Hybrid OFDM body coupled communication transceiver

• US 10,277,334 B2
• Filed: 11/03/2017
• Issued: 04/30/2019
• Est. Priority Date: 11/03/2016
• Status: Active Grant

• Current Assignee: Khalifa University Of Science, Technology & Research
• Original Assignee: Khalifa University of Science and Technology
• Inventors: Yoo, Jerald, Saadeh, Wala
• Primary Examiner(s): Nguyen, Hai V
• Application Number:
  US15/803,711
• Publication Number:
  US 20180123704A1
• Time in Patent Office: 543 Days
• Field of Search: 455 412
• CPC Class Codes: H04B 13/005 Transmission systems in which the medium consists of the human body
• CPC Class Codes: H04L 27/12 Modulator circuits; Transmitter circuits
• CPC Class Codes: H04L 27/2634 Inverse fast Fourier transform [IFFT] or inverse discrete Fourier transform [IDFT] modulators in combination with other circuits for modulation
• CPC Class Codes: H04L 27/26524 Fast Fourier transform [FFT] or discrete Fourier transform [DFT] demodulators in combination with other circuits for demodulation
• CPC Class Codes: H04L 27/2697 in combination with other modulation techniques
• CPC Class Codes: H04L 5/0012 Hopping in multicarrier systems for frequency hopping in spread spectrum systems H04B1/713
• CPC Class Codes: H04W 4/80 Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication

Abstract

A radio-frequency (RF) body-coupled communications (BCC) transceiver is disclosed according to one embodiment of the present disclosure. The RF BCC transceiver includes an RF BCC transmitter and an RF BCC receiver, such that the RF BCC transmitter transmits an RF signal to the RF BCC receiver via a body area network (BAN) of a human body.

Claims

1. A radio-frequency (RF) body-coupled communications (BCC) transceiver (TRX) configured to function as a hybrid orthogonal frequency-division multiplexing (H-OFDM) TRX and comprising:

an RF BCC transmitter, comprising;

a baseband phase-shift keying (BPSK) modulator and an inverse fast Fourier transform (IFFT) processing block configured to process transmit (TX) data to provide a baseband TX signal; and

a frequency hopping (FH) and frequency shift keying (FSK) RF modulator configured to RF modulate the baseband TX signal to provide an RF TX signal; and

an RF BCC receiver;

wherein the RF BCC transmitter is configured to transmit the RF TX signal to the RF BCC receiver via a body area network (BAN) of a human body.

2. The RF BCC TRX of claim 1 wherein the RF BCC transmitter is further configured to transmit the RF TX signal to the RF BCC receiver via a head of the human body.

3. The RF BCC TRX of claim 1 wherein the BAN of the human body is configured to be based on magnetic resonance coupling, such that the RF BCC transmitter is further configured to transmit the RF TX signal to the RF BCC receiver using the magnetic resonance coupling between the RF BCC transmitter and the RF BCC receiver, wherein each of the RF BCC transmitter and the RF BCC receiver comprises a corresponding one of a pair of magnetically coupled coils.

4. The RF BCC TRX of claim 1 wherein the BAN of the human body is configured to be galvanic current based, such that the RF BCC transmitter is further configured to transmit the RF TX signal to the RF BCC receiver using the galvanic current from the RF BCC transmitter to the RF BCC receiver via the human body.

5. The RF BCC TRX of claim 1 wherein the RF BCC transmitter is configured to be located adjacent to one ear of a pair of ears of the human body and the RF BCC receiver is configured to be located adjacent to another ear of the pair of ears.

6. The RF BCC TRX of claim 1 wherein the BAN of the human body comprises a primary signal path and a return signal path, such that the primary signal path is via the human body and the return signal path is via parasitic capacitance external to the human body.

7. The RF BCC TRX of claim 6 wherein at least a portion of the return signal path is configured to be provided by clothing worn by the human body.

