Method and apparatus for enabling the transmission of multiple wide bandwidth electrical signals

• US 5,966,056 A
• Filed: 07/03/1996
• Issued: 10/12/1999
• Est. Priority Date: 01/26/1996
• Status: Expired due to Term

• Current Assignee: ClearCube Technology Incorporated
• Original Assignee: INT Labs Incorporated
• Inventors: Thornton, Barry
• Primary Examiner(s): Lee, Benny T.
• Application Number:
  US08/674,626
• Time in Patent Office: 1,196 Days
• Field of Search: 333/4, 333/5, 333/236, 174/34, 174/32, 174/113 R, 379/90.01, 379/93.01, 348/8, 348/12, 455/3.1, 455/6.3
• US Class Current: 333/5
• CPC Class Codes: H04L 5/20 using different combinations of lines, e.g. phantom working

Abstract

Method and apparatus for enabling the transmission of high bandwidth analog and digital data over cable lengths of more than 1000 feet through low cost semishielded or unshielded four wire cable are disclosed. Three balanced mode signals are transmitted using four conductors. In this configuration, the components A+ and A- of a first balanced mode signal A are respectively carried on a first pair of conductors, the components B+ and B- of a second balanced mode signal B are respectively carried on a second pair of conductors, and the components C+ and C- of a third balanced mode signal C are respectively carried on a pair of conductors synthesized through the commonality of the first and second conductor pairs, respectively. Using this technique, a new additional virtual ground plane is created wherein signal energy can be transmitted without interfering or combining with the other signals being transmitted on the remaining conductor pairs.

Claims

1. A method of transmitting three balanced mode signals using two pairs of conductors, the method comprising:

transmitting a first one of said balanced mode signals on a first pair of said two pairs of conductors;

transmitting a second one of said balanced mode signals on a second pair of said two pairs of conductors;

synthesizing a third pair of conductors from said first and second pairs of conductors;

transmitting a third one of said balanced mode signals using said synthesized third pair of conductors; and

piggybacking additional low bandwidth signals on one or more of said three balanced mode signals for transmission therewith.

5. The method of claim 1 wherein said three balanced mode signals comprise wide bandwidth RGB video data with imbedded vertical and horizontal sync signals.

6. The method of claim 1 further comprising transmitting one or more of said three balanced mode signals in opposite directions simultaneously.

7. The method of claim 1 further comprising arranging said first and second pairs of said two pairs of conductors in an adjacent mode pattern.

8. The method of claim 1 wherein said two pairs of conductors comprise a four-wire telephone cable.

9. The method of claim 1 wherein said three balanced mode signals comprise stereo audio and video signals.

10. The method of claim 1 further comprising arranging said first and second pairs of said two pairs of conductors in an opposite mode pattern.

2. A method of transmitting three balanced mode signals using two pairs of conductors, the method comprising the steps of:

transmitting a first one of said three balanced mode signals on a first pair of said two pairs of conductors;

transmitting a second one of said three balanced mode signals on a second pair of said two pairs of conductors;

synthesizing a third pair of conductors from said first and second pairs of conductors;

transmitting a third one of said three balanced mode signals using said synthesized third pair of conductors;

using first, second and third virtual ground planes created by said three balanced mode signals on said first, second and third pairs of conductors, respectively, to electrically isolate said three balanced mode signals from one another.

3. A method of transmitting three balanced mode signals using two pairs of conductors, the method comprising the steps of:

transmitting a first one of said three balanced mode signals on a first pair of said two pairs of conductors;

transmitting a second one of said three balanced mode signals on a second pair of said two pairs of conductors;

synthesizing a third pair of conductors from said first and second pairs of conductors; and

transmitting a third one of said three balanced mode signals using said synthesized third pair of conductors;

said three balanced mode signals on said first, second and third pairs of conductors generating first, second and third virtual ground planes, respectively;

said first, second and third pairs of conductors arranged such that said first, second and third pairs of conductors are electrically isolated from one another by said first, second and third virtual ground planes.

4. The method of claim 3 wherein said synthesizing is performed using an encode resistor matrix, coupled to said first and second ones of said two pairs of conductors, such that said third one of said three balanced mode signals is shared equally by said first and second conductor pairs.

15. The method of claim 4, wherein said second number is equal to 4ⁿ, where n is a natural number.

17. The method of claim 4 wherein said first and second conductor pairs comprise telephone cable.

18. The method of claim 4 further comprising transmitting one or more of said first number of balanced mode signals in opposite directions simultaneously on said respective conductor pair.

