Customhation of vertical antenna diFectivity to reduce cochannel htexfemnce in a cellular communication system

The effect of antenna vertical directivity is usually ignond in estimating the C/I in a cellularnetwodc, i.e., tbe fomula C/I=(D/R)rdoes not explicitly or implicit- ly camy the antenna gain factor. A new type of base station antenna has been developed to see if Cn can be impmved by antenna vertleal pattern. The antenna hs a sharp mll-off on the top half of the main lobe while maintaining mini- mum sidelobes in the upper hemispben. Common of the custom designed antenna's peltomawe with that of a =gular antenna in both &an and subwban area indicates that significant C/I impmvement is possible.