Hybrid spread spectrum radio system

• US 7,656,931 B2
• Filed: 12/31/2003
• Issued: 02/02/2010
• Est. Priority Date: 12/31/2003
• Status: Expired due to Fees

• Current Assignee: UT-Battelle LLC
• Original Assignee: UT-Battelle LLC
• Inventors: Smith, Stephen F., Dress, William B.
• Primary Examiner(s): BURD, KEVIN MICHAEL
• Application Number:
  US10/750,432
• Publication Number:
  US 20050141594A1
• Time in Patent Office: 2,225 Days
• Field of Search: 375130-132, 375/135, 375/140, 375/143, 375/146, 375/295, 375/316
• US Class Current: 375/131
• CPC Class Codes: H04B 1/692 Hybrid techniques using combinations of two or more spread spectrum techniques
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04B 1/713 using frequency hopping

Abstract

Systems and methods are described for hybrid spread spectrum radio systems. A method includes modulating a signal by utilizing a subset of bits from a pseudo-random code generator to control an amplification circuit that provides a gain to the signal. Another method includes: modulating a signal by utilizing a subset of bits from a pseudo-random code generator to control a fast hopping frequency synthesizer; and fast frequency hopping the signal with the fast hopping frequency synthesizer, wherein multiple frequency hops occur within a single data-bit time.

Claims

1. A transmitter for generating a hybrid spread-spectrum signal to transmit data bits, wherein each of the data bits has a data bit time, the transmitter comprising:

a pseudo-random code generator configured to generate a first stream of pseudo-random code words and a second stream of pseudo-random code words, wherein the second stream of pseudo-random code words is generated as a function of the first stream of pseudo-random code words to interrelate the second stream of pseudo-random code words to the first stream of pseudo-random code words based upon a predetermined relationship;

a direct sequence generation circuit configured to receive the data bits to be transmitted and the first stream of pseudo-random code words, the direct sequence generation circuit configured to generate a direct sequence spread spectrum signal including a plurality of sub-sequences of chips for each of the data bits based upon the first stream of pseudo-random code words;

a programmable direct digital frequency synthesizer coupled to the pseudo-random code generator to receive the second stream of pseudo-random code words, the programmable direct digital frequency synthesizer configured to generate a carrier signal at a sequence of carrier frequencies for each of the data bits based upon a sequence of the pseudo-random code words of the second stream of pseudo-random code words received by the programmable direct digital frequency synthesizer during each data bit time; and

a modulator in communication with the direct sequence generation circuit and the programmable direct digital frequency synthesizer, the modulator configured to modulate the carrier signal with the direct sequence spread spectrum signal to generate a direct sequence fast frequency hopped spread spectrum signal.

2. The transmitter of claim 1, wherein the sequence of carrier frequencies generated by the programmable direct digital frequency synthesizer includes a first carrier frequency and a second carrier frequency;

wherein the direct sequence fast frequency hopped spread spectrum signal for each of the data bits includes at least a first sub-sequence of chips and a second subsequence of chips, and

wherein the carrier signal at the first carrier frequency is modulated by the first sub-sequence of chips and the carrier signal at the second carrier frequency is modulated with the second sub-sequence of chips.

3. The transmitter of claim 1, wherein the first stream of the pseudo-random code words includes “

n”

bits per data bit time;

wherein the second stream of pseudo-random code words includes “

m”

bit frequency-hopping control words to produce “

H”

frequency hops per data bit time; and

wherein n>

m×

H.

4. The transmitter of claim 3, wherein each of the sub-sets of chips includes the same number of chips per frequency hop.

5. The transmitter of claim 1, wherein the direct sequence fast frequency hopped spread spectrum signal corresponds to a respective data bit and includes a sub-sequence of chips for each frequency of the carrier signal used to transmit the respective data bit.

6. The transmitter of claim 1, wherein the predetermined relationship that interrelates the first stream of pseudo-random code words and the second stream of pseudo-random code words is a first predetermined relationship;

wherein the pseudo-random code generator is further configured to generate a third stream of pseudo-random code words; and

wherein the third stream of pseudo-random code words is generated as a function of a third predetermined relationship and at least one of the first stream of pseudo-random code words, the second stream of pseudo-random code words, or a combination thereof, and wherein the stream of third pseudo-random code words is interrelated by a second predetermined relationship to the at least one of the first stream of pseudo-random code words, the second stream of pseudo-random code words, and the combination thereof.

