Downlink Coverage Probability in Multi-Tier Rician Fading HetNets

Heterogeneous cellular networks (HetNets), consisting of macrocells overlaid with small cells, have become an integral part of existing cellular wireless networks to satisfy an ever increasing demand for mobile broadband applications and services. In this paper, the coverage probability in a downlink HetNet, comprising of multi-tier MIMO Base Stations (BSs) serving multiple users, assuming Rician-Rayleigh fading has been evaluated. Also, comparison of the Area Spectral Efficiency (ASE) for multi-user (MU) MIMO with the single-input single-output (SISO) case, demonstrates the gain in performance MIMO techniques can provide. Through simulation it has been demonstrated that as the number of users increase, the inter-stream interference increases, resulting in a reduction of coverage probability.