Optimization Of Speech Quality Of Zhengzhou Metro

As the mobile Internet gradually enters people’s lives,people have higher and higher requirements for Internet speed and call quality.4G is currently the main network of mobile communications.Although 4G greatly improves[1] the Internet speed,the problem of voice drop when making and receiving calls is one of the important issues that 4G networks need to solve.Vo LTE technology[2]is the main solution to this problem and has entered the commercialization stage.VoLTE voice[3] relies on the 4G data network.Therefore,to improve the voice call quality,it is necessary to optimize the 4G network[4].The optimization of 4G networks requires testing and evaluation of related networks,so as to discover the problems and provide index references for subsequent optimization.Currently,there are two ways to evaluate voice quality: subjective evaluation and objective evaluation.Subjective evaluation is relatively arbitrary,so the commonly used evaluation method is MOS[5] value evaluation in objective evaluation.Compared with the traditional evaluation based on bit error rate,the voice quality evaluation based on MOS value can be more objective and accurate performance of the voice quality of mobile users.Therefore,MOS test is widely used for voice evaluation and also used for network evaluation.Quality assessment.Therefore,it is a very important task to determine the factors that affect the MOS value and use it in actual engineering practice to optimize network performance.This article mainly analyzes the factors that affect the MOS value from the aspects of RTP[6] packet loss,signal coverage,signal strength,and time delay.Actual measurement and analysis show that in actual networks,signal coverage and signal strength in the coverage area are the main factors that affect the quality of user calls.On this basis,the PESQ[7] method is used to analyze the factors affecting the voice quality and optimize the calculation.Finally,based on theoretical analysis and optimization scheme design,the areas with poor Vo LTE voice signal[8]quality on Zhengzhou Metro Line 1 and Line 2 were selected for relevant optimization.After optimization,the voice quality of relevant areas has been significantly improved.