19. The method of claim 4 further comprising arranging said first and second pairs of conductors in an adjacent mode pattern.

20. The method of claim 4 further comprising arranging said first and second pairs of conductors in an opposite mode pattern.

11. A method of transmitting three balanced mode signals using two pairs of conductors, the method comprising:

transmitting a first one of said three balanced mode signals on a first pair of said two pairs of conductors;

transmitting a second one of said three balanced mode signals on a second pair of said two pairs of conductors;

synthesizing a third pair of conductors from said first and second pairs of conductors;

transmitting a third one of said three balanced mode signals using said synthesized third pair of conductors; and

piggybacking additional low bandwidth signals on one or more of said three balanced mode signals for transmission therewith.

12. A system for using four-conductor cable to transmit three balanced mode signals, the system comprising:

an encode matrix coupled to first and second pairs of conductors of said four-conductor cable, said encode matrix transmitting a first balanced mode signal via said first pair of conductors of said four-conductor cable, a second balanced mode signal via said second pair of conductors of said cable, and a third balanced mode signal via a third pair of conductors synthesized from said first and second pairs of conductors; and

a decode matrix coupled to said first and second pairs of conductors of said cable and connected to said encode matrix via said first and second pairs of conductors of said cable, said decode matrix comprising a plurality of resistors, said plurality of resistors of said decode matrix recovering said first, second and third balanced mode signals from said cable;

wherein one of said plurality of resistors comprises a load resistor for said third signal.

13. The system of claim 12 wherein said load resistor has a resistance which is fifty percent (50%) greater than an impedance associated with said four-conductor cable.

14. A method of transmitting a first number of balanced mode signals using a second number of conductors, the method comprising the steps of:

a. transmitting a first one of said first number of balanced mode signals using a first pair of said second number of conductors;

b. transmitting a second one of said first number of balanced mode signals using a second pair of said second number of conductors;

c. synthesizing a third pair of conductors from said first and second pairs of conductors;

d. transmitting a third one of said first number of balanced mode signals using said synthesized third pair of conductors;

e. said first one of said first number of balanced mode signals, said second one of said first number of balanced mode signals and said third one of said first number of balanced mode signals on said first pair of said second number of conductors, said second pair of said second number of conductors and said third pair of conductors synthesized from said first and second pairs of conductors, respectively, generating first, second and third virtual ground planes, respectively;

f. said first pair of said second number of conductors, said second pair of said second number of conductors and said third pair of conductors synthesized from said first and second pairs of conductors arranged such that said first pair of said second number of conductors, said second pair of said second number of conductors and said third pair of conductors synthesized from said first and second pairs of conductors are electrically isolated from one another by said first, second and third virtual ground planes; and

g. repeating steps a-f for the remainder of said first number of balanced mode signals and said second number of conductors.

16. The method of claim 14 wherein said synthesizing is performed using an encode resistor matrix, coupled to said first pair of said second number of conductors and said second pair of said second number of conductors, for causing each of said third one of said first number of balanced mode signals to be shared equally by said respective first pair of said second number of conductors and said second pair of said second number of conductors from which said corresponding third conductor pair is synthesized.

21. A method of transmitting a first number of balanced mode signals using a second number of conductors, the method comprising the steps of:

a. transmitting a first one of said first number of balanced mode signals using a first pair of said second number of conductors;

b. transmitting a second one of said first number of balanced mode signals using a second pair of said second number of conductors;

c. synthesizing a third pair of conductors from said first and second pairs of conductors;

d. transmitting a third one of said first number of balanced mode signals using said synthesized third pair of conductors;

e. using a first virtual ground plane created by said first one of said first number of balanced mode signals using said first pair of said second number of conductors, a second virtual ground plane created by said second one of said first number of balanced mode signals using said second pair of said second number of conductors and a third virtual ground plane created by said third one of said first number of balanced mode signals using said third pair of conductors synthesized from said first and second pair of conductors to electrically isolate said first number of balanced mode signals from one another;

f. repeating steps a-d for the remainder of said first number of balanced mode signals and said second number of conductors.

22. Apparatus for transmitting three balanced mode signals using two pairs of conductors, the apparatus comprising:

means for transmitting a first one of said three balanced mode signals on a first pair of said two pairs of conductors;

means for transmitting a second one of said three balanced mode signals on a second pair of said two pairs of conductors;

means for synthesizing a third pair of conductors from said first and second pairs of conductors;

means for transmitting a third one of said three balanced mode signals using said synthesized third pair of conductors; and

means for electrically isolating said first, second and third ones of said three balanced mode signals from one another using first, second and third virtual ground planes created by said first, second and third ones of said three balanced mode signals on said first, second and third pairs of conductors, respectively.

