Radio resource management (RRM) is an important component of a mobile wireless network that efficiently utilizes the limited radio resources such as spectrum, transmission power, and network infrastructure. Unfortunately, current RRM schemes do not support cooperative multiple point (CoMP), a promising technology that extends coverage, increases capacity, and improves the spectral efficiency of the next generation broadband network, i.e., 4G network. Specifically, to coordinate with CoMP, a RRM scheme should be aware of three main properties of CoMP - cooperative transmitting information, coordinated scheduling transmission, and single interference noise ratio (SINR) improvement. However, few of the existing RRM schemes consider these properties, since they were designed based on the conventional mobile data networks without CoMP technology. In this dissertation, I present a series of new CoMP aware RRM schemes for ensuring users' throughput and maximizing network capacity in an integrated PON-OFDM network, which is a norm of the 4G network and can best implement the CoMP technology. I call the PON-OFDM network with CoMP a CoMP Network (CoMPNet). I provide two classes of RRM schemes for two practical CoMP technologies, cooperative transmission (CT) and coordinated scheduling (CoS), respectively. In the first class, I propose two groups of RRM schemes using the CT technology. In the first group, three OFDM-TDMA based RRM schemes are designed for three different users' moving speeds. The objective of these schemes is to minimize time slot consumption. The RRM schemes in the third group are contrived for an OFDM-FDMA based CoMPNet. I provide four linear programming (LP) based optimal schemes, one for minimizing bandwidth usage, one for minimizing transmission power consumption, and two for balancing resource costs. An optimized resource allocation solution can be obtained by flexibly choosing one of the schemes according to network load. In the second class, I present a sub-optimal RRM scheme for an OFDM-FDMA based CoMPNet. The CoS technology is applied for ICI mitigation. I formulate the system optimal task into constrained optimization problems for maximizing network capacity. To improve the computation efficiency, fast yet effective heuristic schemes are introduced for divide-and-conquer. The proposed heuristic schemes are featured by CoS based timeslots/subcarriers assignment mechanisms, which are further incorporated with intelligent power control schemes. Through simulations, I study the proposed RRM schemes performances and discuss the effect of the CoMP technology. The performance benefits of CoMP on bandwidth saving and capacity increasing are shown by comparing the new schemes with the conventional schemes without CoMP.

Au fur et ?? mesure que le nombre de baby-boomers qui atteignent l?????ge de la retraite s???accro??t, le nombre d???employ??s issus de l???immigration augmente, compte tenu de leur pr??sence de plus en plus grande dans la population active. La gestion de la diversit?? culturelle est donc devenue une r??alit?? quotidienne pour de nombreux gestionnaires des organisations canadiennes, notamment au Qu??bec. Cette nouvelle r??alit?? pose de nouveaux d??fis pour l???ensemble des processus de gestion des organisations. Ceci demande aux gestionnaires de d??velopper de nouvelles habilet??s en mati??re de gestion de la diversit?? culturelle (GDC). Les approches actuelles de d??veloppement de comp??tence en GDC restent peu efficaces. Cette ??tude vise ?? identifier des strat??gies qui peuvent s???av??rer ??tre les plus appropri??es, pour am??liorer chez les gestionnaires leur comp??tence de gestion en contexte pluriethnique. Une collecte de donn??es a ??t?? r??alis??e au moyen d???entrevues de type semi-structur?? aupr??s de 36 gestionnaires d???une grande entreprise situ??e ?? Montr??al. ?? travers une analyse de contenu, cette ??tude de type exploratoire a permis de contextualiser le d??veloppement de la comp??tence en identifiant en un premier temps les principales ressources jug??es pertinentes ?? la GDC. Les r??sultats permettent ensuite de mettre en lumi??re l???importance de la compl??mentarit?? entre les situations d???apprentissage formelles et informelles dans ce contexte, les premi??res semblant ??tre les plus appr??ci??es par les participants. Au premier plan des r??sultats figurent comme assises au d??veloppement de la comp??tence en GDC l???ouverture ?? la diff??rence et les interactions avec des personnes d???autres cultures, qu???elles soient internes ?? l???organisation ou dans l???environnement de celle-ci. En outre, les participants situent clairement leur besoin d???agir avec efficacit?? en mati??re de diversit?? culturelle dans le cadre de l???exercice d???un leadership rassembleur. La discussion des r??sultats permet de voir que la conception qu???ont les participants de strat??gies efficaces de d??veloppement des comp??tences de GDC concorde avec les perspectives pr??sent??es par plusieurs auteurs ayant ??crit sur le sujet. Les r??sultats de l?????tude rapport??e dans la pr??sente th??se offrent aux dirigeants d???entreprises, aux gestionnaires et aux professionnels des param??tres importants ?? consid??rer dans l?????laboration de strat??gies visant ?? soutenir les gestionnaires dans le d??veloppement de la comp??tence en GDC.

