Abstract:High data rates and high mobility induced Doppler shifts introduce time and frequency selectivity in wireless links. The quality of channel acquisition has a major impact on the overall system performance. In this paper, relying on a basis expansion channel model, a scheme is proposed for estimating doubly selective channel parameters . The receiver does not have to know the statistic information of the channels and will not estimate the power of noise in advance, and has low-complexity. Along with the estimation scheme, the optimal pilot sequence is derived based on minimizing mean-square error of the channel estimation. Simulation results demonstrate the performance of the proposed scheme is better than existing scheme for a range of SNR, where a frequency- selective channel is randomly generated with different Doppler spreads via Jakes’ model.