On the Error Performance of Space-Time Codes Over MIMO Nakagami Fading Channels With Blockage

In this paper, we derive a closed-form upper bound on the error performance of space-time codes over Nakagami-m fading channels. Our upper bound is based on the pairwise error probability (PEP). We then examine the resulting diversity and coding gains to propose design criteria that maximize these gains. Orthogonal spacetime block codes are shown to achieve the maximum diversity gain but not the maximum coding gain. Indeed, we show that there exists a trade-off between the diversity gain and the coding gain. Furthermore, we investigate the effect of blockage on the error performance using stochastic geometry. Our analysis and simulations show that blockage only reduces the coding gain and does not affect the diversity gain. This reduction in the coding gain is a function of the probability of line-of-sight (LOS) communication, path loss exponents, the distance between transceivers, and the coding gain without considering the effect of blockage. For instance, in a typical indoor environment, blockage due to humans or other obstacles can reduce the coding gain by up to 1.5 dB for a bit error probability of 10-3.