Narrow band chaotic bi-phase shift keying

• US 20040177310A1
• Filed: 11/20/2003
• Published: 09/09/2004
• Est. Priority Date: 05/21/2001
• Status: Active Grant

• Current Assignee: Atlinks USA Incorporated (Verdoso Investmentssa)
• Original Assignee: Atlinks USA Incorporated (Verdoso Investmentssa)
• Inventors: Mohan, Chandra, Lee, Jeffrey Huat-Chye
• Granted Patent: US 7,254,187 B2
• Time in Patent Office: Days
• US Class Current: 714/776
• CPC Class Codes: H04L 27/001 using chaotic signals for secret or secure communication H04L9/001

Abstract

A system (110) and method for signal transmission and reception by narrow band chaotic bi-phase shift keying includes a forward error correction encoder (118) for receiving input data, a data packetizer (120) in signal communication with the forward error correction encoder, a compression encoder (122) in signal communication with the data packetizer, a radio frequency link (114) in signal communication with the compression encoder, a compression decoder (124) in signal communication with the radio frequency link, a data depacketizer (126) in signal communication with the compression decoder, and a forward error correction decoder (128) in signal communication with the data depacketizer for recovering the input data by controlling the orbits of chaos; where the method includes the steps of transmitting a signal indicative of chaotic bi-phase shift keyed data, propagating the transmitted signal within a narrow frequency band, and receiving the propagated signal substantially without degradation of the indicated data by controlling the orbits of chaos.

Claims

1. A method for signal transmission and reception comprising:

transmitting a signal indicative of chaotic bi-phase shift keyed data;

propagating the transmitted signal within a narrow frequency band; and

receiving the propagated signal substantially without degradation of the indicated data by controlling the orbits of chaos.

2. A method as defined in claim 1 wherein said transmitting comprises:

providing input data;

encoding the provided data for forward error correction;

packetizing the encoded data; and

compressing the packetized data to supply encoded data for modulation.

3. A method as defined in claim 1 wherein the narrow frequency band comprises a radio frequency band of less than about 20 kHz bandwidth.

4. A method as defined in claim 1 wherein said receiving comprises:

decompressing the data indicated by the propagated signal;

de-packetizing the decompressed data; and

decoding the de-packetized data to provide output data substantially without degradation from the transmitted data.

5. A method as defined in claim 2 wherein said encoding comprises modulating a composite information and chaos signal onto a carrier signal by bi-phase shift keying to form the chaotic bi-phase shift keyed data.

6. A method as defined in claim 2 wherein said compressing comprises:

bi-phase modulating a composite information and chaos signal onto a carrier signal in accordance with a non-linear mapping function;

combining the bi-phase modulated signals to form a double side-band signal with suppressed carrier signal; and

rejecting the suppressed carrier signal and one of the upper side-band signal and the lower side-band signal.

7. A method as defined in claim 6 wherein said compressing further comprises mapping a bit interval into itself in accordance with a skewed tent map corresponding to the non-linear mapping function.

8. A method as defined in claim 7 wherein said skewed tent map exhibits flow.

9. A method as defined in claim 4 wherein said decoding comprises demodulating a composite information and chaos signal from a carrier signal by high-speed detection to substantially recover the transmitted data.

10. A method as defined in claim 9 wherein said high-speed detection comprises phase detection.

11. A method as defined in claim 1 wherein the encoded data is represented with Reed-Solomon error-correction code.

12. A method as defined in claim 1 wherein the signal indicative of chaotic bi-phase shift keyed data is responsive to chaos generation using a non-linear mapping function to aid synchronization between said transmitting and said receiving.

13. A method as defined in claim 12 wherein said non-linear mapping function comprises a skewed tent map.

14. A method as defined in claim 1 wherein the signal indicative of chaotic bi-phase shift keyed data is an intermediate frequency signal.

15. A method as defined in claim 1, further comprising at least one of:

buffering the signal indicative of chaotic bi-phase shift keyed data prior to propagation; and

buffering the signal indicative of chaotic bi-phase shift keyed data following propagation.

16. A method as defined in claim 2 wherein said encoding comprises deriving a chaos signal by bi-phase shift keying in accordance with a non-linear mapping function that exhibits flow.

17. A method as defined in claim 16 wherein said non-linear mapping function that exhibits flow is a skewed tent map.

18. A method as defined in claim 4 wherein said decoding comprises deriving a chaos signal by at least one of a phase comparison and a frequency comparison in accordance with a non-linear mapping function that exhibits flow.

19. A method as defined in claim 18 wherein said non-linear mapping function comprises a skewed tent map.

20. A method as defined in claim 18 wherein said decoding further comprises:

generating an exact replica of a transmitter map for comparison in accordance with said at least one of a phase comparison and a frequency comparison; and

generating an error signal for correction.

21. A method as defined in claim 1, further comprising synchronizing said receiving with an initial pattern followed by periodic resetting of a clock signal to control the orbits of chaos.

