The main goal of this thesis will be the design and implementation of a 2048-point FFT on an FPGA through the use of VHDL code.The FFT will use a butterfly Radix-2 architecture with focus on the comparison of the parameters between the system with different Worlengths, Coefficient Wordlengths and Symbol Error rates as well as different modulation types, comparing 64QAM and 256QAM for the 5Gsystem.This implementation will replace an FFT function block in a Matlab based open source 5G NR simulator based on the 3GPP 15 standard and simulate spectrum, MSE payload,and SER performance.

The objective of this thesis research is to optimize network throughput and fairness, and enhance bandwidth utilization in wireless mobile multi-hop relay (MMR) networks. To enhance bandwidth utilization, we propose an adaptive OFDMA frame structure which is used by the base station and the non-transparent relay stations. To optimize throughput and fairness, we develop an adaptive OFDMA allocation algorithm by using the proposed adaptive OFDMA frame. The effectiveness of the proposed schemes has been verified by numeric simulations. Providing ubiquitous coverage with wireless metropolitan area networks (WMANs) can be costly, especially in sparsely populated areas. In this scenario, cheaper relay stations (RSs) can be used to provide coverage instead of expensive base stations (BSs). The RS extends the coverage area of traditional BSs. This sort of network is known as a wireless MMR network. This thesis focuses on MMR networks that use orthogonal frequency division multiple access (OFDMA) and time division duplex (TDD) as a multiple access scheme and a duplex communication technique (e.g., WiMAX). The use of OFDMA resources (e.g., OFDMA symbols and subcarriers) and how they are shared in current schemes can reduce system capacity and network throughput in certain scenarios. To increase the capacity of the MMR network, we propose a new protocol that uses an adaptive OFDMA frame structure for BSs and RSs. We also propose adaptive OFDMA resource allocation for subscriber stations (SSs) within a BS or RS. We derive the maximum OFDMA resources that RSs can be assigned and synchronize access zones and relay zones between a superior station and its subordinate RSs. This is bounded by three properties defined in this thesis: a data relay property, a maximum balance property, and a relay zone limitation property. Finally, we propose max-min and proportional fairness schemes that use the proposed adaptive frame structure. The proposed scheme is the first approach that incorporates the adaptive technique for wireless MMR networks. We evaluate our scheme using simulations and numerical analysis. Results show that our technique improves resource allocation in wireless MMR networks. Further, in asymmetric distributions of SSs between access zones and relay zones, the proposed OFDMA allocation scheme performs two times better than the non-adaptive allocation scheme in terms of average max-min fairness and 70% better in terms of average throughput.

Zugl.: Aachen, Techn. Hochsch., Diss., 2008.

Nous proposons dans cette thèse d'exploiter la Modulation Hiérarchique (MH) dans un système OFDMA avec et sans utilisation des relais en vue d'améliorer d'avantage la capacité du système en tirant profit de la diversité d'utilisateurs. MH permet de transmettre un flux supplémentaire à un utilisateur de bonnes conditions radio sur une sous-porteuse initialement allouée à un utilisateur de mauvaises conditions radio. Ceci est différent des techniques classiques d’allocation de ressources proposées dans la littérature qui respectent une orthogonalité parfaite lors de l'allocation : une sous-porteuse est allouée à un seul utilisateur et aucun autre utilisateur ne pourra l'utiliser en même temps. Dans la littérature, la plupart des travaux qui se sont intéressés à l'utilisation de la MH se sont concentrés seulement sur les performances en termes de couche basse avec un nombre fixe d'utilisateurs dans le système correspondant à une configuration statique. Toutefois, cette configuration ne reflète pas la dynamicité du nombre d'utilisateurs dans un tel système, où les utilisateurs arrivent selon une loi aléatoire et partent après avoir fini leurs services. Dans cette thèse, nous exposons l'étude des performances de l'utilisation de la MH avec des configurations dynamiques d'utilisateurs correspondant à une étude au niveau flux. Cela nous permet d'évaluer les performances en termes de nouvelles métriques à savoir le temps moyen de