Faster than Nyquist, Slower than Tropp
The sampling rate of analog-to-digital converters is severely limited by underlying technological constraints. Recently, Tropp et al. proposed a new architecture, called a Random Demodulator (RD) that attempts to circumvent this limitation by sampling sparse, band-limited signals at a rate much lower than the Nyquist rate. An integral part of this architecture is a random bi-polar Modulating Waveform (MW) that changes polarity at the Nyquist rate of the input signal. Technological constraints also limit how fast such a waveform can change polarity, so the authors propose an extension of the RD that uses a run-length limited MW which changes polarity at a slower rate.