Robust Channel Estimation of OFDM Systems

摘要

A system and method for estimating a channel in wireless communication systems using Orthogonal Frequency Division Multiplexing (OFDM). From the received OFDM symbols, Maximum Likelihood (ML) estimate of the channel frequency response is obtained at the pilot locations. A hypothesis test is performed on the ML estimates and the outcome of the hypothesis test is used to decide a shrinkage target. Biased estimation methods are used to shrink the ML estimates towards the shrinkage target to obtain better estimates of the channel frequency response at the pilot locations and these estimates are interpolated using a Filter to get a set of complete estimates of the channel over the resource block. The Filter is an Empirical Weiner Filter or a robust 2D-MMSE filter and the biased estimation is done using either a James-Stein (JS) estimator or a shrinkage estimator or an empirical Bayes estimator.