transfert et la probabilité de blocage qui sont importantes pour l'utilisateur et pour l'opérateur. / We investigate, in this thesis, the use of Hierarchical Modulation (HM), a physical layer technique that enables to exploit multiuser diversity, for resource allocation in OFDMA-based systems with and without use of relaying, so as to improve the system capacity. HM allows the sharing of the resources, namely subcarriers and power, between users of different radio conditions by sending an additional stream to a user with good radio conditions on a subcarrier that was initially allocated to carry an original stream to a user with lower radio conditions. And this, without affecting the original user's rate nor the total amount of power assigned to the shared subcarrier. In the literature, most of the works that consider the use of HM focus solely on the physical layer performance, notably in terms of the bit error rate. And this for a static user scenario,i.e., with a fixed number of users in the system, each with an infinite service duration. This configuration however does not reflect the real system behavior where the number of users is dynamic, i.e., the users come to the system at random time epochs and leave it after a finite duration, corresponding to the completion of their services. The study of the system at the flow-level, as opposed to the packet level, for a dynamic user configuration, enables us to investigate the realistic relationship between capacity and demand and to quantify several system-level performance metrics, such as mean transfer times and blocking rates, which are meaningful both to the user and the network operator/provider.

Dans les systèmes de communications sans fils, l'allocation de ressources reste toujours un défi considérable afin de satisfaire les demandes des utilisateurs et de fournir de bonnes performances avec une perpétuelle demande en applications gourmandes en ressources. Les techniques multiporteuses essentiellement les techniques dérivant de l'OFDM sont généralement utilisées pour transmettre les données dans des sous-porteuses orthogonales. De plus, de nouvelles stratégies de relayage sont proposées pour améliorer les performances en bordures de cellules. Plusieurs types de relais peuvent être sollicités comme les relais fixes faisant partie de l'infrastructure du système ou les relais mobiles qui ne nécessitent pas un coût additionnel de déploiement.Dans cette thèse, nous étudions principalement l'allocation des ressources pour le sens montant d'un système cellulaire OFDMA assurant les exigences de qualité de service et l'équité entre les utilisateurs. Les algorithmes d'allocation de ressources les plus utilisés sont présentés et un nouvel algorithme se basant sur l'équité proportionnelle pondérée (WPF) est proposé afin d'approcher les bornes supérieures de débit et d'équité. L'algorithme WPF propose un poids variable par utilisateur permettant d'allouer un nombre plus élevé de sous-porteuses au centre de la cellule qu'en bordure tout en gardant une bonne équité entre les utilisateurs. Nous établissons une étude théorique afin de comparer l'algorithme proposé à l'algorithme classique d'équité proportionnelle (PF). Nous étendons ensuite l'algorithme WPF à un système multi-cellulaire où l'interférence inter-cellulaire (ICI) dégrade les performances du système. Enfin, nous étudions les stratégies d'annulation de l'ICI et proposons une nouvelle méthode pour réduire l'ICI en se basant sur la coopération entre les stations de base (BSs) et sur les indicateurs d'interférence. Nous proposons un nouvel indicateur d'interférence (EII) à valeurs entières échangé par les BSs pour indiquer les niveaux d'interférence des sous-porteuses. En prenant en compte les valeurs de EII échangées, chaque BS alloue dynamiquement les sous-porteuses de manière à éviter de fortes valeurs d'ICI.Dans un deuxième temps, nous étudions la communication coopérative en utilisant des relais mobiles. Pour cela, de simples utilisateurs mobiles ayant des positions avantageuses peuvent relayer d'autres utilisateurs en bordure de cellule en plus de transmettre leurs propres données. Un relai utilisant le protocole DF multiplexe ainsi ses propres données aux données relayées avant de transmettre à la BS. L'allocation de ressource est formulée sous forme d'un problème d'optimisation dont le but est de minimiser la puissance totale d'émission du système tout en assurant un débit cible par utilisateur. Dans un premier temps, nous proposons une méthode de sélection des