Systems/methods of transmitting information via baseband waveforms comprising agility in frequency content and an orthogonality therebetween

• US 8,879,606 B2
• Filed: 05/27/2014
• Issued: 11/04/2014
• Est. Priority Date: 06/22/2005
• Status: Active Grant

• Current Assignee: Odyssey Wireless, Inc.
• Original Assignee: Odyssey Wireless, Inc.
• Inventors: Karabinis, Peter D.
• Primary Examiner(s): FILE, ERIN M
• Application Number:
  US14/287,429
• Publication Number:
  US 20140269845A1
• Time in Patent Office: 161 Days
• US Class Current: 375/146
• CPC Class Codes: H04B 1/69 Spread spectrum techniques
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04B 1/7097 Interference-related aspects
• CPC Class Codes: H04B 2201/70715 with application-specific features
• CPC Class Codes: H04K 1/00 Secret communication
• CPC Class Codes: H04K 2203/18 for wireless local area networks or WLAN
• CPC Class Codes: H04K 3/25 based on characteristics of target signal or of transmission as countermeasure against surveillance H04K3/827, e.g. using direct sequence spread spectrum or fast frequency hopping spread spectrum techniques H04B1/69
• CPC Class Codes: H04K 3/827 using characteristics of target signal or of transmission as countermeasure against jamming H04K3/25, e.g. using direct sequence spread spectrum or fast frequency hopping spread spectrum techniques H04B1/69
• CPC Class Codes: H04L 1/0043 Realisations of complexity reduction techniques, e.g. use of look-up tables
• CPC Class Codes: H04L 1/009 arrangements specific to transmitters
• CPC Class Codes: H04L 1/0091 arrangements specific to receivers, e.g. format detection detection of data rate H04L25/0262; detection of coding rate H04L1/0046
• CPC Class Codes: H04L 23/02 adapted for orthogonal signalling
• CPC Class Codes: H04L 25/03834 using pulse shaping
• CPC Class Codes: H04L 25/03866 using scrambling
• CPC Class Codes: H04L 25/03987 Equalisation for sparse channels
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04W 12/04 Key management, e.g. using generic bootstrapping architecture [GBA]
• CPC Class Codes: H04W 12/06 Authentication
• CPC Class Codes: H04W 12/08 Access security
• CPC Class Codes: H04W 12/50 Secure pairing of devices
• CPC Class Codes: H04W 36/18 : for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 36/185 : using make before break
• CPC Class Codes: H04W 48/02 : Access restriction performed under specific conditions
• CPC Class Codes: H04W 84/045 : using private Base Stations, e.g. femto Base Stations, home Node B
• CPC Class Codes: H04W 88/08 : Access point devices

Abstract

Communications systems and/or methods are disclosed that may be used to convey information by forming, and then using, a plurality of frequency agile baseband waveforms, wherein any two different waveforms of the plurality of frequency agile baseband waveforms comprise an orthogonality therebetween. The systems/methods disclosed can convey information by mapping an information sequence into a baseband waveform sequence that includes waveforms of the plurality of baseband waveforms, and by transmitting the baseband waveform sequence. Such systems and/or methods can provide extreme privacy, cognitive radio capability, robustness to fading and interference, communications performance associated with M-ary orthonormal signaling and/or high multiple-access capacity.

Claims

1. A communications method comprising:

providing a frequency content by Fourier transforming a signal;

then

forming at baseband a desired spectrum shape that differs from the frequency content, responsive to the frequency content;

then

generating at baseband a waveform by inverse Fourier transforming the desired spectrum shape; and

then

transmitting the waveform by using a plurality of elements thereof, sequentially one after another, to modulate a single carrier frequency;

wherein generating at baseband a waveform by inverse Fourier transforming the desired spectrum shape comprises;

generating at baseband a discrete time-domain waveform U(nT) without resorting to chipping of the inverse Fourier transform of the desired spectrum shape with a binary waveform;

wherein n denotes a discrete time index of U(nT), wherein n=1, 2, . . . , N; and

NT≦

τ

;

wherein τ

denotes a time span of the discrete time-domain waveform U(nT); and

wherein T>

0; and

wherein transmitting the waveform by using a plurality of elements thereof, sequentially one after another, to modulate a single carrier frequency comprises;

using substantially all of the elements of U(nT) sequentially to modulate the single carrier frequency by using U(T), followed by using U(2T), . . . , followed by using U(NT).

