Contrasting Orthogonal and Non-orthogonal Space-Time Schemes for Perfectly-Known and Estimated MIMO Channels

We consider the space-time coding issue in MIMO structures and compare the two potential choices of orthogonal and non-orthogonal schemes with a simple iterative detector for the latter case. We show that the choice of non-orthogonal schemes is quite rational and justified, regarding the substantial gain that we can obtain, compared to orthogonal coding. Two cases of perfectly-known channel at receiver and pilot-only-based channel estimation are studied