1,158 research outputs found
On the Frequency Dependency of Radio Channel's Delay Spread: Analyses and Findings From mmMAGIC Multi-frequency Channel Sounding
This paper analyzes the frequency dependency of the radio propagation
channel's root mean square (rms) delay spread (DS), based on the
multi-frequency measurement campaigns in the mmMAGIC project. The campaigns
cover indoor, outdoor, and outdoor-to-indoor (O2I) scenarios and a wide
frequency range from 2 to 86 GHz. Several requirements have been identified
that define the parameters which need to be aligned in order to make a
reasonable comparison among the different channel sounders employed for this
study. A new modelling approach enabling the evaluation of the statistical
significance of the model parameters from different measurements and the
establishment of a unified model is proposed. After careful analysis, the
conclusion is that any frequency trend of the DS is small considering its
confidence intervals. There is statistically significant difference from the
3GPP New Radio (NR) model TR 38.901, except for the O2I scenario.Comment: This paper has been accepted to the 2018 12th European Conference on
Antennas and Propagation (EuCAP), London, UK, April 201
Radio frequency channel characterization for energy harvesting in factory environments
This thesis presents ambient energy data obtained from a measurement campaign carried out at an automobile plant. At the automobile plant, ambient light, ambient temperature
and ambient radio frequency were measured during the day time over two days. The measurement results showed that ambient light generated the highest DC power. For plant and operation managers at the automobile plant, the measurement data can be used in system design considerations for future energy harvesting wireless sensor nodes at the plant.
In addition, wideband measurements obtained from a machine workshop are presented in this thesis. The power delay profile of the wireless channel was obtained by using a frequency domain channel sounding technique. The measurements were compared with
an equivalent ray tracing model in order to validate the suitability of the commercial propagation software used in this work.
Furthermore, a novel technique for mathematically recreating the time dispersion created by factory inventory in a radio frequency channel is discussed. As a wireless receiver
design parameter, delay spread characterizes the amplitude and phase response of the radio channel. In wireless sensor devices, this becomes paramount, as it determines the
complexity of the receiver. In reality, it is sometimes difficult to obtain full detail floor plans of factories for deterministic modelling or carry out spot measurements during
building construction. As a result, radio provision may be suboptimal. The method presented in this thesis is based on 3-D fractal geometry. By employing the fractal overlaying algorithm presented, metallic objects can be placed on a floor plan so as to
obtain similar radio frequency channel effects. The environment created using the fractal approach was used to estimate the amount of energy a harvesting device can accumulate
in a University machine workshop space
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