Matched filter for scalable spread spectrum communications systems

• US 7,539,235 B2
• Filed: 09/04/2007
• Issued: 05/26/2009
• Est. Priority Date: 09/24/2003
• Status: Expired due to Fees

• Current Assignee: Recon Dynamics LLC (Tricon Sales LLC)
• Original Assignee: S5 Wireless, Inc. (Tricon Sales LLC)
• Inventors: Ostermiller, Dirk, Dobson, W. Kurt, Prestwich, Sy, Bevan, Scott
• Primary Examiner(s): Bayard; Emmanuel
• Application Number:
  US11/849,944
• Publication Number:
  US 20070291821A1
• Time in Patent Office: 630 Days
• Field of Search: 375/130, 375/141, 375/135, 375/136, 375/295, 375/143, 375/146, 375/147
• US Class Current: 375/130
• CPC Class Codes: H04B 1/7093 Matched filter type
• CPC Class Codes: H04B 2201/70703 using multiple or variable rates
• CPC Class Codes: H04B 2201/70707 Efficiency-related aspects
• CPC Class Codes: H04J 13/0022 PN, e.g. Kronecker

Abstract

A spread spectrum communications system using long, scalable PN sequences to achieve variable communication rates using a low-complexity and scalable matched filter architecture to provide a large processing gain, robust recovery of multiple devices in long reach, high ambient-noise environments.

Claims

1. A transmitter for a spread spectrum communications system, comprising:

a data source;

a first multiplier/mixer spreading data from said data source with a first pseudo noise source;

a second multiplier/mixer spreading data from said first mixer with a second pseudo noise source, wherein the first pseudo noise source and the second pseudo noise source are not used to lock a receiver to the transmitter; and

an RF transmitter.

2. A spread spectrum communications system, as recited in claim 1, wherein said first pseudo noise source provides a variable length code sequence.

3. A spread spectrum communications system, as recited in claim 1, wherein said first pseudo noise source provides a fixed length code sequence.

4. A spread spectrum communications system, as recited in claim 1, wherein said second pseudo noise source provides a fixed length code sequence.

5. A spread spectrum communications system, as recited in claim 1, wherein said second pseudo noise source provides a variable length code sequence.

6. A spread spectrum communications system, as recited in claim 1, wherein said first multiplier mixer spreads said data from said data source with a variable length PN code.

7. A spread spectrum communications system, as recited in claim 1, wherein said first multiplier mixer spreads said data from said data source with a fixed length PN code.

8. A spread spectrum communications system, as recited in claim 1, wherein said second multiplier mixer spreads said data from said first mixer with a fixed length PN code.

9. A spread spectrum communications system, as recited in claim 1, wherein said second multiplier mixer spreads said data from said first mixer with a variable length PN code.