7. The transmitter of claim 6, further comprising:

an amplification circuit in communication with the modulator, the amplification circuit configured to amplify the direct sequence fast frequency hopped spread spectrum signal to generate an amplitude controlled direct sequence fast frequency hopped spread spectrum signal based upon an amplification control signal.

8. The transmitter of claim 7, further comprising

an amplitude control circuit in communication with the pseudo-random code generator and the amplification circuit, the amplitude control circuit configured to dither the amplification control signal based upon the third stream of pseudo-random code words.

9. The transmitter of claim 6, wherein each of the first predetermined relationship and the second predetermined relationship include an interrelationship based upon at least one of direct subsets of bits of the pseudo-random code generator, rolling code segments of the pseudo-random code generator, scrambling of code vectors of the pseudo-random code generator, and table-based reassignments of bit-pattern relationships of the pseudo-random code generator, or a combination thereof.

10. The transmitter of claim 6, wherein the pseudo-random code generator is further configured to generate a pseudo-random coincidence gate control signal as a function of at least one of the first stream of pseudo-random code words, the second stream of pseudo-random code words, the third stream of pseudo-random code words by the third predetermined relationship, and a combination thereof, the transmitter further comprising:

a coincidence gate coupled between the modulator and the amplification circuit, the coincidence gate configured to receive the pseudo-random coincidence gate control signal from the pseudo-random code generator; and

the coincidence gate further configured to time gate the direct sequence fast frequency hopped spread spectrum signal based upon the pseudo-random coincident gate control signal.

11. The transmitter of claim 6, wherein each of the first predetermined relationship, the second predetermined relationship, and the third predetermined relationship include an interrelationship based upon at least one of direct subsets, rolling code segments, scrambling of code vectors and table-based reassignments of bit-pattern relationships, or a combination thereof.

12. The transmitter of claim 1, wherein the pseudo-random code generator is further configured to generate a pseudo-random coincidence gate control signal;

the transmitter further comprising;

a coincidence gate in communication with the modulator and the pseudo-random code generator, the coincidence gate configured to receive the direct sequence fast frequency hopped spread spectrum signal and the pseudo-random coincidence gate control signal from the pseudo-random code generator; and

wherein the coincidence gate is configured to time gate the direct sequence fast frequency hopped spread spectrum signal based upon the coincident gate control signal to generate a time hopped direct sequence fast frequency hopped spread spectrum signal.

13. The transmitter of claim 12, wherein the predetermined relationship that interrelates the first stream of pseudo-random code words and the second stream of pseudo-random code words is a first predetermined relationship;

and

wherein the pseudo-random coincidence gate control signal is generated as a function of at least one of the first stream of pseudo-random code words, the second stream of pseudo-random code words, and a combination thereof based upon a fourth predetermined relationship.

14. The transmitter of claim 13, wherein the fourth predetermined relationship includes an interrelationship based upon at least one of direct subsets of bits of the pseudo-random code generator, rolling code segments of the pseudo-random code generator, scrambling of code vectors of the pseudo-random code generator, and table-based reassignments of bit-pattern relationships of the pseudo-random code generator, or a combination thereof.

15. The transmitter of claim 1, wherein the modulator is a balanced modulator.

16. The transmitter of claim 1, wherein the programmable direct digital frequency synthesizer is further configured to receive a band select input signal;

and

wherein the programmable direct digital frequency synthesizer is further configured to generate the carrier signal within a frequency band as a function of the second stream of pseudo-random code words and the band select input signal.

17. A transmitter for generating an electromagnetically polarized hybrid spread spectrum signal to transmit data bits, the transmitter comprising:

a pseudo-random code generator configured to generate a first stream of pseudo-random code words and a second stream of pseudo-random code words, wherein the second stream of pseudo-random code words is generated as a function of the first stream of pseudo-random code words to interrelate the first stream of pseudo-randsom code words to the second stream of pseudo random code words based upon a predetermined relationship;

