Measurement-Based 5G Millimeter-Wave Propagation Characterization in
Vegetated Suburban Macrocell Environments
Abstract
An empirically based analysis of propagation characteristics in two
vegetated suburban areas with different types and fractions of
vegetation cover in 5G millimeter-wave bands is presented. A basic
distance-dependent path loss model with a Gaussian random variance for
shadow fading is utilized in accordance with the maximum-power
directional and omnidirectional measurement data, therein exploiting
significant path loss exponents in the presence of vegetation. In
comparison with the existing ITU-R and 3GPP models, the effect of
dense-leaved trees on path loss prediction is similar to that of
buildings, whereas these standard models are inapplicable for sparse
obstacle-line-of-sight (OLoS) links. Consequently, an
azimuth-angle-based path loss characterization is proposed considering
the antenna pattern, beam misalignment, and blockage effects. Moreover,
several composite and cluster-level small-scale channel parameters, such
as the number of clusters, delay spread, and angular spread, are
extracted. Analysis of the first-arrival cluster in the OLoS setting
reveals that forward scattering through foliage is still dominant and is
expected to produce a larger azimuth angular spread of the arrival and
compact multipath components in the time domain compared with
line-of-sight and reflected clusters. Measurement results improve
existing 3GPP channel models for suburban macrocell scenarios in
millimeter-wave bands.