Mobile radio signal correlation versus antenna height and spacing

In mobile radio communications, a given correlation value between two signals received at a base station can be achieved by adjusting the antenna spacing and height; this has been experimentally verified [1], [2]. From this fact, a parameter η, defined as η=antenna height/antenna spacing is proposed as a measure of correlation for design purposes. Data from field experiments using horizontally spaced, vertically polarized base-station antennas have been analyzed in terms of η and are presented here. These data provide an upper bound correlation coefficient for any antenna separation and height. The upper bound value can be directly applied in system design.