Radio resource management (RRM) is an important component of a mobile wireless network that efficiently utilizes the limited radio resources such as spectrum, transmission power, and network infrastructure. Unfortunately, current RRM schemes do not support cooperative multiple point (CoMP), a promising technology that extends coverage, increases capacity, and improves the spectral efficiency of the next generation broadband network, i.e., 4G network. Specifically, to coordinate with CoMP, a RRM scheme should be aware of three main properties of CoMP - cooperative transmitting information, coordinated scheduling transmission, and single interference noise ratio (SINR) improvement. However, few of the existing RRM schemes consider these properties, since they were designed based on the conventional mobile data networks without CoMP technology. In this dissertation, I present a series of new CoMP aware RRM schemes for ensuring users' throughput and maximizing network capacity in an integrated PON-OFDM network, which is a norm of the 4G network and can best implement the CoMP technology. I call the PON-OFDM network with CoMP a CoMP Network (CoMPNet). I provide two classes of RRM schemes for two practical CoMP technologies, cooperative transmission (CT) and coordinated scheduling (CoS), respectively. In the first class, I propose two groups of RRM schemes using the CT technology. In the first group, three OFDM-TDMA based RRM schemes are designed for three different users' moving speeds. The objective of these schemes is to minimize time slot consumption. The RRM schemes in the third group are contrived for an OFDM-FDMA based CoMPNet. I provide four linear programming (LP) based optimal schemes, one for minimizing bandwidth usage, one for minimizing transmission power consumption, and two for balancing resource costs. An optimized resource allocation solution can be obtained by flexibly choosing one of the schemes according to network load. In the second class, I present a sub-optimal RRM scheme for an OFDM-FDMA based CoMPNet. The CoS technology is applied for ICI mitigation. I formulate the system optimal task into constrained optimization problems for maximizing network capacity. To improve the computation efficiency, fast yet effective heuristic schemes are introduced for divide-and-conquer. The proposed heuristic schemes are featured by CoS based timeslots/subcarriers assignment mechanisms, which are further incorporated with intelligent power control schemes. Through simulations, I study the proposed RRM schemes performances and discuss the effect of the CoMP technology. The performance benefits of CoMP on bandwidth saving and capacity increasing are shown by comparing the new schemes with the conventional schemes without CoMP.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-05-30T23:20:44Z No. of bitstreams: 1 JulianaRicardoDeSouza_TESE.pdf: 14513350 bytes, checksum: 9e7d4d9cfe9132db18a4d5ee9940a771 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-01T23:23:24Z (GMT) No. of bitstreams: 1 JulianaRicardoDeSouza_TESE.pdf: 14513350 bytes, checksum: 9e7d4d9cfe9132db18a4d5ee9940a771 (MD5) / Made available in DSpace on 2016-06-01T23:23:24Z (GMT). No. of bitstreams: 1 JulianaRicardoDeSouza_TESE.pdf: 14513350 bytes, checksum: 9e7d4d9cfe9132db18a4d5ee9940a771 (MD5) Previous issue date: 2015-06-05 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / A estocagem de rejeitos de scheelita a ?c?u aberto? resultante da explora??o da mina Breju? da regi?o de Currais Novos, Rio Grande do Norte, Brasil, tem gerado, no per?odo 1960-2015, um forte passivo ambiental. O pol?mero politetrafluoretileno (PTFE) majora em sistemas de deslizamento e reduz significativamente custos de manuten??o, devido ?s suas excelentes propriedades mec?nicas, tais