Reduced Complexity Receiver Design for MIMO-OFDM Systems with Space-Time-Frequency Coding

Space-time-frequency coding is an important technology for OFDM (Orthogonal Frequency Division Multiplexing) under MIMO (multiple-input and multiple-output) channels to achieve high speed wireless multimedia transmission. Traditionally, multiple DFT (Discrete Fourier Transform) blocks, each corresponding to one receive antenna, are employed at the receiver of a MIMO-OFDM system with space-time-frequency coding, which induces huge complexity. In this paper, we propose a pre-DFT processing scheme for such a system, where the number of DFT blocks employed can be adjusted, thus enabling effective complexity and performance tradeoff. Simulation results will show that, under some channel conditions, the performance of the proposed scheme can be almost as good as the traditional optimal scheme but with much lower complexity.