Digital communications modulation method and apparatus

• US 5,640,422 A
• Filed: 09/26/1995
• Issued: 06/17/1997
• Est. Priority Date: 08/02/1994
• Status: Expired due to Term

• Current Assignee: International Automated Systems
• Original Assignee: International Automated Systems
• Inventors: Johnson, Neldon P.
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): GHEBRETINSAE, TEMESGHEN
• Application Number:
  US08/533,618
• Time in Patent Office: 630 Days
• Field of Search: 375/259, 375/260, 375/295, 370/95.1, 370/95.3, 370/110.1, 370/110.4, 455/59
• US Class Current: 375/259
• CPC Class Codes: H04J 3/02 Details electronic switching or gating H03K17/00
• CPC Class Codes: H04J 3/0614 the synchronising signal being characterised by the amplitude, duration or polarity
• CPC Class Codes: H04J 3/26 in which the information and the address are simultaneously transmitted
• CPC Class Codes: H04J 4/00 Combined time-division and frequency-division multiplex systems H04J13/00 takes precedence ; data transmission H04L5/26; telemetry G08C15/00
• CPC Class Codes: H04J 99/00 Subject matter not provided for in other groups of this subclass
• CPC Class Codes: H04L 25/4923 using ternary codes H04L25/4927 takes precedence
• CPC Class Codes: H04L 27/2602 Signal structure
• CPC Class Codes: H04L 7/044 using a single bit, e.g. start stop bit
• CPC Class Codes: H04L 7/06 the synchronisation signals differing from the information signals in amplitude, polarity or frequency or length
• CPC Class Codes: H04L 7/08 the synchronisation signals recurring cyclically

Abstract

A method and apparatus for single signal, multiple channel digital information transfer through waves with time slot allocation. The apparatus consists of one or more transmitting devices and one or more receiving devices. Multiple source signals are each allocated a unique time slot between successive synchronization waves. Digital signals from each source are converted to analog information waves having a positive wave segment and a negative wave segment. The ratio of the amplitude of the positive wave segment to the amplitude of the negative wave segment, the positive-to-negative ratio, for each signal source, is a function of the magnitude of the source digital. The sum of the amplitude of the positive wave segment and the absolute value of the amplitude of the negative wave segment, the positive-to-negative offset, is maintained at a pre-set value at transmission. The total signal, which consists of successive synchronization waves interspersed with information waves for each signal source, each within its allocated time slot, is transmitted to the receivers which extract the positive-to-negative ratio and positive-to-negative offset for each signal source, calibrate the received signals and generate output signals which reproduce the transmitted inputs.

Claims

1. An apparatus for digital information transfer comprising:

a) means for allocating one or more source digital signals to unique, repetitive time slots;

b) means for generating an analog information wave for each said source digital signal, each said information wave having a positive wave segment and a negative wave segment and having a positive-to-negative ratio which is a function of the magnitude of the corresponding source digital signal as measured during the allocated time slot for the signal;

c) means for transmitting each of the analog information waves within its allocated time slot;

d) means for receiving each of the analog information waves within its allocated time slot;

e) means for extracting a positive-to-negative ratio for each analog information wave received during its allocated time slot; and

f) means for generating an output digital signal for each information wave received during its allocated time slot, said output digital signal having a digital magnitude which is a function of said extracted positive-to-negative ratio.

2. An apparatus as claimed in claim 1 further comprising:

a) means for transmitting each information wave with a pre-set positive-to-negative offset;

b) means for extracting a positive-to-negative offset for each analog information wave received during its allocated time slot; and

c) means for calibrating the output digital signal magnitudes by comparison of the positive-to-negative offsets of the information waves as transmitted and the positive-to-negative offsets of the information waves as received.

3. An apparatus as claimed in claim 1 wherein the means for generating said analog information waves for said source digital signals and the means for transmitting the information waves within the allocated time slots are deployed at a plurality of transmission locations.

