Interference Modeling And Simulation Of Multi-beam Satellite Communication System Based On OPNET

The inter-beam co-channel interference caused by the sidelobes of satellite multi-beam antennas is an important basis for beam management and spectrum planning of multi-beam satellite communication systems,and the signals will generate random fading of amplitude and power under the influence of randomly changing wireless channels,thus affecting Interference between beams and communication quality.Therefore,modeling and simulation of satellite channel and inter-beam interference can provide a reference for system beam management and spectrum planning.Research work of this thesis focuses on modeling and simulation of satellite channel and inter-beam co-channel interference.Firstly,it briefly introduces the satellite communication system architecture of multi-star network and the structural design of its simulation platform,then analyzes the wireless propagation characteristics of satellite channels and simulates the typical satellite channel model.Finally,the mechanism of multi-beam satellite communication system interference generation in multi-star network is derived from the perspective of information transmission.Based on the study of the radiation characteristics of satellite spot beam antennas,a more accurate ground coverage model of satellite multi-beam antennas is designed.At the same time,the inter-beam downlink co-channel interference and uplink co-channel interference caused by the antenna sidelobes in the multi-beam satellite communication system are modeled.Based on the simulation mechanism of network simulation software OPNET,according to the simulation software of the designed three-state Markov channel model,the channel random numbers which characterize different channel characteristics under different environments and satellite elevation angles are simulated.Based on the channel random number,the inter-beam uplink co-channel interference and downlink co-channel interference in multi-beam satellite communication systems with different frequency reuse modes are simulated,and according to the simulation results,the bandwidth of the system under different frequency reuse modes and the packet loss rate of different received carrier-to-interference ratio thresholds are analyzed.The simulation results show that in the urban environment with poor channel conditions,the 7-color multiplex networking mode should be selected to ensure the packet loss rate.At this time,the system bandwidth capacity is about 25.93 times of the available bandwidth of the system.In the open environment 3 Color multiplex is a networking scheme that guarantees the packet loss rate requirement and the band capacity.The band capacity at this time is about 36.3 times of the available bandwidth,which is about 1.4 times that of the urban environment.Therefore,in a better channel environment,a frequency planning scheme with a smaller frequency reuse factor can be used to effectively improve the system spectrum utilization.