Virtual Receive Antenna System with Frequency Domain Equalization

Vertical Bell laboratory layered space-time (V-BLAST) is one of the promising multiple input multiple output (MIMO) architectures. Layered space time processing in V-BLAST requires the number of receive antennas to be equal to or larger than the number of transmit antennas. However, it is impractical for small-sized mobile units to accommodate all the required antennas. Focusing on this problem, we have presented a novel concept of virtual receive antennas (VRA) for spatial multiplexing system in flat fading channels. In that work, time domain equalization is utilized to eliminate inter-symbol interference, which is generated in the VRA. However, the employed time domain equalizer has a high computational complexity. In this paper, the VRA system with low complexity frequency domain equalizer (FDE) is investigated. Moreover, as the noise in the VRA system is correlated due to oversampling, we also present the noise decorrelating filter design. Through complexity and performance evaluation, FDE is demonstrated to be more suitable for the VRA system.