4. An apparatus as claimed in claim 1 wherein the means for receiving the information waves within the allocated time slots, the means for extracting the positive-to-negative ratios for the analog information waves received during the allocated time slots, and the means for generating output digital signals with digital magnitudes which are a function of said extracted positive-to-negative ratios for the information waves received are deployed at a plurality of receiving locations.

5. An apparatus as claimed in claim 1 wherein the means for generating analog information waves generates an information wave for each said source digital signal the positive-to-negative ratio of which is proportional to the magnitude of the corresponding source digital signal as measured during the allocated time slot for the signal.

6. An apparatus as claimed in claim 1 wherein the means for generating output digital signals generates output digital signals having magnitudes which are proportional to the extracted positive-to-negative ratios for the information waves received.

34. An apparatus as claimed in claim 1 wherein the means for generating an analog information wave for each said source digital signal further includes a means for simultaneously generating and adding analog signals for two or more source signals for a single information wave.

46. An apparatus as claimed in claim 1 wherein the means for generating an analog information wave further provides for generating a zero wave segment between the positive wave segment and the negative wave segment, and the means for extracting a positive-to-negative ratio for each analog information wave received during its allocated time slot further provides for a zero correction of the zero wave segment, thereby interposing an interim zero correction on the positive wave segment and the negative wave segment as received.

7. An apparatus for digital information transfer comprising:

a) means for generating synchronizing waves of pre-set wave form and frequency;

b) means for allocating one or more source digital signals to unique time slots between successive synchronizing waves;

c) means for generating an analog information wave for each source digital signal, said information wave having a positive wave segment and a negative wave segment, said information wave having a positive-to-negative ratio which is a function of the magnitude of the corresponding source digital signal as measured during the allocated time slot for the source digital signal, and said information wave having a pre-set positive-to-negative offset;

d) means for transmitting the information wave for each source digital signal within its allocated time slot;

e) means for receiving the information wave for each source digital signal during the allocated time slot for the source digital signal as referenced to successive synchronizing waves;

f) means for extracting a positive-to-negative offset and a positive-to-negative ratio for each information wave received during its allocated time slot;

g) means for generating an output digital signal for each information wave received during its allocated time slot, said output digital signal having a digital magnitude which is a function of said extracted positive-to-negative ratio; and

h) means for calibrating the digital magnitude of each output digital signal by comparison of the positive-to-negative offset of the corresponding information wave as transmitted with the positive-to-negative offset of the information wave as received.

8. An apparatus as claimed in claim 7 wherein the means for generating an analog information wave for each source digital signal and the means for transmitting the information wave for each source digital signal within its allocated time slot are deployed at a plurality of transmission locations.

9. An apparatus as claimed in claim 7 wherein the means for receiving the information wave for each source digital signal during its allocated time slot, the means for extracting said positive-to-negative offset and said positive-to-negative ratio for each information wave received during its allocated time slot, the means for generating an output digital signal for each information wave received during its allocated time slot which is a function of the extracted positive-to-negative ratio, and the means for calibrating the digital magnitude of each output digital signal are deployed at a plurality of receiving locations.

10. An apparatus as claimed in claim 7 wherein the means for generating analog information waves generates an information wave for each said source digital signal the positive-to-negative ratio of which is proportional to the magnitude of the corresponding source digital signal as measured during the allocated time slot for the signal.

11. An apparatus as claimed in claim 7 wherein the means for generating output digital signals generates output digital signals having magnitudes which are proportional to the extracted positive-to-negative ratios for the information waves received.

35. An apparatus as claimed in claim 7 wherein the means for generating an analog information wave for each source digital signal further includes a means for simultaneously imputing two or more source digital signals, generating an analog information signal for each source digital signal, and combining the analog information signals of said two or more source digital signals for a single information wave.

47. An apparatus as claimed in claim 7 wherein the means for generating an analog information wave for each source digital signal further provides for generating a zero wave segment between the positive wave segment and the negative wave segment, and the means for extracting a positive-to-negative offset and a positive-to-negative ratio for each information wave received during its allocated time slot further provides for a zero correction of the zero wave segment, thereby interposing an interim zero correction on the positive wave segment and the negative wave segment.

