The Research Of Interference Coordination At New Indoor Distributed System Based On LampSite

In the future network planning,more and more communication scenes take place in indoors.Indoor communication plays an increasingly important role.However,uneven indoor coverage and insufficient system capacity have always hindered its development.Indoor distributed antenna system is one of the ways to solve these problems.When deploying these systems,same frequency network can solve the problem of shortage of frequency resources.But it will cause co-frequency interference,which affects the overall performance of the system and reduces the network coverage.Therefore,it is of practical significance to consider interference coordination during the construction and deployment of indoor distributed antenna systems.The main work of the thesis is as follows:1.Aiming at the interference problem caused by the use of the same frequency networking method in the LampSite new distributed antenna systems,an improved indoor channel propagation model for high-rise buildings is proposed to solve the co-channel interference problem.In the model,the system interference sources are divided into indoor penetration propagation and outdoor reflection propagation.Use OFDM technology to transmit signals and Signal propagation through indoor antennas,Finally,demodulate the desired signal and interference signal at the receiving end,and calculate the system downlink capacity.After considering the influence of building floor penetration loss,glass reflection loss,frequency reuse distance,user location,distance to adjacent buildings on the indoor signal downlink capacity,so then determine the most appropriate deployment method.The simulation results show that the model is more suitable for general high-rise buildings with high accuracy of capacity analysis.2.Aiming at the problem of resource allocation in indoor distributed system interference management,a multi-level soft frequency reuse dynamic algorithm based on user satisfaction is proposed.Firstly,the algorithm generates the network topology.And then the indoor cells are divided into several areas according to the SINR threshold.Secondly,the system randomly generates users and calculates user satisfaction in each area.Finally,the allocation of each area is dynamically adjusted according to the satisfaction Resources,thereby reducing inter-cell interference.The simulation results show that the algorithm in this thesis effectively improves the user satisfaction of the cell while satisfying the throughput of edge users.The throughput of central users is higher than other algorithms and reduces the outage probability.