Extended Fourier series representation of signals with time-varying bandwidth

Abstract

The paper proposes an extension of the classical Fourier series for analysis of signals with time-varying spectral content. This, in comparison to classical series, allows reducing the number of coefficients that represent the signal if the fundamental frequency of the extended Fourier series is chosen according to the time-varying bandwidth of the signal. The advantage of the proposed series is demonstrated by numerical results for various test signals.