Model-independent approach for Chirp Parameter Estimation employing collection of filters

Abstract

The various techniques available for Chirp Parameter Estimation (CPE) can be categorized as Transform-based approaches, filter-bank approaches and statistical estimation based approaches. CPE involves estimation of time versus instantaneous frequency relationship and estimation of amplitude-variation of chirp-envelope with time. This paper introduces a new approach for estimating the parameters of an incoming noisy chirp signal by passing it through a collection of filters of known responses. Instantaneous frequency of the noisy chirp is then `collectively' estimated from the responses of these known filters to the chirp. The main advantage of the proposed approach is that, no a-priori information regarding the time versus instantaneous frequency relationship is required. Moreover, the technique works equally well for various types of modulations in the chirp. Results are encouraging even when amplitude of chirp-envelope is time-varying.