An Optimum Decision Algorithm for MIMO Channel Enhancement

Given a Space-Time Block Code (STBC) Multiple-Input Multiple-Output SpatialMultiplexing system (MIMO-SM), both diversity gain and spatial multiplexing gain can be obtained simultaneously [1, 2]. An optimum decision algorithm is proposed to achieve an additional weight gain in the Multiple-Input Multiple-Output (MIMO) Space-Time Block Coding (STBC) wireless system design without increased hardware complexity. The optimum weight vector generated using the Bayes decision algorithm [3] maximizes the most likely ‘closest’ transmitted signal power to the received vector with a minimum ‘Risk’ criterion based on the firstand second-order statistics of the measured MIMO sub-channels, and then multiplies the received sub-channels respectively. Hence, this proposed scheme maximizes the received signal-to-noise ratio (SNR) over the spatiallycorrelated multipath fading channel. The simulation analyses show that our proposed design provides a system performance improvement of about 3 dB in comparison with the conventional design without adopting an optimum decision scheme.