Transmit Preprocessing Using Channel Selection for Multi-Antenna Ultra-Wideband Communications

In this paper, we propose a novel transmit preprocessing scheme using Channel Selection (CS) to jointly design PreRake and Precoding for multiple-input multiple-output Ultra-Wideband (MIMO-UWB) communications. The PreRake technique is implemented to exploit the advantage of multipath diversity and can achieve spatial multiplexing based on our proposed CS. The combination of CS and PreRake transforms the UWB frequency selective fading channel into an equivalent flat fading channel and an equivalent channel matrix (ECM) is calculated. CS can construct the ECM as a well-conditioned matrix so that higher data transmission rate can be provided by spatial multiplexing. Then, Precoding method can be introduced to enhance system performance via diagonalizing the ECM. The simple but effective channel inversion (CI) precoding is employed in the proposed transmit preprocessing scheme which we denote as CS-CI-PreRake. Simulations results show the proposed scheme achieves a solid performance.