como baixo coeficiente de atrito (0,01< m <0,10) e limite de escoamento da ordem de 10 MPa. No entanto, apresenta elevadas taxas de desgaste (10-13 m2/N) e por despertar o interesse cient?fico e tecnol?gico nas ind?strias petroqu?mica e aeroespacial na forma de lubrificantes s?lidos, objetivou-se desenvolver comp?sitos polim?ricos com matriz de PTFE utilizando-se o rejeito de scheelita como carga, viabilizando tamb?m processos de remedia??o ambiental. O Rejeito de Scheelita foi caracterizado na condi??o como adquirido, atrav?s de an?lises de DRX, FRX, MEV, EDS, granulometria por Peneiramento e a Laser, registrando-se tra?os de tungst?nio e metais estrat?gicos igualmente importantes. O PTFE foi analisado por TGA, DSC, MEV, DRX, FRX. Para o desenvolvimento dos comp?sitos misturou-se mecanicamente os p?s de PTFE e Rejeito de Scheelita, devidamente preparados e pesados. Para moldagem por compress?o ? quente projetou-se um molde cil?ndrico de a?o acoplado a uma resist?ncia inseridos numa prensa hidr?ulica. Avaliaram-se o desempenho tribol?gico dos comp?sitos obtidos a partir de Rugosidade, Dureza, Molhabilidade, Absor??o ao impacto, Esclerometria, Pino Disco e Analise Morfol?gica. Os resultados indicam que a varia??o no teor de rejeito de scheelita influ?ncia nos resultados de rugosidade, dureza e absor??o ao impacto. Comp?sitos molhados com ?gua salina e destilada caracterizaram-se como hidrof?bicos, enquanto que os molhados com ?leo paraf?nico e naft?nico como oleof?licos. Correlacionando os resultados dos ensaios tribol?gicos e custos constatou-se que a composi??o de 20% de Rejeito de Scheelita apresentou a melhor planicidade, baixo consumo de energia de deforma??o espec?ficica (<0,30 J/mm3), a menor perda m?ssica (8x10-3g) e afundamento da pista (<0,4 ?m/km). / The storage scheelite tailings in the open air as a result of Breju? mine exploration, located near Currais Novos, Rio Grande do Norte, Brazil, between 1960 and 2015, a strong environmental passive. The polymer polytetrafluoroethylene (PTFE) outstands in sliding systems and significantly reduces maintenance costs, due to its excellent mechanical properties, such as low friction coefficient (0,01< ? <0,10) and yield limit to the order of 10MPa. However, it has high wear rates (10-13 m2/N) and for arousing scientific and technological interests at petrochemical and aerospace industry, in the form of solid lubricants, the target was to develop polymeric composites with a PTFE matrix using tailings of scheelite as charge, enabling also environmental remediation processes. The tailing of Sheelite was characterized in acquired conditions, through XRD, XRF, SEM, EDS, granulometry by screening and by laser, recording traces of tungsten and strategic metals equally important. The PTFE was analyzed by TG, DSC, SEM, XRD, XRF. To the composites development, powders of PTFE and tailings of sheelite were mechanically mixed, previously prepared and weighed. To hot compression molding, a designed cylindrical steel mould was coupled with a resistor and placed in a hydraulic press. The composite?s tribological performance was evaluated from roughness, hardness, wettability, impact absorption, sclerometry, pin on disc, and morphological analysis. The results show that the variation in the tailing of scheelite concentration influences the results of roughness, hardness and impact absorption. Wet composites with saline and distilled water were characterized as hydrophobic, and the ones wet with paraffenic and naphtenic oil, they acted oleophilic. Correlating the results of tribological tests and costs, it was found that the composition of 20% mineral filler showed better planeness, low specific deformation energy consumption (<0,30J/mm?), the lowest mass loss (8x10-4g) and trail shipwreck (<0,4?m/km).

