(WO/1998/059458) CHAOTIC DIGITAL CODE-DIVISION MULTIPLE ACCESS (CDMA) COMMUNICATION SYSTEMS
- Note: OCR Text
- Note: Text based on automatic Optical
Character Recognition processes. Please
use the PDF version for legal matters
- Note: Text based on automatic Optical
What is claimed is: 1. A method of modulating a code-division- multiple access device that receives information to be transmitted from a selected device, said method comprising the steps of: a. chaotically generating a seed signal; b. spreading the spectrum of said seed signal of step a. to generate a spread spectrum signal; and c. modulating said spread spectrum signal from step b. with said information to be transmitted.
2. A method of modulating a code-division multiple access device as in claim 1 wherein step c. includes the steps of: d. digitizing said information to be transmitted; and e. modulating said spread spectrum signal from step b. with said digitized information from step d.
3. A method of modulating a code-division multiple access device as in claim 1 further including the step of: d. scrambling said spread spectrum signal prior to step c.
4. A method of modulating a code-division multiple access device as in claim 1 further including the step of: d. preceding step a., randomly selecting and applying initial conditions to a chaotic circuit to generate said seed signal.
5. A method of modulating a code-division multiple access device as in claim 4 wherein said chaotic circuit is Chua's circuit.
6. A method of modulating a code-division
7. A method of communication between first and second code-division multiple access devices that transmit selected information therebetween via a selected medium, said method comprising the steps of: a. chaotically generating a seed signal; b. applying said seed signal of step a. to a first spectrum spreading device in said first code-division multiple access device to generate a first spread spectrum signal in said first code-division multiple access device; c. modulating said first spread spectrum signal from step b. with said information to be transmitted by said first code-division multiple access device; d. applying said modulated signal of step c. to said medium for transmission to said second code-division multiple access device; e. applying said seed signal of step a. to a second spectrum spreading device in said second code- division multiple access device to generate a second spread spectrum signal in said second code-division multiple access device; f. multiplying said modulated signal received from said medium of step d. together with said second spread spectrum signal of step e. to create a combined signal; and g. demodulating said combined signal of step f. to generate a recovered information signal.
8. A method of communication between first and
second code-division multiple access devices as in claim 7
wherein step c. includes the steps of:
h. digitizing said information to be
transmitted; and
i. modulating said first spread spectrum signal
from step b. with said digitized information from step h.
9. A method of communication between first and second code-division multiple access devices as in claim 7 further including the steps of: h. scrambling said first spread spectrum signal prior to step c. with a selected key signal; and i. scrambling said second spread spectrum signal prior to step f. with said selected key signal.
10. A method of communication between first and second code-division multiple access devices as in claim 7 wherein step f. includes the steps of: h. filtering said modulated signal from said medium to remove transmission noise from said modulated signal; and i. multiplying said filtered modulation signal from step h. together with said second spread spectrum signal of step e. to create said combined signal.
11. A method of communication between first and second code-division multiple access devices as in claim 7, preceding step a., further including the step of: h. randomly selecting and applying initial conditions to a chaotic circuit to generate said seed signal.
12. A method of communication between first and
second code-division multiple access devices as in claim 11
wherein:
there is a first chaotic circuit associated with said
first code-division multiple access device and a second
chaotic circuit associated with said second code-division
multiple access device with said randomly selected initial
conditions being applied to each of said first and second
chaotic circuits; and
said method further includes the step of:
i. applying impulsive synchronization to
each of said first and second chaotic
13. A method of modulating a code-division multiple access device as in claim 7 or 11 wherein said chaotic circuit is Chua's circuit.
14. A method of modulating a code-division multiple access device as in claim 7 or 11 wherein said chaotic circuit is a Chua's circuit that includes a Chua's diode and said seed signal is a normalized signal of the voltage across said Chua's diode.
15. A method of modulating a code-division multiple access device as in claim 12 wherein each of said first and second chaotic circuits is Chua's circuit.