a programmable direct digital frequency synthesizer coupled to the pseudo random code generator to receive the second stream of pseudo-random code words, the programmable direct digital frequency synthesizer configured to directly generate a carrier signal having a carrier frequency based upon the second stream of pseudo-random code words, and wherein in response to the second stream of pseudo-random code words, the programmable direct digital frequency synthesizer is further configured to hop the carrier frequency of the carrier signal during a data bit time for each of the data bits, wherein multiple carrier frequency hops occur within each data bit time;

a balanced modulator in communication with the programmable frequency direct digital synthesizer, the modulator configured to receive a direct sequence spread spectrum signal generated with the second stream of pseudo-random code words, and the balanced modulator further configured to generate a fast frequency hopped direct sequence spread spectrum signal as a function of the carrier signal having multiple carrier frequency hops during each data bit time as a function of the first stream of pseudo-random code words;

a first antenna having a first polarization, the first antenna in communication with the balanced modulator, the first antenna configured to emit the fast frequency hopped direct sequence spread spectrum signal as a first fast frequency hopped direct sequence spread spectrum signal with the first polarization; and

a second antenna having a second polarization, the second antenna in communication with the balanced modulator, the second antenna configured to emit the fast frequency hopped direct sequence spread spectrum signal as a second fast frequency hopped direct sequence spread spectrum signal with the second polarization.

18. The transmitter of claim 17, wherein the predetermined relationship includes an interrelationship based upon at least one of direct subsets of bits of the pseudo-random code generator, rolling code segments of the pseudo-random code generator, scrambling of code vectors of the pseudo-random code generator, and table-based reassignments of bit-pattern relationships of the pseudo-random code generator, or a combination thereof.

19. The transmitter of claim 17, further comprising:

a splitter coupled between the balanced modulator and the first antenna, and the splitter also coupled between the balanced modulator and the second antenna, wherein the splitter is configured to split the fast frequency hopped direct sequence spread spectrum signal into a first signal and a second signal; and

wherein the first signal is emitted by the first antenna as the first fast frequency hopped direct sequence spread spectrum signal and the second signal is emitted by the second antenna as the second fast frequency hopped direct sequence spread spectrum signal.

20. The transmitter of claim 17, further comprising:

a first RF amplifier coupled between the balanced modulator and the first antenna, the first RF amplifier configured to amplify the first fast frequency hopped direct sequence spread spectrum signal with a first amplification level; and

a second RF amplifier coupled between the balanced modulator and the second antenna, the second RF amplifier configured to amplify the second fast frequency hopped direct sequence spread spectrum signal with a second amplification level.

21. The transmitter of claim 20, further comprising:

the pseudo-random code generator further configured to generate a third stream of pseudo-random code words; and

an amplitude controller coupled to the pseudo-random code generator, the amplifier controller in communication with the first RF amplifier and the second RF amplifier, wherein the amplifier controller is configured to dither the first amplification level and the second amplification level as a function of the third stream of pseudo-random code words.

22. The transmitter of claim 21, wherein the predetermined relationship that interrelates the first stream of pseudo-random code words and the second stream of pseudo-random code words is a first predetermined relationship;

and

wherein the third stream of pseudo-random code words is generated as a function of at least one of the first stream of pseudo-random code words, the second stream of pseudo-random code words, and a combination thereof based upon a second predetermined relationship.

23. The transmitter of claim 22, wherein each of the first predetermined relationship and the second predetermined relationship includes an interrelationship based upon at least one of direct subsets of bits of the pseudo-random code generator, rolling code segments of the pseudo-random code generator, scrambling of code vectors of the pseudo-random code generator, and table-based reassignments of bit-pattern relationships of the pseudo-random code generator, or a combination thereof.

24. The transmitter of claim 17, wherein the first amplification level and the second amplification level are dithered at a rate greater than a reflection coefficient of a multipath condition.

25. The transmitter of claim 17, further comprising:

a first RF amplifier coupled between the balanced modulator and the first antenna, the first RF amplifier configured to amplify the first fast frequency hopped direct sequence spread spectrum signal with a first amplification level;

a second RF amplifier coupled between the balanced modulator and the second antenna, the second RF amplifier configured to amplify the second fast frequency hopped direct sequence spread spectrum signal with a second amplification level; and

an amplitude controller coupled to the pseudo-random code generator, the amplitude controller in communication with the first RF amplifier and the second RF amplifier, wherein the amplitude controller is configured to adjust the first amplification level relative to the second amplification level to maintain a relative power ratio between the first fast frequency hopped direct sequence spread spectrum signal and the second fast frequency hopped direct sequence spread spectrum signal.

