Multipath measurements over obstructed radio transmission paths

Abstract

To provide PSTN to isolated subscribers BC TEL employs Exchange Area Radio telephone Service (EARS) in the 409 MHz/420 MHz UHF band. Usually LOS cornrnunication is not possible, and repeaters are used. To determine if diversity techniques could be used to improve performance and eliminate the use of repeaters, a measurement program was undertaken. The two-channel measurement system to detect and only record propagation fades in mountainous area over an obstructed LOS path is described. The fading results are presented, and the mechanisms for fading are explained. The PDF and CDF of the measured signals are compared with Rayleigh distributions, and the performance improvement that can be realized is given. Finally, a suitable diversity technique is identified.