16. A method of modulating a code-division multiple access device as in claim 15 wherein each of Chua's circuits includes a Chua's diode and said seed signal from each of said Chua's circuits is a voltage across said Chua's diode that is normalized.
17. A method of communication between first and second code-division multiple access devices as in any one of claims 7-12 further includes the repetition of all of the recited steps for transmitting information from said second code-division multiple access device to said first code- division multiple access device.
18. A method of communication between first and
second code-division multiple access devices as in any one
of claims 7-12 wherein:
said medium is ether;
19. A method of communication between first and second code-division multiple access devices as in any one of claims 7-12 wherein: said medium is a wire cable; step d. includes the step of applying said modulated signal to said wire cable through an appropriate first connector; and said method, prior to step f., further includes the step of receiving said modulated signal from said wire cable through an appropriate second connector.
20. A method of communication between first and second code-division multiple access devices as in any one of claims 7-12 wherein: said medium is a fiber optic cable; step d. includes the steps of: converting said modulated signal to a modulated light signal; and applying said modulated light signal to said fiber optic cable; and said method, prior to step f., further includes the steps of: receiving said modulated light signal from said fiber optic cable; and converting said modulated light signal to a modulated electronic signal.
21. A method of communication between first and
second code-division multiple access devices as in any one
of claims 7-12 wherein:
22. A method of communication between first and second code-division multiple access devices as in any one of claims 7-12 wherein: said medium is a solid material; step d. includes the steps of: converting said modulated signal to a modulated ultrasonic signal; and applying said modulated ultrasonic signal to said solid material; and said method, prior to step f., further includes the steps of: receiving said modulated ultrasonic signal from said solid material; and converting said modulated ultrasonic signal to an electronic modulated signal.
23. A method of communication between first and
second code-division multiple access devices as in any one
of claims 7-12 wherein:
said medium is an optical system;
step d. includes the steps of:
24. A code-division multiple access device to
transmit and receive selected information to and from other
code-division multiple access devices, said code-division
multiple access device comprising:
a processor coupled to each component of said
code-division multiple access device to control the transmit
and receive operations thereof;
a message interface disposed to process a message
signal for transmission and to provide a received message
signal to and from a message source;
a spectrum spreading device disposed to receive a
chaotic seed signal to control the generation of a carrier
signal;
an input/output transducer disposed to deliver a
message signal to a selected transmission medium for
transmission to a second code-division multiple access
device or to receive a message signal from said selected
medium that was transmitted from a second code-division
multiple access device;
a multiplier coupled to said spectrum spreading
device, said message interface, and said input/output
transducer to modulate said carrier signal with said message
signal with the modulated signal applied to said
input/output transducer in a transmit mode, and to multiply
25. A code-division multiple access device as in claim 24 wherein said message interface includes a digital encoder/decoder to digitally encode a message for transmission as said message signal and to decode said received message signal.
26. A code-division access device as in claim 25 wherein said digital encoder/decoder includes an analog to digital converter to encode said message as said message signal, and a digital to analog converter to decode said received message signal.
27. A code-division access device as in claim 24 further includes a key signal generator couple to said spectrum spreading device to scramble said carrier signal using a preselected code.
28. A code-division access device as in claim 24 wherein said chaotic seed signal is generated by chaotic circuit having the same preselected initial conditions as assigned to said second code-division multiple access device with which communication is established.
29. A code-division multiple access device as in claim 28 wherein said chaotic circuit is Chua's circuit.
30. A code-division multiple access device as in
claim 29 wherein Chua's circuit includes a Chua's diode and
said seed signal is a voltage across said Chua's diode that
31. A code-division multiple access device as in claim 24 further including a noise filter coupled to said input/output transducer and said multiplier to filter said received message signal before being applied to said multiplier.