26. The transmitter of claim 17, wherein the direct sequence fast frequency hopped spread spectrum signal for each of the data bits includes at least a first sub-sequence of chips and a second subsequence of chips;

wherein the sequence of carrier frequencies includes a first carrier frequency and a second carrier frequency; and

wherein the carrier signal at the first carrier frequency is modulated by the first sub-sequence of chips and, subsequently, the carrier signal at the second carrier frequency is modulated by the second sub-sequence of chips.

27. The transmitter of claim 17, wherein

the first stream of pseudo-random code words generated with the pseudo-random code generator includes a “

n”

bit pseudo-random codeword per data bit time; and

wherein the second stream of pseudo-random code words generated with the pseudo-random code generator includes a plurality of “

m”

bit frequency-hopping control words to produce “

H”

frequency hops per data bit time; and

wherein n>

m×

H.

28. The transmitter of claim 27, wherein each of the sub-sets of chips includes the same number of chips per frequency hop.

29. The transmitter of claim 17, wherein the first polarization and the second polarization are linearly polarized.

30. A transmitter capable of generating a fast frequency hybrid spread-spectrum signal to transmit a plurality of data bits, each of the data bits having a data bit time, the transmitter comprising:

a pseudo-random code generator configured to generate a first stream of pseudo-random code words, a second stream of pseudo-random code words, and a third stream of pseudo-random code words, wherein pseudo-random code words included in the second stream of pseudo-random code words and the pseudo-random code words included in the third stream of pseudo-random code words are a function of the pseudo-random code words included in the first steam of pseudo-random code words based upon a predetermined relationship;

a direct sequence generation module in communication with the pseudo-random code generator, the direct sequence generation module configured to receive the data bits to be transmitted and the first stream of pseudo-random code words, the direct sequence generation module further configured to generate a plurality of chips as a plurality of sub-sequences of chips for each of the received data bits based upon the first stream of pseudo-random code words;

a programmable direct digital frequency synthesizer in communication with the pseudo-random code generator to receive the second stream of pseudo-random code words, the programmable direct digital frequency synthesizer configured to generate a carrier signal based upon the second stream of pseudo-random code words;

wherein in response to the second stream of pseudo-random code words, the programmable direct digital frequency synthesizer is further configured to hop the carrier signal during each data bit time of each of the respective data bits, wherein multiple carrier frequency hops occur within each data bit time to generate a plurality of pseudo-random carrier frequencies as a sequence of carrier frequencies;

a balanced modulator in communication with the direct sequence generation circuit and the direct programmable frequency synthesizer, the balanced modulator configured to modulate the carrier signal with chips, wherein for each of the pseudo-random carrier frequencies, the carrier signal is modulated by a respective sub-sequence of the chips of the plurality of sub-sequences of chips, to generate a fast frequency hopped direct sequence spread spectrum signal; and

a coincidence gate coupled to the pseudo-random code generator and the balanced modulator, the coincidence gate configured to gate the fast frequency hopped direct sequence spread spectrum signal as a function of the third stream of pseudo-random code words to generate a time hopped fast frequency hopped direct spread spectrum signal.

31. The transmitter of claim 30, wherein the pseudo-random code generator is further configured to generate a fourth stream of pseudo random code words as a function of at least one of the pseudo random codes words of the first stream, the second stream, the third stream, and a combination thereof based upon a known relationship, the transmitter further comprising:

an amplifier in communication with the coincident gate and configured to receive the time hopped fast frequency hopped direct sequence spread spectrum signal, wherein the amplifier is further configured to amplify the time hopped fast frequency hopped direct sequence spread spectrum signal based upon an amplification control signal; and

an amplitude controller including an amplitude control input coupled to the pseudo-random code generator to receive the fourth stream of pseudo random code words, and the amplitude controller further including the amplification control signal in communication with the amplifier, wherein the amplitude controller is further configured to dither the amplification of the time hopped fast frequency hopped direct sequence spread spectrum signal based upon in response to the fourth stream of pseudo random code words.

32. The transmitter of claim 30, wherein the first stream of pseudo-random code words, the second stream of pseudo-random code words, and the third stream of pseudo-random code words are interrelated by a polynomial function which is also known at a receiver of the time hopped fast frequency hopped direct spread spectrum signal.

