SIGNAL PROCESSING AND TRANSMISSION BY MEANS OF WALSH FUNCTIONS

• US 3,678,204 A
• Filed: 10/26/1970
• Issued: 07/18/1972
• Est. Priority Date: 10/26/1970
• Status: Expired due to Term

• Current Assignee: ITT Corporation (ITT, Inc.)
• Original Assignee: Henning Friedolf Harmuth
• Inventors: Harmuth, Henning Friedolf
• Primary Examiner(s): Blakeslee, Ralph D.
• Application Number:
  US05/084,025
• Time in Patent Office: 631 Days
• Field of Search: 179/15BC
• US Class Current: 177/15
• CPC Class Codes: H04J 13/0048 Walsh
• CPC Class Codes: H04L 23/02 adapted for orthogonal signalling

Abstract

In the transmission by carrier waves a plurality of signals are produced and each multiplied by one of 12 Paley functions derived from a Hadamard matrix of rank 12. The resulting signals are added to form a multiplexed signal. The multiplexed signal is frequency limited by sampling it with a trigger function and passing the samples through a bandpass filter. Reconversion of the multiplex signal is accomplished at the receiver.

Claims

1. A method for the transmission of information by carrier waves comprising the steps of:

multiplying each of a plurality of signals by a different Paley function;

adding said multiplied signals to form a multiplexed signal;

sampling said multiplexed signal to form trigger pulses;

passing said trigger pulses through a bandpass filter to produce a frequency band limited signal;

transmitting said frequency band limited signal to a receiver;

receiving said frequency band limited signal in a receiver and reconverting said frequency band limited signal according to Paley functions into the original plurality of signals.

2. A method according to claim 1 further including the step of shifting the frequency of said frequency band limited signal.

3. An apparatus for the transmission of information by carrier waves, comprising:

a first source of information signals to be transmitted;

a second source of signals representing Paley functions;

means coupled to said first and second source for multiplying each f said first source of signals by a different one of said second source of signals representing Paley functions;

means for adding the outputs of said multiplying means to form a sequency multiplexed signal;

means for converting said multiplexed signal into a frequency band limited signal;

means for receiving said frequency band limited signal;

means coupled to said band limited signal for reconverting said band limited signal into said sequency multiplexed signal; and

means for reconverting said sequency multiplexed signal back into said information signals.

4. An apparatus according to claim 3 wherein said reconverting means includes integrating means coupled to said sequency multiplexed signal to produce the original information signals.