Sub-Nyquist Sampling and Gridless Frequency Estimation Based on Channelization

Gridless compressed sensing technology mainly relies on multi-coset sampling method. Considering the difficulties it faces in practice, we propose an improved multi-coset sampling method based on modulated wideband converter and channelization, which first preserves the phase information between sampling channels through channel delay. The delayed signals can be sampled at low speed after being multiplied by the periodic signal and subjected to low-pass filtering. After digital channelization, unambiguous frequency estimation can be achieved when conditions are met. The proposed method significantly improves the time interval between sampling channels and the array aperture based on channelization, which is beneficial for estimation accuracy and clock synchronization between sampling channels. And the numerical simulations demonstrate the effectiveness of the parameter estimation and hardware implementation, as well as the noise robustness.