Comparison of channel estimation algorithms for MIMO downlink LTE systems

The definition of LTE and LTE-Advanced standards aims at improving the performance of cellular networks with the final goal of a fair competition between wired and wireless communication systems. In order to guarantee excellent performance, one of the crucial challenge to cope with is the introduction of advanced channel estimation techniques for Multiple Inputs Multiple Outputs (MIMO) systems. In this paper, we will review and compare several Pilot-Based Channel Estimation algorithms for MIMO LTE downlink communications. Channel estimation algorithms will be analysed for different multi-antenna schemes, namely 2×2 and 4×4 with Alamouti space-frequency coding. The performance of all of these schemes will be considered both for uncoded and coded systems. The simulation results will be obtained for a multipath fading channel, assuming high speed mobility for the mobile terminals.