2. The communications method according to claim 1, wherein said forming at baseband a desired spectrum shape is performed at a transmitter.

3. The communications method according to claim 1, wherein said forming at baseband a desired spectrum shape is performed at a distance from a transmitter and is then relayed to the transmitter.

4. The communications method according to claim 1, wherein said forming at baseband a desired spectrum shape comprises:

using a first plurality of frequencies over a first time interval to form at baseband a first desired spectrum shape and then, using the first desired spectrum shape and without resorting to chipping with a binary waveform, to generate at baseband a first waveform; and

using a second plurality of frequencies over a second time interval to form at baseband a second desired spectrum shape and then, using the second desired spectrum shape and without resorting to chipping with a binary waveform, to generate at baseband a second waveform;

wherein the first plurality of frequencies differs from the second plurality of frequencies in at least one frequency; and

wherein the first and second desired spectrum shapes differ therebetween.

5. The communications method according to claim 4, wherein the first waveform comprises a first time duration and wherein the second waveform comprises a second time duration that differs from the first time duration.

6. The communications method according to claim 1, wherein said generating at baseband a waveform by inverse Fourier transforming the desired spectrum shape further comprises:

generating at baseband first and second waveforms comprising respective first and second time durations that differ therebetween.

7. The communications method according to claim 1, wherein said forming at baseband a desired spectrum shape comprises:

forming the desired spectrum shape to include a first frequency set comprising a first spectral level that is non-zero and to also include a second frequency set comprising a second spectral level that is also non-zero.

8. The communications method according to claim 7, further comprising:

separating the first and second frequency sets by a third frequency set comprising a spectral level that is substantially zero.

9. The communications method according to claim 1, wherein said generating at baseband a waveform further comprises:

processing so that a maximum amplitude value at an output of the inverse Fourier transform be limited in order to reduce non-linear distortion effects in an amplification stage of a transmitter.

10. The communications method according to claim 1, wherein said waveform comprises first and second waveforms at least one of which is generated pseudo-randomly and independently of an information symbol sequence that is to be transmitted/received, responsive to a predetermined statistical distribution.

11. The communications method according to claim 10, wherein the predetermined statistical distribution comprises a Gaussian distribution.

12. The communications method according to claim 1, wherein the waveform is devoid of a regularly repeating peak amplitude level during said transmitting.

13. The communications method according to claim 10, wherein each one of the first and second waveforms comprises a waveform that is generated pseudo-randomly and independently of the information symbol sequence that is to be transmitted/received;

and wherein the first and second waveforms comprise a statistical independence and an orthogonality therebetween.

14. A communications method comprising:

providing a frequency content by Fourier transforming a signal;

then

forming at baseband a desired spectrum shape that differs from the frequency content, responsive to the frequency content;

then

generating at baseband a waveform by inverse Fourier transforming the desired spectrum shape and without resorting to chipping of the inverse Fourier transform of the desired spectrum shape with a binary waveform; and

then

transmitting the waveform by using a plurality of elements thereof, sequentially one after another, to modulate a single carrier frequency;

wherein forming at baseband a desired spectrum shape comprises;

selecting a frequency interval over which the waveform is to exist;

allowing at least one frequency that is included in the selected frequency interval to provide a frequency content to the waveform; and

excluding at least one frequency that is included in the selected frequency interval from providing a frequency content to the waveform.

15. The communications method according to claim 14, wherein said forming at baseband a desired spectrum shape is performed at a transmitter.

16. The communications method according to claim 14, wherein said forming at baseband a desired spectrum shape is performed at a distance from a transmitter and is then relayed to the transmitter.

17. The communications method according to claim 14, wherein said forming at baseband a desired spectrum shape comprises:

using a first plurality of frequencies over a first time interval to form at baseband a first desired spectrum shape and then, using the first desired spectrum shape and without resorting to chipping with a binary waveform, to generate at baseband a first waveform; and

using a second plurality of frequencies over a second time interval to form at baseband a second desired spectrum shape and then, using the second desired spectrum shape and without resorting to chipping with a binary waveform, to generate at baseband a second waveform;

wherein the first plurality of frequencies differs from the second plurality of frequencies in at least one frequency and wherein the first and second desired spectrum shapes differ therebetween.

