Compressed sampling (i.e., combined sampling with compression operations) as the efficient method to achieve real-time spectrum estimation at a sub-Nyquist sampling rate has attracted substantial research efforts, which is motivated by the fact that there are plenty of temporarily unemployed spectrum holes in the wideband scenario.
The CS theory states that [r.sup.j.sub.t] can be accurately reconstructed by using a sub-Nyquist sampling rate; that is, [f.sub.s] < 2([f.sub.u] - [f.sub.d]).
Sadle, "Cyclic Feature Detection With Sub-Nyquist Sampling
for Wideband Spectrum Sensing," IEEE Journal of Selected Topics in Signal Processing, vol.6, no.
Eldar, "From theory to practice: sub-Nyquist sampling
of sparse wideband analog signals," IEEE Journal on Selected Topics in Signal Processing, vol.
Subsequently, the analog to digital converter (ADC) with a Nyquist sampling rate is changed into an analog to information (A2I) converter with a sub-Nyquist sampling
rate by a switch.
Sadler, Cyclic feature detection with sub-Nyquist sampling
for wideband spectrum sensing, IEEE Journal of Selected Topics in Signal Processing, vol.
An alternative Xampling method uses the Sum of Sincs filter, following by uniform sampling of the output with sub-Nyquist sampling
rate as described in .
Compressed sensing (CS) allows sensing of sparse signals at sub-Nyquist sampling
rates, and their reliable signal recovery via computationally efficient algorithms [8-10].
Li, "Deception jamming method for ISAR based on sub-Nyquist sampling
technology," ICSP'2010 Proceedings, 2023-2026, 2010.
It has been explored for a wide range of applications, such as: medical imaging [15-18], radar imaging [19-26], sub-Nyquist sampling
systems [27, 28], channel coding [29, 30], single-pixel cameras , and etc..