Interference Analysis for Downlink Transmission in Two-tier Heterogeneous Networks

In this paper, we analyze the performance of outage probability for downlink transmission in two-tier heterogeneous cellular networks. In order to save spectrum resources, we adopt frequency reuse scheme, which will result in cross-tier interferences. The macro base station (MBS) provides useful signal for macro user equipment (MUE), in contrast, the signals provided by small base stations (SBSs) around MUE becoming the interferences. We use Fenton-Wilkinson method and Farley method to approximate the sum of multiple interferences, these two methods can simplify the calculation of outage probability and then we compare the approximation results. The derived expressions are validated by the Monte Carlo simulations and simulation results are generated to assess the feasibility of two methods' accuracy and the circumstance of applications.