32. A code-division multiple access communication
system comprising:
a chaotic device to generate a chaotic seed signal;
a selected transmission medium;
a first code-division multiple access device;
a second code division multiple access device;
wherein each of said first and second code-
division multiple access devices are disposed to
transmit and receive selected information between
each other, and each includes:
a processor coupled to each component of
said code-division multiple access device to
control the transmit and receive operations
thereof;
a message interface disposed to process
a message signal for transmission and to
provide a received message signal to and from
a message source;
a spectrum spreading device disposed to
receive said chaotic seed signal to control
the generation of a carrier signal;
an input/output transducer disposed to
deliver a message signal to said selected
transmission medium for transmission to
another code-division multiple access device
or to receive a message signal from said
selected transmission medium that was
transmitted from another code-division
multiple access device;
33. A code-division multiple access communication system as in claim 32 wherein said message interface includes a digital encoder/decoder to digitally encode a message for transmission as said message signal and to decode said received message signal.
34. A code-division multiple access communication system as in claim 33 wherein said digital encoder/decoder includes an analog to digital converter to encode said message as said message signal, and a digital to analog converter to decode said received message signal.
35. A code-division multiple access communication system as in claim 32 wherein each of said first and second code-division multiple access devices further includes a key signal generator coupled to said spectrum spreading device to scramble said carrier signal each using a matching preselected code.
36. A code-division multiple access
communication system as in claim 32 wherein said chaotic
37. A code-division multiple access communication system as in claim 36 wherein each of said first and second chaotic circuit is a Chua's circuit.
38. A code-division multiple access communication system as in claim 37 wherein Chua's circuit includes a Chua's diode and said seed signal is a voltage across said Chua's diode that is normalized.
39. A code-division multiple access communication system as in claim 36 or 37 further includes a synchronization circuit to randomly select and apply said initial conditions to each of said first and second chaotic circuits and to apply impulsive synchronization to each of said first and second chaotic circuits at preselected intervals to maintain said first and second spread spectrum signals substantially the same during interaction between said first and second code-division multiple access devices.
40. A code-division multiple access communication system as in claim 35 further includes a synchronization circuit to randomly select and apply said preselected code to each of said key signal generators.
41. A code-division multiple access communication
system as in claim 32 wherein each of said first and second
code-division multiple access devices further includes a
noise filter coupled to said input/output transducer and
said multiplier to filter said received message signal
before being applied to said multiplier.
42. A code-division multiple access communication system as in any one of claims 32-41 wherein: said medium is ether; and said input/output transducer in each of said first and second code-division multiple access devices is an antenna to apply said modulated signal to, and receive a radiated signal from, said ether.
43. A code-division multiple access communication system as in any one of claims 32-41 wherein: said medium is a wire cable; and said input/output transducer in each of said first and second code-division multiple access device includes an appropriate connector to apply said modulated signal to, and receive a signal from, said wire cable.
44. A code-division multiple access communication system as in any one of claims 32-41 wherein: said medium is a fiber optic cable; and said input/output transducer in each of said first and second code-division multiple access device includes an electric/optical converter to convert said modulated signal to a modulated light signal for application of a modulated light signal to said fiber optic cable, and to convert said modulated light signal received from said fiber otic cable to a modulated electronic signal.
45. A code-division multiple access communication
system as in any one of claims 32-41 wherein:
said medium is a liquid; and
said input/output transducer in each of said first and
second code-division multiple access device includes an
acoustic transducer to convert said modulated signal to a
modulated acoustic signal for application to said liquid,
and to convert said modulated acoustic signal received from
said liquid to a modulated electronic signal.
46. A code-division multiple access communication system as in any one of claims 32-41 wherein: said medium is a solid material; and said input/output transducer in each of said first and second code-division multiple access device includes an ultrasonic transducer to convert said modulated signal to a modulated ultrasonic signal for application to said solid material, and to convert said modulated ultrasonic signal received from said solid material to a modulated electronic signal.
47. A code-division multiple access communication system as in any one of claims 32-41 wherein: said medium is an optical system; and said input/output transducer in each of said first and second code-division multiple access device includes: a light source coupled to said optical system; a light driver coupled to said light source coupled to receive said modulated signal to cause said light source to emit and apply a modulated light beam to said optical system; and a light detector coupled to said optical system to detect and convert a received modulated light beam from said optical system to said received modulated electronic signal.