relais comme phase d'initialisation et offrons une heuristique itérative pour optimiser l'allocation de puissance et des blocs de ressources radio (RBs). Dans un second temps, nous traitons la sélection des relais comme une variable d'optimisation additionnelle. Pour la résolution, la décomposition de Lagrange et la méthode duale sont utilisées et le problème global est divisé en sous problèmes résolus de manière itérative afin d'approcher la solution optimale. Enfin, nous étendons ce modèle coopératif à un modèle à antennes multiples (MIMO) afin d'étudier l'influence des antennes multiples sur la puissance totale de transmission. Les paramètres à optimiser sont la sélection des relais, l'allocation des puissances et l'allocation des RBs. Afin d'allouer la puissance sur les antennes d'un utilisateur, nous avons étudié la répartition égale des puissance (EPA) et le beamforming. Les expressions théoriques correspondantes sont établies et les résultats de simulation sont présentés pour comparer le modèle avec EPA et le modèle avec beamforming au modèle non coopératif. / In wireless systems, resource allocation is still an important challenge to satisfy user requirements and to ensure good system performances with always greedy data applications. Multicarrier techniques especially the Orthogonal Frequency Division Multiplexing (OFDM) techniques are generally used to carry data into orthogonal subcarriers. Furthermore, relaying strategies are used to enhance cell edge performances. Many types of relays can be investigated as fix relays being part of the network infrastructure or mobile relays without additional deployment cost.In this thesis, we mainly consider the resource allocation for an uplink Orthogonal Frequency Division Multiple Access (OFDMA) system for a cellular system model ensuring Quality of Service (QoS) requirements and fairness between users. The most used resource allocation algorithms are presented and a novel Weighted Proportional Fair (WPF) algorithm is proposed to approach upper bounds of both throughput and fairness. The WPF algorithm considers user weights to allocate more subcarriers in the cell center than in the cell edge keeping sufficient fairness between users. We establish a theoretical analysis to compare the behavior of the proposed WPF algorithm to the classical Proportional Fair (PF) algorithm. Then, we extend this WPF algorithm to a multi-cell system model where the Inter-Cell Interference (ICI) limits the system performance. Moreover, we study ICI mitigation strategies and propose a novel method to reduce the ICI based on Base Station (BS) cooperation and interference indicators. We propose the Enhanced Interference Indicator (EII) with integer values to be exchanged by the BSs indicating interference levels for the subcarriers. Function of these communicated EII values, each BS allocates dynamically subcarriers in order to reduce the ICI. Our contributions in the multi-cell system model are the WPF and the EII.Moreover, we investigate in this dissertation the cooperative communication using mobile relays and propose multiple contributions. For this, simple mobile users with advantageous positions can relay cell edge users to carry data to the BS in addition to their own data. A Decode and Forward (DF) relay multiplex then its own data and relayed data before transmitting to the BS. The resource allocation is formulated as an optimization problem aiming to minimize the system transmit power and respecting a required target data rate per user constraint. In a first time, we propose an initialization method for the paring step to associate source-relay pairs and propose an iterative heuristic to optimize both power and Resource Blocks (RB) allocations. In a second time, we consider the relay selection as an optimization variable in addition of power and RB allocations. For resolution, Lagrangian decomposition and Dual method are used and the global problem is divided into subproblems iterativelly resolved to approach the optimal solution. Finally, we extend this cooperative system model to a Multiple Input Multiple Output (MIMO) system model to study the influence of multiple antennas on the system transmit power. The features to optimize are relay selection, power and RBs allocation. Moreover, to allocate power in the different antennas for each user, both Equal Power Allocation (EPA) and beamforming are studied. Theoretical expressions are established and simulations results are presented to compare EPA, beamforming and non-cooperative system.