18. The communications method according to claim 17, wherein the first waveform comprises a first time duration and wherein the second waveform comprises a second time duration that differs from the first time duration.

19. The communications method according to claim 14, wherein said generating at baseband a waveform by inverse Fourier transforming the desired spectrum shape comprises:

generating at baseband first and second waveforms comprising respective first and second time durations that differ therebetween.

20. The communications method according to claim 14, wherein said forming at baseband a desired spectrum shape comprises:

forming the desired spectrum shape to include a first frequency set comprising a first spectral level that is non-zero and to also include a second frequency set comprising a second spectral level that is also non-zero.

21. The communications method according to claim 20, further comprising:

separating the first and second frequency sets by a third frequency set comprising a spectral level that is substantially zero.

22. The communications method according to claim 14, wherein said generating at baseband a waveform comprises:

processing so that a maximum amplitude value at an output of the inverse Fourier transform be limited in order to reduce non-linear distortion effects in an amplification stage of a transmitter.

23. The communications method according to claim 14, wherein the waveform comprises first and second waveforms at least one of which is generated pseudo-randomly and independently of an information symbol sequence that is to be transmitted/received, responsive to a predetermined statistical distribution.

24. The communications method according to claim 23, wherein the predetermined statistical distribution comprises a Gaussian distribution.

25. The communications method according to claim 14, wherein the waveform is devoid of a regularly repeating peak amplitude level during said transmitting.

26. The communications method according to claim 23, wherein each one of the first and second waveforms comprises a waveform that is generated pseudo-randomly and independently of the information symbol sequence that is to be transmitted/received;

and wherein the first and second waveforms comprise a statistical independence and an orthogonality therebetween.

27. A communications system comprising;

a processor that is configured to provide a frequency content by Fourier transforming a signal;

to form at baseband a desired spectrum shape that differs from the frequency content, responsive to the frequency content; and

to generate at baseband a waveform by inverse Fourier transforming the desired spectrum shape without resorting to chipping of the inverse Fourier transform of the desired spectrum shape with a binary waveform; and

a transmitter that is configured to transmit the waveform, comprising a plurality of elements, by using the plurality of elements, sequentially one after another, to modulate a single carrier frequency;

wherein the waveform comprises a discrete time-domain waveform U(nT);

wherein n denotes a discrete time index of U(nT), wherein n=1, 2, . . . , N; and

NT≦

τ

;

wherein τ

denotes a time span of the discrete time-domain waveform U(nT); and

wherein T>

0; and

wherein the transmitter is further configured to use substantially all of the elements of U(nT) sequentially to modulate the single carrier frequency by using U(T), followed by using U(2T), . . . , followed by using U(NT).

28. The communications system according to claim 27, wherein the processor is substantially co-located with the transmitter.

29. The communications system according to claim 27, wherein the processor is at a distance from the transmitter.

30. The communications system according to claim 27, wherein said desired spectrum shape comprises first and second desired spectrum shapes over respective first and second time intervals and wherein the first desired spectrum shape comprises:

a first plurality of frequencies that is used to generate at baseband a first waveform without resorting to chipping with a binary waveform; and

wherein the second desired spectrum shape comprises;

a second plurality of frequencies that is used to generate at baseband a second waveform, without resorting to chipping with a binary waveform;

wherein the first plurality of frequencies differs from the second plurality of frequencies in at least one frequency and wherein the first and second desired spectrum shapes differ therebetween.

31. The communications system according to claim 30, wherein the first waveform comprises a first time duration and wherein the second waveform comprises a second time duration that differs from the first time duration.

32. The communications system according to claim 27, wherein the waveform further comprises first and second waveforms comprising respective first and second time durations that differ therebetween.

33. The communications system according to claim 27, wherein said desired spectrum shape includes a first frequency set comprising a first spectral level that is non-zero and also includes a second frequency set comprising a second spectral level that is also non-zero.

34. The communications system according to claim 33, wherein the processor and/or the transmitter is/are configured to:

separate the first and second frequency sets by a third frequency set comprising a spectral level that is substantially zero.

