Performance Analysis in Indoor Femtocell Networks using ESPAR Antennas

Abstract

This paper investigates the performance of the indoor downlink femtocell networks, where the co-channel interference is mitigated by employing the electronically steerable parasitic array receptor (ESPAR) antenna, which relays on a single radio frequency (RF) chain. Thus, the ESPAR antenna fulfills the requirements of modern wireless terminals constrained on low-cost, low-power and small-size. To increase the coverage probability, the ESPAR antennas are deployed at the user terminals, whose beam-patterns are formed to divide the whole angular space into several sectors by simply tuning a number of reactance loads of parasitic elements. The femtocell access points are assumed to be distributed as a homogenous spatial poisson point process (SPPP), where each femtocell access point is equipped with an omni-directional antenna. We derive the coverage probability by introducing a simplified mathematical model to provide an approximate indoor femtocell co-channel interference distribution, considering two conditions that the interfering femtocell access points are located within a circle of radius R and their angles of arrival (AoAs) lie within the sector specified by the AoA of the desired femtocell access point. The numerical results show that the coverage performance of the system is improved by using the ESPAR antenna at the user terminal for interference suppression.