An adaptive diversity receiver for OFDM in fading channels

Interest in OFDM has renewed with the standardization of OFDM for digital audio broadcasting in Europe. In this paper, we consider an adaptive, diversity receiver for OFDM signals in a Rayleigh fading channel. The diversity receiver has L branches with each branch receiving the signal from L independently fading diversity channels. We model the fading process as a vector auto-regressive process and use the Kalman filter to obtain the MMSE optimum channel estimates for each branch. The channel estimates and the signals are combined using the maximal ratio combining rule to obtain the decision variables. We analyze the performance of this receiver and provide a numerical example to highlight the advantage of using diversity.