Frequency-domain channel tracking for MIMO-OFDM systems, validated with an experimental data in 5.2 GHz wireless channel

This paper proposes a channel tracking technique for MIMO-OFDM system, in order to solve timing sensitivity issue with the pilot-based Channel Estimator (CE) reported in [1]. The proposed technique exploits the pilot symbols embedded within the OFDM symbol to estimate the MIMO channel coefficients. Then the estimated channel values of the pilot subcarriers, as well as the initial LTF-based channel estimated values are processed to provide a weighting factor, which is used to track the channel coefficients for the entire transmission packet. The performance of the proposed CE is evaluated with the aid of actual captured data. Our performance study considers a Non-LOS indoor environment, where the transmitter and receiver are approximately 15 meters apart, and located in different rooms. Our study shows that the proposed CE successfully mitigates the susceptibility of the original pilot-based CE to the timing synchronization error.