Maximizing available diversity in a MIMO fading channel

The effects of Rayleigh fading on a wireless communications link and MIMO technique to combat fading is explored in this paper. In harnessing spatial diversity, the use of Quasi-Orthogonal space-time block code (QO-STBC) is proposed to combat fading. QO-STBC codes are able to achieve a unity rate with more than two antennas. The concept of constellation rotation for QO codes to maximize the available diversity is demonstrated. QO codes are shown by simulation to be able to achieve full diversity, despite the fact that the codes are non-orthogonal.