23. The method of claim 22 wherein said first and second pairs of said two pairs of conductors are arranged in an adjacent mode pattern.

24. The method of claim 22 wherein said first and second pairs of said two pairs of conductors are arranged in an opposite mode pattern.

25. The apparatus of claim 22 further comprising an encode resistor matrix, coupled to said first and second ones of said two pairs of conductors, for performing said synthesizing, said encode resistor matrix causing said third one of said three balanced mode signals to be shared equally by said first and second conductor pairs.

26. The apparatus of claim 22 wherein said three balanced mode signals comprise wide bandwidth RGB video data with imbedded vertical and horizontal sync signals.

27. The apparatus of claim 22 wherein one or more of said three balanced mode signals can be transmitted in opposite directions simultaneously.

28. The apparatus of claim 22 wherein said three balanced mode signals comprise stereo audio and video signals.

29. The apparatus of claim 22 wherein said two pairs of conductors comprise a four-wire telephone cable.

30. Apparatus for transmitting three balanced mode signals using two pairs of conductors, the apparatus comprising:

means for transmitting a first one of said three balanced mode signals on a first pair of said two pairs of conductors;

means for transmitting a second one of said three balanced mode signals on a second pair of said two pairs of conductors;

means for synthesizing a third pair of conductors from said first and second pairs of conductors; and

means for transmitting a third one of said three balanced mode signals using said synthesized third pair of conductors;

wherein additional low bandwidth signals are piggybacked on one or more of said three balanced mode signals for transmission therewith.

31. A system for using four-conductor cable to transmit three balanced mode signals, the system comprising:

an encode matrix coupled to first and second pairs of conductors of said fourconductor cable, said encode matrix transmitting a first balanced mode signal via first and second conductors of said four-conductor cable, a second balanced mode signal via third and fourth conductors of said four-conductor cable, and a third balanced mode signal via a third pair of conductors synthesized from said first, second, third and fourth conductors of said four-conductor cable; and

a decode matrix coupled to said first, second, third and fourth conductors of said four-conductor cable and connected to said encode matrix via said first, second, third and fourth conductors of said four-conductor cable, said decode matrix recovering said first, second and third balanced mode signals from said fourconductor cable;

wherein;

first and second components of said first balanced mode signal are transmitted over said first and second conductors, respectively;

first and second components of said second balanced mode signal are transmitted over said third and fourth conductors, respectively;

a first component of said third balanced mode signal is transmitted over each of said first and fourth conductors; and

a second component of said third balanced mode signal is transmitted over each of said second and third conductors.

32. The system of claim 31 wherein said first, second, third and fourth conductors are arranged in an adjacent mode pattern.

33. The system of claim 31 wherein said first, second, third and fourth conductors are arranged in an opposite mode pattern.

34. The system of claim 31 further comprising:

at least one device connected to inputs of said encode matrix for generating said first, second and third balanced mode signals; and

at least one device connected to outputs of said decode matrix for receiving said recovered first, second and third balanced mode signals.

35. The system of claim 31 wherein said encode matrix comprises eight equal resistors for creating summing nodes at each of said first, second, third and fourth conductors of said four-conductor cable coupled to said encode matrix.

36. The system of claim 31 wherein said decode matrix comprises a plurality of resistors for recovering said first, second and third balanced mode signals from said first, second, third and fourth conductors of said four-conductor cable coupled to said decode matrix.

37. A system for using four-conductor cable to transmit three balanced mode signals, the system comprising:

an encode matrix coupled to first and second pairs of conductors of said four-conductor cable, said encode matrix comprising eight equal resistors for creating summing nodes at each of said first and second pairs of conductors of said four-conductor cable, said encode matrix transmitting a first balanced mode signal via said first pair of conductors of said four-conductor cable, a second balanced mode signal via said second pair of conductors of said four-conductor cable, and a third balanced mode signal via a third pair of conductors synthesized from said first and second pairs of conductors; and

a decode matrix coupled to said first and second pairs of conductors of said four-conductor cable and connected to said encode matrix via said first and second pairs of conductors of said four-conductor cable, said decode matrix recovering said first, second and third balanced mode signals from said four-conductor cable;

wherein each of said resistors has a resistance which is equal to two times an impedance associated with said four-conductor cable.