Model of Incoming Waves at Base Station to Evaluate the Performance of Intersector Soft Handover

A propagation model is needed to evaluate the performance of handover in mobile-communication systems. Generally, the received signal level from base stations (BSs) is calculated assuming path loss, and a lognormal (shadow)-fading model is used for evaluating intercell handover. The lognormal fading was assumed to be uncorrelated between cells. However, since the correlation between sectors is not clarified, an appropriate shadow-fading model to evaluate intersector handover has not yet been proposed. To obtain shadow-fading characteristics between neighboring sectors, the change in signal level and the direction of arrival of incoming waves at a BS must be clarified. This paper proposes a simple model of incoming waves to evaluate the performance of intersector handover. The validity of the proposed model is confirmed by comparing the difference between signal levels in BS sectors that are calculated using the proposed model and the measured power azimuth spectrum.