Adaptive system for efficient transmission of power and data through acoustic media

• US 9,054,826 B2
• Filed: 03/28/2012
• Issued: 06/09/2015
• Est. Priority Date: 04/12/2011
• Status: Active Grant

• Current Assignee: Rensselaer Polytechnic Institute
• Original Assignee: Rensselaer Polytechnic Institute
• Inventors: Lawry, Tristan J., Saulnier, Gary J., Wilt, Kyle R., Ashdown, Jonathan D., Scarton, Henry A.
• Primary Examiner(s): Jaroenchonwanit, Bunjob
• Application Number:
  US14/007,871
• Publication Number:
  US 20140016558A1
• Time in Patent Office: 1,168 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H04B 11/00 Transmission systems employing sonic, ultrasonic or infrasonic waves
• CPC Class Codes: H04J 11/00 Orthogonal multiplex systems, e.g. using WALSH codesH04J13/00 takes precedence
• CPC Class Codes: H04L 27/2657 Carrier synchronisation
• CPC Class Codes: H04L 27/2697 in combination with other modulation techniques
• CPC Class Codes: H04L 27/2698 double density OFDM/OQAM system, e.g. OFDM/OQAM-IOTA system
• CPC Class Codes: H04L 5/0046 Determination of how many bits are transmitted on different sub-channels

Abstract

An apparatus and method for transmitting data and power through a metal barrier using ultrasonic waves, having ultrasonic transmission channels through the barrier formed by coupling ultrasonic transducers on opposite sides of the barrier. A power transmitter sends power over a channel and forward and reverse data transmitters send forward and reverse data signals by orthogonal frequency-division multiplexing OFDM over a separate channel. The data signals are made up of plural sub-carriers at plural different sub-carrier frequencies with none of the sub-carriers of the forward transmission signal being at a power harmonic frequency.

Claims

1. An apparatus for transmitting data and power through a barrier using ultrasonic waves, the barrier having a delay spread that is a function of acoustic properties of the barrier, an inverse of the delay spread being a coherence bandwidth of the barrier, the apparatus comprising:

at least two ultrasonic channels through the barrier, each channel comprising at least one ultrasonic transducer acoustically coupled to the barrier on each of a transmission side of the barrier and a receiving side of the barrier;

a power transmitter for sending a power signal at a power delivery frequency (f_power) over one of the channels via one of the ultrasonic transducers on the transmission side of the barrier, there being a plurality of power harmonic frequencies that are each at an integer multiple of the power delivery frequency;

a forward data transmitter for sending a forward transmitted data signal over one of the channels via one of the ultrasonic transducers on the transmission side of the barrier;

a forward data receiver for receiving the forward transmission data signal over the one channel and at one of the ultrasonic transducers on the receiving side of the barrier, the data receiver including a demodulator for recreating the forward transmitted data signal on the receiving side of the barrier;

a power receiver for receiving the power signal over the one channel and at one of the ultrasonic transducers on the receiving side of the barrier, the power receiver including a power converter for harvesting power at the receiving side of the barrier;

a reverse data transmitter having an orthogonal frequency-division multiplexing modulator for receiving the demodulated forward transmitted data signal and a reverse transmitted data signal, the orthogonal frequency-division multiplexing modulator creating and sending a reverse data signal over one of the channels and via one of the ultrasonic transducers on the receiving side of the barrier;

the orthogonal frequency-division multiplexing modulator sending the reverse data signal as a signal that is made up of a multiplicity of sub-carriers at a multiplicity of different sub-carrier frequencies (f_subcarrier) that are each spaced from each other by a subcarrier frequency spacing (f_{subcarrier spacing}), each sub-carrier having a bandwidth that is smaller than the coherence bandwidth of the channel;

the power delivery frequency (f_power) being selected to be an integer multiple (N) of the frequency spacing (f_{subcarrier spacing}) and at least some of the sub-carrier frequencies (f_subcarrier) being selected to be an integer multiple (M) of the power delivery frequency (f_power),

the orthogonal frequency-division multiplexing modulator using none of the at least some sub-carrier frequencies that are integer multiples of the power delivery frequency; and

a reverse data receiver for receiving the reverse data signal, the reverse data receiver including a demultiplexer and a demodulator for recreating the reverse data signal on the transmission side of the barrier.

