Frequency hopping spread spectrum passive acoustic wave identification device

• US 7,023,323 B1
• Filed: 10/14/2003
• Issued: 04/04/2006
• Est. Priority Date: 08/18/1997
• Status: Expired due to Fees

• Current Assignee: X-Cyte Inc.
• Original Assignee: X-Cyte Inc.
• Inventors: Nysen, Paul A.
• Primary Examiner(s): Horabik, Michael
• Assistant Examiner(s): BANGACHON, WILLIAM L
• Application Number:
  US10/684,602
• Time in Patent Office: 903 Days
• Field of Search: 340/10.1, 340/10.3, 340/10.4, 340/10.41, 340/573.1, 342/41, 342/42, 342/44, 342/51, 370/321, 370/315, 370/310, 455/133, 455/14, 455/55.1, 375/131, 701/300, 310/318, 310/313.R
• US Class Current: 340/10.1
• CPC Class Codes: G01S 13/755 using delay lines, e.g. acoustic delay lines
• CPC Class Codes: G06K 19/0672 with resonating marks
• CPC Class Codes: G06K 7/10009 sensing by radiation using wavelengths larger than 0.1 mm, e.g. radio-waves or microwaves

Abstract

A system and method for interrogating a passive acoustic transponder, producing a transponder signal having characteristic set of signal perturbations in response to an interrogation signal, comprising a signal generator, producing an interrogation signal having a plurality of differing frequencies; a receiver, for receiving the transponder signal; a mixer, for mixing the transponder signal with a signal corresponding to the interrogation signal, to produce a mixed output; an integrator, integrating the mixed output to define an integrated phase-amplitude response of the received transponder signal; and an analyzer, receiving a plurality of integrated phase-amplitude responses corresponding to the plurality of differing frequencies, for determining the characteristic set of signal perturbations of the passive acoustic transponder.

Claims

1. A communication method, comprising:

(a) providing a representation of an information pattern having a plurality of degrees of freedom;

(b) imposing the information pattern as a set of time domain parameters on a signal having at least as many excitation conditions as degrees of freedom of the information pattern, to produce an information communication signal;

(c) transmitting the information communication signal;

(d) receiving the information communication signal; and

(e) demodulating the received information communication signal to determine the set of time domain parameters from a set of respective baseband phase-amplitude responses.

2. The communication method according to claim 1, wherein the information communication signal comprises a plurality of frequency components, each frequency component being analyzed separately.

3. The communication method of claim 2, wherein the demodulating step determines a phase-amplitude response for each respective frequency component.

4. The communication method of claim 2, wherein information is communicated over at least two communication channels simultaneously.

5. The communication method of claim 2, wherein a number of time domain parameters is less than or equal to a number of frequency components.

6. The communication method according to claim 1, wherein the set of time domain parameters comprises an acoustic reflection pattern.

7. The communication method according to claim 1, wherein the set of time domain parameters comprises a set of phase shifts.

8. The communication method according to claim 2, wherein the set communication band comprises a frequency band having a center frequency in the range of between about 300 MHz to about 30 GHz.

9. The communication method according to claim 2, wherein the set communication band comprises a frequency in a band between about 800 MHz and 1.3 GHz and having a bandwidth of between about 1–

3%.

10. The communication method according to claim 2, wherein the frequency components are generated simultaneously.

11. The communication method according to claim 2, wherein the frequency components are about evenly spaced across the communication band.

12. The communication method according to claim 1, wherein the demodulator comprises a homodyne demodulator that is operable to mix the received information communication signal with a demodulation signal, to produce, in a steady state condition, a signal whose amplitude corresponds to a relative phase-amplitude difference between said information communication signal and said demodulation signal.

13. The communication method according to claim 1, wherein the demodulator comprises a double balanced mixer.

14. The communication method according to claim 1, wherein the set of respective baseband phase-amplitude responses is detected by a low pass filter.

15. The communication method according to claim 1, wherein the set of respective baseband phase-amplitude responses is detected by a low pass filter having at least two poles in its transfer function.

16. The communication method according to claim 1, wherein the set of respective baseband phase-amplitude responses is represented as a scalar value.

17. The communication method according to claim 1, wherein time domain parameters include a maximum significant time constant of less than about 5 μ

S and comprises a pattern selected from a signal perturbation space having about 16 degrees of freedom.

18. The communication method according to claim 1, wherein the demodulator determines self-consistency of received data.

19. A communication system, comprising:

(a) an input receiving a representation of an information pattern having a plurality of degrees of freedom;

(b) a modulator configured to modulate the information pattern as a set of time domain parameters on a signal having at least as many excitation conditions as degrees of freedom of the information pattern, to produce an information communication signal;

(c) a demodulator configured to demodulate the received information communication signal to determine the set of time domain parameters from a set of respective demodulated baseband phase-amplitude response; and

(d) an analyzer configured to regenerate the information pattern.