An Enhanced DFT-based Channel Estimator for LTE-A Uplink

In this paper, we investigate the popular DFT-based channel estimator (D-bCE) for LTE-Advanced uplink. Due to limitation of the current pilot pattern, the orthogonality among channels of multiple antennas at time-domain does not hold exactly. This degrades the performance of conventional D-bCE severely. Therefore, we propose a novel enhancement of D-bCE by using the frequency-domain weighting scheme. By analyzing the mean square error, we present a heuristic way to design the weights and reformulate the resulting optimization into a second-order cone programming problem, which does not rely on the channel covariance matrix. Simulation results validate the effectiveness of our proposed method.