Modeling and characterization of urban radio channels for mobile communications

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dc.contributor Aalto-yliopisto fi
dc.contributor Aalto University en
dc.contributor.author El-Sallabi, Hassan
dc.date.accessioned 2012-02-10T08:52:03Z
dc.date.available 2012-02-10T08:52:03Z
dc.date.issued 2003-07-07
dc.identifier.isbn 951-22-6666-0
dc.identifier.issn 1456-3835
dc.identifier.uri https://aaltodoc.aalto.fi/handle/123456789/2099
dc.description.abstract Results of this thesis contribute in modeling and characterization of radio channels for future mobile communications. The results are presented mainly in three parts: a) modeling of propagation mechanisms, b) methodology of developing a propagation model, c) characterization of urban radio channel. One of the main propagation physical phenomena that have an important role in diverting signals to non line of sight scenarios is the diffraction process. This thesis proposes diffraction coefficients that have better agreement with finite difference time domain solution and rigorous diffraction theory than the coefficient commonly used in propagation predictions for mobile communications. The importance of diffuse scattering has also been investigated and showed that this physical process may have a key role in urban propagation, with a particular impact on the delay spread and angular spread of the signal at the receiver. This thesis proposes wideband propagation models for main and perpendicular streets of urban street grids. The propagation models are ray-based and are given in explicit mathematical expressions. Each ray is characterized in terms of its amplitude, delay, and angle of arrival, angle of departure for vertical and horizontal polarizations. Each of these characteristics is given in a closed mathematical form. Having wideband propagation model in explicit expression makes its implementation easy and computation fast. Secondary source modeling approach for perpendicular streets has also been introduced in this thesis. The last part of the thesis deals with characterization of urban radio channels for extracting parameters that help in successful design of mobile communication systems. Knowledge of channel characteristics enables reaching optimum trade off between system performance and complexity. This thesis analyzes measurement results at 2 GHz to extract channel parameters in terms of Rake finger characteristics in order to get information that helps to optimize Rake receiver design for enhanced-IMT2000 systems. Finger life distance has also been investigated for both micro- and small cell scenarios. This part of the thesis also presents orthogonality factor of radio channel for W-CDMA downlink at different bandwidths. Characterization of dispersion metrics in delay and angular domains for microcellular channels is also presented at different base station antenna heights. A measure of (dis-) similarity between multipath components in terms of separation distance in delay and angular domains is introduced by the concept of distance function, which is a step toward in development of algorithm extraction and analysis multipath clustering. In summary, the significant contributions of the thesis are in three parts. 1) Development of new diffraction coefficients and corrections of limitations of existing one for accurate propagation predictions for mobile communications. 2) Development of wideband propagation models for urban street grid. The novelty of the model is the development in explicit mathematical expressions. The developed models can be used to study propagation problem in microcellular urban street grids. 3) Presenting channel parameters that will help in the design of future mobile communication systems (enhanced-IMT2000), like number of active fingers, finger life distance, and orthogonality factors for different bandwidths. In addition, a technique based on multipath separation distance is proposed as a step toward in development of algorithms for extraction and analysis of multipath clusters. en
dc.format.extent 48, [116]
dc.format.mimetype application/pdf
dc.language.iso en en
dc.publisher Helsinki University of Technology en
dc.publisher Teknillinen korkeakoulu fi
dc.relation.ispartofseries Helsinki University of Technology Radio Laboratory publications. S en
dc.relation.ispartofseries 261 en
dc.relation.haspart El-Sallabi H. M., Liang G., Bertoni H. L., Rekanos I. T. and Vainikainen P., 2002. Influence of diffraction coefficient and corner shape on ray prediction of power and delay spread in urban microcells. IEEE Transactions on Antennas and Propagation 50, No. 5, pages 703-712. Special Issue on Wireless Communications, May 2002.
dc.relation.haspart El-Sallabi H. M., Rekanos I. T. and Vainikainen P., 2002. A new heuristic diffraction coefficient for lossy dielectric wedges at normal incidence. IEEE Antennas and Wireless Propagation Letters 1, pages 165-168.
dc.relation.haspart El-Sallabi H. M. and Vainikainen P., 2003. Improvement in heuristic UTD diffraction coefficient. IEE Electronics Letters 39, No. 1, pages 10-12.
dc.relation.haspart Degli-Esposti V., El-Sallabi H. M., Guiducci D., Kalliola K., Azzi P., Vuokko L., Kivinen J. and Vainikainen P., 2002. Analysis and simulation of the diffuse scattering phenomenon in urban environment. Proceedings of the XXVIIth General Assembly of the International Union of Radio Science (URSI 2002). 17-24 August 2002, paper no. 1734 in CD, 4 pages.
dc.relation.haspart El-Sallabi H. M. and Vainikainen P., 2000. Physical modeling of line-of-sight wideband propagation in a city street for microcellular communication. Journal of Electromagnetic Waves and Applications 14, pages 905-927.
dc.relation.haspart El-Sallabi H. M. and Vainikainen P., 2003. Radio wave propagation in perpendicular streets of urban street grid for microcellular communications. Part I: Channel modeling. Progress In Electromagnetics Research (PIER) 40, pages 229-254, an abstract version in Journal of Electromagnetic Waves and Applications 17, No. 8, pages 1157-1158.
dc.relation.haspart El-Sallabi H. M., 2000. Fast path loss prediction by using virtual source technique for urban microcells. Proceedings of the IEEE Vehicular Technology Conference (VTC'2000). Tokyo, Japan, May 2000, Vol. 3, pages 2183-2187.
dc.relation.haspart El-Sallabi H. M. and Vainikainen P., 2003. Influence of chip frequency on characterizing radio channels for Rake receiver fingers for CDMA systems in microcellular environment. Accepted for publication in IEICE Transaction on Fundamentals of Electronics and in Communications and Computer Sciences, to appear in October 2003.
dc.relation.haspart El-Sallabi H. M., Bertoni H. L. and Vainikainen P., 2002. Channel characterization for CDMA Rake receiver design for urban environment. Proceedings of the IEEE Communication Conference (ICC2002). NYC, USA, April 2002, Vol. 2, pages 911-915.
dc.relation.haspart El-Sallabi H. M., Bertoni H. L. and Vainikainen P., 2002. Experimental evaluation of Rake finger life distance for CDMA Systems. IEEE Antennas and Wireless Propagation Letters 1, pages 50-52.
dc.subject.other Electrical engineering en
dc.title Modeling and characterization of urban radio channels for mobile communications en
dc.type G5 Artikkeliväitöskirja fi
dc.description.version reviewed en
dc.contributor.department Department of Electrical and Communications Engineering en
dc.contributor.department Sähkö- ja tietoliikennetekniikan osasto fi
dc.subject.keyword propagation model en
dc.subject.keyword urban radio channel en
dc.subject.keyword diffraction process en
dc.subject.keyword diffuse scattering en
dc.subject.keyword Rake receiver design en
dc.subject.keyword finger life distance en
dc.identifier.urn urn:nbn:fi:tkk-000679
dc.type.dcmitype text en
dc.type.ontasot Väitöskirja (artikkeli) fi
dc.type.ontasot Doctoral dissertation (article-based) en
dc.contributor.lab Radio Laboratory en
dc.contributor.lab Radiolaboratorio fi


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