System and method for wirelessly transmitting and receiving digital data using acoustical tones

• US 20040081078A1
• Filed: 06/19/2003
• Published: 04/29/2004
• Est. Priority Date: 06/21/2002
• Status: Active Grant

• Current Assignee: Disney Enterprises Incorporated (The Walt Disney Company)
• Original Assignee: Disney Enterprises Incorporated (The Walt Disney Company)
• Inventors: McKnight, Thomas Richard, Haseltine, Eric C.
• Granted Patent: US 7,764,716 B2
• Time in Patent Office: Days
• US Class Current: 370/210
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems
• CPC Class Codes: H04L 27/30 wherein each code element is represented by a combination of frequencies

Abstract

A system and a method for the transmission and reception of digital data wirelessly using acoustic tones comprises a device having an encoder, a modulator system, a demodulator system, and a decoder. The modulator system uses dual tone multiple frequency (DTMF) tones that are amplitude modulated. The received signal is demodulated and detected by Fourier analysis. An expanded Hamming code based decoder is used for correcting errors occurring during transmission.

Claims

1. A digital data transmitting system using acoustic tones, the system comprising:

a) at least one generator generating digital data;

b) a modulator system, said modulator system modulating DTMF tones with the digital data; and

c) at least one loudspeaker, the loudspeaker transmitting the modulated tones.

2. The digital data transmitting system according to claim 1, wherein the digital data comprises a pseudo random code.

3. The digital data transmitting system according to claim 2, wherein the digital data further comprises a plurality of message bits.

4. The digital data transmitting system according to claim 3, wherein the digital data further comprises a plurality of correction bits.

5. The digital data transmitting system according to claim 4, wherein the correction bits are based on an expanded Hamming code.

6. The digital data transmitting system according to claim 1, wherein the digital data is of length 32 bits.

7. The digital data transmitting system according to claim 1, wherein the modulator system is an amplitude modulator.

8. The digital data transmitting system according to claim 1, further comprising a summer for summing the modulated tones.

9. The digital data transmitting system according to claim 1, wherein the tones lie between 20 Hz and 20 kHz.

10. The digital data transmitting system according to claim 1, wherein the tones lie in the infrasonic band.

11. The digital data transmitting system according to claim 1, wherein the tones lie in the ultrasonic band.

12. The digital data transmitting system according to claim 1, wherein the DTMF tones are generated by a controller.

13. A method for transmitting digital data using acoustic tones, the method comprising:

a) generating digital data;

b) modulating a plurality of pure tones with the digital data, wherein the plurality of pure tones are DTMF tones; and

c) transmitting the modulated tones through a loudspeaker.

14. The method for transmitting digital data using acoustic tones according to claim 13, further comprising the step of summing the modulated tones after modulation.

15. The method for transmitting digital data using acoustic tones according to claim 13, wherein the digital data comprises a pseudo random code.

16. The method for transmitting digital data using acoustic tones according to claim 15, wherein the digital data further comprises a plurality of message bits.

17. The method for transmitting digital data using acoustic tones according to claim 16, wherein the digital data further comprises a plurality of correction bits.

18. The method for transmitting digital data using acoustic tones according to claim 17, wherein the correction bits are based on an expanded Hamming code.

19. The method for transmitting digital data using acoustic tones according to claim 18, wherein the digital data is of length 32 bits.

20. The digital data transmitting system according to claim 13, wherein the modulation is performed by an amplitude modulator.

21. The digital data transmitting system according to claim 13, wherein the tones lie in the infrasonic band.

22. The digital data transmitting system according to claim 13, wherein the tones lie in the ultrasonic band.

23. A receiver for receiving acoustic tones modulated by digital data, the receiver comprising:

a) means for computing Fourier transform through at least one overlapping window;

b) means for identifying at least one frame marker in the at least one overlapping window;

c) means for determining the at least one marker alignment by optimizing alignment of the, at least one window for maximum energy from the at least one marker;

d) means for determining a set of substantially optimally aligned windows for identifying pure tones in each frame;

e) means for decoding the pure tones for each of the optimally aligned windows in said each frame; and

f) means for converting the decoded pure tones to bits.