Made available in DSpace on 2014-12-17T14:58:10Z (GMT). No. of bitstreams: 1 YgorAAF.pdf: 1834910 bytes, checksum: ddd6f585ec4f1145f34bbec8197b2e39 (MD5) Previous issue date: 2006-05-19 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / In this work, were produced ceramic matrix composites based in SiCxOy e Al2O3 reinforced with NbC, by hydrosilylation reaction between D4Vi and poly(methylhydrosiloxane) mixtured with Al2O3 as inert filler, Nb and Al as reactive filler. After the mixture and compactation at 80?C (warm pressing), the samples were pyrolised at 1200 and 1400?C and infiltred with ICZ and LZSA respectively, and thermically, physical and structurally characterized by X-ray diffraction, density and porosity, flexural mechanical strength and fracture surface by scanning electron microscopy. The yield ceramic obtained after pyrolysis for studied composition at 1200?C was 95%. The obtained phases had been identified as being Al3Nb, NbSi2 and NbC. The composite material presented apparent porosity varying of 15 up to 32% and mechanical flexural strenght of 32 up to 37,5MPa. After the fracture surface analysis, were observed a phases homogeneous dispersion, with some domains of amorphous and crystalline aspect. The samples that were submitted the infiltration cycle presented a layer next the surface with reduced pores number in relation to the total volume / Neste trabalho foram produzidos comp?sitos de matriz cer?mica baseados em SiCxOy e Al2O3 refor?ados com NbC, a partir da rea??o de hidrossila??o entre os olig?meros D4Vi (1,3,5,7 tetrametil 1,3,5,7 tetravinilciclotetrasiloxano) e D1107 - Poli(metilhidrogeniosiloxano), misturados com Al2O3 como carga inerte, Nb e Al como aditivos reativos. Ap?s a mistura e compacta??o em 80 ?C (warm pressing), as amostras foram pirolisadas ? 1200 e 1400?C e infiltradas com ICZ e LZSA respectivamente, e caracterizadas t?rmica, f?sica e estruturalmente atrav?s de an?lises t?rmicas (TG e DTA), identifica??o de fases cristalinas por difratometria de raios-x, densidade e porosidade, resist?ncia mec?nica ? flex?o e superf?cie de fratura por microscopia eletr?nica de varredura. O Rendimento cer?mico obtido para a composi??o estudada ? 1200?C foi de 95%. As fases formadas ap?s a pir?lise foram identificadas como sendo Al3Nb, NbSi2 e NbC os comp?sitos apresentaram porosidade aparente variando de 15 a 32 por cento e resist?ncia mec?nica a flex?o, de 32 a 37,5MPa. Ap?s a an?lise da superf?cie de fratura observou-se uma dispers?o homog?nea de fases, com algumas regi?es de aspecto amorfo e cristalino. As amostras que foram submetidas a ciclo de infiltra??o apresentaram uma camada pr?xima a superf?cie com reduzido n?mero de poros em rela??o ao volume total

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-02-20T22:32:00Z No. of bitstreams: 1 GustavoSantosDeLucenaLira_DISSERT.pdf: 3769609 bytes, checksum: 905dd4b5e1b62301b226e882500c5d84 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-02-23T22:29:34Z (GMT) No. of bitstreams: 1 GustavoSantosDeLucenaLira_DISSERT.pdf: 3769609 bytes, checksum: 905dd4b5e1b62301b226e882500c5d84 (MD5) / Made available in DSpace on 2017-02-23T22:29:34Z (GMT). No. of bitstreams: 1 GustavoSantosDeLucenaLira_DISSERT.pdf: 3769609 bytes, checksum: 905dd4b5e1b62301b226e882500c5d84 (MD5) Previous issue date: 2016-09-29 / A participa??o das cargas naturais nos comp?sitos tem possibilitado a melhoria de sua estrutura mec?nica, bem como, a economia de aplica??o de cargas sint?ticas, as quais al?m de possu?rem alto valor de mercado, envolvem processos de fabrica??o e reciclagem nocivos a sa?de do homem. Nesse sentido, foram fabricados comp?sitos polim?ricos ? base de polipropileno, como matriz, e o particulado do endocarpo do Cocos Nuc?fera Linn (10 e 20 %wt), na fun??o de carga. Com o objetivo de obter uma eficiente intera??o na interface do particulado com a matriz e uma distribui??o uniforme do particulado no pol?mero, foi utilizada uma faixa granulom?trica do particulado de 0,5 a 0,263 mm. J? para fabrica??o dos corpos-de-prova, o material foi processado por extrus?o, com extrusora dupla rosca, e, em seguida, a inje??o, variando a temperatura de processamento em at? 200 ?C, no intuito de atingir um valor acima da temperatura de transi??o v?trea do res?duo lignocelul?sico, a fim de que a resina natural (lignina) auxilie a ades?o com a matriz. Para a caracteriza??o do particulado do endocarpo do coco utilizou-se a an?lise termogravim?trica e a microscopia eletr?nica de varredura, enquanto para os comp?sitos foram utilizados os ensaios de densidade volum?trica, de tra??o, de flex?o e a microscopia eletr?nica de varredura. Dessa forma, apesar da presen?a da carga ter