2. The apparatus of claim 1, wherein the power signal is a continuous-wave power delivery signal, the power receiver including a clock recovery and distribution system for recovering the continuous-wave power delivery signal and using it as a reference clock to which the orthogonal frequency-division multiplexing modulator is synchronized, the clock recovery and distribution system having multiplier and divider stages through which the power delivery signal is passed to generate a clock at the sub-carrier spacing frequency, rates of a remainder of the orthogonal frequency-division multiplexing modulator being derived directly from the sub-carrier spacing frequency using additional clock multipliers and dividers.

3. The apparatus of claim 1, wherein the reverse data receiver creates side information in response to at least one acoustic property of the barrier, the forward transmitter sending the side information to the forward receiver, the reverse data transmitter being connected to the forward data receiver for receiving the side information for adjusting the orthogonal frequency-division multiplexing modulator in response to the side information.

4. The apparatus of claim 1, wherein the reverse data transmitter adds a cyclic prefix before the reverse transmitted data signal that has a length substantially greater than or equal to the delay spread.

5. The apparatus of claim 1, wherein the reverse data transmitter adds a cyclic prefix before the reverse transmitted data signal that has a length substantially greater than or equal to the delay spread, and the reverse data receiver removes the cyclic prefix from the reverse data signal.

6. The apparatus of claim 1, wherein the power converter creates side information in response to at least one acoustic property of the barrier, the reverse data transmitter receiving the side information and sending the side information to the reverse data receiver being connected to the power transmitter for adjusting the power delivery frequency in response to the at least one acoustic property of the barrier.

7. The apparatus of claim 1, wherein:

the at least two ultrasonic channels comprise first, second and third ultrasonic channels through the barrier, each channel comprising at least one ultrasonic transducer acoustically coupled to the barrier on each of the opposite sides of the barrier;

the reverse data transmitter creating and sending the reverse data signal over the second channel and via one of the ultrasonic transducers on the receiving side of the barrier, the reverse data signal including side information representing at least one acoustic property of the barrier;

the reverse data receiver being connected to the forward data transmitter for adjusting the orthogonal frequency-division multiplexing modulator in response to the side information and the at least one acoustic property of the barrier represented by the side information;

the power transmitter being connected to its associated ultrasonic transducer on the transmission side of the first channel; and

the forward data transmitter being connected to its associated ultrasonic transducer on the transmission side of the third channel.

8. The apparatus of claim 1, wherein the at least two ultrasonic channels comprise a first and a second ultrasonic channel through the barrier, each channel comprising at least one ultrasonic transducer acoustically coupled to the barrier on each of the opposite sides of the barrier;

the reverse data transmitter creating and sending the reverse data signal over the second channel and via one of the ultrasonic transducers on the receiving side of the barrier, the reverse data signal including side information representing at least one acoustic property of the barrier;

the reverse data receiver receiving the reverse data signal at the at least one ultrasonic transducer of the second channel on the transmission side of the barrier, the reverse data receiver being connected to the forward data transmitter for adjusting the orthogonal frequency-division multiplexing modulator in response to the side information and the at least one acoustic property of the barrier represented by the side information;

the power transmitter being connected to its associated ultrasonic transducer on the transmission side of the first channels;

the forward data transmitter and the forward data receiver being connected to the ultrasonic transducers of the second channel; and

time-sharing circulators connecting the forward data transmitter and the reverse data receiver to the transducer on the transmission side of the second channel, and connecting the reverse data transmitter and the forward data receiver on the receiving side of the second channel.

9. The apparatus of claim 1, wherein the at least two ultrasonic channels comprise a first and a second ultrasonic channel through the barrier, each channel comprising at least one ultrasonic transducer acoustically coupled to the barrier on each of the opposite sides of the barrier;

the reverse data transmitter creating and sending the reverse data signal over the second channel and via one of the ultrasonic transducers on the receiving side of the barrier, the reverse data signal including side information representing at least one acoustic property of the barrier;

the reverse data receiver receiving the reverse data signal at the at least one ultrasonic transducer of the second channel on the transmission side of the barrier, the reverse data receiver being connected to the forward data transmitter for adjusting the orthogonal frequency-division multiplexing modulator in response to the side information and the at least one acoustic property of the barrier represented by the side information;

the power transmitter being connected to its associated ultrasonic transducer on the transmission side of the first channels;

the forward data transmitter and the forward data receiver being connected to the ultrasonic transducers of the second channel; and

the sub-carriers of the forward transmission signal being at different frequencies from the sub-carriers of the reverse data signal.