22. A system (110) for narrow band chaotic bi-phase shift keying comprising:

a forward error correction encoder (118) for receiving input data;

a data packetizer (120) in signal communication with said forward error correction encoder;

a compression encoder (122) in signal communication with said data packetizer;

a radio frequency link (114) in signal communication with said compression encoder;

a compression decoder (124) in signal communication with said radio frequency link;

a data depacketizer (126) in signal communication with said compression decoder; and

a forward error correction decoder (128) in signal communication with said data depacketizer for recovering said input data by controlling the orbits of chaos.

23. A system as defined in claim 22 wherein said forward error correction encoder comprises:

an encoder (214) for receiving high-speed bit-stream data;

a map generator (216) in signal communication with said encoder;

a local oscillator (218) in signal communication with said map generator;

an intermediate frequency filter (224) in signal communication with said local oscillator; and

at least one of a radio frequency filter (232) and an amplifier in signal communication with said intermediate frequency filter wherein the at least one radio frequency filter or amplifier is responsive to a carrier signal.

24. A system as defined in claim 23 wherein said encoder comprises:

an edge detector (316) for receiving input data;

at least one clock divider (312, 314) in signal communication with said edge detector for receiving a clock signal;

at least one sequence generator (318, 320) in signal communication with said edge detector and said at least one clock divider; and

a multiplexer (322) in signal communication with said at least one sequence generator.

25. A system as defined in claim 22 wherein said forward error correction decoder comprises:

a local oscillator (416);

at least one of a low noise amplifier and a mixer (414) in signal communication with said local oscillator for receiving a propagated signal;

a band-pass filter (418) in signal communication with said at least one low noise amplifier or mixer;

an intermediate frequency amplifier (420) in signal communication with said band-pass filter;

a demodulator (422) in signal communication with said intermediate frequency amplifier;

at least one of a level translator and a filter (424) in signal communication with said demodulator; and

a data decoder (426)) in signal communication with said at least one level translator or filter for driving a high-speed data channel.

26. A system as defined in claim 25 wherein said band-pass filter is tunable.

27. A system as defined in claim 25 wherein said data decoder comprises:

an edge detector (512) for receiving encoded data;

at least one counter (516, 520) in signal communication with said edge detector;

at least one count detector (518, 522) in signal communication with said at least one counter;

a synchronizer (526) in signal communication with said at least one count detector; and

a latch (528) in signal communication with said synchronizer for latching output data.

28. A system as defined in claim 25 wherein said data decoder further comprises at least one of a phase comparator and a frequency comparator.

29. A system for signal transmission and reception, the system comprising:

means for transmitting a signal indicative of at least one of chaotic bi-phase shift keyed data and chaotic phase shift keyed data;

means for propagating the transmitted signal within a narrow frequency band; and

means for receiving the propagated signal substantially without degradation of the indicated data by controlling the orbits of chaos.

30. A system as defined in claim 29 wherein said means for transmitting comprises:

means for providing input data;

means for encoding the provided data for forward error correction;

means for packetizing the encoded data; and

means for compressing the packetized data to supply encoded data for modulation.

31. A system as defined in claim 29 wherein the narrow frequency band comprises a radio frequency band of less than about 10 kHz bandwidth.

32. A system as defined in claim 29 wherein said means for receiving comprises:

means for decompressing the data indicated by the propagated signal;

means for de-packetizing the decompressed data; and

means for decoding the de-packetized data to provide output data substantially without degradation from the transmitted data.

33. A system as defined in claim 30 wherein said means for encoding comprises means for modulating a composite information and chaos signal onto a carrier signal by bi-phase shift keying to form the chaotic bi-phase shift keyed data.

34. A system as defined in claim 30 wherein said means for compressing comprises means for modulating a composite information and chaos signal onto a carrier signal in accordance with a non-linear mapping function.

35. A system as defined in claim 34 wherein said means for compressing further comprises means for mapping a bit interval into itself in accordance with a skewed tent map.

36. A system as defined in claim 35 wherein said skewed tent map exhibits flow.

37. A system as defined in claim 32 wherein said means for decoding comprises means for demodulating a composite information and chaos signal from a carrier signal by means for high-speed detection to substantially recover the transmitted data.

38. A system as defined in claim 37 wherein said means for high-speed detection comprises means for at least one of phase detection and frequency detection.

39. A system as defined in claim 29, further comprising means for representing the encoded data with Reed-Solomon error-correction code.

40. A system as defined in claim 29 wherein the signal indicative of chaotic bi-phase shift keyed data is responsive to chaos generation using a means for non-linear mapping to aid synchronization between said means for transmitting and said means for receiving.

41. A system as defined in claim 40 wherein said means for non-linear mapping comprises means for defining a skewed tent map.

42. A system as defined in claim 29 wherein the signal indicative of chaotic bi-phase shift keyed data is an intermediate frequency signal.

