On the performance of space-time coded and spatially multiplexed MIMO systems with linear receivers

We consider multi-antenna systems utilizing groupwise layered space-time coding. Simple, yet accurate approximations for the probability density function (PDF) of the signalto- interference-plus-noise ratio (SINR) at the output of a linear zero-forcing (ZF) and minimum mean square error (MMSE) data estimators are presented. It is shown that the derived PDFs are exact in the limit of large number of receive antennas. We also demonstrate via numerical examples that the approximations are accurate already for relatively small numbers of receive antennas. Closed form expressions in terms of some well-known special functions for the uncoded bit error probability as well as frame error probability (FEP) of turbo-like coded system with iterative sum-product based decoder are derived. For comparison, we also give analytical lower bounds for the FEP of a coded multiantenna system utilizing conventional spatial multiplexing and linear ZF or MMSE based estimator at the receiver.