12. An apparatus for digital information transfer comprising:

a) a synchronization wave generation circuit;

b) a circuit for allocating one or more source digital signals to unique time slots between successive synchronizing waves;

c) one or more digital to analog signal generators for generating an analog information wave for each source digital signal, which information wave has a positive wave segment and a negative wave segment and has a positive-to-negative ratio which is a function of the digital magnitude of the corresponding source digital signal as measured during the allocated time slot for the source digital signal, and which information wave has a pre-set positive-to-negative offset;

d) one or more transmitters for transmitting the information wave for each source digital signal within its allocated time slot;

e) one or more receivers for receiving the information wave for each source digital signal within the allocated time slot for the source digital signal as referenced to successive synchronization waves;

f) one or more circuits for extracting the positive-to-negative ratio and the positive-to-negative offset of each information wave received during its allocated time slot;

g) one or more analog to digital convertors for generating an output digital signal for each information wave received during its allocated time slot, said output digital signal having a digital magnitude which is a function of said extracted positive-to-negative ratio;

h) one or more circuits for calibrating the digital magnitude of each output digital signal by comparison of the positive-to-negative offset of the corresponding information wave as transmitted with the positive-to-negative offset of the information wave as received.

13. An apparatus as claimed in claim 12 wherein the digital to analog signal generators for generating an analog information wave for each source digital signal within its allocated time slot and the transmitters for transmitting the information wave for each source digital signal within its allocated time slot are deployed at a plurality of transmission locations.

14. An apparatus as claimed in claim 12 wherein the receivers, the circuits for extracting the positive-to-negative ratio and the positive-to-negative offset of each information wave received during its allocated time slot, the analog to digital convertors for generating an output digital signal for each information wave received during its allocated time slot, and the circuits for calibrating the digital magnitude of each output digital signal are deployed at a plurality of receiving locations.

15. An apparatus as claimed in claim 12 wherein the digital to analog signal generators generate an information wave for each said source digital signal the positive-to-negative ratio of which is proportional to the magnitude of the corresponding source digital signal as measured during the allocated time slot for the signal.

16. An apparatus as claimed in claim 12 wherein the analog to digital signal generators generate output digital signals having digital magnitudes which are proportional to the extracted positive-to-negative ratios for the information waves received.

36. An apparatus as claimed in claim 12 further including one or more additional digital to analog signal generators to permit the simultaneous input of two or more source digital signals and including a circuit for combining the analog signals for said two or more source digital signals for a single analog information wave.

48. An apparatus as claimed in claim 12 wherein the digital to analog signal generators further generate a zero wave segment between the positive wave segment and the negative wave segment, and the circuits for extracting the positive-to-negative ratio and the positive-to-negative offset of each information wave received during its allocated time slot further provide for a zero correction of the zero wave segment, thereby interposing an interim zero correction on the positive wave segment and the negative wave segment.

17. An apparatus for digital information transfer comprising:

a) means for generating synchronizing waves of pre-set wave form and frequency;

b) means for transmitting said synchronizing waves to one or more remote transmission locations;

c) means for receiving said synchronizing waves at each remote transmission location;

d) means for allocating one or more source digital signals at each remote transmission location to unique time slots between successive synchronizing waves;

e) means for generating an analog information wave for each source digital signal, said information wave having a positive wave segment and a negative wave segment, said information wave having a positive-to-negative ratio which is a function of the magnitude of the corresponding source digital signal as measured during the allocated time slot for the source digital signal, and said information wave having a pre-set positive-to-negative offset;

f) means for transmitting the information wave for each source digital signal from each remote transmission location;

g) means for receiving, at one or more locations, the information wave for each source digital signal transmitted from each remote transmission location, the information wave being received within its allocated time slot as referenced to successive synchronization waves;

h) means for extracting a positive-to-negative offset and a positive-to-negative ratio for each information wave received during its allocated time slot at one or more locations;

i) means for generating an output digital signal for each information wave received during its allocated time slot, said output digital signal having a digital magnitude which is a function of said extracted positive-to-negative ratio; and

j) means for calibrating the digital magnitude of each output digital signal by comparison of the positive-to-negative offset of the corresponding information wave as transmitted with the positive-to-negative offset of said information wave as received.

