Pilot Aided Channel Estimation of MIMO OFDM Systems

Multiple transmit-and-receive antennas can be used in orthogonal frequency division multiplexing (OFDM) systems to improve communication quality and capacity. In this paper, an improved channel estimation for MIMO-OFDM system is proposed by exploiting a new method of pilot insert by which pilots are inserted into different carriers at different time. The method can estimate the CSI of all frequencies, so it will enhance the ability to resist frequency selective fading. Then it regards the results of interpolation as pre-estimation and takes different Averaged Channel Estimation in the Time-domain (ACE-T) on different channel conditions to get final channel estimation. The effectiveness of the new technique is demonstrated through the simulation of an OFDM system with two-transmit and two-receive antennas.