Expression of Concern: A prototype hardware for random demodulation based compressive analog-to-digital conversion

In this paper, we utilize recent advances in compressive sensing theory to enable signal acquisition beyond Nyquist sampling constraints. We successfully recover signals sampled at sub-Nyquist sampling rates by exploiting additional structure other than bandlimitedness. We present a working prototype of compressive analog-to-digital converter (CADC) based on a random demodulation architecture. The architecture is particularly suitable for wideband signals that are sparse in the time-frequency plane. CADC has the advantage of enhancing the performance of communication and multimedia systems by increasing the transmission rate for the same bandwidth. We report successful reconstruction of AM modulated signals at sampling rates down to 1/8 of the Nyquist-rate, which represents an up to 87.5% savings in the bandwidth and the storage memory.