18. An apparatus as claimed in claim 17 wherein the means for generating analog information waves generates an information wave for each said source digital signal the positive-to-negative ratio of which is proportional to the magnitude of the corresponding source digital signal as measured during the allocated time slot for the signal.

19. An apparatus as claimed in claim 17 wherein the means for generating output digital signals generates output digital signals having magnitudes which are proportional to the extracted positive-to-negative ratios for the information waves received.

37. An apparatus as claimed in claim 17 wherein the means for generating an analog information signal for each source digital signal further includes a means for simultaneously imputing two or more source digital signals, generating an analog information signal for each source digital signal, and combining the analog signals for a single information wave.

49. An apparatus as claimed in claim 17 wherein the means for generating an analog information wave for each source digital signal further provides for generating a zero wave segment between the positive wave segment and the negative wave segment, and the means for extracting a positive-to-negative offset and a positive-to-negative ratio for each information wave received during its allocated time slot further provides for a zero correction of the zero wave segment, thereby interposing an interim zero correction on the positive wave segment and the negative wave segment.

20. A method for digital information transfer comprising the steps of:

a) allocating one or more source digital signals to unique, repetitive time slots;

b) generating an analog information wave for each said source digital signal, each said information wave having a positive wave segment and a negative wave segment and having a positive-to-negative ratio which is a function of the magnitude of the corresponding source digital signal as measured during the allocated time slot for the signal;

c) transmitting each of the analog information waves within its allocated time slot;

d) receiving each of the analog information waves within its allocated time slot;

e) extracting a positive-to-negative ratio for each analog information wave received during its allocated time slot; and

f) generating an output digital signal for each information wave received during its allocated time slot, said output digital signal having a digital magnitude which is a function of said extracted positive-to-negative ratio.

21. Method claimed in claim 20 further comprising the steps of:

a) transmitting each said information wave with a pre-set positive-to-negative offset;

b) extracting a positive-to-negative offset for each analog information wave received during its allocated time slot; and

c) calibrating the output digital signal magnitudes by comparison of the positive-to-negative offsets of the information waves as transmitted and the positive-to-negative offsets of the information waves as received.

22. Method claimed in claim 20 wherein the step of generating said analog information waves for said source digital signals and the step of transmitting the information waves within the allocated time slots are performed at a plurality of transmission locations.

23. Method claimed in claim 20 wherein the step of receiving the information waves within the allocated time slots, the step of extracting the positive-to-negative ratios for the analog information waves received during the allocated time slots, and the step of generating output digital signals with digital magnitudes which are a function of said extracted positive-to-negative ratios for the information waves received are performed at a plurality of receiving locations.

24. Method claimed in claim 20 wherein the step of generating analog information waves generates an information wave for each said source digital signal the positive-to-negative ratio of which is proportional to the magnitude of the corresponding source digital signal as measured during the allocated time slot for the signal.

25. Method claimed in claim 20 wherein the step of generating output digital signals generates output digital signals having magnitudes which are proportional to the extracted positive-to-negative ratios for the information waves received.

38. Method claimed in claim 20 wherein the step of generating an analog information wave for each said source digital signal further includes a step of simultaneously generating and adding analog signals for two or more source signals for a single information wave.

50. Method as claimed in claim 20 wherein the step of generating an analog information wave for each said source digital signal further includes generating a zero wave segment between the positive wave segment and the negative wave segment and the step of extracting a positive-to-negative ratio for each analog information wave received during its allocated time slot further includes the step of making a zero correction of the zero wave segment, thereby interposing an interim zero correction on the positive wave segment and the negative wave segment.