La communication mobile est considérée comme l'un des piliers des villes intelligentes, où les citoyens devraient pouvoir bénéficier des services de télécommunications partout et quand ils les souhaitent, d'une manière sûre et peu coûteuse. Cela est possible grâce à un déploiement dense des réseaux mobiles à large bande de dernière génération. Ce déploiement dense entraînera une consommation énergétique plus élevée et donc plus d'émissions de gaz et de pollution. Par conséquent, il est crucial d'un point de vue environnemental de réduire la consommation d'énergie. Dans le cadre de cette thèse, nous introduisons des méthodes dynamiques de gestion de ressources permettant d'augmenter le débit et l'efficacité énergétique, et réduisant ainsi la pollution. Ainsi, nous ciblons les réseaux multicellulaires verts où l'augmentation de l'efficacité énergétique doit tenir en compte de l'accroissement de la demande de débit par les utilisateurs mobiles. Cette augmentation, exponentielle en terme de débit, a poussé les opérateurs à utiliser la totalité du spectre fréquentiel dans toutes les cellules des réseaux mobiles de dernière génération. Par conséquence, l'interférence intercellulaire (ICI : Inter-Cell Interference) devient prépondérante et dégrade la performance des utilisateurs, en particulier ceux ayant de mauvaises conditions radios. Dans cette thèse, nous nous focalisons sur la technique du contrôle de puissance considérée comme une des méthodes clé de la coordination d'interférence Intercellulaire (ICIC : Inter-Cell Interference Coordination), tout en mettant l'accent sur des méthodes efficaces énergétiquement. Nous formulons ce problème d'allocation de la puissance, sur le lien descendant en mettant en œuvre des méthodes centralisées et décentralisées: les méthodes centralisées ayant recours à l'optimisation convexe alors que les méthodes décentralisées se basant sur la théorie des jeux non-coopératifs. Par ailleurs nous proposons ensuite une heuristique de contrôle de puissance qui a l'avantage d'être stable et basée sur des messages de signalisation déjà existant dans le système. Cette heuristique permet d'éviter le gaspillage de la bande passante par des signalisations intercellulaires et de réduire le ICI. De plus, le problème de contrôle de puissance a un impact important sur l'allocation des ressources radios et sur l'association des utilisateurs mobiles à une station de base. Ainsi, dans la deuxième partie de la thèse, nous avons formulé un problème globale englobant le contrôle de puissance, le contrôle d'allocation de ressources radios, et le contrôle de l'association des utilisateurs à une station de base, cela afin d'obtenir une solution globalement efficace. Ces trois sous problèmes sont traités itérativement jusqu'à convergence de la solution globale. En particulier nous proposons pour la problématique d'association des utilisateurs trois algorithmes: un algorithme centralisé, un algorithme semi-distribué et finalement un algorithme complètement distribué se basant sur l'apprentissage par renforcement. Par ailleurs, pour l'allocation de puissance, nous implémentons des solutions centralisées et des solutions distribuées. Les preuves de convergence des algorithmes ont été établies et les simulations approfondies ont permis d'évaluer et de comparer quantitativement les performances, l'efficacité énergétique et le temps de convergence des algorithmes proposés. / Mobile communication is considered as one of the building blocks of smart cities, where citizens should be able to benefit from telecommunications services, wherever they are, whenever they want, and in a secure and non-costly way. This can be done by dense deployment of the latest generation of mobile broadband networks. However, this dense deployment will lead to higher energy consumption, and thus more gas emission and pollution. Therefore, it is crucial from environmental point of view to propose solution reducing energy consumption. In this thesis, we introduce dynamic resource management methods that increase throughput and energy efficiency, and thus reduce pollution. In this framework, we are targeting green multi-cell networks where increased energy efficiency must take into account the increased demand of data by mobile users. This increase, which is exponential in terms of throughput, pushed operators to use the entire frequency spectrum in all cells of the latest generation of mobile networks. As a result, Inter-Cellular Interference (ICI) became preponderant and degraded the performance of users, particularly those with poor radio conditions. In this thesis, we focus on the techniques of power control on the downlink direction, which is considered as one of the key methods of Inter-Cell Interference Coordination (ICIC) while focusing on energy efficient methods. We propose centralized and decentralized methods for this problem of power allocation: centralized methods through convex optimization, and decentralized methods based on non-cooperative game theory. Furthermore, we propose a power control heuristic which has the advantage of being stable and based on signaling messages already existing in the system. The power control problem has a relevant impact on the allocation of radio resources and on the association of mobile users with their servicing Base Station. Therefore, in the second part of the thesis, we formulated a global problem encompassing power control, radio resources allocation, and control of users’ association to a base station. These three sub-problems are treated iteratively until the convergence to the overall solution. In particular, we propose three algorithms for the user association problem: a centralized algorithm, a semi-distributed algorithm and finally a fully distributed algorithm based on reinforcement learning. In addition, for power allocation we implement centralized solutions and distributed solutions. The proof of convergence for the various algorithms is established and the in-depth simulations allow us to evaluate and compare quantitatively the performance, the energy efficiency, and the convergence time of the proposed algorithms.

