Analysis of Space-Time Coded and Spatially Multiplexed MIMO Systems with ZF Receivers

We present an asymptotically (in number of receive antennas) exact probability density function for the signal-to-noise-plus-interference ratio (SINR) of the output of a zero-forcing (ZF) estimator in a multi-antenna system utilizing groupwise layered space-time (GLST) transmission. We show that the approximation is extremely accurate also for finite and relatively small numbers of receive antennas. Closed form expression for the uncoded bit error probability (BEP) is given in the case of binary or quadrature phase shift keying (BPSK/QPSK). Frame error probability (FEP) lower bound for turbo-like codes and iterative sum-product based decoder is presented.