gerado diminui??o da ductilidade e resist?ncia mec?nica, concluiu-se que a adi??o do particulado na matriz de Polipropileno possibilitou aumento no m?dulo de elasticidade ? tra??o de 4,0% para o comp?sito com 10,0 %wt e de 11% para o de 20%wt. No ensaio de flex?o, a carga possibilitou aumento do m?dulo de elasticidade em 6,4% para comp?sito com 10%wt e em 8,8% para o de 20%wt em rela??o ao polipropileno puro. Para a an?lise termogravim?trica, foram obtidos os patamares de temperaturas de degrada??o dos res?duos lignoc?lulosicos, sendo: a degrada??o da hemicelulose entre 210,80 e 255,32 ?C, a da celulose entre 255,32 e 328,31 e, por fim, a da lignina entre 328,31 e 495,82 ?C. Para os ensaios de densidade, observou-se que os comp?sitos possuem valores de densidades pr?ximos ao polipropileno puro, permitindo a aplica??o destes em estruturas leves. / The use of natural residues as a reinforcement in the production of plastic composites has enabled the improvement of its mechanical structure and saved the utilization of synthetic reinforcement that has manufacturing processes and recycling harmful to human health. In this study were fabricated polypropylene composites with 10 and 20 %wt of coconut (Cocos Nuc?fera Linn) shell load. To the optimization of the interfacial bond between particulate and polymer matrix were utilized a granulometric range of 0,5 a 0,263 mm and fabricated using temperature maximum of 200 ?C, above the glass transition temperature of lignocellulosic residue, by extrusion and injection moulding. The properties of particulate, composites and polymers were investigated by density, tensile and flexural testing, thermogravimetry and Scanning electron microscope. The polymer had its ductility and mechanical resistance decreased with particulate addition, thus, its modulus of elasticity increased 4,0% to 10%wt and 11,0% to 20%wt in relation to polypropylene. The flexural modulus of elasticity increased 6,4% to 10%wt and 8,8 to 20%wt in relation to polypropylene. The thermogravimery demonstrated the degradation temperatures of lignocellulosic residues (hemicellulose between 210,80 and 255,32 ?C, cellulose between 255,32 and 328,31, lignin between 328,31 e 495,82 ?C. For density testing, it was observed that the composites have a density values close to polypropylene, allowing the application in lightweight structures.

No description available.

The demand of mobile users with high data-rate services continues to increase. To satisfy the needs of such mobile users, operators must continue to enhance their existing networks. The radio interface is a well-known bottleneck because the radio spectrum is limited and therefore expensive. Efficient use of the radio spectrum is, therefore, very important. To utilise the spectrum efficiently, any of the channels can be used simultaneously in any of the cells as long as interference generated by the base stations using the same channels is below an acceptable level. In cellular networks based on Orthogonal Frequency Division Multiple Access (OFDMA), inter-cell interference reduces the performance of the link throughput to users close to the cell edge. To improve the performance of cell-edge users, a technique called Coordinated Multi-Point (CoMP) transmission is being researched for use in the next generation of cellular networks. For a network to benefit from CoMP, its utilisation of resources should be scheduled efficiently. The thesis focuses on the resource scheduling algorithm development for CoMP joint transmission scheme in OFDMA-based cellular networks. In addition to the algorithm, the thesis provides an analytical framework for the performance evaluation of the CoMP technique. From the system level simulation results, it has been shown that the proposed resource scheduling based on a joint maximum throughput provides higher spectral efficiency compared with a joint proportional fairness scheduling algorithm under different traffic loads in the network and under different criteria of making cell-edge decision. A hybrid model combining the analytical and simulation approaches has been developed to evaluate the average system throughput. It has been found that the results of the hybrid model are in line with the simulation based results. The benefit of the model is that the throughput of any possible call state in the system can be evaluated. Two empirical path loss models in an indoor-to-outdoor environment of a residential area have been developed based on the measurement data at carrier frequencies 900 MHz and 2 GHz. The models can be used as analytical expressions to estimate the level of interference by a femtocell to a macrocell user in link-level simulations.

