Low complexity MMSE based channel estimation algorithm in frequency domain for fixed broadband wireless access system

In this paper, we have studied the effects of channel estimation in uncoded WiMax system using IEEE802.16d standard. Two different channel estimation approaches in frequency domain namely LS and MMSE have come under investigation. Results showed that the MMSE method performs significantly better than the LS estimator, however, computational complexity associated with the MMSE estimation method is relatively high if compared to the conventional LS method. So we have proposed a new simplified MMSE channel estimator which is based on the rank-reduction of the correlation matrix in the frequency domain. The proposed method achieves almost the same performance as the full-rank MMSE method, while significantly reducing the computational complexity.