Non-uniform Sampling for Spectral Analysis of Multi-band Signals

Recently, sub-Nyquist sampling of wideband signals has gained much attention in wireless communications. One of the main reasons for this popularity is the reduction in energy consumption in the ADCs. In this paper, we present an overview of the best known non-uniform sub-Nyquist sampling techniques and the associated spectral analysis. Spectral analysis using sub-Nyquist samples can be done in two ways. We can reconstruct the original Nyquist samples from the sub-Nyquist samples and then by using Fourier transform we can obtain the estimated power spectral density using classical methods like Welch method. We can also obtain the power spectral estimate directly from the sub-Nyquist samples without reconstructing the Nyquist samples. Both approaches can be used based on the application.