33. A method for generating a hybrid spread spectrum signal to transmit a plurality of data bits, wherein each of the data bits has a data bit time, the method comprising:

generating a first stream of pseudo-random code words with a pseudo-random number generator;

generating, with the pseudo-random number generator, a second stream of pseudo-random code words as a function of the first set of pseudo-random code words based upon a predetermined relationship wherein there are “

H”

pseudo-random code words per data bit time;

generating a spread spectrum signal that includes a plurality of sub-sets of chips, each of the sub-sets of chips including at least three chips, for each of the data bits to be transmitted based upon the first stream of pseudo-random code words;

generating, with a programmable direct digital frequency synthesizer, a sequence of “

H”

carrier signals per data bit time, each of the carrier signals having a pseudo-random carrier frequency, based upon the second stream of pseudo-random code words; and

modulating each of the carrier signals with a respective sub-set of chips from among the plurality of sub-sets of chips to generate a fast frequency hopped spread spectrum signal.

34. The method of claim 33, wherein generating the first stream of pseudo-random code words with the pseudo-random number generator further comprises:

generating a “

n”

bit pseudo-random codeword per data bit time; and

wherein generating the second stream of pseudo-random code words as a function of the first set of pseudo-random code words based upon the predetermined relationship further includes;

generating “

m”

kit frequency-hopping control words to produce “

H”

frequency hops per data bit time; and

wherein n>

m×

H.

35. The method of claim 33, wherein each of the sub-sets of chips includes the same number of chips per frequency hop.

36. The method of claim 33, further comprising:

generating a third stream of pseudo-random code words; and

dithering an amplitude of the fast frequency hopped spread spectrum signal as a function of the third stream of pseudo-random code words.

37. The method of claim 36, wherein the predetermined relationship used to generate the second stream of pseudo-random code words as a function of the first pseudo-random number generator is a first predetermined relationship;

and

wherein the third stream of pseudo-random code words is a function of at least one of the first stream of pseudo-random code words, the second stream of pseudo-random code words, and a combination thereof based upon a second predetermined relationship.

38. The method of claim 36, wherein each of the first predetermined relationship and the second predetermined relationship are interrelated by at least one of direct subsets of bits of the pseudo-random code generator, rolling code segments of the pseudo-random code generator, scrambling of code vectors of the pseudo-random code generator, and table-based reassignments of bit-pattern relationship of the pseudo-random code generator, or a combination thereof.

39. The method of claim 36, further comprising:

generating a fourth stream of pseudo-random code words; and

time gating the dithered fast frequency hopped spread spectrum signal as a function of the fourth stream of pseudo-random code words to generate a hybrid spread spectrum signal.

40. The method of claim 36, wherein generating the fourth stream of pseudo-random code words comprises:

generating the fourth stream of pseudo-random code words as a function of at least one of the first stream of pseudo-random code words, the second-pseudo-random code words, and a combination thereof based upon the predetermined relationship.

41. The method of claim 40, wherein generating the third stream of pseudo-random code words comprises:

generating the third stream of pseudo-random code-words as a function of at least one of the first stream of pseudo random code words, the second stream of pseudo-random code words, the fourth stream of pseudo-random code-words, and a combination thereof based upon the predetermined relationship.

42. The method of claim 36, wherein the spread spectrum signal is a direct sequence spread spectrum signal.

43. The method of claim 33, further comprising:

generating an additional stream of pseudo-random code words; and

time gating the fast frequency hopped spread spectrum signal as a function of the additional stream of pseudo-random code words to generate a hybrid spread spectrum signal.

44. The method of claim 33, wherein the additional stream of pseudo-random code words is generated as a function of at least one of the first stream of pseudo-random code words, the second stream of pseudo-random code words, and a combination thereof based upon a predetermined functional relationship.

45. The method of claim 33, wherein the first stream and the second stream of pseudo-random code words are functionally interrelated by one or more relationships based upon at least one of direct subsets of bits of the pseudo-random code generator, rolling code segments of the pseudo-random code generator, scrambling of code vectors of the pseudo-random code generator, and table-based reassignments of bit-pattern relationships of the pseudo-random code generator, or a combination thereof.

