A novel joint channel estimation and equalization algorithm for MIMO-SCFDE systems over doubly selective channels

This paper considers a novel joint channel estimation and equalization (JCEE) algorithm for multiple-input-multiple-output single-carrier frequency-domain-equalization (MIMO-SCFDE) systems over doubly selective channels for the first time. Given that the doubly selective channels can no longer support the assumption that the channel frequency-domain response remains invariant for the duration of one block, most of the channel estimation methods cannot be applied directly in it. And the lack of the information interaction between channel estimation and channel equalization degrades the overall performance. By using iterative expectation maximization-based (EM-based) least square (LS) channel estimation, combined with the inter-frequency interference (IFI) based minimum mean square error (MMSE) equalization, time-domain IFI cancellation and data detector based on hard decision, the JCEE algorithm is proposed. Both analysis and simulation results validate the improved performance for MIMO-SCFDE systems over doubly selective channels.