×

Code division multiplex system using selectable length spreading code sequences

  • US 4,930,140 A
  • Filed: 01/13/1989
  • Issued: 05/29/1990
  • Est. Priority Date: 01/13/1989
  • Status: Expired due to Fees
First Claim
Patent Images

1. A method of communicating an input data signal between a transmitter and a receiver in a spread spectrum code division multiplex system, said method comprising the steps of:

  • selecting a transmitter spread spectrum spreading code sequence of a given length at said transmitter;

    generating said transmitter spread spectrum spreading code sequence of said selected given length;

    selecting a transmitter time delay substantially equal to the length of said selected transmitter spread spectrum spreading code sequence;

    differentially encoding said spread spectrum spreading code sequence in accordance with said input data signal using said selected transmitter time delay;

    transmitting said differentially encoded spread spectrum spreading code sequence as a spread spectrum signal; and

    at said receiver;

    receiving said differentially encoded spread spectrum spreading code sequence;

    selecting a receiver time delay corresponding to a given length of a receiver spread spectrum spreading code sequence said receiver time delay having a length substantially equal to the length of said selected transmitter time delay;

    differentially correlating said received spread spectrum signal with said selected given length of said receiver spread spectrum spreading code sequence using said selected receiver time delay substantially equal to the length of said selected receiver spread spectrum spreading code sequence to recover said input data signal.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×