The widespread application of wireless services and the requirements of ubiquitous access have recently triggered rapidly booming energy consumption in wireless communications networks. Such escalation of energy consumption in wireless networks causes high operational expenditure from electricity bills for operators, unsatisfactory user experience due to limited battery capacity of wireless devices, and a large amount of greenhouse gas emission. Green radio (GR), which emphasizes both energy efficiency (EE) and spectral efficiency (SE), has been proposed as an effective solution and is becoming the mainstream for future wireless network design. Unfortunately, EE and SE do not always coincide and may even sometimes conflict. In this dissertation, we focus on energy-efficient transmission and resource allocation techniques for orthogonal frequency division multiple access (OFDMA) networks and the joint energy-efficient design of OFDMA and other promising wireless communications techniques, such as cognitive radio (CR) and two-way relay. Firstly, we investigate the principles of energy-efficient design for pure OFDMA networks. As the first step, we study the fundamental interrelationship between EE and SE in downlink OFDMA networks and analyze the impacts of channel gain and circuit power on the EE-SE relationship. We establish a general EE-SE optimization framework, where the overall EE, SE and per-user quality-of-service (QoS) are all considered. Under this framework, we find that EE is quasiconcave in SE and decreases with SE when SE is large enough. These findings are very helpful guidelines for designing energy- and spectral-efficient OFDMA. To facilitate the application of energy-efficient resource allocation, we then investigate the energy-efficient resource allocation in both downlink and uplink OFDMA networks. For the downlink transmission, the generalized EE is maximized while for the uplink case the minimum individual EE is maximized, both under prescribed per-user minimum data rate requirements. For both transmission scenarios, we first provide the optimal solution and then develop an computationally efficient suboptimal approach by exploring the inherent structure and property of the energy-efficient design. Then we study energy-efficient design in downlink OFDMA networks with effective capacity-based delay provisioning for delay-sensitive traffic. By integrating information theory with the concept of effective capacity, we formulate and solve an EE optimization problem with statistical delay provisioning. We also analyze the tradeoff between EE and delay, the relationship between spectral-efficient and energy-efficient designs, and the impact of system parameters, including circuit power and delay exponents, on the overall performance. Secondly, we consider joint energy-efficient design of OFDMA and CR and two-way relay, respectively, to further enhance the EE and SE of wireless networks. We study energy-efficient opportunistic spectrum access strategies for an OFDMA-based CR network with multiple secondary users (SUs). Both worst EE and average EE of the SUs are considered and optimized subject to constraints including maximum transmit power and maximum interference to primary user (PU) system. For both cases, we first find the optimal solution and then propose a low-complexity suboptimal alternative. The results show that the energy-efficient CR strategies significantly boost EE compared with the conventional spectral-efficient CR ones while the low-complexity suboptimal approaches can well balance the performance and complexity. Then we study energy-efficient resource allocation for OFDMA-based two-way relay, which aims at maximizing the aggregated EE utility while provisioning proportional fairness in EE among different terminal pairs. Different from most exist energy-efficient design, we consider a new circuit power model, where the dynamic circuit power is proportional to the number of active subcarrier. For low-complexity solution, we propose an EE-oriented sequential subchannel assignment policy and discover the sufficient condition for early termination of the sequential subchannel assignment without losing the EE optimality. It is found that the energy-efficient transmission does not necessarily make all the subcarriers active, which is another useful principle for practical energy-efficient system design.

