SWITCHING CIRCUITS EMPLOYING ORTHOGONAL AND QUASI-ORTHOGONAL PSEUDO-RANDOM CODE SEQUENCES

• US 3,715,508 A
• Filed: 09/15/1967
• Issued: 02/06/1973
• Est. Priority Date: 09/15/1967
• Status: Expired due to Term

• Current Assignee: Herman L. Blasbalg
• Original Assignee: Herman L. Blasbalg
• Inventors: Blasbalg, Herman L.
• Primary Examiner(s): Claffy, Kathleen H.
• Assistant Examiner(s): Stewart, David L.
• Application Number:
  US04/667,972
• Time in Patent Office: 1,971 Days
• Field of Search: 179/18GF,15BC,1.5S 178/22
• US Class Current: 370/203
• CPC Class Codes: H04J 13/00 Code division multiplex systems for frequency hopping H04B1/713
• CPC Class Codes: H04K 1/02 by adding a second signal to make the desired signal unintelligible
• CPC Class Codes: H04L 23/02 adapted for orthogonal signalling

Abstract

Switching circuits employing pseudo-random orthogonal or quasiorthogonal code sequences to accomplish line to line or line group to line group switching in both a linear and nonlinear mode.

Claims

1. Switching means for directly switching a message from a first line to a second line comprising, in combination:

a first line over which message samples of a predetermined time interval are transmitted;

a second line to which said message samples are to be switched;

clocking means for providing a time reference;

first generating means connected to said clocking means for generating a first psuedo-random sequence of duration equal to said predetermined time interval when driven by said clocking means;

first combining means connected to said first line and to said first generating means for combining said pseudo-random sequence with each of said message samples to form a first intermediate signal having successive predetermined time intervals equal to those of said message samples;

second generating means, synchronized with said first generating means, for generating a pseudo-random sequence identical with said first pseudo random sequence, said second generating means having a code select input for selectively initializing said second generating means to said predetermined sequence of said first generating means;

second combining means connected to said first combining means and to said second generating means for combining said identical pseudo-random sequence with said first intermediate signal; and

integrating means having an input connected to said second combining means and an output connected to said second line, said integrating means synchronized with said first and second generating means, for reconstructing said message samples.

2. The combination of claim 1 wherein said first pseudo-random sequence is orthogonal.

3. The combination of claim 1 wherein said first pseudo-random sequence is quasi-orthogonal.

4. Switching means for directly switching a message from a first line to a second line comprising, in combination:

a first line over which message samples of a predetermined time interval are transmitted;

a second line to which said message samples are to be switched;

clocking means for providing a time reference;

first generating means connected to said clocking means for generating a first pseudo-random sequence of duration equal to said predetermined time interval when driven by said clocking means;

frequency multiplying means connected to said clocking means for generating frequencies which are multiples of a frequency of said clocking means;

first combining means connected to said frequency multiplying means and to said first generating means, for forming a first intermediate signal having successive predetermined time intervals equal to those of said message samples;

second combining means connected to said first combining means and to said first line for forming a second intermediate signal having successive predetermined time intervals equal to those of said message samples;

second generating means, synchronized with said first intermediate signal for generating a pseudo-random sequence identical to said first pseudo-random sequence, said second generating means having a code select input for selectively initializing said second generating means to said predetermined sequence of said first generating means;

third combining means connected to said second generating means and to said second combining means for combining said identical pseudo-random sequence with said second intermediate signal during said successive predetermined time intervals to form intermediate signals; and

integrating means connected to said second line and to said third combining means, and synchronized with said first and second generating means to reconstruct said message samples on said second line.

5. The combination of claim 4 wherein said pseudo-random sequence is orthogonal.

6. The combination of claim 4 wherein said pseudo-random sequence is quasi-orthogonal.

7. Switching means for directly switching a message from a sending line in a group of sending lines to a receiving line in a group of receiving lines comprising, in combination:

a first group of sending lines, each individual sending line of said group for transmitting a message comprising message samples having a predetermined time interval;

