Dissertation•
Determination of rainfall parameters for specific attenuation due to rain for different integration times for terrestrial line-of-sight links in South Africa.
01 Jan 2016-
TL;DR: In this paper, the authors presented a master of science in Electronic Engineering at the University of KwaZulu-Natal, Howard College, South Africa, KwaNgala, 2016.
Abstract: Master of Science in Electronic Engineering. University of KwaZulu-Natal, Howard College 2016.
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TL;DR: Based on the DSD, rain specific attenuation is estimated at 72 and 84 GHz with Mie scattering theory and these estimated rain attenuations can be used and validated for rain attenuation analysis of the millimeter wave propagation experiments under similar climate conditions.
Abstract: The raindrop size distribution (DSD) is essential information for understanding rain attenuation effects at millimeter wavelengths. The DSD was measured in Albuquerque, NM, USA, as a part of the W/V-band Terrestrial Link Experiment. An optical disdrometer from Thies Clima was used to measure both size and velocity of rain droplets. The measured DSD consistently showed a unique property of two log-linear distributions regionally separable by drop size under variable rain rates. The functional fit that best represents our measured data with rain rates under 40 mm/h is presented. Based on the DSD, rain specific attenuation is estimated at 72 and 84 GHz with Mie scattering theory. These estimated rain attenuations can be used and validated for rain attenuation analysis of the millimeter wave propagation experiments under similar climate conditions. This letter will guide millimeter wave communication system designers to estimate the rain attenuation based on their own DSD measurements.
14 citations
Cites background from "Determination of rainfall parameter..."
...Laws-Parsons [13], modified Gamma [14], and Weibull [15] as the DSD measurement/analysis are lacking at places with...
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...Our measurement demonstrates how much the DSD can differ from well-known DSD models such as Marshall and Palmer [12], Laws-Parsons [13], modified Gamma [14], and Weibull [15] as the DSD measurement/analysis are lacking at places with orographic lifted rain cells at high altitude dry conditions....
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DOI•
TL;DR: In this article , the long-term attenuation over typical building-to-building radio links in the built environment, which constitute two 36 m links along a direct link and an indirect side link at 25.84 and 77.54 GHz and a 200 m link at 77.125 GHz, was measured using precipitation data from a high end accurate disdrometer weather station.
Abstract: Several millimeter Wave (mmWave) bands, which suffer from rain attenuation, were identified in the World Radiocommunication Conference 2019 (WRC‐19) for fifth generation (5G) radio networks. In this paper, long‐term attenuation is measured over typical building to building radio links in the built environment, which constitute two 36 m links along a direct link and an indirect side link at 25.84 and 77.54 GHz and a 200 m link at 77.125 GHz. The attenuation was also estimated using precipitation data from a high end accurate disdrometer weather station using the drop size distribution and the International Telecommunication Union (ITU) models. The results indicate that attenuation using Mie theory is in agreement with the ITU model for most of the rainfall events; with higher attenuation being measured than predicted when snow grains and raindrops mix. Raindrops with diameter between 0.1 and 4 mm indicate that the dominant raindrops have considerable influence on the measured attenuation, especially at light and moderate rainfall events. The maximum distance factor restriction of 2.5 in ITU‐R P.530‐17 is shown not to be suitable for short‐range fixed links as it excessively underestimates attenuation.
4 citations
01 Jan 1990
3 citations
References
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Book•
15 Jan 1996
TL;DR: WireWireless Communications: Principles and Practice, Second Edition is the definitive modern text for wireless communications technology and system design as discussed by the authors, which covers the fundamental issues impacting all wireless networks and reviews virtually every important new wireless standard and technological development, offering especially comprehensive coverage of the 3G systems and wireless local area networks (WLANs).
Abstract: From the Publisher:
The indispensable guide to wireless communicationsnow fully revised and updated!
Wireless Communications: Principles and Practice, Second Edition is the definitive modern text for wireless communications technology and system design. Building on his classic first edition, Theodore S. Rappaport covers the fundamental issues impacting all wireless networks and reviews virtually every important new wireless standard and technological development, offering especially comprehensive coverage of the 3G systems and wireless local area networks (WLANs) that will transform communications in the coming years. Rappaport illustrates each key concept with practical examples, thoroughly explained and solved step by step.
