Improved instantaneous power spectrum (IPS) performance: A group delay approach

Abstract

The instantaneous power spectrum (IPS) has many advantages over the Wigner–Ville distribution. However, it suffers from ringing effect and poor frequency resolution. In this paper, a new method, improved IPS (IIPS) based on modified group delay function (GDFM) has been suggested for reducing the ringing effect. In this approach, since the ringing effect has been removed without using any common window function, it provides improved frequency resolution. Further, in IIPS, the GDFM enables signal-to-noise ratio (SNR) enhancement, in the time–frequency representation (TFR), as it not only reduces the effect of zeros which cause ringing but also those due to noise associated with the signal. The performance of the proposed method is illustrated by simulation for FSK and linear chirp signals and it has been observed that it improves: the frequency resolution significantly and the SNR.