Fast and Accurate Amplitude Demodulation of Wideband Signals

TL;DR

This paper introduces a novel, highly efficient amplitude demodulation method for wideband signals, enabling real-time and large-scale processing with high accuracy, surpassing existing techniques significantly.

Contribution

The authors develop a new iterative demodulation algorithm based on alternating projections that generalizes to wideband signals and achieves unprecedented computational efficiency.

Findings

Method outperforms existing techniques by orders of magnitude in speed.

High accuracy in demodulating wideband signals demonstrated.

Applicable to real-world signals like speech and synthetic data.

Abstract

Amplitude demodulation is a classical operation used in signal processing. For a long time, its effective applications in practice have been limited to narrowband signals. In this work, we generalize amplitude demodulation to wideband signals. We pose demodulation as a recovery problem of an oversampled corrupted signal and introduce special iterative schemes belonging to the family of alternating projection algorithms to solve it. Sensibly chosen structural assumptions on the demodulation outputs allow us to reveal the high inferential accuracy of the method over a rich set of relevant signals. This new approach surpasses current state-of-the-art demodulation techniques apt to wideband signals in computational efficiency by up to many orders of magnitude with no sacrifice in quality. Such performance opens the door for applications of the amplitude demodulation procedure in new contexts. In particular, the new method makes online and large-scale offline data processing feasible, including the calculation of modulator-carrier pairs in higher dimensions and poor sampling conditions, independent of the signal bandwidth. We illustrate the utility and specifics of applications of the new method in practice by using natural speech and synthetic signals.