26. A method for digital information transfer comprising the steps of:

a) generating synchronizing waves of pre-set wave form and frequency;

b) allocating one or more source digital signals to unique time slots between successive synchronizing waves;

c) generating an analog information wave for each source digital signal, said information wave having a positive wave segment and a negative wave segment, said information wave having a positive-to-negative ratio which is a function of the magnitude of the corresponding source digital signal as measured during the allocated time slot for the source digital signal, and said information wave having a pre-set positive-to-negative offset;

d) transmitting the information wave for each source digital signal within its allocated time slot;

e) receiving the information wave for each source digital signal during the allocated time slot for the source digital signal as referenced to successive synchronizing waves;

f) extracting a positive-to-negative offset and a positive-to-negative ratio for each information wave received during its allocated time slot;

g) generating an output digital signal for each information wave received during its allocated time slot, said output digital signal having a digital magnitude which is a function of said extracted positive-to-negative ratio; and

h) calibrating the digital magnitude of each output digital signal by comparison of the positive-to-negative offset of the corresponding information wave as transmitted with the positive-to-negative offset of the information wave as received.

27. Method claimed in claim 26 wherein the step of generating an analog information wave for each source digital signal and the step of transmitting the information wave for each source digital signal within its allocated time slot are performed at a plurality of transmission locations.

28. Method claimed in claim 26 wherein the step of receiving the information wave for each source digital signal during its allocated time slot, the step of extracting said positive-to-negative offset and said positive-to-negative ratio for each information wave received during its allocated time slot, the step of generating an output digital signal for each information wave received during its allocated time slot which is a function of the extracted positive-to-negative ratio, and the step of calibrating the digital magnitude of each output digital signal are performed at a plurality of receiving locations.

29. Method claimed in claim 26 wherein the step of generating analog information waves generates an information wave for each said source digital signal the positive-to-negative ratio of which is proportional to the magnitude of the corresponding source digital signal as measured during the allocated time slot for the signal.

30. Method claimed in claim 26 wherein the step of generating output digital signals generates output digital signals having magnitudes which are proportional to the extracted positive-to-negative ratios for the information waves received.

39. Method claimed in claim 26 wherein the step of generating an analog information wave for each source digital signal further includes a step of simultaneously imputing two or more source digital signals, generating an analog information signal for each source digital signal, and combining the analog information signals of said two or more source digital signals for a single information wave.

51. Method as claimed in claim 26 wherein the step of generating an analog information wave for each said source digital signal further includes generating a zero wave segment between the positive wave segment and the negative wave segment and the step of extracting a positive-to-negative ratio for each analog information wave received during its allocated time slot further includes the step of making a zero correction of the zero wave segment, thereby interposing an interim zero correction on the positive wave segment and the negative wave segment.

31. A method for digital information transfer comprising the steps of:

a) generating synchronizing waves of pre-set wave form and frequency;

b) transmitting said synchronizing waves to one or more remote transmission locations;

c) receiving said synchronizing waves at each remote transmission location;

d) allocating one or more source digital signals at each remote transmission location to unique time slots between successive synchronizing waves;

e) generating an analog information wave for each source digital signal, said information wave having a positive wave segment and a negative wave segment, said information wave having a positive-to-negative ratio which is a function of the magnitude of the corresponding source digital signal as measured during the allocated time slot for the source digital signal, and said information wave having a pre-set positive-to-negative offset;

f) transmitting the information wave for each source digital signal from each remote transmission location;

g) receiving, at one or more locations, the information wave for each source digital signal transmitted from each remote transmission location, the information wave being received within its allocated time slot as referenced to successive synchronization waves;

h) extracting a positive-to-negative offset and a positive-to-negative ratio for each information wave received during its allocated time slot at one or more locations;

i) generating an output digital signal for each information wave received during its allocated time slot, said output digital signal having a digital magnitude which is a function of said extracted positive-to-negative ratio; and

j) calibrating the digital magnitude of each output digital signal by comparison of the positive-to-negative offset of the corresponding information wave as transmitted with the positive-to-negative offset of the information wave as received.

32. Method claimed in claim 31 wherein the step of generating analog information waves generates an information wave for each said source digital signal the positive-to-negative ratio of which is proportional to the magnitude of the corresponding source digital signal as measured during the allocated time slot for the signal.