10. An apparatus for transmitting data and power through a barrier using ultrasonic waves, the barrier having a delay spread that is a function of acoustic properties of the barrier, an inverse of the delay spread being a coherence bandwidth of the barrier, the apparatus comprising:

at least two ultrasonic channels through the barrier, each channel comprising at least one ultrasonic transducer acoustically coupled to the barrier on each of a transmission side of the barrier and a receiving side of the barrier;

a power transmitter for sending a power signal at a power delivery frequency (f_power) over one of the channels via one of the ultrasonic transducers on the transmission side of the barrier, there being a plurality of power harmonic frequencies that are each at an integer multiple of the power delivery frequency;

a forward data transmitter for sending a forward transmitted data signal over one of the channels via one of the ultrasonic transducers on the transmission side of the barrier;

a forward data receiver for receiving the forward transmission data signal over the one channel and at one of the ultrasonic transducers on the receiving side of the barrier, the data receiver including a demodulator for recreating the forward transmitted data signal on the receiving side of the barrier;

a power receiver for receiving the power signal over the one channel and at one of the ultrasonic transducers on the receiving side of the barrier, the power receiver including a power converter for harvesting power at the receiving side of the barrier;

a reverse data transmitter having an orthogonal frequency-division multiplexing modulator for receiving the demodulated forward transmitted data signal and a reverse transmitted data signal, the orthogonal frequency-division multiplexing modulator creating and sending a reverse data signal over one of the channels and via one of the ultrasonic transducers on the receiving side of the barrier;

the orthogonal frequency-division multiplexing modulator sending the reverse data signal as a signal that is made up of a multiplicity of sub-carriers at a multiplicity of different sub-carrier frequencies (f_subcarrier) that are each spaced from each other by a subcarrier frequency spacing (f_{subcarrier spacing}), each sub-carrier having a bandwidth that is smaller than the coherence bandwidth of the channel;

the power delivery frequency (f_power) being selected to be an integer multiple (N) of the frequency spacing (f_{subcarrier spacing}) and at least some of the sub-carrier frequencies (f_subcarrier) being selected to be an integer multiple (M) of the power delivery frequency (f_power);

the orthogonal frequency-division multiplexing modulator using none of the at least some sub-carrier frequencies that are integer multiples of the power delivery frequency; and

a reverse data receiver for receiving the reverse data signal, the reverse data receiver including a demultiplexer and a demodulator for recreating the reverse data signal on the transmission side of the barrier;

the power signal being a continuous-wave power delivery signal, the power receiver including a recovery and distribution system for recovering the continuous-wave power delivery signal and using it as a reference clock to which the orthogonal frequency-division multiplexing modulator is synchronized, the clock recovery and distribution system having multiplier and divider stages through which the power delivery signal is passed to generate a clock at the sub-carrier spacing frequency, rates of a remainder of the orthogonal frequency-division multiplexing modulator being derived directly from the sub-carrier spacing frequency using additional clock multipliers and dividers.

11. The apparatus of claim 10, wherein the reverse data transmitter adds a cyclic prefix before the reverse transmitted data signal that has a length greater than or equal to the delay spread.

12. The apparatus of claim 10, wherein the forward data transmitter and power transmitter share the same channel.

13. The apparatus of claim 10, including time-share circulators connected to the forward data transmitter and to the reverse data transmitter so that the forward data transmitter and the reverse data transmitter share the same channel.

14. The apparatus of claim 10, including the forward data transmitter and the reverse data transmitter operating at different frequencies and being connected to the same channel.

15. The apparatus of claim 10, wherein the forward data transmitter, the power transmitter and the reverse data transmitter are connected to three different channels.

