Resource allocation in multibeam satellites

In this thesis resource allocation in multibeam satellites is studied. The multi-beam satellites transmit narrow beams using the available power and bandwidth. Multi-beam satellites provide many benefits in data communication by focusing on narrow surfaces on the earth. They are useful for lowering the cost of the earth station?s equipments. The surfaces on the earth which are illuminated by the transmitted beams are called cells. The system capacity increases by reusing the same frequencies in multiple cells. The purpose of the resource allocation in multi-beam satellites is to allocate power and beams optimally according to the users? traffic situation and channel conditions and to maintain the fairness among the users. In this thesis, previous studies on resource allocation in Multi-beam Satellites, and convex optimization for the optimal power allocation is discussed. Some greedy algorithms that are near-optimal are developed. The performances of the greedy algorithms and the Lagrange multiplier-based algorithm are compared. The rain and scintillation fadings that are the major channel problem in the Ka-bands are applied during the simulations. For this purpose atmospheric channel impairments in the Ka-band are also indicated. The characteristics of the multi-beam satellites, which have multi-beam satellite and phased array antenna are described. Resource allocation algorithms for the multi-beam satellite antennas proposed in the inter-beam interference situation and the system performance is investigated. The interference model in the literature for phased array satellite is applied. The performance of the algorithm in the literature and the algorithm that we proposed are compared.