Voice Quality Accessment And Performance Optimization In LTE System

With the rapid evolution of wirelees communication technology, the services that mobilesystem can provide are increasingly rich and diverse. Among all this mobile communicationservices, voice application is always the most basic one. For LTE system which is in large-scale commercial stage, the voice service will no longer be carried by the traditional circuitdomain, but provided by the packet switched domain. Therefore, how to ensure userexperience for voice service quality in LTE system is one of the most important issues incurrent study. This paper analyzes the performance of three major solutions for voice servicein LTE system, and proposes some optimization ideas to ensure the quality of user experience.Besides, this paper put forwards a novel cell range expansion scheme based on userexperience on different services. The specific work and results are listed as follows.Firstly, this paper studies and analyzes the KPI and KQI indicator system of the transitionalvoice solutions CSFB. And then establishes the mapping models between KQI and KPIaccording to signaling flow analysis method to estimate the correspond-ing KQI byexamining the measurable KPI indicators in network level.Secondly, the inter-system handover scheme SRVCC/eSRVCC for voice service in LTEsystem is discussed, and we build a simulation platform for eSRVCC scheme based onOPNET network simulation software. On the basis of the simulation results, the factors thataffecting the handover performance are analyzed, and then some performance optimizationideas are proposed including the handover trigger policy and user priorities.Thirdly, the network parameters based voice quality evaluation model for objective voicesolutions in LTE system VoLTE is established according to the data collected from VoIPnetwork simulation platform. Besides, we analyze the KQI and KPI indicators system forVoLTE and build the mapping models between them.Finally, taking into account usersdifferent needs for power and quality of experience, anew cell range expansion scheme with adaptive bias setting is proposed. And then we builda MATLAB simulation platform to verify the performance of this algorithm.