A grande popularidade dos dispositivos móveis que provêm acesso ubíquo à Internet de banda larga, através de redes de rádio, e o volume de tráfego gerado por estes dispositivos estão aumentando a cada ano. Além disso, vem ampliando consideravelmente a frequência com que usuários de dispositivos móveis estão usando serviços baseados na Web. Alguns destes usuários podem estar acessando serviços que precisam de transmissão contínua como, por exemplo, vídeos interativos, outros podem estar apenas lendo e-mails, o que não exige um fluxo contínuo de dados. Mais do que isso, usuários com altos níveis de sinal podem atingir melhores taxas de transferência do que os com níveis menores. Portanto, encontrar a melhor relação entre os usuários que estão acessando serviços sensíveis ao atraso e aqueles que maximizam a taxa de transferência, e ainda ser justo na transmissão, é um relevante desafio para o escalonamento dos recursos de uma rede sem fio. Embora as pesquisas de escalonamento de recursos em redes sem fio tenham evoluído neste sentido, o recente aumento do volume de tráfego mencionado pode levar a uma sobrecarga no sistema, comprometendo o escalonamento. A fim de enfrentar estes desafios, o Orthogonal Frequency Division Multiple Access (OFDMA), tecnologia fundamental para o acesso múltiplo em redes de quarta geração, tem sido considerado também para ser utilizado na próxima geração de rádios móveis. Para implementar um serviço efetivo aos usuários, requisitos, tais como, altas taxas de transferência, tolerância baixa ao atraso, minimização da perda de pacotes e maximização da justiça no escalonamento, devem somar-se à característica, de alta densidade de usuários, que surgiu após o advento da popularização dos dispositivos móveis. Portanto, novas estratégias de escalonamento devem ser idealizadas. Nesta dissertação, deu-se um passo além na proposição de um escalonador para as redes móveis de próxima geração, que busca melhorar a relação entre taxa de transferência e atraso, consequentemente, levando a maiores índices de justiça no escalonamento resultante. O escalonador foi especialmente desenvolvido para lidar com altas densidades de usuários, inerentes às redes modernas, e as redes LTE foram utilizadas como caso de estudo. Desta forma, um novo escalonador ótimo que considera provisão dos requisitos acima mencionados, é modelado. Além disso, uma nova heurística parametrizável, baseada na qualidade do canal do usuário, no atraso permitido por cada serviço e na justiça do escalonamento é proposta, a fim de lidar com cenários sobrecarregados. Resultados demonstram que a abordagem de escalonamento proposta leva a uma taxa de transferência apenas 7,5% menor que os valores ótimos, com 25% a menos de perda de pacotes em cenários sobrecarregados. O modelo também garante que o escalonamento resultante seja pelo menos 0,91 na escala do índice de justiça de Jain. Finalmente, os resultados mostram uma melhor relação entre a eficiência espectral e as métricas de QoS. / The huge popularity of mobile devices that provides a ubiquitous Internet broadband access via radio networks and the volume of traffic generated by these devices in the base stations are increasing every year. Furthermore, the frequency which, mobile users are using web-based services, is increasing, requiring high transfer rates such as transmission of interactive videos. These factors have become the main challenges for the scheduling of radio resources. In order to meet these challenges, the Orthogonal Frequency Division Multiple Access (OFDMA), a key technology for multiple access in fourth generation networks, has also been considered for use in next-generation mobile radios. To implement an effective service to users, requirements such as high transfer rates, lower delay tolerance, minimum packet loss and maximum scheduling fairness, should be added to the requirements that emerged after the advent of the popularity of mobile devices. Therefore, new scheduling strategies should be projected. Despite efforts to solve the downlink (DL) scheduling problem on wireless networks, we are not aware of previous attempts that have addressed the above requirements in a single strategy. In this thesis, we took a step further in this direction and still considering the high densities in small cells inherent in modern networks. In additional, we address the radio DL resource scheduling problem for multiple users using LTE networks as a case study. A new optimal scheduler is modeled regarding Quality of Service (QoS) provisioning. In addition, a parameterized heuristic based on user channel quality and service delay is proposed to reach scheduling solutions for overbooked scenarios. Results demonstrate that the proposed scheduling approaches led to a throughput of 7.5% lower than the optimal ones and 25% lower packet losses in overloaded scenarios. Our model also ensures that the resultant scheduling is at least as fair as 0.91 in Jain fairness index. Additionally, the obtained results show a reasonable trade-off between spectral efficiency and QoS metrics.

