Photonic implementation of jamming avoidance response

Patent metadata

Field	Value
Publication number	US-9954619-B2
Application number	US-201615335672-A
Country	US
Kind code	B2
Filing date	Oct 27, 2016
Priority date	Oct 27, 2015
Publication date	Apr 24, 2018
Grant date	Apr 24, 2018

Abstract

Various examples are provided for jamming avoidance response (JAR), and photonic implementations thereof. In one example, a method includes generating optical pulses that correspond to raising envelope of a beat signal associated with an interference signal and a reference signal; generating optical spikes that correspond to positive zero crossing points of the reference signal; providing a phase output that indicates whether the beat signal is leading or lagging the reference signal, the phase output based at least in part upon the optical spikes; and determining an adjustment to the reference frequency based at least in part upon the optical pulses and the phase output. In another example, a JAR system includes a photonic P-unit to generate the optical pulses; a photonic ELL/T-unit to generate the optical spikes; a photonic TS unit to provide the phase output; and a logic unit to determine the adjustment to the reference frequency.

First claim

Therefore, at least the following is claimed:

1. A jamming avoidance response (JAR) system, comprising:
a photonic P-unit configured to generate optical pulses that correspond to a raising envelope of a beat signal associated with an interference signal and a reference signal;
a photonic ELL/T-unit configured to generate optical spikes that correspond to positive zero crossing points of the reference signal;
a photonic TS unit configured to provide a phase output that indicates whether the beat signal is leading or lagging the reference signal, the phase output based at least in part upon the optical spikes; and
a logic unit configured to determine an adjustment to a reference frequency based at least in part upon the optical pulses and the phase output.

2. The JAR system of claim 1 , wherein the photonic P-unit comprises:
an envelope detector configured to generate an envelope signal corresponding to the beat signal;
a first electro-optic intensity modulator (EOM) configured to generate an amplitude modulated optical signal based upon the envelope signal;
a second EOM configured to generate an inverted amplitude modulated optical signal based upon the envelope signal;
a temporal delay configured to delay the inverted amplitude modulated optical signal by a predefined amount of time to produce a delayed inverted amplitude modulated optical signal;
a fiber coupler configured to add intensities of the amplitude modulated optical signal and the delayed inverted amplitude modulated optical signal to produce a combined optical signal; and
a length of highly nonlinear fiber (HNLF) that generates the optical pulses from the combined optical signal.

3. The JAR system of claim 2 , wherein the first EOM is biased at a positive slope to generate the amplitude modulated optical signal and the second EOM is biased at a negative slope to generate the inverted amplitude modulated optical signal.

4. The JAR system of claim 2 , further comprising a bandpass filter configured to filter the optical pulses from the length of HNLF.

5. The JAR system of claim 2 , further comprising an optical amplifier configured to amplify the combined optical signal provided to the length of HNLF.

6. The JAR system of claim 1 , wherein the photonic ELL/T-unit comprises:
an electro-optic intensity modulator (EOM) configured to generate an amplitude modulated optical signal based upon the reference signal;
a thresholder configured to clamp an amplitude of the amplitude modulated optical signal to generate a clamped optical signal; and
a length of highly nonlinear fiber (HNLF) that generates the optical spikes from the clamped optical signal.

7. The JAR system of claim 6 , further comprising a bandpass filter configured to filter the optical spikes from the length of HNLF.

8. The JAR system of claim 6 , further comprising an optical amplifier configured to amplify the clamped optical signal provided to the length of HNLF.

9. The JAR system of claim 1 , wherein the photonic TS unit comprises:
an electro-optic intensity modulator (EOM) configured to generate an amplitude modulated optical signal based upon the beat signal;
a fiber coupler configured to add intensities of the amplitude modulated optical signal and the optical spikes from the photonic ELL/T-unit to produce a combined optical signal; and
a semiconductor optical amplifier (SOA) configured to generates the phase output from the combined optical signal.

10. The JAR system of claim 9 , further comprising a bandpass filter configured to filter the phase output from the SOA.

11. The JAR system of claim 9 , wherein the phase output comprises an optical spike having an amplitude that indicates whether the beat signal is leading or lagging the reference signal.

12. A jamming avoidance response (JAR) method, comprising:
generating optical pulses that correspond to raising envelope of a beat signal associated with an interference signal and a reference signal;
generating optical spikes that correspond to positive zero crossing points of the reference signal;
providing a phase output that indicates whether the beat signal is leading or lagging the reference signal, the phase output based at least in part upon the optical spikes; and
determining an adjustment to the reference frequency based at least in part upon the optical pulses and the phase output.

13. The JAR method of claim 12 , wherein generating the optical pulses comprises:
generating an envelope signal corresponding to the beat signal;
generating an amplitude modulated optical signal based upon the envelope signal;
generating an inverted amplitude modulated optical signal based upon the envelope signal;
delaying the inverted amplitude modulated optical signal by a predefined amount of time to produce a delayed inverted amplitude modulated optical signal; and
adding intensities of the amplitude modulated optical signal and the delayed inverted amplitude modulated optical signal to produce a combined optical signal for generation of the optical pulses.

14. The JAR method of claim 13 , wherein a length of highly nonlinear fiber (HNLF) generates the optical pulses from the combined optical signal.

15. The JAR method of claim 12 , wherein generating the optical spikes comprises:
generating an amplitude modulated optical signal based upon the reference signal; and
clamping an amplitude of the amplitude modulated optical signal to generate a clamped optical signal for generation of the optical spikes.

16. The JAR method of claim 15 , wherein a length of highly nonlinear fiber (HNLF) generates the optical spikes from the clamped optical signal.

17. The JAR method of claim 12 , wherein providing the phase output comprises:
generating an amplitude modulated optical signal based upon the beat signal; and
adding intensities of the amplitude modulated optical signal and the optical spikes from the photonic ELL/T-unit to produce a combined optical signal for generation of the phase output.

18. The JAR method of claim 17 , wherein a semiconductor optical amplifier (SOA) generates the phase output from the combined optical signal.

19. The JAR method of claim 17 , wherein the phase output comprises an optical spike having an amplitude that indicates whether the beat signal is leading or lagging the reference signal.

20. The JAR method of claim 12 , wherein the reference frequency is increased when the phase output indicates a leading beat signal and the optical pulses indicate an increasing amplitude, or when the phase output indicates a lagging beat signal and the optical pulses indicate a decreasing amplitude.

Assignees

• Univ Georgia

Inventors

• Fok Mable P
• Toole Ryan

Classifications

• H04K3/226

  Selection of non-jammed channel for communication (spectrum sharing arrangements H04W16/14; selection of wireless resources by user or terminal H04W72/02) · CPC title

• H04B10/54 Primary

  Intensity modulation · CPC title

• H04B10/80

  Optical aspects relating to the use of optical transmission for specific applications, not provided for in groups H04B10/03 - H04B10/70, e.g. optical power feeding or optical transmission through water · CPC title

• H04K3/25

  based on characteristics of target signal or of transmission (as countermeasure against surveillance H04K3/827), e.g. using direct sequence spread spectrum or fast frequency hopping (spread spectrum techniques H04B1/69) · CPC title

• H04J11/003 Primary

  at the transmitter (transmission to multiple receive units in multiple input multiple output [MIMO] H04B7/0452; transmit antenna weighting H04B7/0615) · CPC title