24 GHz cmwave radio propagation through vegetation: Suburban tree clutter attenuation

Abstract

This paper presents a measurement-based analysis of cm-wave radio propagation through vegetation at 24 GHz. A set of dedicated directional measurements were performed with horn antennas located close to street level inside a denselyvegetated area illuminated from above. The full azimuth was examined for the elevation range from +10 to +30 degrees at each of the measurement positions in order to explore the directional characteristics of the channel. The detailed analysis of the spatial multipath components scattered from the trees suggests, in average, the presence of 5 strong treescattered components per location with an azimuthal deviation of approximately 20 degrees between the strongest and the direct transmitter-receiver components. A diversity gain of approximately 7 dB is estimated, plus 2 dB extra in the case of considering multi-beam combining techniques. Tree clutter attenuation was found to be in the range 2.6-3.8 dB/m for the first meters inside the vegetated area. This attenuation can be predicted by the current ITU-R models, although some modifications are suggested. Single-tree attenuation was estimated to be approximately 20 dB. The different models and observations presented along the paper are useful for simulation and radio network planning of future wireless systems operating at 24 GHz in presence of vegetation.

Measurement-Based 5G Millimeter-Wave Propagation Characterization in Vegetated Suburban Macrocell Environments

“…In the industrial park environment, the composite delay and angular dispersion results for the OLoS link are significantly greater than the results for the LoS link and generally decrease with increasing carrier frequency. This result is comparable to the site-specific foliage measurement results at 24 GHz and 28 GHz [28], [30]. As a comparison of the results in the villa district over all OLoS RX positions, propagation in sparse vegetated areas is likely to increase the delay and angular spreads due to the greater number of airy spaces, which will contribute to lower vegetation attenuation and increased forward MPCs.…”

“…The theoretical and empirical modeling of the effect of vegetation media at mmWave frequencies has been extensively conducted [15], [26]- [31]. Following the proposed models in Recommendation ITU-R P.833 [32], an exponential function with respect to carrier frequency, vegetation depth, and elevation angle is utilized to model the foliage attenuation when the transmitter (TX) and receiver (RX) are both outside the vegetated area [15], [28], [29]; in addition, the terrestrial model varying with vegetation depth is used for the case in which only one terminal is located within the extensive vegetation [29], [30]. However, there is limited knowledge on the interaction between channel dispersion (e.g., delay spread [33], [34] and angular spread [15]) and scattering phenomena in the presence of vegetation across multiple mmWave bands.…”

Measurement-Based Characterization of 39 GHz Millimeter-Wave Dual-Polarized Channel Under Foliage Loss Impact

“…Thus, it's worthwhile to analyze the attenuation through the vegetation. A so-called ''foliage attenuation'' which is defined as the power loss per unit length while waves propagate through the vegetated area in addition to the free space path loss was adopted to characterize the influence of vegetation [13].…”

Scattering Effects of Residential Trees on Very Hugh Frequency Radio Wave Propagation

“…Karam used the geometrical optics approximation that satisfies Feynman diagram to account for absorbing amplitude and phase effects from trees, using real physical conductivity and random distribution of branches and leaves as adopted in this work. Investigations of tree canopy effects on radio channel characteristics have been more focused on coherent scattering due to its obvious attenuation of radio waves propagation through foliage as deduced by [15] , [16]. [17], [18] and [19].…”