A first group of synchronized individual generating means, each of said individual means generating a pseudo-random sequence;

a first group of combining means, each individual member of said group connected to one of said sending lines and to one of said individual generating means of said first group of generating means for combining said message on said one of said sending lines with said pseudo-random sequence from said one of said individual generating means, for forming a first intermediate signal having successive predetermined intervals equal to those of said message samples;

multiplexing means connected to each of said first group of combining means for combining each of said first intermediate signals into a group of first intermediate signals;

a group of receiving lines, each line for receiving a message switched from one of said group of sending lines;

a second group of individual generating means synchronized with said first group of individual generating means, each of said second group of generating means generating a pseudo-random sequence identical to a pseudo-random sequence generated by one of said generating means of said first group of individual generating means, each of said individual generating means of said second group having a code select input for initializing eAch of said individual generating means of said second group to said predetermined sequence of any of at least one of said individual generating means of said first group;

a second group of combining means, each individual member of said group connected to said multiplexing means and to one of said individual generating means of said second group of individual generating means, each of said second group of combining means forming a second intermediate signal;

a group of integrating means synchronized with said first and second group of generating means, each member of said group of intergrating means connected to one of said second group of combining means and to one of said group of receiving lines and accepting said second intermediate signal from said one of said second group of combining means to reconstruct said message transmitted on said individual sending line.

8. The combination of claim 7 wherein said multiplexing means is linear and said pseudo-random sequences are orthogonal.

9. The combination of claim 7 wherein said multiplexing means is linear and said pseudo-random sequences are quasi-orthogonal.

10. The combination of claim 7 wherein said multiplexing means is nonlinear and said pseudo-random sequences are orthogonal.

11. The combination of claim 7 wherein said multiplexing means is nonlinear and said pseudo-random sequences are quasi-orthogonal.

12. Switching means for multiplexing a plurality of groups of messages onto a group of sending lines and for switching said groups of messages from any one of said group of sending lines to any one of a group of receiving lines comprising, in combination:

a plurality of message group forming means for forming message groups, each message group of said message groups comprising messages made up of message samples having a predetermined time interval, each of said plurality of message group forming means including;

a first group of generating means, each generating means of said first group of generating means being driven at a predetermined clock rate, and each having a code select input for initializing said generating means to a predetermined pseudo-random sequence of length N at said clock rate and providing said pseudo-random sequence at an output, a first group of combining means, each combining means of said first group of combining means having a first input for receiving a message made up of message samples and a second input for receiving the output of a different one of said generating means of said first group of generating means, a multiplexing means connected to an output of each combining means of said first group of combining means, said multiplexing means providing an output which is a signal representative of a group of messages;

a group of sending lines, each sending lines of said group of sending lines being connected to the output of said multiplexing means of a different one of said plurality of message group forming means for accepting one of said message groups therefrom;

a group of receiving lines, each receiving line of said group of receiving lines for receiving one of said message groups;

group switching means connected to each of said sending lines and connected to each of said receiving lines for switching any message group on any of said sending lines onto any of said receiving lines, said group switching means including;

a second group of generating means driven at N times said clock rate, each generating of said second group of generating means being synchronized with said first group of generating and generating at an output, a pseudo-random sequence of length N, N times during said predetermined time interval;

a second group of combining means, each combining means of said second group of combining means having a first input connected to one of said sending lines and having a second input connected to an output of a different one of said generating means of said second group of generating means, each comBining means of said second group of combining means providing an encoded group signal at its output, second multiplexing means having a plurality of inputs each input of said plurality of inputs being connected to an output of a different one of said second group of combining means for combining said encoded group signals into a group of group signals, a third group of combining means, each combining means of said third group of combining means having a first input connected to said output of said second multiplexing means, a third group of generating means synchronized with said second group of generating means, said third group of generating being driven at N times said clock rate, each generating means of said third group of generating means having a code select input for initializing each generating means of said third group of generating means to generate a pseudo-random sequence identical to that generated by any generating means of said second group of generating means, each generating means of said third generating means providing said pseudo-randam sequence at a second input of a different combining means of said third group of combining means, a group of integrating means, each integrating means of said group of integrating means having an output connected to a different one of said receiving lines and an input connected to an output of a different one of said combining means of said third group of combining means for reconstructing one of said message groups to be received by one of said receiving lines.

13. The combination of claim 12 wherein said second multiplexing means are linear and said pseudo-random sequences generated by said second group of generating means are orthogonal.

14. The combination of claim 12 wherein said second multiplexing means are linear and said pseudo-random sequences generated by said second group of generating means are quasi-orthogonal.

15. The combination of claim 12 wherein said second multiplexing means are nonlinear and said pseudo-random sequences generated by said second group of generating means are orthogonal.