Power Techniques for Blind Channel Estimation in Zero-Padded OFDM Systems

This paper revisits the subspace-based channel estimation problem in zero-padded systems and proposes an alternative formulation that leads to a solution to which power techniques are readily applicable. Additionally, a lower-complexity post-DFT implementation that also allows the use of power techniques is derived. Both solutions are shown to be equivalent. Furthermore, links to previous related work are established. Mean square error and bit error rate performance analysis of the estimators through computer simulations reveals that for moderate signal to noise ratio, power techniques with powers as low as m = 3 achieves performance similar to the conventional SVD-based estimator.