Constrained optimized resource allocation for multiuser multicarrier wireless systems

(eng) Multicarrier transmission schemes have been widely adopted in wireless communication systems. Multiple users can share a multicarrier wireless channel using multiple access mechanisms such as multi-carrier code division multiple access (MC-CDMA) or orthogonal frequency division multiple access (OFDMA). In multiuser systems, users are allowed to have different quality of service (QoS) requirements. On another hand, users have channels of different quality. Therefore the achievement of fairness among the users while satisfying users' QoS requirements is an important issue. Due to the limited resources available at the base station, e.g. bandwidth and power, optimized allocation of these resources to users is crucial for delivering the best possible QoS to the user with least cost. This thesis proposes a new class of algorithms which achieves the users' fairness and QoS requirements under total power constraint. In most of previous works on multicarrier resource allocation, it has been assumed that perfect channel state information (CSI) is available at the transmitter. However, perfect CSI at the transmitter is rarely possible due to channel estimation errors and channel feedback delay. This thesis develops analytical framework and derives practical algorithms for downlink resource allocation assuming that only statistical channel information is available at the base station. The most intuitive and up to now, the most widely used strategy to increase coverage in wireless networks, is to shrink the size of the cell, effectively increasing the number of base stations (BS) over a given area. Although this strategy likely will increase coverage because users are much closer to their serving BSs, its benefit is limited because of the exceeding cost of BSs. For each BS, the provider must pay for antenna space and the wired backhaul to the network, not to mention the digital and radio frequency equipment itself. Instead, an increasingly attractive strategy is to insert relaying stations into the cell whose sole purpose is to aid communication from BS to mobile station (MS) and vice versa. Such communications are called cooperative communications. This thesis extends the analytical framework and algorithms proposed for resource allocation in non-cooperative communication systems to resource allocation strategies in cooperative communication systems.