46. The method of claim 45, wherein the spread spectrum signal is a direct sequence spread spectrum signal.

47. The method of claim 33, further comprising:

generating a pseudo-random dither control signal;

splitting the fast frequency hopped spread spectrum signal into a first component and a second component, wherein the first component and the second component have substantially identical signal power; and

dithering an amplitude of at least one of the first component and the second component to control a polarization between the first component and the second component based upon the pseudo-random dither control signal.

48. The method of claim 47, wherein dithering the amplitude of at least one of the first component and the second component to control the polarization between the first component and the second component further comprises:

controlling a power level of the first component and a power level of the second component to optimize signal diversity between the first component and the second component.

49. The method of claim 33, further comprising:

transmitting the fast frequency hopped spread spectrum signal from a radio frequency tag.

50. The method of claim 33, wherein the spread spectrum signal is a direct sequence spread spectrum signal.

51. A method for transmitting data bits in a high multipath environment with a hybrid spread spectrum signal, the method comprising:

generating a stream of pseudo-random codes comprising a plurality of bits;

generating within a data bit time, with a programmable direct digital frequency synthesizer, a plurality of carrier signals, each of the carrier signals having a respective pseudo-random carrier frequency as a function of a first subset of bits of the stream of pseudo-random codes; and

modulating each of the carrier signals generated during the data bit time, as a function of a second subset of bits of the stream of pseudo-random codes, with a plurality of sub-segments of chips;

generating a direct sequence fast frequency hopped spread spectrum signal, wherein each of the sub-segments of chips modulates one of the plurality of carrier signal; and

wherein the second sub-set of bits is a function of the first sub-set of bits of the bits of the stream of pseudo-random codes.

52. The method of claim 51, further comprising:

splitting the direct sequence fast frequency hopped spread spectrum signal into a first direct sequence fast frequency hopped spread spectrum signal and a second direct sequence fast frequency hopped spread spectrum signal;

linearly polarizing the first direct sequence fast frequency hopped spread spectrum signal and the second direct sequence fast frequency hopped spread spectrum signal;

transmitting the first direct sequence fast frequency hopped spread spectrum signal with a first antenna having a first polarization; and

transmitting the second direct sequence fast frequency hopped spread spectrum signal with a second antenna having a second polarization.

53. The method of claim 51, wherein the functional relationship between

the first subset of bits and the second subset of bits is based upon a predetermined relationship to be used at a receiver configured to receive the direct sequence fast frequency hopped spread spectrum.

54. The method of claim 53, further comprising:

splitting the direct sequence fast frequency hopped spread spectrum signal into a first direct sequence fast frequency hopped spread spectrum signal and a second direct sequence fast frequency hopped spread spectrum signal;

linearly polarizing the first direct sequence fast frequency hopped spread spectrum signal and the second direct sequence fast frequency hopped spread spectrum signal;

transmitting the first direct sequence fast frequency hopped spread spectrum signal with a first antenna having a first polarization; and

transmitting the second direct sequence fast frequency hopped spread spectrum signal with a second antenna having a second polarization.

55. The method of claim 54, wherein transmitting the first direct sequence fast frequency hopped spread spectrum signal with the first antenna and transmitting the second direct sequence fast frequency hopped spread spectrum signal with the second antenna further comprises:

dithering an amplitude of at least one of the first direct sequence fast frequency hopped spread spectrum signal and the second direct sequence fast frequency hopped spread spectrum signal.

56. A method of claim 54, wherein transmitting the first direct sequence fast frequency hopped spread spectrum signal with the first antenna and transmitting the second direct sequence fast frequency hopped spread spectrum signal with the second antenna further comprises:

generating a first amplitude control signal and a second amplitude control signal based upon the stream of pseudo-random codes;

modulating an amplitude of the first direct sequence fast frequency hopped spread spectrum signal based upon the first amplitude control signal; and

modulating an amplitude of the second direct sequence fast frequency hopped spread spectrum signal based upon the second amplitude control signal.

57. The method of claim 56, wherein the transmitted first direct sequence fast frequency hopped spread spectrum signal and the transmitted second direct sequence fast frequency hopped spread spectrum signal have a combined power level, the method further comprising:

controlling the first amplitude control signal relative to the second amplitude control signal to maintain a desired emitted power level envelope of the combined power level.

