CE-BEM Based Doubly Selective Channel Estimation and Equalization for MIMO-OFDM Transmission

High data rate and high mobility of the next generation wireless communication lead to both frequency and time selective fading in wireless channels, which makes channel estimation and equalization a big challenge. Since multiple-input-multiple-output combined with orthogonal-frequency-division-multiplexing (MIMO-OFDM) has been considered as a promising candidate for the next generation wireless communication, doubly selective channel estimation and equalization for MIMO-OFDM transmission is of great significance in both theoretical and practical fields. This paper employs a complex exponential basis expansion model (CE-BEM) to achieve doubly selective channel estimation and equalization in MIMO-OFDM block transmission environments, in which space-time block codes (STBC) is utilized for OFDM block construction and diversity gain acquisition. Doubly selective channels generated via Jakes' models can be represented as CE-BEMs so as to reduce the complexity of channel estimation and equalization, which brings convenience to channel estimation and the following equalization under both the least square (LS) and minimum mean square error (MMSE) criterions. Simulation results demonstrate that the proposed scheme has good performance on both normalized mean square error (NMSE) of channel estimation and bit error rate (BER) of signal transmission, compared with the perfect estimation scenarios.