8. The RF BCC TRX of claim 1 wherein a connection between the RF BCC transmitter and the human body comprises a transmitter skin-electrode contact impedance, such that a signal strength of the RF TX signal is directly related to an estimate of the transmitter skin-electrode contact impedance.

9. The RF BCC TRX of claim 8 wherein the estimate of the transmitter skin-electrode contact impedance is based on a resistance/capacitance settling time measurement.

10. The RF BCC TRX of claim 8 wherein a connection between the RF BCC receiver and the human body has a receiver skin-electrode contact impedance, such that the signal strength of the RF TX signal is further directly related to an estimate of the receiver skin-electrode contact impedance.

11. The RF BCC TRX of claim 1, wherein:

the IFFT processing block is an

8 -point IFFT processing block; and

the RF BCC receiver comprises;

an FSK receiver configured to receive and down convert an RF receive (RX) signal to provide a baseband RX signal; and

an 8-point fast Fourier transform (FFT) processing block and BPSK demodulator configured to process the baseband RX signal to provide RX data.

12. The RF BCC TRX of claim 11 further comprising control circuitry configured to provide the TX data and receive the RX data.

13. The RF BCC TRX of claim 11 wherein the 8-point FFT processing block and BPSK demodulator is configured to calculate an 8-point FFT using division by the square root of 2.

14. The RF BCC TRX of claim 11 wherein:

the FH and FSK RF modulator comprises an RF TX amplifier configured to amplify the RF TX signal to provide an amplified RF TX signal; and

the FSK receiver comprises an RF RX amplifier configured to receive and amplify the RF RX signal.

15. The RF BCC TRX of claim 14 wherein:

a gain of the RF TX amplifier is adjustable;

a gain of the RF RX amplifier is adjustable;

the FH and FSK RF modulator further comprises a TX impedance monitor configured to monitor an impedance associated with the amplified RF TX signal; and

the FSK receiver further comprises an RX impedance monitor configured to monitor an impedance associated with the RF RX signal.

16. A hybrid orthogonal frequency-division multiplexing (H-OFDM) transceiver (TRX) comprising:

a transmitter comprising;

a physical layer (PHY) modulation block and inverse fast Fourier transform (IFFT) processing block configured to calculate an 8-point IFFT and process transmit (TX) data to provide a baseband TX signal; and

a modulator configured to modulate the baseband TX signal to provide a TX signal; and

a receiver comprising;

a PHY demodulation block configured to receive and down convert a receive (RX) signal to provide a baseband RX signal; and

an OFDM baseband fast Fourier transform (FFT) processing block configured to process the baseband RX signal to provide recovered RX data.

18. The H-OFDM TRX of claim 16 wherein:

the modulator comprises a radio-frequency (RF) TX amplifier configured to amplify the TX signal to provide an amplified TX signal, wherein the TX signal is an RF signal; and

the receiver comprises an RF RX amplifier configured to receive and amplify the RX signal.

19. The H-OFDM TRX of claim 18 wherein:

a TX gain of the RF TX amplifier is adjustable;

an RX gain of the RF RX amplifier is adjustable;

the modulator further comprises a TX impedance monitor configured to monitor a TX impedance associated with the amplified TX signal and further configured to adjust the TX gain based on the TX impedance; and

the receiver further comprises an RX impedance monitor configured to monitor an RX impedance associated with the RX signal and further configured to adjust the RX gain based on the RX impedance.

17. A hybrid orthogonal frequency-division multiplexing (H-OFDM) transceiver (TRX) comprising:

a transmitter comprising;

a physical layer (PHY) modulation block and an inverse fast Fourier transform (IFFT) processing block configured to process transmit (TX) data to provide a baseband TX signal; and

a modulator configured to modulate the baseband TX signal to provide a TX signal; and

a receiver comprising;

a PHY demodulation block configured to receive and down convert a receive (RX) signal to provide a baseband RX signal; and

an OFDM baseband fast Fourier transform (FFT) processing block configured to calculate an 8-point FFT using division by the square root of 2 and process the baseband RX signal to provide recovered RX data.