58. The method of claim 56, wherein modulating the amplitude of the first direct sequence fast frequency hopped spread spectrum signal based upon the first amplitude control signal and modulating the amplitude of the second direct sequence fast frequency hopped spread spectrum signal based upon the second amplitude control signal further comprises:

dithering the amplitude of the first direct sequence fast frequency hopped spread spectrum signal and the amplitude of the second direct sequence fast frequency hopped spread spectrum signal at a rate at least equal to an estimated rate of successively received reflected signals.

59. The method of claim 51, further comprising:

generating a coincident gate control signal based upon a third subset of the bits of the stream of pseudo-random codes;

gating transmission of the first direct sequence fast frequency hopped spread spectrum signal and the second direct sequence fast frequency hopped spread spectrum signal based upon the coincident gate control signal to time hop the transmitted first direct sequence fast frequency hopped spread spectrum signal and the transmitted second direct sequence fast frequency hopped spread spectrum, and

wherein the third subset of bits is a function of at least one of the first subsets of bits, the second subset of bits, and a combination thereof.

60. The method of claim 59, further comprising:

interrelating the first subset of bits of the pseudo-random codes, the second subset of bits of the pseudo-random codes, and the third subset of bits of the pseudo-random codes based upon a known relationship at the receiver.

61. The method of claim 59, wherein at least two of the first subset of bits, the second subset of bits and the third subset of bits are programmably related by one or more relationships based upon at least one of direct subsets of bits of the pseudo-random code generator, rolling code segments of the pseudo-random code generator, scrambling of code vectors of the pseudo-random code generator, and table-based reassignments of bit-pattern relationships of the pseudo-random codes of the pseudo-random code generator, or a combination thereof.

62. A method for transmitting data in a high-multipath environment, the method comprising:

generating a first stream of pseudo-random codes having a first sequence length based upon predetermined interrelationships between the first stream of pseudo random codes, a second stream of pseudo-random codes and a third stream of pseudo random codes;

generating the second stream of pseudo-random codes having a second sequence of codes, as a function of the first stream of pseudo-random codes length that is longer than the first sequence length based upon the predetermined interrelationships;

generating a third stream of pseudo-random codes as a function of at least one of the first stream of pseudo-random codes, the second stream of pseudo-random codes or a combination thereof, based upon the predetermined interrelationships;

generating multiple carrier frequencies within the data bit time with a programmable direct digital frequency synthesizer based upon the second stream of pseudo-random codes to produce a fast frequency hopped carrier signal having “

H”

frequency hops per each data bit time;

generating a direct sequence spread spectrum signal representative of the data based upon the first stream of pseudo-random codes,

wherein the direct sequence spread spectrum signal includes “

n”

chips, and wherein “

n”

is evenly divisible by “

H”

;

modulating the fast frequency hopped carrier signal with the direct sequence spread spectrum signal to form a fast frequency hopped direct sequence spread spectrum signal; and

gating the fast frequency hopped direct sequence spread spectrum signal based upon the third stream of pseudo random codes to generate a hybrid spread spectrum signal.

63. The method of claim 62, wherein generating multiple carrier frequencies within the data bit time with the programmable direct digital frequency synthesizer based upon the second stream of pseudo-random codes to produce a fast frequency hopped carrier signal further comprises:

frequency sweeping the programmable direct digital frequency synthesizer to generate the fast frequency hopped carrier signal.

64. The method of claim 62, further comprising:

modulating an amplitude of the hybrid spread spectrum signal based upon a fourth steam of pseudo-random codes.

65. The method of claim 62, wherein the predetermined relationships that interrelate the respective codes of the first stream of pseudo random codes, the second stream of pseudo random codes, and the third stream of pseudo random codes are based upon at least one of direct subsets of bits of the pseudo-random code generator, rolling code segments of the pseudo-random code generator, scrambling of code vectors of the pseudo-random code generator, and table-based reassignments of bit-pattern relationships of the pseudo-random code generator, or a combination thereof.

66. The method of claim 62, further comprising:

splitting the hybrid spread spectrum signal into a plurality of component signals, wherein each of the component signals is substantially identical in amplitude; and

modulating the amplitude of at least one of the plurality of component signals to control polarization of plurality of components based upon at least one pseudo-random sequence of amplitude control words.