PERFORMANCE ANALYSIS OF BANDED EQUALIZERS FOR OFDM SYSTEMS IN TIME-VARYING CHANNELS

OFDM systems affected by severe time-varying channels greatly benefit from equalization schemes based on intercarrier interfer-ence (ICI) mitigation, which guarantee improved performance with respect to conventional one-tap equalizers. By exploiting a semi-analytical approach, this paper assesses the BER performance of the so-called banded equalizers, i.e., those equalizers that take into account only the ICI produced by the closest subcarriers. Specifi-cally, by exploiting the Gaussian approximation of the residual ICI at the equalizer output, we evaluate the BER of block linear equal-izers designed under a minimum mean-squared error (MMSE) criterion. Simulation results show a very good agreement with the theoretical analysis. In addition, we derive a lower bound and an approximate upper bound for the BER of block decision-feedback equalizers