Submitted by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-10-05T11:34:54Z No. of bitstreams: 1 TES_LUIS_FERNANDO_MELEGARI_COMPLETO.pdf: 6221745 bytes, checksum: 6fea166b18494e244d24dddc530d9abc (MD5) / Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-10-05T11:35:04Z (GMT) No. of bitstreams: 1 TES_LUIS_FERNANDO_MELEGARI_COMPLETO.pdf: 6221745 bytes, checksum: 6fea166b18494e244d24dddc530d9abc (MD5) / Made available in DSpace on 2017-10-05T11:35:13Z (GMT). No. of bitstreams: 1 TES_LUIS_FERNANDO_MELEGARI_COMPLETO.pdf: 6221745 bytes, checksum: 6fea166b18494e244d24dddc530d9abc (MD5) Previous issue date: 2017-07-25 / The use of polymeric materials to substitute an array of others like metal has its development level increased when new compounds are applied as well as new formation technologies. An approach of the main factors lately used for its assessment was necessary to prove the polymeric material?s behavior when applied in gears for strength transmission. The presented analysis were based on practical experiences and through methods of finite elements, using diverse composites and addition loads to form the tested polymers in controlled conditions for torque, temperature and rotation, making use of the device development of movement and specific control. The polymeric gears behave in different ways according to specific conditions of temperature, rotation and torque request, presenting a variety of results due to the polymers used in its formation. The geometry of the project and the profile construction of the conical gears? tooth had direct influence under the performance, being possible to reduce the tensions in the tooth?s root. The injected pieces supply a body of proves to a mechanic dynamic thermal analysis, these results present discrepancy among the base materials regarding Tm. The replacement of metallic materials for polymeric materials must consider the characteristics of each application. / A utiliza??o de materiais polim?ricos em substitui??o a diversos outros como o metal tem seu n?vel de desenvolvimento aumentado na aplica??o de novos compostos bem como novas tecnologias de forma??o. Uma abordagem dos principais fatores ultimamente utilizados para sua avalia??o fez-se necess?ria para a comprova??o do comportamento dos materiais polim?ricos na aplica??o em engrenagens de transmiss?o de for?a. As an?lises apresentadas foram baseadas em experimenta??es pr?ticas e atrav?s de m?todos de elementos finitos, utilizando diversos comp?sitos e cargas de adi??o para forma??o dos pol?meros testados em condi??es controladas de torque, temperatura e rota??o, utilizando-se de desenvolvimento de dispositivo de movimenta??o e controle espec?fico. As engrenagens polim?ricas comportaram-se de diferentes formas em condi??es espec?ficas de temperatura, rota??o e solicita??o de torque, apresentando resultados variados em fun??o dos pol?meros utilizados em sua forma??o. A geometria de projeto e constru??o do perfil do dente das engrenagens c?nicas teve influ?ncia direta em rela??o ao desempenho, sendo poss?vel a redu??o das tens?es na raiz do dente. As pe?as injetadas forneceram corpos de prova para an?lises t?rmico din?mico mec?nicas, os resultados destas apresentaram discrep?ncia entre os materiais base no que se refere a Tm. A substitui??o de materais met?licos por materiais polim?ricos deve levar em considera??o as caracter?sticas para cada aplica??o.

L'étude de dimensionnement d'un réseau cellulaire est une phase de conception qui doit permettre de déterminer les performances d'un système dans une configuration donnée. Elle inclut l'étude de couverture et l'analyse de trafic. De complexes simulations sont possibles pour connaître les paramètres de performances d'un réseau mais seules les études analytiques fournissent des résultats rapides. Par ailleurs, pour faire face à la demande de hauts débits, à la rareté du spectre fréquentiel et à l'impossibilité d'émettre à de plus fortes puissances, de nouvelles techniques de transmissions sont apparues. Nous sommes ainsi passés d'un système classique à une seule antenne à des systèmes à multiple antennes et même à des scénarios de coopération entre stations de base. Dans cette thèse, nous proposons des modèles analytiques pour l'étude des performances, notamment en termes de probabilités de coupure, de ces évolutions des réseaux cellulaires. Dans une première phase, nous considérons des systèmes multicellulaires à une antenne émettrice et une antenne réceptrice (SISO). Nous proposons deux méthodes d'étude de l'impact conjoint de l'affaiblissement de parcours, de l'effet de masque et des évanouissements rapides. Nous étudions, par la suite, un système à large bande utilisant le retournement temporel comme technique de transmission. Dans une deuxième phase, nous considérons des systèmes multicellulaires à antennes multiple à l'émission ou à la réception (MISO/MIMO) implémentant les schémas de diversité Alamouti et de combinaison par rapport maximal (MRC). Ensuite, nous considérons un système multicellulaire multi-utilisateurs à précodage de forçage à zéro (ZFBF).