35. The communications system according to claim 27, wherein the processor is further configured to function so that a maximum amplitude value at an output of the inverse Fourier transform be limited in order to reduce non-linear distortion effects in an amplification stage of the transmitter.

36. The communications system according to claim 27, wherein the waveform comprises first and second waveforms at least one of which is generated pseudo-randomly and independently of an information symbol sequence that is to be transmitted/received, responsive to a predetermined statistical distribution.

37. The communications system according to claim 36, wherein the predetermined statistical distribution comprises a Gaussian distribution.

38. The communications system according to claim 27, wherein the waveform is devoid of a regularly repeating peak amplitude level while the waveform is being transmitted by the transmitter.

39. The communications system according to claim 36, wherein each one of the first and second waveforms comprises a waveform that is generated pseudo-randomly and independently of the information symbol sequence that is to be transmitted/received;

and wherein the first and second waveforms comprise a statistical independence and an orthogonality therebetween.

40. A communications system comprising:

a processor that is configured to provide a frequency content by Fourier transforming a signal;

to form at baseband a desired spectrum shape that differs from the frequency content, responsive to the frequency content; and

to generate at baseband a waveform by inverse Fourier transforming the desired spectrum shape without resorting to chipping of the inverse Fourier transform of the desired spectrum shape with a binary waveform; and

a transmitter that is configured to transmit the waveform, comprising a plurality of elements, by using the plurality of elements, sequentially one after another, to modulate a single carrier frequency;

wherein the processor is further configured to;

select a frequency interval over which the waveform is to exist;

allow at least one frequency that is included in the selected frequency interval to provide a frequency content to the waveform; and

exclude at least one frequency that is included in the selected frequency interval from providing a frequency content to the waveform.

41. The communications system according to claim 40, wherein the processor is further configured to use the frequency interval that is selected over a first time interval and then to change the frequency interval that is selected and to use the changed frequency interval over a second time interval.

42. The communications system according to claim 40, wherein the processor and the transmitter are substantially co-located therebetween.

43. The communications system according to claim 40, wherein the processor is located a distance from the transmitter.

44. The communications system according to claim 40, wherein said desired spectrum shape comprises first and second desired spectrum shapes over respective first and second time intervals and wherein the first desired spectrum shape comprises:

a first plurality of frequencies that is used to generate at baseband a first waveform without resorting to chipping with a binary waveform; and

wherein the second desired spectrum shape comprises;

a second plurality of frequencies that is used to generate at baseband a second waveform without resorting to chipping with a binary waveform;

wherein the first plurality of frequencies differs from the second plurality of frequencies in at least one frequency and wherein the first and second desired spectrum shapes differ therebetween.

45. The communications system according to claim 44, wherein the first waveform comprises a first time duration and wherein the second waveform comprises a second time duration that differs from the first time duration.

46. The communications system according to claim 40, wherein the waveform further comprises first and second waveforms comprising respective first and second time durations that differ therebetween.

47. The communications system according to claim 40, wherein said desired spectrum shape includes a first frequency set comprising a first spectral level that is non-zero and also includes a second frequency set comprising a second spectral level that is also non-zero.

48. The communications system according to claim 47, wherein the processor and/or the transmitter is/are configured to:

separate the first and second frequency sets by a third frequency set comprising a spectral level that is substantially zero.

49. The communications system according to claim 40, wherein the processor is further configured to function so that a maximum amplitude value at an output of the inverse Fourier transform be limited in order to reduce non-linear distortion effects in an amplification stage of the transmitter.

50. The communications system according to claim 40, wherein the waveform comprises first and second waveforms at least one of which is generated pseudo-randomly and independently of an information symbol sequence that is to be transmitted/received, responsive to a predetermined statistical distribution.

51. The communications system according to claim 50, wherein the predetermined statistical distribution comprises a Gaussian distribution.

52. The communications system according to claim 40, wherein the waveform is devoid of a regularly repeating peak amplitude level while the waveform is being transmitted by the transmitter.

53. The communications system according to claim 50, wherein each one of the first and second waveforms comprises a waveform that is generated pseudo-randomly and independently of the information symbol sequence that is to be transmitted/received;

and wherein the first and second waveforms comprise a statistical independence and an orthogonality therebetween.