Method and apparatus for generating pulses from analog waveforms

• US 6,476,744 B1
• Filed: 04/13/2001
• Issued: 11/05/2002
• Est. Priority Date: 04/13/2001
• Status: Expired due to Fees

• Current Assignee: National University of Singapore
• Original Assignee: National University of Singapore
• Inventors: Joe, Jurianto, Lye, Kin M.
• Primary Examiner(s): JEAN PIERRE, PEGUY
• Application Number:
  US09/835,182
• Publication Number:
  US 20020196065A1
• Time in Patent Office: 571 Days
• Field of Search: 341/157, 341/133, 341/111, 330/284, 331/74, 318/798, 327/514
• US Class Current: 341/133
• CPC Class Codes: H03K 3/0231 Astable circuits H03K3/0315 takes precedence
• CPC Class Codes: H03K 3/315 the devices being tunnel diodes
• CPC Class Codes: H04L 27/001 using chaotic signals for secret or secure communication H04L9/001

Abstract

A method and apparatus that allows an analog waveform to carry multilevel of information is disclosed. This allows information capacity enhancement in pulse decoding communication system by concatenating several information regions in one cycle of analog waveform.

Claims

1. A method for generating pulses, comprising:

providing a circuit having a transfer function comprising two or more unstable operating regions and two or more stable operating regions, said circuit having an operating point;

exciting said circuit with a first signal, said operating point being forced to a first of said unstable regions in response thereto to produce first oscillations; and

exciting said circuit with a second signal different from said first signal, said operating point being forced to a second of said unstable regions in response thereto to produce second oscillations different from said first oscillations.

2. The method of claim 1 further including providing said first oscillations at a first output terminal of said circuit and providing said second oscillations at a second output terminal of said circuit.

3. The method of claim 2 wherein said second output terminal is absent oscillations when said first output terminal is providing said first oscillations, and said first output terminal is absent oscillations when said second output terminal is providing said second oscillations.

4. The method of claim 1 wherein said unstable regions and said stable regions are arranged in alternating fashion.

5. The method of claim 4 wherein said unstable regions are bounded by said stable regions.

6. The method of claim 1 wherein said circuit is sensitive to an amplitude of an excitation signal, said operating point being forced to one of said unstable regions depending on said amplitude.

7. The method of claim 1 wherein said circuit is sensitive to a slope of an excitation signal, said operating point being forced to one of said unstable regions depending on said slope.

8. A method for generating pulses, comprising:

receiving a first analog waveform, a first portion of which has a first slope;

applying said first analog waveform to a circuit characterized by having two or more unstable operating regions and two or more stable operating regions, said circuit having an operating point;

in response to said first slope, forcing said operating point to a first of said unstable regions to produce first pulses;

receiving a second analog waveform, a portion of which corresponds to said first portion and which has a second slope different from said first slope;

applying said second analog waveform to said circuit; and

in response to said second slope, forcing said operating point to a second of said unstable regions to produce second pulses.

9. The method of claim 8 wherein said first pulses are produced at a first output terminal of said circuit and said second pulses are produced at a second output terminal of said circuit.

10. The method of claim 9 wherein said second output terminal is absent pulses when said first output terminal is producing said first pulses, and said first output terminal is absent pulses when said second output terminal is producing said second pulses.

11. The method of claim 8 wherein said unstable regions and said stable regions are arranged in alternating fashion.

12. The method of claim 11 wherein said unstable regions are bounded by said stable regions.

13. A method for producing information from analog waveforms, comprising:

providing a circuit having at least two unstable operating regions separated by a stable operating region;

applying a first analog waveform to said circuit, and in response thereto forcing said circuit to operate in a first of said unstable operating regions to produce first oscillations;

producing a first symbol based on said first oscillations;

applying a second analog waveform to said circuit, and in response thereto forcing said circuit to operate in a second of said unstable operating regions to produce second oscillations; and

producing a second symbol based on said second oscillations,

wherein said information comprises said first and second symbols.

