Robust channel estimation for OFDM wireless communication systems - an H∞ approach

By representing the time-frequency correlation function of the fading channel as the product of the correlation functions in the time domain and the frequency domain, a robust channel estimation algorithm based on the H_∞ filtering approach is proposed for OFDM wireless communication systems. The estimation criterion is to minimize the worst possible amplification of the estimation errors in terms of the exogenous input disturbances such as multiplicative and additive noise. The criterion is different from the traditional minimum variance estimation error criterion for the modified Wiener or Kalman estimation algorithms, and requires no a priori knowledge of the disturbance statistics. It is shown that the proposed H_∞ channel estimation algorithm is more robust compared with the Kalman estimation counterparts in terms of model uncertainty, and is more suitable to practical OFDM wireless communication systems.