On Time-Varying FIR Decision Feedback Equalization of Doubly Selective Channels

We consider decision feedback equalization of doubly selective channels modeled via basis expansion models (BEM). Recently there has been some interest in designing time-variant serial FIR (finite impulse response) decision feedback equalizers (DFE) using complex exponential (CE-) BEMs for equalizers in addition to using CE-BEM for modeling the channel itself. In this paper we show that an alternative formulation of the FIR DFE based on a CE-BEM channel model yields the same or an improved BER at a lower computational cost, without incuring the approximation error inherent in CE-BEM modeling of equalizers.