33. Method claimed in claim 31 wherein the step of generating output digital signals generates output digital signals having magnitudes which are proportional to the extracted positive-to-negative ratios for the information waves received.

40. Method claimed in claim 31 wherein the step of generating an analog information signal for each source digital signal further includes a step of simultaneously imputing two or more source digital signals, generating an analog information signal for each source digital signal, and combining the analog signals for a single information wave.

52. Method as claimed in claim 31 wherein the step of generating an analog information wave for each said source digital signal further includes generating a zero wave segment between the positive wave segment and the negative wave segment and the step of extracting a positive-to-negative ratio for each analog information wave received during its allocated time slot further includes the step of making a zero correction of the zero wave segment, thereby interposing an interim zero correction on the positive wave segment and the negative wave segment.

41. An apparatus for digital information transfer comprising:

a) a synchronization wave generation circuit;

b) a circuit for allocating one or more source digital signals to unique time slots between successive synchronizing waves;

c) two or more digital to analog signal generators for simultaneously receiving two or more source digital signals which are allocated the same time slot, simultaneously generating an analog information signal for each of said two or more source digital signals;

d) a circuit for combining said analog information signals for a single combined analog information wave, which combined information wave has a positive wave segment and a negative wave segment and has a positive-to-negative ratio which is a function of the digital magnitudes of the corresponding two or more source digital signals as measured during the allocated time slot for the source digital signals, and which combined information wave has a pre-set positive-to-negative offset;

e) one or more transmitters for transmitting each combined information wave within its allocated time slot;

f) one or more receivers for receiving the combined information wave within the allocated time slot for the source digital signals as referenced to successive synchronization waves;

g) one or more circuits for extracting the positive-to-negative ratio and the positive-to-negative offset of each combined information wave received during its allocated time slot;

h) one or more analog to digital convertors for generating an output digital signal for each combined information wave received during its allocated time slot, said output digital signal having a digital magnitude which is a function of said extracted positive-to-negative ratio;

i) one or more circuits for calibrating the digital magnitude of each output digital signal by comparison of the positive-to-negative offset of the corresponding combined information wave as transmitted with the positive-to-negative offset of the combined information wave as received.

42. An apparatus as claimed in claim 41 wherein the digital to analog signal generators for simultaneously generating an analog information signal for two or more source digital signals within the allocated time slot, the circuit for combining the analog information signals for a single combined analog information wave, and the transmitters for transmitting the combined information wave within its allocated time slot are deployed at a plurality of transmission locations.

43. An apparatus as claimed in claim 41 wherein the receivers for receiving the combined information wave within the allocated time slot for the source digital signals as referenced to successive synchronization waves, the circuits for extracting the positive-to-negative ratio and the positive-to-negative offset of each combined information wave received during its allocated time slot, the analog to digital convertors for generating an output digital signal for each combined information wave received during its allocated time slot, and the circuits for calibrating the digital magnitude of each output digital signal by comparison of the positive-to-negative offset of the corresponding combined information wave as transmitted with the positive-to-negative offset of the combined information wave as received are deployed at a plurality of receiving locations.

44. An apparatus as claimed in claim 41 wherein the circuit for combining the analog information signals for the two or more source digital signals for a combined analog information wave generates a combined information wave the positive-to-negative ratio of which is proportional to the combined magnitude of the corresponding source digital signals as measured during the allocated time slot.

45. An apparatus as claimed in claim 41 wherein the analog to digital signal generators generate output digital signals having digital magnitudes which are proportional to the extracted positive-to-negative ratios for the combined information waves as received.

53. An apparatus as claimed in claim 41 wherein the circuit for combining said analog information signals for a single combined analog information wave further generates a zero wave segment between the positive wave segment and the negative wave segment, and the circuits for extracting the positive-to-negative ratio and the positive-to-negative offset of each combined information wave received during its allocated time slot further provide for a zero correction of the zero wave segment, thereby interposing an interim zero correction on the positive wave segment and the negative wave segment.