Emparelhamento de subportadoras e alocação de potência de transmissão para redes cooperativas

Abstract

present in the fourth generation of mobile communications due to its potential to combat fading and extend the cell coverage area. In addition, efficient radio resource management when applied to relay networks is capable of improving the performance of mobile communication systems in terms of space diversity, coverage, spectral and energy efficiencies. One of the main assumption in our work is a discrete mapping between channel quality and transmit data rate. This discrete mapping models the use of finite MCSs and has been neglected by most of the articles in the literature. In this master thesis we formulate two problems. The first problem consists in the maximization of the total data rate in a cooperative system through subcarrier pairing and transmit power allocation. The second problem aims at maximizing the number of satisfied users with the demanded QoS. For both problems we provide the optimal solution, some basic properties and suboptimal solutions with low computational complexity. By means of computational simulations, we show that the proposed solution to the total data rate maximization problem has a maximum error to the optimal solution lower than 0.1%. Furthermore, the heuristic solution proposed to the problem of maximizing the number of satisfied users is capable of attaining a performance loss in the number of satisfied users not higher than 10% to the optimal solution with much lower transmit power leading to energy efficiency gains.