Research On Multi-User Transmission Technology Of Millimeter Wave Multi-Beam Satellite

With the development of 5G technology,low-frequency communication can no longer meet the growing demand for wireless communication services.High-frequency millimeter-wave(mm Wave)multiple-input multiple-output(MIMO)technology has gradually become one of the key technologies in future wireless communication.On the other hand,with the development of high-throughput multi-beam satellites,satellite communication is more than a supplement to modern communication systems.Satellite communication will become an irreplaceable part of future wireless communication networks.This paper focuses on the channel modeling of mm Wave multi-beam satellites and user scheduling in multi-user scenarios.The details are as follows.Compared with traditional satellites,mm Wave satellites have the advantages of abundant spectrum re-sources,high throughput,and flexible beam pointing.However,since mm Wave signals are easily affected by factors such as obstacle shadowing and rain attenuation during long-distance transmission,it is difficult to establish an accurate channel model.In this paper,based on the ground mm Wave MIMO channel model,the time correlation and Doppler effect are introduced in the channel modeling.Then an algorithm using Markov multiple-state transition is provided to generate the mm Wave satellite MIMO channels.Then,beam training is performed on the modeled mm Wave satellite MIMO channel on this basis.Besides,a user scheduling algorithm based on a multi-beam satellite communication system is studied in this paper.The algorithm divides all user terminals into several groups.On the one hand,the whole user service cycle is divided into several time slots by time division multiple access,and different groups are provided with services in different time slots.On the other hand,different users are served with different beams within each group through space division multiple access.On this basis,this paper proposes a user grouping algorithm with channel correlation and channel gain weighting.The algorithm takes the channel correlation of different users and the channel gains of different users as the selection criteria for each group of users.Users who meet the criteria are permitted to join each group subsequently.Besides,a user grouping algorithm based on full selection is proposed to solve that part of users cannot obtain services.The simulation results show that the proposed algorithm further improves the fairness of system users and effectively reduces the complexity of the algorithm on the premise of ensuring the system and rate.Simulation results show that the proposed algorithm takes the fairness of users and the algorithm complexity into consideration on the premise of the sum-rate of system.