Efficient OFDM channel estimation for realistic band-limited and non-sample-spaced channels

In this paper, we propose computationally efficient channel estimation methods to minimize energy leakage which is caused by non-sample-spaced channels as well as band-limited OFDM signal with virtual subcarriers. The energy leakage effect mainly resulted from conventional channel estimation methods which do not utilize channel statistics information for low complexity such as DFT-based estimation and correlation error cancellation (CEC). The proposed methods solve the problem through a modified non-ideal correlation function which is derived by expanded DFT. Simple analyses and simulation results verify that the proposed methods can achieve MSE performance close to that of optimal LMMSE estimation with sufficiently low complexity.