Customization of vertical antenna directivity to reduce cochannel interference in a cellular communication system

The effect of antenna vertical directivity is usually ignored in estimating the C/I in a cellular network, i.e., the formula C/I=(D/R)/sup /spl gamma// does not explicitly or implicitly carry the antenna gain factor. A new type of base station antenna has been developed to see if C/I can be improved by antenna vertical pattern. The antenna has a sharp roll-off on the top half of the main lobe while maintaining minimum sidelobes in the upper hemisphere. Comparison of the custom designed antenna's performance with that of a regular antenna in both urban and suburban area indicates that significant C/I improvement is possible.<
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