The fundamentally fluctuating nature of the strength of a wireless link poses a significant challenge when seeking to achieve reliable communication at high data rates. Common sense, supported by information theory, tells us that one can move closer towards achieving higher data rates if the transmitter is provided with a priori knowledge of the channel. Such channel knowledge is typically provided to the transmitter by a feedback channel that is present between the receiver and the transmitter. The quality of information provided to the transmitter is proportional to the bandwidth of this feedback channel. Thus, the design of feedback channels is a key aspect in enabling high data rates. In the past, these feedback channels have been designed locally, on a link-by-link basis. While such an approach can be globally optimal in some cases, in many other cases, this is not true. In this thesis, we identify various settings in wireless networks, some already a part of existing standards, others under discussion in future standards, where the design of feedback channels is a problem that requires global, network-wide optimization. In general, we propose the treatment of feedback bandwidth as a network-wide resource, as the next step en route to achieving Gigabit wireless. Not surprisingly, such a global optimization initiative naturally leads us to the important issue of computational efficiency. Computational efficiency is critical from the point-of-view of a network provider. A variety of optimization techniques are employed in this thesis to solve the large combinatorial problems that arise in the context of feedback allocation. These include dynamic programming, sub-modular function maximization, convex relaxations and compressed sensing. A naive algorithm to solve these large combinatorial problems would typically involve searching over a exponential number of possibilities to find the optimal feedback allocation. As a general theme, we identify and exploit special application-specific structure to solve these problems optimally with reduced complexity. Continuing this endeavour, we search for more intricate structure that enables us to propose approximate solutions with significantly-reduced complexity. The accompanying analysis of these algorithms studies the inherent trade-offs between accuracy, efficiency and the required structure of the problem. / text

La demande des systèmes de communication sans fil pour des débits élevés continue d'augmenter, et il n'y a pas de signes que cette tendance va se ralentir. Trois des techniques les plus importantes qui ont émergé pour répondre à de telles demandes sont l'OFDMA, le relais coopératif et le MIMO. Afin d'utiliser pleinement les capacités des systèmes appliquant de telles techniques, il est essentiel de développer des algorithmes efficaces d'ordonnancement et, plus généralement, des algorithmes efficaces d'allocation de ressources. Les études classiques sur ce sujet examinent des systèmes où les demandes de données des utilisateurs ne sont pas prises en considération et/ou un CSI parfait et complet est supposée être disponible pour le mécanisme d'ordonnancement. Cependant, dans la pratique, différentes limitations peuvent entraîner l'absence d'une connaissance parfaite et/ou complète du CSI, telles que les ressources limitées pour le feedback, le co^ut de sondage et le retard dans le processus de feedback.Par conséquent, dans cette thèse nous examinons les problèmes d'ordonnancement et de feedback sous des considérations réalistes concernant la connaissance du CSI. L'analyse est effectuée au niveau des paquets et considère la dynamique des files d'attente avec des processus d'arrivée arbitraires, et où la mesure de performance principale que nous adoptons est la stabilité des files d'attente. La première partie de la thèse considère un système MIMO multipoint à multipoint utilisant le mode TDD, tout en supposant un backhaul à capacité limitée et en tenant compte du coût du feedback. En ce qui concerne la technique de gestion de l'interférence, nous appliquons l'alignement d'interférence (IA) si plus d'une paire sont actives et SVD si une seule paire est active. La deuxième partie de la thèse considère un système OFDMA avec plusieurs utilisateurs et canaux, où un feedback retardé et limité est pris en compte. Deux scénarios sont étudiés, à savoir le système sans relais et le système avec relais. Pour ce dernier, nous considérons une imperfection supplémentaire supposant que les utilisateurs ont une connaissance incomplète des coefficients du fading entre la station de base et le relais. / Demand of wireless communication systems for high throughputs continues to increase, and there are no signs this trend is slowing down. Three of the most prominent techniques that have emerged to meet such demands are OFDMA, cooperative relaying and MIMO. To fully utilize the capabilities of systems applying such techniques, it is essential to develop eficient scheduling algorithms and, more generally, eficient resource allocation algorithms. Classical studies on this subject investigate in much detail settings where the data requests of the users are not taken into consideration or where the perfect and full CSI is assumed to be available for the scheduling mechanism. In practice, however, diferent limitations may result in not having perfect or full CSI knowledge, such as limited feedback resources, probing cost and delay in the feedback process. Accordingly, in this thesis we examine the problems of scheduling and feedback allocations under realistic considerations concerning the CSI knowledge. Analysis is performed at the packet level and considers the queueing dynamics in the systems with arbitrary arrival processes, where the main performance metric we adopt is the stability of the queues. The first part of the thesis considers a multi-point to multi-point MIMO system with TDD mode under limited backhaul capacity and taking into account the feedback probing cost. Regarding the interference management technique, we apply interference alignment (IA) if more than one pair are active and SVD if only one pair is active. The second part of the thesis considers a multiuser multichannel OFDMA-like system where delayed and limited feedback is accounted for. Two scenarios are investigated, namely the system without relaying and the system with relaying. For the latter one, an additional imperfection we account for is that the users have incomplete knowledge of the fading coeficients between the base-station and the relay.