Space diversity schemes for STBC-based MIMO systems and pre-FDE SIMO systems

In wireless communications, multiple receive antennas can be used with orthogonal frequency division multiplexing (OFDM) or single-carrier (SC), and frequency domain equalization (FDE) or frequency domain pre-equalization (pre-FDE) to significantly improve system capacity and performance. However, the complexity of such combination can be very large because multiple discrete Fourier transform (DFT) blocks, each for one receive antenna, are required to fully take advantage of the space diversity. Reference Defeng Huang et al., (2004) proposed a receive space diversity architecture for OFDM systems using orthogonal designs. Using this architecture, the number of DFT blocks can be reduced but performance degradation will be introduced. In this paper, we propose space diversity schemes for space-time block coding (STBC) based multiple-input multiple-output (MIMO) systems and frequency domain pre-equalization single-input multiple-output (SIMO) systems. These schemes can be used with OFDM and SC transmission techniques. Using these schemes, the total number of Fourier transform (FT) blocks can be further reduced and the performance can be significantly improved at higher signal-to-noise ratio. Simulation results show the benefits of the proposed schemes