Receiver diversity evaluation for a VHF band broadband mobile communication system

In this paper, diversity receiver performance at base station for VHF-band broadband mobile communication systems is examined by using measurement results. Diversity gain of two RX antennas for link budget calculation has been calculated by using a selective combining and an equal gain combining schemes. By analyzing the diversity gain statistically, it is found that the diversity gain of selective combining and its variation are increased in larger antenna separation and shorter transmission range. On the other hand, the diversity gain of equal gain combining and its variation are decreased in larger antenna separation and in shorter transmission range. In addition, a path loss model has been developed for a link budget design. The path loss model parameters are extracted for over 1 km transmission range. By considering the path loss model with analytically-extracted constant diversity gains for BS antenna separation lengths of 1, 5, and 10 wavelengths, the system service coverage can be estimated.