Full duplex wireless transmission with channel phase-based encryption

• US 10,211,965 B2
• Filed: 01/09/2018
• Issued: 02/19/2019
• Est. Priority Date: 05/13/2012
• Status: Active Grant

• Current Assignee: Amir Keyvan Khandani
• Original Assignee: Amir Keyvan Khandani
• Inventors: Khandani, Amir Keyvan
• Primary Examiner(s): Edouard, Patrick
• Assistant Examiner(s): Hughes, Eboni
• Application Number:
  US15/866,218
• Publication Number:
  US 20180159677A1
• Time in Patent Office: 406 Days
• CPC Class Codes: H04B 1/123 using adaptive balancing or compensation means adaptive filter circuits and algorithms H03H
• CPC Class Codes: H04B 1/525 with means for reducing leakage of transmitter signal into the receiver
• CPC Class Codes: H04B 7/026 Co-operative diversity, e.g. using fixed or mobile stations as relays
• CPC Class Codes: H04B 7/0413 MIMO systems
• CPC Class Codes: H04B 7/0417 Feedback systems
• CPC Class Codes: H04B 7/0478 Special codebook structures directed to feedback optimisation
• CPC Class Codes: H04B 7/0626 Channel coefficients, e.g. channel state information [CSI]
• CPC Class Codes: H04B 7/0669 using different channel coding between antennas space-time coding H04L1/0618
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity
• CPC Class Codes: H04L 1/18 Automatic repetition systems, e.g. Van Duuren systems
• CPC Class Codes: H04L 1/1825 Adaptation of specific ARQ protocol parameters according to transmission conditions
• CPC Class Codes: H04L 1/1896 ARQ related signaling
• CPC Class Codes: H04L 2001/0097 Relays
• CPC Class Codes: H04L 5/14 Two-way operation using the same type of signal, i.e. duplex
• CPC Class Codes: H04W 12/04 Key management, e.g. using generic bootstrapping architecture [GBA]
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks

Abstract

An apparatus includes a first transceiver, at least two antennas coupled to the first transceiver to exchange one or more keys and phase data with a second transceiver via a plurality of rounds of phase data exchange, each round including: a first pilot signal sent from a first of the antennas of the first transceiver to the second transceiver, a second pilot signal received from the second transceiver, the second pilot signal modulated using a measured first phase of the first pilot signal, a third pilot signal received from the second transceiver; a fourth pilot signal sent from a second of the antennas of the first transceiver to the second transceiver, the fourth pilot signal modulated using a measured second phase of the third pilot signal, and wherein between the plurality of rounds of phase exchange, the first transceiver perturbs a radio frequency (RF) environment surrounding the at least two antennas.

Claims

1. An apparatus comprising:

a first transceiver;

at least two antennas coupled to the first transceiver to exchange one or more keys and phase data with a second transceiver via a plurality of rounds of phase data exchange, each round including;

a first pilot signal sent from a first of the antennas of the first transceiver to the second transceiver;

a second pilot signal received from the second transceiver, the second pilot signal modulated using a measured first phase of the first pilot signal;

a third pilot signal received from the second transceiver;

a fourth pilot signal sent from a second of the antennas of the first transceiver to the second transceiver, the fourth pilot signal modulated using a measured second phase of the third pilot signal; and

wherein between the plurality of rounds of phase exchange, the first transceiver perturbs a radio frequency (RF) environment surrounding the at least two antennas.

2. The apparatus of claim 1, wherein the modulated second pilot signal is received at the second antenna of the antennas;

and

the modulated fourth pilot signal is sent to the second transceiver, each of the modulated second pilot signal and the modulated fourth pilot signal having respective round-trip phase shifts.

3. The apparatus of claim 2, wherein the first transceiver further includes:

a random key generator;

a processor coupled to the random key generator to;

code one or more keys generated by the random key generator as a plurality of constellation points; and

rotate each of the constellation points by a respective first round-trip phase shift measured in a respective one of the plurality of rounds of phase exchange.

4. The apparatus of claim 3, wherein the first transceiver transmits the rotated constellation points to the second transceiver to enable the second transceiver to decode the one or more keys via de-rotating each of the received constellation points by a respective second round-trip phase shift measured in a respective one of the rounds of phase exchange.

5. The apparatus of claim 4, wherein the first transceiver conducts encrypted communications between the first and second transceiver using the one or more keys.

6. The apparatus of claim 3, wherein each plurality of constellation points is a phase-shift keying (PSK) constellation.

7. The apparatus of claim 3, wherein the one or more keys each have a bit length of K, and wherein N bits are used to encode the keys with a channel code rate of K/N.

8. The apparatus of claim 7, wherein each plurality of constellation points includes 2^r constellation points, and wherein the N bits of each key are mapped to N/r constellation symbols.

9. An apparatus comprising:

a first transceiver including;

a transmitter configured to transmit at least two symbols and retransmit at least two returned symbols, the transmitter further including a perturber to change a channel phase and configured to transmit a subsequent phase modulated signal using a mask derived from a first relative phase of one of the at least two returned symbols and a second relative phase of another of the at least two returned symbols, wherein the subsequent phase modulated signal includes an encryption key encoded with an error-correction code;

a receiver coupled to the transmitter via a loop-back channel, the receiver including a multiplier to perform phase angle addition of the loop-back channel; and

at least two antennas coupled to the transmitter and the receiver, the at least two antennas equipped to exchange one or more keys and phase data with a second transceiver via a plurality of rounds of phase data exchange.