Research On Beam Handover Of GEO Satellite Based On Beam Hopping

Multi-beam GEO satellites have greatly improved the communication capacity through key technologies such as multi-point beam and high gain,and solved the problem of small communication capacity of traditional satellites.Due to the fixed allocation of on-board resources,multi-beam GEO satellite systems are prone to waste of resources,and beam-hopping technology comes into being.Beam-hopping technology can solve problems such as unequal resource allocation,and at the same time,in order to meet the communication needs of mobile terminals under the beam-hopping GEO satellite system,it is necessary to study effective beam handover technology.Due to the discontinuity of the beam-hopping GEO satellite,the beam handover is very different from the beam handover of multi-beam GEO satellites.Under beam-hopping GEO satellites,each beam can serve many wave levels,while under multi-beam GEO satellites,the beams and wave levels correspond one-to-one.Aiming at the beam handover problem of beam-hopping GEO satellites,this paper first establishes a spatio-temporal two-dimensional model of high-speed mobile user services,then simulates and analyzes the handover performance of the dynamic time slot reservation handover algorithm based on the remaining time,and finally simulates and verifies the system for the jump beam handover.The specific research contents and their results are as follows.Spatio-temporal two-dimensional traffic modeling of high-speed mobile terminal.Due to the superiority of multibeam technology,many scholars started to study beam handover algorithms,most of these studies are based on randomly generated services,proving the theoretical performance of these algorithms without real handover scenarios as well as handover services.To address this problem,this paper selects some schedules of China Eastern Airlines and China High Speed Rail as the business,and visualizes the business in spatial dimension and temporal dimension through statistics and simulation.In the spatial dimension,firstly,the map grid is divided,and for the convenience of calculation,the flights are regarded as straight lines,and the latitude and longitude coordinates of the routes can be known through the starting latitude and longitude coordinates,and then through the accumulation,the final value is displayed as a heat map,and then through the "grid number-beam number" correspondence,the spatial handover business model is obtained in terms of wave position.In the time dimension,by counting the number of terminals in operation in each period,we finally obtain the time handover service model.The simulation results show that there are obvious differences in the handover service volume in spatial and temporal dimensionsDynamic timeslot reservation handover algorithm based on remaining time.For the handover judgment stage,the beam handover judgment mechanism of traditional multibeam satellite systems mostly selects a single variable as the trigger for handover.For example,the received signal strength(RSS),geographic location,etc.This handover judgment mechanism is likely to cause ping-pong handover of terminals,increase the communication delay,and affect the handover quality.To address this problem,this paper adopts the remaining residence time of the terminal at the wave position as the departure handover factor,which incorporates three variables: terminal speed,terminal’s route,and terminal’s geographic location.For the handover decision stage,most of the traditional multibeam satellite systems use channel reservation mechanism,compared to the hopping beam communication system,the terminal needs to be allocated to the corresponding time slot resources to be able to transmit information,so this paper will allocate time slot resources to the user terminal of the call according to the call priority.Finally,the theoretical performance of the handover algorithm is simulated and analyzed by theoretical derivation based on randomly generated services.System simulation and validation for beam-hopping.In the hopping beam scenario,beam handover can be divided into intra-cluster handover and inter-cluster handover.For intra-cluster handover,it is essentially the allocation of time slot resources within the cluster.As long as the corresponding wave position of the beam synchronization hopping is allocated time slot resources for the terminal,the handover is regarded as successful;inter-cluster handover involves the establishment of the communication link and the allocation of time slot resources.This chapter elaborates the two handover interaction processes and the interaction information formats.Meanwhile,in order to further verify the actual performance of the above handover algorithm,this chapter takes the spacetime service model as input,divides the wave position for the eastern region of China,combines the actual travel time of the flight,processes the handover request of the terminal through the handover mechanism of the remaining time,judges the time slot and channel resources,and completes the call request of the terminal.The theoretical performance of the previous chapter is verified by the simulation results.