Robust and improved channel estimation for OFDM systems in frequency selective fading channels

We present an improved and robust channel estimation method for OFDM mobile communication systems based on the use of pilot subcarriers. Specifically, we present an inter-path interference cancellation (IPIC) method to estimate the channel multipath time delays. With the multipath time delays information, a minimum mean square error (MMSE) estimator is then derived to estimate the channel multipath gains. It is demonstrated that the proposed channel estimation scheme can significantly improve the performance of OFDM systems and that it is also quite robust to the variations in the channel statistics.