Micro scale site diversity over a tropical site in India and evaluation of diversity gain with synthetic storm technique

Abstract

An experiment has been conducted to evaluate micro scale site diversity (MSD) at Ahmedabad, a tropical site in India. Rain data is collected by a linear array of tipping bucket rain gauges during 2007 and 2008 monsoon periods. Spatial variation of rain fall has been studied with the help of joint probability and correlation coefficients derived for the collected data. The results support the existence of micro rain cells (MRC), which are the closed contours of continuous rain with dimensions of few hundred meters. Large attenuation of signals (above 10 GHz) occursed while passing through MRCs. MSD is proposed to counteract attenuation and ensure higher link availability. An attenuation of 30 GHz signal has been estimated using synthetic storm technique (SST) in this paper and used to obtain diversity gain. The estimated diversity gain has been presented for different site separations to explore dimension of MRCs for different percentages of service availability.