Broadband Microwave Spectrum Sensing Based on Photonic RF Channelization and Compressive Sampling

Abstract

A novel approach to realize broadband microwave spectrum sensing based on photonic RF channelization and compressive sampling (CS) is proposed. The photonic RF channelization system is used to slice the input broadband signal into multiple sub-channel signals with narrow bandwidth in parallel and thus the rate of pseudo-random binary sequence (PRBS) and the bandwidth of the MZM for CS can be largely decreased. It is shown that a spectrally sparse signal within a wide bandwidth can be captured with a sampling rate far lower than the Nyquist rate thanks to both photonic RF channelization and CS. In addition, the influence of the non-ideal filtering of the photonic channelizer is evaluated and a novel approach based on measuring twice is proposed to overcome the problem of frequency aliasing induced by the non-ideal filtering. It is demonstrated that a system with 20 Gbit/s PRBS and 2.5 GS/s digitizer can be used to capture a signal with multiple tones within a 40 GHz bandwidth, which means a sampling rate 32 times lower than the Nyquist rate.

Frequency-comb response of a parametrically-driven Duffing oscillator to a small added ac excitation

“…The envelopes are obtained from the averaged slowly-varying dynamics given in Eqs. (8). The envelope of the pulses obeys approximately the time-inversion symmetry.…”

“…The envelopes are obtained from the averaged slowlyvarying dynamics given in Eqs. (8). Note the broken time-inversion symmetry in the time series parametric beats.…”

“…The semi-analytic approximation to the numerical FT spectrum was obtained from the numerical integration of the corresponding averaged system, given in Eqs. (8), with the transformation defined in Eq. ( 2).…”

“…One might be interested in a very sensitive high gain amplifier with a spread spectrum, so as to sample selectively a broad band of frequencies. This is particularly interesting for applications requiring spectrum sensing, and one way to achieve this is through the use of frequency combs [7,8]. The response of frequency combs to a narrowband small signal is given by a series of narrow peaks equally spaced in frequency.…”

“…A parametric occurs in the interval0.01386 < F s < 0.01811. This corresponds to a period-doubled solution of the averaged system of Eqs (8)…”