Multi-beam Satellite Communication System Based On Coordinated Multi-point Transmission

The next generation satellite communication system has developed towards higher throughput and transmission speed.And the multi-beam antennas has been widely applied in the space satellites due to its high gain and space isolation etc.To maximize spectrum utilization,full frequency reuse is mostly adopted among beams.How to effectively eliminate inter-beam interference and manage beam handover to ensure communication quality become quite necessary.This paper compared channels used in data interaction between multi-beam and multi-users in ground segment with the ground distributed MIMO system to study the satellite communication system based on coordinated multiple transmission.The effect of precoding technology in eliminating inter-beam interference was further studied.This paper mainly studied the principle and performance of traditional precoding algorithm in an ideal channel state.It is simulated and compared under the terrestrial MIMO system and the 7-beam satellite coverage model.It was simulated and compared under the terrestrial MIMO system and the 7-beam satellite coverage model.Then a MMEE algorithm based on DPC principle was proposed.The simulation results indicated that the performance of the low complexity algorithms is between linear and nonlinear algorithms,which achieved the balance between complexity and system performance.Further,in the non-ideal Channel State Information,according to the channel error model,this paper put forward the robust precoding based on MMSE criteria,the robust precoding based on average power minimization and the interrupt probability constrained robust precoding based on SLNR criteria.The semi-definite relaxation theorem was used to optimize target.Applying MATLAB software simulation to compare robustness design,system capacity and bit error in the non-ideal CSI proved that the robust precoding design can achieve better system performance under non-ideal CSI condition.Finally,aiming at beam handover management,this paper mainly explored the handover scheme during collaboration among beams.The collaborative-based handover invitation mechanism was proposed based on studies about the user mobility model,the collaborative handover principle and the slide window mechanism.The MATLAB simulation verified that handover invitation can effectively improve the handover success rate and simplify the process of signal measurement and decision.