IEEE Access (Jan 2024)
Polarimetric Vegetation Propagation Measurements on a Brazilian University Campus Scenario
Abstract
This paper discusses a polarimetric measurement campaign conducted in two distinct environments, with data collected at the Federal University of Minas Gerais (UFMG) in Brazil. The study investigates millimeter wave propagation through vegetation at a frequency of 36.6 GHz in two scenarios: the Central Square of UFMG and a forested area within the campus. In the first scenario, measurements were conducted along a main street with varying degrees of vegetation obstruction, focusing on analysing fast fading. For the fast-fading analysis, Rayleigh, Rice, and m-Nakagami distributions were considered. Results from the first scenario indicate that the m-Nakagami distribution provides the best fit for both vertical and horizontal polarisations, surpassing traditional models such as Rayleigh and Rice. In the second scenario, measurements were taken within a forested area, and the study was undertaken to analyse fast fading and excess loss. Considering the excess loss study, measurements were compared with three traditional models (CCIR, Weissberger, and COST 235). Excess loss analysis showed that traditional excess loss propagation models tend to exhibit a minimum RMS error of 10.6 dB for vertical polarisation and 15 dB for horizontal polarisation (Weissberger model), whereas the proposed model demonstrated improved accuracy over log-distance models, particularly for vertical polarisation, presenting an RMS error of 5.8 dB, and for the horizontal polarisation a RMS error of 10.2 dB, at least 4.8 dB smaller than the Weissberger model. Considering the fast fading analysis, the m-Nakagami distribution tends to provide better results in both polarisation. These findings underscore the importance of accurate propagation models tailored to specific environmental conditions, such as vegetation, to enhance the reliability of future 5G evolution and 6G microwave communication systems.
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