Multi-beam Satellite Resource Allocation Optimization for Beam Hopping Transmission

Multi-beam satellite systems have been studied a lot in the last ten years. They have many promising features like power gain, interference reduction, high flexibility to adapt the asymmetric traffic distribution, and the improvement of the system capacity compared with single-beam systems. In multi-beam satellite systems, the beamforming antenna can generate a number of spot beams over the coverage area. However, each beam will compete with others for resources to achieve satisfactory communication. This is due to the fact that the traffic demand is potentially highly asymmetrical throughout the satellite coverage. Therefore, in order to achieve a good match between offered and requested traffic, the satellite requires a certain degree of flexibility in allocating power, bandwidth and time-slot resources. Current multibeam satellite systems with regular frequency reuse and uniform power allocation can not satisfy these increasing requirements, which motivate us to investigate new transmission schemes to replace the current ones. In this dissertation, we first propose a novel system design, flexible system, which is an extension of current multi-beam systems. It is characterized by the non-regular frequency reuse and the flexibility in bandwidth and power allocation. Then, the Beam Hopping (BH) system is proposed to evaluate the performance improvement with the flexibility in time/space and power domain. As we know, the flexible system and BH system operate in frequency and time/space domain, respectively. In order to know which domain shows the best overall performance, we propose a novel formulation of the Signal-to-Interference plus Noise Ratio (SINR) which allows us to prove the time/frequency duality of these two schemes. Furthermore, to efficiently utilize the satellite resources (e.g., power and bandwidth), we propose two capacity optimization approaches subject to per-beam SINR constraints. Moreover, due to the realistic implementation, a general methodology is formulated including the technological constraints, which prevent the two systems dual of each other (named as technological gap). The Shannon capacity (upper bound) and the state-of-art Modulation and Coding (MODCOD) are analyzed in order to quantify the gap and evaluate the performance of the two candidate schemes. Comparing with the current conventional systems, simulation results show significant improvements in terms of power gain, spectral efficiency and traffic matching ratio. They also show that the BH system is less complex design and outperforms the flexible system specially for non-real time services. This part of the Ph.D. work supported by an ESA-funded project on next generation system of “Beam Hopping Techniques for Multi-beam Satellite Systems”. This research is in close collaboration with the leading space industry (e.g. INDRA,