CS: The Technion Modulated Wideband Converter, From Theory to Practice: Sub-Nyquist Sampling of Sparse Wideband Analog Signals

[Update: Yonina also let me know that a video where she explains the subject can be found here.]

Moshe Mishali just let me know that he and Yonina Eldar have recently updated their manuscript about sub-Nyquist sampling using CS techniques with the title: From Theory to Practice: Sub-Nyquist Sampling of Sparse Wideband Analog Signals (version 1 was covered here). There abstract reads:

Conventional sub-Nyquist sampling methods for analog signals exploit prior information about the spectral support. In this paper, we consider the challenging problem of sub-Nyquist sampling of multiband signals, whose unknown frequency support occupies only a small portion of a wide spectrum. Our primary design goals are efficient hardware implementation and low computational load on the supporting digital processing. We propose a system, named the modulated wideband converter, which first multiplies the analog signal by a bank of periodic waveforms. The product is then lowpass filtered and sampled uniformly at a low rate, which is orders of magnitude smaller than Nyquist. Perfect recovery from the proposed samples is achieved under certain necessary and sufficient conditions.We also develop a digital architecture, which allows either reconstruction of the analog input, or processing of any band of interest at a low rate, that is, without interpolating to the high Nyquist rate. Numerical simulations demonstrate many engineering aspects: robustness to noise and mismodeling, potential hardware simplifications, realtime performance for signals with time-varying support and stability to quantization effects. We compare our system with two previous approaches: periodic nonuniform sampling, which is bandwidth limited by existing hardware devices, and the random demodulator, which is restricted to discrete multitone signals and has a high computational load. In the broader context of Nyquist sampling, our scheme has the potential to break through the bandwidth barrier of state-of-the-art analog conversion technologies such as interleaved converters.

Also of importance, Moshe tells me that they are also publishing the code for the simulations at:

http://www.technion.ac.il/~moshiko/software.html

They are working on the electronic implementation of the scheme as can be seen from the photos.

I am adding this entry in the Compressive Hardware page.