La thèse étudie des méthodes d'allocation de ressources, distribuées par station de base (BS) dans les réseaux OFDMA multi-cellulaires. L'objectif est de fournir la Qualité de Service (QdS) requise par chaque utilisateur, quelle que soit sa localisation dans la cellule. Les travaux portent d'abord sur la coordination causale de réseaux. Deux BSs forment un lien MIMO virtuel pour les utilisateurs localisés en bordure de cellule. Ces utilisateurs bénéficient d'un gain de diversité et d'une diminution de l'interférence inter-cellulaire. L'efficacité de la méthode d'allocation de ressources associée dépend de l'équité du contrôle de puissance. En conséquence, la coordination de réseaux est utilisée pour les utilisateurs à Débit Contraint (DC), mais pas pour les utilisateurs Best Effort (BE), dans un algorithme permettant de gérer conjointement les deux objectifs de QdS. La thèse étudie ensuite les réseaux totalement distribués. Pour les utilisateurs DC, une méthode d'allocation de ressources incluant une allocation de puissance itérative est déterminée pour résoudre le problème Margin Adaptive. Cette méthode est étendue aux utilisateurs DC en MIMO, lorsque le transmetteur connaît tout l'information de canal, ou uniquement ses caractéristiques statistiques. Pour les utilisateurs BE, enfin, l'objectif est de maximiser la somme des débits pondérés, le poids de chaque utilisateur étant proportionnel à la longueur de sa file d'attente. Une méthode d'allocation de sous-porteuses, déduite d'un graphe d'interférence, et une méthode de contrôle de puissance distribuée sont proposées pour résoudre ce problème d'optimisation.

This master thesis investigates the uplink transmition from User Equipment (UE) to base station in LET (Long Term Evolution) and channel estimation using pilot symbols with parameter defined in 3GPP (3rd Generation Partnership Project) specifications. The purpose of the thesis was to implement a simulator which can generate uplink signal as it is generated by UE. The Third Generation (3G) mobile system was given the name LTE. This thesis focus on the uplink of LTE where single carrier frequency division multiple access (SC-FDMA) is utilized as a multiple access technique. The advantage over the orthogonal frequency division multiple access (OFDMA), which is used in downlink is to get better peak power characteristics. Because in uplink communication better peak power characteristic is necessary for better power efficiency in mobile terminals. To access the performance of uplink transmition realistic channel model for wireless communication system is essential. Channel models used are proposed by International Telecommunication Union (ITU) and the correct knowledge of these models is important for testing, optimization and performance improvements of signal processing algorithms. The channel estimation techniques used are Least Square (LS) and Least Minimum Mean Square Error (LMMSE) for different channel models. Performance of these algorithms has been measured in term of Bit Error Rate (BER) and Signal to Noise Ratio (SNR).