14. The method according to claim 13 wherein said first and second oscillations, each is a group of one or more pulses.

15. The method according to claim 13 wherein said analog waveforms are cyclical.

16. The method of claim 13 wherein said analog waveforms are selected from the group consisting of sinusoidal, ramp, asymmetric, sawtooth, square and channel-optimized symbol.

17. The method according to claim 13 wherein said analog waveforms are cyclical and wherein said cycles comprise mixtures of different waveform types, including time-varying channel-optimized symbols.

18. The method of claim 13 further including providing said first oscillations at a first output terminal of said circuit and providing said second oscillations at a second output terminal of said circuit.

19. The method of claim 18 wherein said second output terminal is absent oscillations when said first output terminal is providing said first oscillations, and said first output terminal is absent oscillations when said second output terminal is providing said second oscillations.

20. The method of claim 13 wherein said unstable regions and said stable regions are arranged in alternating fashion.

21. The method of claim 20 wherein said unstable regions are bounded by said stable regions.

22. The method of claim 13 wherein said circuit is sensitive to amplitudes of said analog waveforms, said operating point being forced to one of said unstable regions depending on said amplitudes.

23. The method of claim 13 wherein said circuit is sensitive to a slopes of said analog waveforms, said operating point being forced to one of said unstable regions depending on said slopes.

24. A device for producing pulses, comprising;

an input for receiving signals;

a circuit coupled to said input, said circuit having at least two unstable operating regions and at least two stable operating regions; and

an output coupled to said circuit for outputting pulses,

said circuit responsive to sensing a first signal to operate in one of said unstable operating regions to produce first pulses,

said circuit further responsive to sensing a second signal to operate in another of said unstable operating regions to produce second pulses different from said first pulses.

25. The device according to claim 24 wherein said stable and said unstable operating regions are arranged in alternating fashion.

26. The device according to claim 24 wherein said unstable operating regions are bounded by said stable operating regions.

27. The device according to claim 24 wherein said circuit is sensitive to amplitudes of said signals.

28. The device according to claim 24 wherein said circuit is sensitive to slopes of said signals.

29. The device according to claim 24 wherein said output comprises a first output terminal for outputting said first pulses and a second output terminal for outputting said second pulses.

30. The device according to claim 24 wherein said circuit includes a first circuit portion to produce said first pulses in response to said first signal and a second circuit portion to produce said second pulses in response to said second signal.

31. The device according to claim 30 wherein said output comprises a first output terminal coupled to said first circuit portion to output said first pulses substantially exclusive of said second pulses, and a second output terminal coupled to said second circuit portion to output said second pulses substantially exclusive of said first pulses.

32. The device according to claim 31 wherein said first output terminal and said second output terminal are in electrical communication at a node, whereby said node produces said first and second pulses.

33. The device according to claim 30 wherein said circuit further includes at least a third circuit portion to produce third pulses different from said first and said second pulses, and wherein said output comprises a first output terminal coupled to said first circuit portion, a second output terminal coupled to said second circuit portion, and a third output terminal coupled to said third circuit portion.

34. A device for producing information from analog waveforms, comprising;

a circuit having a first unstable region separated from a second unstable region by a stable region, said circuit having an input terminal for receiving said analog waveforms, said circuit having first and second output terminals; and

a decoder coupled to receive said first and second output terminals,

said circuit configured to operate in said first unstable region in response to receiving a first analog waveform to produce first oscillations at said first output terminal,

said decoder, in response to detecting said first oscillations, producing a first symbol,

said circuit further configured to operate in said second unstable region in response to receiving a second analog waveform to produce second oscillations at said second output terminal,

said decoder, in response to detecting said second oscillations, producing a second symbol.

35. The device according to claim 34 wherein said first and second oscillations each comprises a group of one or more pulses.

36. The device according to claim 34 wherein said circuit is sensitive to amplitudes of said analog waveforms.

37. The device according to claim 34 wherein said circuit is sensitive to slopes of said analog waveforms.

38. The device according to claim 34 wherein said circuit further includes a node to which said first output terminal and said second output terminal are in electrical connection, said node producing said first and said second oscillations.