CDMA/TDMA communication method and apparatus for wireless communication using cyclic spreading codes

• US 7,031,371 B1
• Filed: 09/25/2000
• Issued: 04/18/2006
• Est. Priority Date: 09/25/2000
• Status: Active Grant

• Current Assignee: Intellectual Ventures Holding 81 LLC (Intellectual Ventures LLC)
• Original Assignee: Pulse-Link Incorporated
• Inventors: Lakkis, Ismail A.
• Primary Examiner(s): Vanderpuye, Kenneth
• Assistant Examiner(s): Perilla, Jason M.
• Application Number:
  US09/670,054
• Time in Patent Office: 2,031 Days
• Field of Search: 375/347, 375/342, 375/335, 375/337, 375/418, 375/130, 375/131, 375/140, 375/141, 375/152, 375/145, 375/147, 375/146, 375/295, 375/148, 375/149, 375/150, 375/151, 375/153
• US Class Current: 375/146
• CPC Class Codes: H04B 1/71632 Signal aspects H04B1/7172 and H04B1/7176 take precedence
• CPC Class Codes: H04B 1/71635 Transmitter aspects H04B1/7174 takes precedence

Abstract

A communication system (20) uses TDMA techniques to distinguish intended recipients of a communication signal (26) from one another, and direct sequence spread spectrum (DSSS) techniques to encode and distinguish diverse parallel substreams (70, 74) of each user'"'"'s data stream. Parallel unspread substreams (70) are spread using cyclic variations of a common spreading code (38). In one embodiment, the common spreading code (38) is chosen for low aperiodic autocorrelation sidelobes and a substantially flat spectral analysis. In another embodiment the common spreading code (38) is chosen for low periodic autocorrelation sidelobes and a substantially flat spectral analysis. In one embodiment, the use of cyclic variations of the spreading code (38) along with a cyclic prefix (114) enables the mathematical communicative matrix multiplication property, thereby permitting equalization for multipath to occur following or in conjunction with despreading.

Claims