A comparative study of robust channel estimators for OFDM systems

In this paper, we investigate robust channel estimation methods for OFDM systems. Three pilot-symbol-aided channel estimation schemes are discussed, i.e., the maximum likelihood estimator (MLE), the estimator based on parametric channel modeling, and the least square (LS) estimation with low-pass interpolation. We analyze the complexities of the estimators and compare the mean square error (MSE) and symbol error rate (SER) over frequency-selective fading channels. It is shown that the low-pass interpolation-based estimation gives the lowest complexity among the three estimators, but its performance is not so good as the other two. The estimator based on parametric channel modeling is simpler than MLE with slightly better performance.