Analytical analysis of Bayesian Cramér-Rao bound for dynamical rayleigh channel complex gains estimation in OFDM system

In this paper, we consider the Bayesian Cramer-Rao bound (BCRB) for the dynamical estimation of multi-path Rayleigh channel complex gains in data-aided (DA) and non-data-aided (NDA) OFDM systems. This bound is derived in an on-line and off-line scenarios for time-invariant and time-varying complex gains within one OFDM symbol, assuming the availability of prior information. In NDA context, whereas this true BCRB is hard to evaluate, we present a closed-form expression of a BCRB, i.e., the Asymptotic BCRB (ABCRB) or the Modified BCRB (MBCRB). We discuss, based on the theoretical and simulation results, the interest of using some past and future observations in terms of Doppler spread for the complex gains estimation. Index Terms Bayesian Cramer-Rao Bound, OFDM, Rayleigh complex gains.