16. The apparatus of claim 10, wherein the power converter creates side information in response to at least one acoustic property of the barrier, the reverse data transmitter receiving the side information and sending the side information to the reverse data receiver being connected to the power transmitter for adjusting the power delivery frequency in response to the at least one acoustic property of the barrier.

17. A method of transmitting data and power through a barrier using ultrasonic waves, the barrier having a delay spread that is a function of acoustic properties of the barrier, an inverse of the delay spread being a coherence bandwidth of the barrier, the method comprising:

providing at least two ultrasonic channels through the barrier, each channel comprising at least one ultrasonic transducer acoustically coupled to the barrier on each of two opposite sides of the barrier;

using a power transmitter for sending a power signal at a power delivery frequency (f_power) over one of the channels via one of the ultrasonic transducers on the transmission side of the barrier, there being a plurality of power harmonic frequencies that are each at an integer multiple of the power delivery frequency;

using a forward data transmitter for sending a forward transmitted data signal over one of the channels via one of the ultrasonic transducers on the transmission side of the barrier;

using a forward data receiver for receiving the forward transmission data signal over the one channel and at one of the ultrasonic transducers on the receiving side of the barrier, the data receiver including a demodulator for recreating the forward transmitted data signal on the receiving side of the barrier;

using a power receiver for receiving the power signal over the one channel and at one of the ultrasonic transducers on the receiving side of the barrier, the power receiver including a power converter for harvesting power at the receiving side of the barrier;

using a reverse data transmitter having an orthogonal frequency-division multiplexing modulator for receiving the demodulated forward transmitted data signal and a reverse transmitted data signal, the orthogonal frequency-division multiplexing modulator creating and sending a reverse data signal over one of the channels and via one of the ultrasonic transducers on the receiving side of the barrier;

the orthogonal frequency-division multiplexing modulator sending the reverse data signal as a signal that is made up of a multiplicity of sub-carriers at a multiplicity of different sub-carrier frequencies (f_subcarrier) that are each spaced from each other by a subcarrier frequency spacing (f_{subcarrier spacing}), each sub-carrier having a bandwidth that is smaller than the coherence bandwidth of the channel;

selecting the power delivery frequency f_power) to be an integer multiple (N) of the frequently spacing (f_{subcarrier spacing}) and at least some of the sub-carrier frequencies (f_subcarrier) being selected to be an integer multiple (M) of the power delivery frequency (f_power);

using none of the at least some sub-carrier frequencies that are integer multiples of the power delivery frequency in the orthogonal frequency-division multiplexing modulator; and

using a reverse data receiver for receiving the reverse data signal, the reverse data receiver including a demultiplexer and a demodulator for recreating the reverse data signal on the transmission side of the barrier.

18. The method of claim 17, including adding a cyclic prefix before the reverse transmitted data signal that has a length substantially greater than or equal to the delay spread.

19. The method of claim 17, wherein the forward data transmitter and power transmitter share the same channel.

20. The method of claim 17, including connecting the forward data transmitter and the reverse data transmitter to same channel and separating forward and reverse signals by one of time-sharing and frequency band differentiation of sub-carriers.

21. The method of claim 17, wherein the power signal is a continuous-wave power delivery signal, the power receiver including a clock recovery and distribution system for recovering the continuous-wave power delivery signal and using it as a reference clock to which the orthogonal frequency-division multiplexing modulator is synchronized, the clock recovery and distribution system having multiplier and divider stages through which the power delivery signal is passed to generate a clock at the sub-carrier spacing frequency, rates of a remainder of the orthogonal frequency-division multiplexing modulator being derived directly from the sub-carrier spacing frequency using additional clock multipliers and dividers.

22. The method of claim 17, including the reverse data receiver creating side information in response at least one acoustic property of the barrier, the forward transmitter sending the side information to the forward receiver, the reverse data transmitter being connected to the forward data receiver for receiving the side information for adjusting the orthogonal frequency-division multiplexing modulator in response to the side information.

23. The method of claim 17, including the power converter creating side information in response to at least one acoustic property of the barrier, the reverse data transmitter receiving the side information and sending the side information to the reverse data receiver being connected to the power transmitter and adjusting the power delivery frequency in response to the at least one acoustic property of the barrier.