43. A system as defined in claim 29, further comprising at least one of:

means for buffering the signal indicative of chaotic bi-phase shift keyed data prior to propagation; and

means for buffering the signal indicative of chaotic bi-phase shift keyed data following propagation.

44. A system as defined in claim 30 wherein said means for encoding comprises means for deriving a chaos signal by bi-phase shift keying in accordance with a means for non-linear mapping that exhibits flow.

45. A system as defined in claim 44 wherein said means for non-linear mapping that exhibits flow comprises means for defining a skewed tent map.

46. A system as defined in claim 32 wherein said means for decoding comprises means for deriving a chaos signal by at least one of a phase comparison and a frequency comparison in accordance with a means for non-linear mapping that exhibits flow.

47. A system as defined in claim 46 wherein said means for non-linear mapping comprises means for defining a skewed tent map.

48. A system as defined in claim 46 wherein said means for decoding further comprises:

means for generating an exact replica of a transmitter map for comparison in accordance with said means for at least one of a phase comparison and a frequency comparison; and

means for generating an error signal for correction.

49. A system as defined in claim 29, further comprising:

means for synchronizing said means for receiving with an initial pattern; and

means for periodic resetting of a clock signal to control the orbits of chaos.

50. A program storage device readable by machine, tangibly embodying a program of instructions executable by the machine to perform method steps for signal transmission and reception, the method steps comprising:

transmitting a signal indicative of at least one of chaotic bi-phase shift keyed data and chaotic phase shift keyed data;

propagating the transmitted signal within a narrow frequency band; and

receiving the propagated signal substantially without degradation of the indicated data by controlling the orbits of chaos.

51. A program storage device as defined in claim 50 wherein said step for transmitting comprises steps for:

providing input data;

encoding the provided data for forward error correction;

packetizing the encoded data; and

compressing the packetized data to supply encoded data for modulation.

52. A program storage device as defined in claim 50 wherein the narrow frequency band comprises a radio frequency band of less than about 10 kHz bandwidth.

53. A program storage device as defined in claim 50 wherein said step for receiving comprises steps for:

decompressing the data indicated by the propagated signal;

de-packetizing the decompressed data; and

decoding the de-packetized data to provide output data substantially without degradation from the transmitted data.

54. A program storage device as defined in claim 51 wherein said step for encoding comprises a step for modulating a composite information and chaos signal onto a carrier signal by bi-phase shift keying to form the chaotic bi-phase shift keyed data.

55. A program storage device as defined in claim 51 wherein said step for compressing comprises a step for modulating a composite information and chaos signal onto a carrier signal in accordance with a non-linear mapping function.

56. A program storage device as defined in claim 55 wherein said step for compressing further comprises a step for mapping a bit interval into itself in accordance with a skewed tent map.

57. A program storage device as defined in claim 56 wherein the skewed tent map exhibits flow.

58. A program storage device as defined in claim 53 wherein said step for decoding comprises a step for demodulating a composite information and chaos signal from a carrier signal by high-speed detection to substantially recover the transmitted data.

59. A program storage device as defined in claim 58 wherein said step for high-speed detection comprises a step for at least one of phase detection and frequency detection.

60. A program storage device as defined in claim 50 wherein the encoded data is represented with Reed-Solomon error-correction code.

61. A program storage device as defined in claim 50 wherein the signal indicative of chaotic bi-phase shift keyed data is responsive to chaos generation using a non-linear mapping function to aid synchronization between said step for transmitting and said step for receiving.

62. A program storage device as defined in claim 61 wherein said non-linear mapping function comprises a skewed tent map.

63. A program storage device as defined in claim 50 wherein the signal indicative of chaotic bi-phase shift keyed data is an intermediate frequency signal.

64. A program storage device as defined in claim 50, further comprising a step for at least one of:

buffering the signal indicative of chaotic bi-phase shift keyed data prior to propagation; and

buffering the signal indicative of chaotic bi-phase shift keyed data following propagation.

65. A program storage device as defined in claim 51 wherein said step for encoding comprises a step for deriving a chaos signal by bi-phase shift keying in accordance with a non-linear mapping function that exhibits flow.

66. A program storage device as defined in claim 65 wherein the non-linear mapping function that exhibits flow is a skewed tent map.

67. A program storage device as defined in claim 53 wherein said step for decoding comprises a step for deriving a chaos signal by at least one of a phase comparison and a frequency comparison in accordance with a non-linear mapping function that exhibits flow.

68. A program storage device as defined in claim 67 wherein the non-linear mapping function comprises a skewed tent map.

69. A program storage device as defined in claim 67 wherein said step for decoding further comprises steps for:

generating an exact replica of a transmitter map for comparison in accordance with said step for at least one of a phase comparison and a frequency comparison; and

generating an error signal for correction.

70. A program storage device as defined in claim 50, further comprising steps for:

synchronizing said step for receiving with an initial pattern; and

periodic resetting of a clock signal to control the orbits of chaos.