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A WIDEBAND CHANNEL MODEL FOR AERONAUTICAL TELEMETRY — PART 1: GEOMETRIC CONSIDERATIONS AND EXPERIMENTAL CONFIGURATIONRice, Michael, Davis, Adam, Bettwieser, Christian 10 1900 (has links)
International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, California / This paper is the first of two papers that present a multipath channel model for wideband
aeronautical telemetry. Channel sounding data, collected at Edwards AFB, California at both L-Band
and lower S-Band, were used to generate channel model. In Part 1, analytic and geometric
considerations are discussed and the frequency domain modeling technique is introduced. In Part
2, the experimental results are summarized and a channel model composed of three propagation
paths is proposed.
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A WIDEBAND CHANNEL MODEL FOR AERONAUTICAL TELEMETRY — PART 2: MODELING RESULTSRice, Michael, Davis, Adam, Bettwieser, Christian 10 1900 (has links)
International Telemetering Conference Proceedings / October 21, 2002 / Town & Country Hotel and Conference Center, San Diego, California / This paper is the second of two papers that present a multipath channel model for wideband
aeronautical telemetry. Channel sounding data were collected at Edwards AFB, California at both
L-Band and lower S-Band. Frequency domain analysis techniques were used to evaluate candidate
channel models. The channel model is composed of three propagation paths: a line-of-sight path,
and two specular reflections. The first specular reflection is characterized by a relative amplitude
of 70% to 96% of the line-of-sight amplitude and and a delay of 10 – 80 ns. This path is the result
of “ground bounces” off the dry lake bed at Edwards and is a typical terrain feature at DoD test
ranges located in the Western USA. The amplitude and delay of this path are defined completely
by the flight path geometry. The second path is a much lower amplitude path with a longer delay.
The gain of this path is well modeled as a zero-mean complex Gaussian random variable. The
relative amplitude is on the order of 2% to 8% of the line-of-sight amplitude. The mean excess
delay is 155 ns with an RMS delay spread of 74 ns.
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[en] WIDEBAND RADIO CHANNEL CHARACTERISTICS AT 3,5 GHZ IN URBAN REGIONS / [pt] CARACTERIZAÇÃO DO CANAL RÁDIO EM BANDA LARGA NA FAIXA DE 3,5 GHZ EM AMBIENTE URBANOCARLOS VINICIO RODRIGUEZ RON 10 January 2018 (has links)
[pt] O correto planejamento de novas redes de comunicação sem fio de voz e dados representa um grande desafio ao incluir serviços cada vez mais avançados com diferentes requisitos de qualidade, suporte a mobilidade, altas taxas de transmissão e capacidades de tráfego elevadas. Os ambientes nos quais estas redes operam são dos mais diversos e contemplam desde na áreas abertas até centros urbanos com alta densidade de edificações.
O presente trabalho apresenta resultados experimentais que permitem caracterizar o canal de radio-propagação num ambiente urbano com mobilidade do receptor. Como resultado de campanhas de medições, são identificados modelos do canal que permitem ao projetista da rede definir a melhor configuração de parâmetros e critérios de projeto para a implantação de uma rede móvel de acesso sem fio em banda larga. As medições foram realizadas nos bairros da Gávea, Leblon e Lagoa, no Rio de Janeiro, com estação transmissora instalada na PUC-Rio (prédio LEME) na frequência de 3,5 GHz, destinada para novos serviços móveis. Os principais resultados obtidos são: o desenvolvimento de uma metodologia
de medição simples e precisa, utilizando a técnica OFDM, e das ferramentas de software para pré-processamento e analise de dados; o desenvolvimento de modelos semi-empíricos para a previsão da perda média de propagação; a obtenção de perfis de retardo do canal e dos valores médio e desvio padrão do retardo em condições de visibilidade (LOS) e obstrução (NLOS), e de
expressões empíricas para sua estimativa; a obtenção do valor médio das amplitudes relativas dos multipercursos e sua modelagem em função do valor de retardo relativo. / [en] Best practices of radio planning for new wireless networks with mixed trac
of voice and data are a big technical challenge due to the need to provide of
advanced services with different quality requirements, high data throughput,
mobility and high traffic demands. Environments for operation of this kind
of networks are diverse and include open areas with low population density
as well as urban centers.
This thesis presents experimental results obtained to characterize the
wideband radiopropagation channel on urban environments with a mobile
receiver. The analysis of measured data allows the identification of channel
models and propagation mechanisms needed for the design engineer to define
the best parameter configuration and project criteria in the deployment
of a wideband mobile wireless network. The measurement campaign was
executed on Gavea neigborhood in Rio de Janeiro city with a transmitter
station located in a PUC-Rio university building (Lcme Building) operating
at 3,5 GHz, frequency used for the new wideband mobile services.
The main results are: the development of a simple and precise methodology
for measuring, using the OFDM technique OFDM, and the software tools
for pre-processing and analysis; the development of semi-empirical models
for predicting the average propagation loss in the urban environment;
measurements of multipath delay profiles of the channel and the average
values and standard deviation of the RMS delay spread in visibility (LOS)
and obstruction (NLOS) conditions, and derivation of empirical expressions
for their estimation; measurements of the average values of multipath
amplitudes its modeling in function of the relative delay.
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Effect of the bandwidth on the accuracy of AOA estimation algorithms in a multipath environmentGhazaany, Tahereh S., Zhu, Shaozhen (Sharon), Jones, Steven M.R., Abd-Alhameed, Raed, Noras, James M., Van Buren, T., Suggett, T., Marker, S. January 2014 (has links)
No / This paper investigates the effect of channel bandwidth on the accuracy of AOA estimation algorithms based on the detection of the direct path. The accurate detection of the Line of Sight (LOS) signal in a multipath environment is crucial for reliable direction finding. In this work, the estimation algorithms are applied to the LOS component in the time domain channel impulse response which is acquired by applying the inverse Fourier transform to the simulated channel transfer function in the desired bandwidth. Different channel bandwidths as well as two AOA estimation methods have been considered in the modelling to investigate the performance of the standard deviation of angle estimation error. It has been shown that increasing the bandwidth in all simulated channel scenarios improves the estimation accuracy. / Seven Technologies Group, KTP project grant No. 008734.
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