Performance Analysis for Two-Tier Cellular Systems based on Probabilistic Distance Models

Tiered networks have been introduced to mitigate the issues related to poor cellular coverage in dead zones and indoor environments. However, the large-scale deployment of multiple tiers can result in severe intra-tier and inter-tier interference that can considerably degrade the performance of users in all tiers. Thus, the network interference analysis has been an important topic in tiered networks. In this paper, we focus on the uplink resource reusing scenario in a two-tier cellular network consisting of a macro cell and multiple femto cells. Without imposing any limitations on the shape of the macro/femto cells (as long as they are approximated by polygons), for the first time in the literature, we obtain the distance distributions associated with tiered structures. Utilizing these distance distributions and the path-loss model in an interference-limited environment, we obtain the distributions of the received signal and interference for both tiers. Further, we give details on how our approach applies to the downlink resource reusing scenario as well as a network with multiple macro cells. Our performance study provides insights into the Signal-to-Interference Ratio and outage probability for macro/femto-cell base stations.