User association to small cells in the presence of Nakagami-m fading and co-channel interference

In this paper we study the association performance of a small cell base station (SBS) when mobile users (MUs) are randomly located around the said SBS according to a homogeneous Poisson point process. In the analysis, we consider noise only, interference-plus-noise, and interference-limited systems. For each case of association metric, a closed form expression for the outage probability of a randomly located MU operating over a Nakagami-m fading environment is derived. The outage probability of each MU is then used to obtain the probability that at least N MUs are associated to the SBS of interest. We then study the effects of MU density, SBS transmit power, association threshold, path-loss exponent, and amount of co-channel interference on the association performance of SBSs deployed over a cellular network.