user signal processing. Routing information is embedded at the periphery of the network CPE'"'"'s rather than at the satellite. Embedding the routing information in this way greatly reduces on-board switching complexity and increases signal to interference ratio for the user.

Claims

1. A communication system comprising:

transmission equipment that is assigned to a particular origination path, encodes user signals originating at or near the transmission equipment based on the origination path and a particular destination path, and transmits the encoded user signals on the particular origination path, the transmission equipment including;

a first digital encoder for applying on a user signal a first code unique to a user and unique to the destination path to create a first intermediate user signal;

a second digital encoder for applying on the first intermediate user signal a second code uniquely mapping the user signal to the particular destination path to create a second intermediate user signal; and

a third digital encoder for applying on the second intermediate user signal a third code orthogonal to the second code, the third code identifying the user signal with the particular origination path;

switching equipment that receives the encoded user signals on the particular origination path, routes the encoded user signals at a path level, and transmits the encoded user signals on the particular destination path; and

reception equipment that is assigned to the particular destination path, receives the encoded user signals on the particular destination path, and decodes the user signals.

2. The system of claim 1, wherein the particular origination path is a particular origination beam and the particular destination path is a particular destination beam and the switching equipment routes the encoded user signals at a beam level.

3. The system of claim 1, wherein the switching equipment is located on a satellite and the transmitting and reception equipment are ground-based.

4. The system of claim 1, wherein the transmission equipment is assigned to a particular origination path based on geographic location.

5. The system of claim 1, wherein the reception equipment is assigned to a particular destination path based on geographic location.

6. The system of claim 1, wherein the origination or reception equipment is mobile.

7. The system of claim 1, wherein the switching equipment determines to which destination path an encoded user signal is destined.

8. The system of claim 1, wherein the switching equipment is located on a satellite;

the transmission equipment encodes user signals and transmits the encoded user signals to the satellite via the origination path; and

the reception equipment receives the encoded user signals from the switching equipment on the satellite via the destination path.

9. The system of claim 1, wherein the transmission equipment encodes user signals from a plurality of users and transmits the encoded user signals to a satellite via the origination path.

10. The system of claim 1, where the reception equipment receives the encoded user signals from the switching equipment on the satellite via the destination path, decodes the encoded user signals, and distributes the decoded user signals to at least one receiving user.

11. The system of claim 1, wherein routing information is encoded in the user signals transmitted by the transmission equipment.

12. The system of claim 11, wherein the switching equipment uses the routing information to route the encoded user signals to the destination path.

13. The system of claim 1, wherein the transmitting and reception equipment use a spread spectrum technique to transmit the encoded user signals.

14. The system of claim 1, wherein the switching equipment determines the origination path and destination path of an encoded user signal based on unique path-specific information.

15. A communication method comprising:

assigning transmission equipment to a particular origination path;

applying on a user signal a first code unique to a user and unique to a destination path to create a first intermediate user signal;

applying on the first intermediate user signal a second code uniquely mapping the user signal to the destination path to create a second intermediate user signal; and

applying on the second intermediate user signal a third code orthogonal to the second code, the third code identifying the user signal with the particular origination path, to create an encoded, user signal;

transmitting the encoded, user signals on the particular origination path;

receiving the encoded, user signals on the particular origination path;

routing the encoded, user signals at a path level;

transmitting the encoded, user signals on the particular destination path;

receiving the encoded, user signals on the particular destination path; and

decoding the encoded, user signals.

16. The communication method of claim 15, wherein the particular origination path is an origination beam and the particular destination path is a destination beam.

17. The communication method of claim 16, wherein routing is performed based on beam codes encoded in the encoded, user signals.

18. The communication method of claim 17, wherein encoding the encoded, user signals encodes the user signals with beam codes associated with the particular origination beam and beam codes associated with the particular destination beam.

19. A communication method comprising:

assigning transmission equipment to a particular origination path;

applying on a user signal a first code unique to a user and unique to a destination path to create a first intermediate user signal;

applying on the first intermediate user signal a second code uniquely mapping the user signal to the destination path to create a second intermediate user signal; and

applying on the second intermediate user signal a third code orthogonal to the second code, the third code identifying the user signal with the particular origination path, to create an encoded, user signal;

transmitting the encoded, user signals on the particular origination path;

receiving the encoded, user signals on the particular origination path;

routing the encoded, user signals at a path level, including summing the user signals on the particular origination path with signals from other origination paths, and decoding the summed user signals for the particular destination path;

transmitting the encoded, user signals on the particular destination path;

receiving the encoded, user signals on the particular destination path; and

decoding the encoded, user signals.

20. The communication method of claim 19, wherein the particular origination path is an origination beam and the particular destination path is a destination beam.

21. The communication method of claim 19, wherein routing is performed based on beam codes encoded in the encoded, user signals.

22. The communication method of claim 21, wherein encoding the encoded, user signals encodes the user signals with beam codes associated with the particular origination beam and beam codes associated with the particular destination beam.