Space-time coding (STC) techniques have become popular since they oer high data rates while achieving low error rates over wireless links. When the transmission rates are increased by making the symbol periods smaller, the channel becomes frequency selective (FS). The optimal receivers for STC systems over FS fading channels require prohibitively high hardware/software complexity. With the motivation of reducing this complexity, this book proposes several simplified approaches for STC transmissions over multiple input multiple output (MIMO) FS fading channels. In the first part of the book, we study a low complexity iterative MIMO receiver based on MIMO decision feedback equalization (DFE). In the second part, we study a soft-input soft-output equalization based on the stack decoding algorithm. In the third part, we study the performance of STC techniques with transmit antenna selection and with joint transmit and receive antenna selection over at fading channels.