Estimation of amplitude and phase of non-stationary signals

We consider the problem of estimating signals consisting of one or more components of the form a(t)e^jφ(t), where the amplitude and phase functions are represented by a linear parametric model. A maximum likelihood algorithm for estimating the phase and amplitude parameters is presented, and the corresponding Cramer Rao bound (CRB) is derived. By analyzing the CRB for the single-component case it is shown that the estimation of the amplitude and the phase are decoupled. The performance of the maximum likelihood algorithm is illustrated by Monte-Carlo simulations, and its statistical efficiency is verified