Analysis of pilot-symbol aided channel estimation for MIMO-OFDM systems

Multiple transmit and receive antennas can be used to form multiple-input multiple-output (MIMO) channels to increase the capacity by a factor of the minimum number of transmit and receive antennas. Orthogonal frequency division multiplexing (OFDM) for MIMO channels (MIMO-OFDM) can improve the performance by mitigating intersymbol interference and enhancing system capacity. The paper investigates pilot-symbol aided channel estimation (PSACE) for MIMO-OFDM systems. Two approaches are investigated: first, zero pilot patterns use all available pilot symbols simultaneously; second, a nonzero pilot pattern is allocated for each transmit antenna exclusively. The Wiener filters are derived for both approaches.