Performance analysis for indoor wireless systems employing directional antennas in the presence of external interference

External interference can cause significant performance degradation in indoor wireless systems such as third/fourth-generation mobile systems and WLANs. Strategic deployment of simple antennas (e.g., the directional patch) at base stations is an attractive low-cost solution that can mitigate, to some extent, the effect of external interference by modifying the propagation of signals in the environment. An experimental investigation of the influence of external interference on the performance of an indoor wireless system is presented. Although appropriate deployment of directional antennas can reduce the impact of external interference, the effectiveness and the optimal antenna arrangement of this deployment strategy are dependent on the relative power level of the external interference.