BER Approximation for Extended V-BLAST Codes with Selection Combining

We present an extension of Vertical Bell Laboratories Layered Space-Time (V-BLAST) codes that provides various encoding rate and investigate bit error rate (BER) performance for the extended V-BLAST codes when zero-forcing (ZF) and selection-combining (SC) techniques are employed at a receiver. In this paper, we make an effort to achieve time diversity in designing extended V-BLAST codes with a ZF receiver. Moreover, in spatially transmit-correlated multiple-input multiple-output (MIMO) channels, BER equations of M-ary QAM and PSK constellations are derived by using a probability density function (PDF) approximation of signal-to-noise ratio (SNR) based on the assumption of independent post-processing SNRs. Simulation and analytic results are compared for time-varying Rayleigh fading channels that are modelled using a first-order Markovian model.