Photonic compressed sensing nyquist folding receiver
AssigneeThe United States of America as represented by the Secretary of the Navy
InventorsRichard Nicholas Shmel, Phillip E. Pace
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Abstract
Disclosed herein is a design, simulation, and hardware build of a photonic compressed sensing Nyquist folding receiver that is able to directly undersample wideband RF signals and detect the original Nyquist zone and frequency information. According to an exemplary embodiment, this is achieved by generating a frequency modulated optical impulse train for directly undersampling the RF environment at the antenna. The impulse train undersamples the signals using an optical modulator configuration at 1550 nm and collects the detected samples in a low pass interpolation filter which is subsequently processed to extract the undersampled signals.
Claims24
A photonic Nyquist Folding Receiver (NYFR) System for compressed sensing of a radio frequency (RF) environment, the photonic NYFR system comprising:
- a continuous wave (CW) laser source generating a CW laser output with a fixed wavelength;
- an electrical modulation signal source generating an electrical modulation impulse train signal output which is linearly swept to vary an amplitude and frequency of the electrical modulation impulse train;
- a wideband radio frequency (RF) antenna operatively associated amplifier generating a wideband electrical RF signal representative of a received RF signal;
- a first modulator operatively connected to the CW laser output and the electrical modulation impulse train signal output, the first modulator converting the CW laser to a sampling frequency modulated (FM) optical pulse train with a linearly swept pulse repetition frequency (PRF) and optical pulse intensity as a function of the frequency and amplitude of the electrical modulation impulse train signal, and the first modulator outputting to an output the sampling FM optical pulse train;
- a second modulator operatively connected to receive the wideband electrical RF signal generated by the wideband RF antenna, and operatively connected to the first modulator output to receive the sampling FM optical pulse train, the second modulator modulating the amplitude of the sampling optical pulses with the wideband electrical RF signal generated by the wideband RF antenna, thereby encoding the RF signal as an amplitude modulated (AM) envelope of the sampling optical pulse train;
- a photonic to electrical converter operatively connected to the second modulator, the photonic to electrical converter converting the AM envelope of the sampling FM optical pulse train to a representative electrical signal;
- and
- a low pass interpolation filter (LPF) operatively connected to the photonic to electrical converter to receive the representative electrical signal of the AM envelope of the sampling FM optical pulse train, the LPF outputting a Nyquist band compressed representation of the AM envelope of the sampling FM optical pulse train.
A photonic Nyquist Folding Receiver (NYFR) for compressed sensing of a radio frequency (RF) environment, the photonic NYFR comprising:
- an electrical modulation signal source generating an electrical modulation impulse train signal output which is linearly swept to varying an amplitude and frequency of the electrical modulation impulse train;
- a first modulator operatively associated with receiving a continuous wave (CW) laser output and the electrical modulation impulse train signal output, the first modulator converting the CW laser output to a sampling frequency modulated (FM) optical pulse train with a linearly swept pulse repetition frequency (PRF) and optical pulse intensity as a function of the frequency and amplitude of the electrical modulation impulse train signal and the first modulator outputting to an output the sampling FM optical pulse train;
- a second modulator operatively associated with receiving a wideband electrical RF signal generated by a wideband RF antenna, and operatively connected to the first modulator output to receive the sampling FM optical pulse train, the second modulator modulating the amplitude of the sampling optical pulses with the wideband electrical RF signal generated by the wideband RF antenna, thereby encoding the RF signal as an amplitude modulated (AM) envelope of the sampling optical pulse train;
- a photonic to electrical converter operatively connected to the second modulator, the photonic to electrical converter converting the AM envelope of the sampling FM optical pulse train to a representative electrical signal;
- and
- a low pass interpolation filter (LPF) operatively connected to the photonic to electrical converter to receive the representative electrical signal of the AM envelope of the sampling FM optical pulse train, the LPF outputting a Nyquist band compressed representation of the AM envelope of the sampling FM optical pulse train.
A photonic Nyquist Folding Receiver (NYFR) System for compressed sensing of a radio frequency (RF) environment, the photonic NYFR system comprising:
- a continuous wave (CW) laser source configured to generate a CW laser output with a fixed wavelength;
- an electrical modulation signal source configured to generate an electrical modulation impulse train signal output which is linearly swept to vary an amplitude and frequency of the electrical modulation impulse train;
- a wideband radio frequency (RF) antenna system configured to generate a wideband electrical RF signal representative of a received RF signal;
- a first modulator operatively connected to the CW laser output and the electrical modulation impulse train signal output, the first modulator configured to convert the CW laser to a sampling frequency modulated (FM) optical pulse train with a linearly swept pulse repetition frequency (PRF) and optical pulse intensity as a function of the frequency and amplitude of the electrical modulation impulse train signal, and the first modulator configured to output to an output the sampling FM optical pulse train;
- a second modulator operatively connected to receive the wideband electrical RF signal generated by the wideband RF antenna, and operatively connected to the first modulator output to receive the sampling FM optical pulse train, the second modulator configured to modulate the amplitude of the sampling optical pulses with the wideband electrical RF signal generated by the wideband RF antenna, thereby encoding the RF signal as an amplitude modulated (AM) envelope of the sampling optical pulse train;
- a photonic to electrical converter operatively connected to the second modular, the photonic to electrical converter configured to convert the AM envelope of the sampling FM optical pulse train to a representative electrical signal;
- and
- a low pass interpolation filter (LPF) operatively connected to the photonic to electrical converter configured to receive the representative electrical signal of the AM envelope of the sampling FM optical pulse train, the LPF configured to output a Nyquist band compressed representation of the AM envelope of the sampling optical pulse train.
Dependencies are inferred from the claim text.