Performance of Fade Mitigation Techniques in a Fixed 48 GHz HAPS Network.

The 48 GHz band has been allocated world-wide for fixed service with HAPS. High-capacity broadband access networks can be implemented in this band. The main drawback is the troposphere effects on the propagation, particularly rain attenuation, that may limit the link availability. In this paper, the performance of HAPS-ground links working in this band is analysed by means of simulation. Experimental slant-path propagation data, gathered at 49.5 GHz, are used in the simulations, so that attenuation levels and their temporal evolution may be considered realistic. The simulated system is defined in ITU-R Rec. F-1500. Only urban coverage links are simulated, as the propagation data correspond to a 400 elevation link. The use of Fade Mitigation Techniques (FMT) is shown to be useful to improve the link performance. The improvement is evaluated for two different FMTs: Power control and adaptive coding. Results are presented regarding link availability and other parameters related to the particular FMT, as well as outage dynamics. [ABSTRACT FROM AUTHOR]