Simulations of site diversity based outage improvements for point-to-multipoint systems in millimeter-wave band

Rain attenuation is one of the main factors limiting performance of point-to-multipoint systems operating in millimeter-wave bands. Site diversity can be used as one of the propagation impairment mitigation techniques thanks to the non-uniform spatial distribution of the rain rate. A diversity gain concept is usually used for diversity evaluations. The motivation to this work is to offer to service providers a simpler way to evaluate possibilities of the site diversity employment for specific scenarios instead of power balance calculations of every potential diversity connection. Outage improvement was studied using space-time simulations of a point-to-multipoint system in a specific area under a specific rain conditions. Large rain event database for Czech Republic was build for the simulations utilizing time sequences of rainfall radar images for 50×50 km area. System outage improvement probability was derived as a straightforward function of the rain fade margin, angle separation and distances of main and diversity hubs. Some of the simulation results at 42 GHz and corresponding outage improvement probability using the site diversity are presented as well.