Coverage includes:
An overview of key wireless technologies: voice, data, cordless, paging, fixed and mobile broadband wireless systems, and beyond
Wireless system design fundamentals: channel assignment, handoffs, trunking efficiency, interference, frequency reuse, capacity planning, large-scale fading, and more
Path loss, small-scale fading, multipath, reflection, diffraction, scattering, shadowing, spatial-temporal channel modeling, and microcell/indoor propagation
Modulation, equalization, diversity, channel coding, and speech coding
New wireless LAN technologies: IEEE 802.11a/b, HIPERLAN, BRAN, and other alternatives
New 3G air interface standards, including W-CDMA, cdma2000, GPRS, UMTS, and EDGE
Bluetooth wearable computers, fixed wireless and Local Multipoint Distribution Service (LMDS), and other advanced technologies
Updated glossary of abbreviations and acronyms, and a thorolist of references
Dozens of new examples and end-of-chapter problems
Whether you're a communications/network professional, manager, researcher, or student, Wireless Communications: Principles and Practice, Second Edition gives you an in-depth understanding of the state of the art in wireless technologytoday's and tomorrow's.
17,102 citations
10,184 citations
"Determination of rainfall parameter..." refers background in this paper
...It is with immense agreement that Mie scattering analysis is often preferred due to its ability to provide reliable results beyond 3 GHz, as compared to Rayleigh scattering technique [Mie, 1908; Bohren and Huffman, 2004; Naicker, 2006; Alonge, 2011]....
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...The real part and the imaginary part of the refractive index of the scatter represent the scattering loss and absorption loss respectively [Mie, 1908]....
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TL;DR: Light scattering by small particles as mentioned in this paper, Light scattering by Small Particle Scattering (LPS), Light scattering with small particles (LSC), Light Scattering by Small Parts (LSP),
Abstract: Light scattering by small particles , Light scattering by small particles , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی
9,737 citations
Book•
01 Dec 1981
TL;DR: Light scattering by small particles as mentioned in this paper, Light scattering by Small Particle Scattering (LPS), Light scattering with small particles (LSC), Light Scattering by Small Parts (LSP),
Abstract: Light scattering by small particles , Light scattering by small particles , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی
6,623 citations
TL;DR: In this paper, a three-parameter gamma distribution was used for dual-measurement techniques to determine rainfall rate, and the relationship between pairs of integral rainfall parameters using a three parameter gamma drop size distribution was investigated.
Abstract: Empirical analyses are shown to imply variation in the shape or analytical form of the raindrop size distribution consistent with that observed experimentally and predicted theoretically. These natural variations in distribution shape are demonstrated by deriving relationships between pairs of integral rainfall parameters using a three parameter gamma drop size distribution and comparing the expressions with empirical. There comparisons produce values for the size distribution parameters which display a systematic dependence of one of the parameters on another between different rainfall types as well as from moment to moment within a given rainfall type. The implications of this finding are explored in terms of the use of a three-parameter gamma distribution in dual-measurement techniques to determine rainfall rate.
1,237 citations
"Determination of rainfall parameter..." refers methods in this paper
...2 Modified Gamma Rainfall DSD Model This is a three-parameter rainfall DSD model given by [Atlas and Ulbrich, 1974; Ulbrich, 1983; Kozu and Nakamura 1991]:...
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...According to Ulbrich (1983), this statistical DSD model responds well to rainfall DSDs at both low and high rainfall rates....
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...This is a three-parameter rainfall DSD model given by [Atlas and Ulbrich, 1974; Ulbrich, 1983; Kozu and Nakamura 1991]: N(Di) = Nm(Di) μexp(−ΛDi) [m −3mm−1] (2.24) Where 𝑁(𝐷𝑖) is the rain drop size distribution, Nm is the scaling parameter, μ is the shape parameter and Λ is the slope parameter…...
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