A comparison of 1920 MHz diversity gain using horizontally and vertically spaced antenna elements

Diversity gain for both a horizontal and a vertical three-element receiving array coupling to a 1920 MHz mobile transmitter in a suburban area is investigated. Various combining techniques are considered (selection diversity, equal gain, maximal ratio). The narrow band (19.6 kHz) diversity gain is greater for the horizontal array than for the vertical array (an average of 10.4 dB vs. 7.2 dB at the 99% fade probability level) as scattering occurs largely in the horizontal plane for the propagation environment chosen. Wider bandwidths (1.25 MHz, 5.0 MHz, and 10.0 MHz) exhibit less fading and thus less diversity gain. Somewhat unexpected is that the three combining techniques yield practically the same results.