000124905 001__ 124905
000124905 005__ 20190509132206.0
000124905 0247_ $$2doi$$a10.5075/epfl-thesis-4150
000124905 02470 $$2urn$$aurn:nbn:ch:bel-epfl-thesis4150-1
000124905 02471 $$2nebis$$a5581010
000124905 037__ $$aTHESIS
000124905 041__ $$aeng
000124905 088__ $$a4150
000124905 245__ $$aEffect of intelligent antennas on radio system planning and on mitigation
000124905 269__ $$a2008
000124905 260__ $$aLausanne$$bEPFL$$c2008
000124905 300__ $$a177
000124905 336__ $$aTheses
000124905 520__ $$aSmart antennas have been recently applied to improve the capacity and the performance of second generation wireless mobile communication systems. In general, smart antennas reduce the effects of multipath fading and improve the signal-to-noise-plus-interference ratio (SNIR). Additional advantages such as channel capacity increase in urban areas, coverage extension in urban areas and spectrum efficiency in general can be obtained with the aid of smart antennas at the base station. Drawbacks are the cost, and both hardware and software complexity. Smart antennas promise a clear advantage in multi-service traffic scenario in comparison with non-adaptive antenna techniques. It is generally accepted that the adaptive antennas technique will be a key enable for the success of the European third generation mobile communication system known as Universal Mobile Telecommunication System (UMTS). The first part of this thesis presents two types of smart antenna systems: switched beam antennas and adaptive arrays. It introduces statistical models for them and investigates the performance measures of cellular radio systems with and without smart antennas deployed at base stations. Employing Monte-Carlo methodology, a tool has been developed to analyze the interference between two different systems that share the same geographical area and have neighboring frequency channels. The statistical smart antennas model has been used to verify the mitigation of the interference compared with others antennas used at the base station. These simulations have been done for TDMA, FDMA and CDMA systems. Wireless communication operating at different frequencies on the non-ionizing radiation (NIR) region of the electromagnetic spectrum has greatly increased in the last few decades, with important benefits for the population. These include mobile communication, such as cellular telephone systems. However, the radiated electromagnetic field levels increased substantially in areas where people may stay during long periods each day. This may result in long-term exposure to the population. International guidelines and standards were developed aiming at protecting the population, and limiting the maximum radiation produced. The methods used by regulation authorities to evaluate the field levels at places of sensitive use yield very conservative results. They need thus to be refined prior to the introduction of adaptive antennas. In the second part of the thesis, a 3D ray tracing tool is developed to predict the propagation for real scenarios using UMTS systems. This tool takes into account 3D radiation diagrams and multipath propagation. It was used in real scenarios to compare the real field levels with the levels obtained by the approximate methods defined by the regulation standards. Finally, this tool was used to predict the field levels in a scenario containing smart antennas. Scenario not foreseen in the method described in the standards.
000124905 6531_ $$asmart antennas
000124905 6531_ $$aadaptive antenna
000124905 6531_ $$aCDMA
000124905 6531_ $$aUMTS
000124905 6531_ $$aray tracing
000124905 6531_ $$apropagation prediction
000124905 6531_ $$amobile communication
000124905 6531_ $$aONIR
000124905 6531_ $$aantennes intelligentes
000124905 6531_ $$aantennes adaptatives
000124905 6531_ $$aCDMA
000124905 6531_ $$aUMTS
000124905 6531_ $$atracé de rayons
000124905 6531_ $$aprédiction de propagation
000124905 6531_ $$acommunication mobile
000124905 6531_ $$aONIR
000124905 700__ $$aIten Chaves Simões, Juliane
000124905 720_2 $$0240432$$aMosig, Juan Ramon$$edir.$$g105917
000124905 720_2 $$0242772$$aSkrivervik Favre, Anja$$edir.$$g106441
000124905 8564_ $$s3492859$$uhttps://infoscience.epfl.ch/record/124905/files/EPFL_TH4150.pdf$$yTexte intégral / Full text$$zTexte intégral / Full text
000124905 909C0 $$0252091$$pLEMA$$xU10374
000124905 909CO $$ooai:infoscience.tind.io:124905$$pthesis-bn2018$$pDOI$$pthesis$$qDOI2$$qGLOBAL_SET
000124905 918__ $$aSTI$$bSTI-SEL$$cIEL
000124905 919__ $$aLEMA
000124905 920__ $$b2008
000124905 970__ $$a4150/THESES
000124905 973__ $$aEPFL$$sPUBLISHED
000124905 980__ $$aTHESIS