24. The receiver according to claim 23, further including means for de-interleaving N b-bit error coded blocks.

25. The receiver according to claim 24, further including means for performing error correction and detection of data bits.

26. The receiver according to claim 23, wherein the window is at least one of a rectangular window, a Hamming window, a Hanning window, a Blackman window, a triangular window, or a raised cosine window.

27. The receiver according to claim 23, wherein the pure tones include DTMF tones.

28. The receiver according to claim 25, wherein the error correction is done by an expanded Hamming code.

29. The receiver according to claim 24, wherein N=8.

30. The receiver according to claim 24, wherein b=8.

31. A method for receiving acoustic tones modulated by digital data, the method comprising:

computing Fourier transform through at least one overlapping window;

identifying at least one frame marker in the at least one overlapping window;

determining alignment of the at least one marker by optimizing alignment of the at least one window for maximum energy from the at least one marker;

determining a set of substantially optimally aligned windows for identifying pure tones in each frame;

decoding the pure tones for each of the optimally aligned windows in said each frame; and

converting the decoded pure tones to bits.

32. The method according to claim 31, further including the step of de-interleaving N b-bit error coded blocks.

33. The method according to claim 32, further including the step of performing error correction and detection of data bits.

34. The method according to claim 31, wherein the window is at least one of a rectangular window, a Hamming window, a Hanning window, a Blackman window, a triangular window, or a raised cosine window.

35. The method according to claim 31, wherein the pure tones include DTMF tones.

36. The method according to claim 33, wherein the error correction is done by an expanded Hamming code.

37. The method according to claim 32, wherein N=8.

38. The method according to claim 32, wherein b=8.

39. A device for transmitting digital data wirelessly, the device comprising:

a modulator for modulating a plurality of pure tones with digital data to generate a signal;

a loudspeaker for transmitting the signal; and

a micro-controller for generating the plurality of pure tones.

40. The device according to claim 39, wherein the device is a handheld device.

41. The device according to claim 40, further including an encoder.

42. The device according to claim 40, wherein the plurality of pure tones are DTMF tones.

43. The device according to claim 40, wherein the modulator is an amplitude modulator.

44. The device according to claim 40, wherein the frequency content of the signal is between 20 Hz and 20 kHz.

45. The device according to claim 40, wherein the frequency content of the signal is in the infrasonic band.

46. The device according to claim 40, wherein the frequency content of the signal is in the ultrasonic band.

47. A device for transmitting and receiving digital data wirelessly, the device comprising:

a transmitter including;

(i) a modulator for modulating DTMF tones with digital data to generate a signal;

(ii) a loudspeaker for transmitting the signal; and

a receiver including;

(i) a microphone for capturing the signal;

(ii) a demodulator connected to said microphone for demodulating the signal;

(iii) a Hamming error correction system for detecting and correcting errors in the demodulated signal.

48. A receiver for receiving acoustic tones modulated by digital data, the receiver comprising:

a fourier transform system for computing Fourier transform through at least one overlapping window;

a first identification system for identifying at least one frame marker in the at least one overlapping window;

an alignment system for determining the at least one marker alignment by optimizing alignment of the at least one window for maximum energy from the at least one marker;

a second identification system for determining a set of substantially optimally aligned windows for identifying pure tones in each frame;

a decoding system for decoding the pure tones for each of the optimally aligned windows in said each frame; and

a conversion system for converting the decoded pure tones to bits.

49. The receiver according to claim 48, further including a de-interleaving system for de-interleaving N b-bit error coded blocks.

50. The receiver according to claim 49, further including an error correction and data bit detection system.

51. The receiver according to claim 48, wherein the window is at least one of a rectangular window, a Hamming window, a Hanning window, a Blackman window, a triangular window, or a raised cosine window.

52. The receiver according to claim 48, wherein the pure tones include DTMF tones.

53. The receiver according to claim 51, wherein the error correction is done by an expanded Hamming code.

54. The receiver according to claim 49, wherein N=8.

55. The receiver according to claim 49, wherein b=8.