摘 要
PESQ是一种基于听觉模型的话音评估方法,能提供主客观相关性较高的音质客观评价,它考虑了人耳的听觉特性,使用听觉感知模型来进行话音质量的评估,评估结果更为贴近用户的通话感受,已成为评估音频通信系统的主流评估手段,提高PESQ算法所得的MOS值对于改善用户可感知的话音质量有很大的影响,因此优化用户可感知的话音质量将成为今后网络优化的方向。本文所要研究的内容是:在现网的网优常规数据中,通过实验室的测量,观察其对话音质量的影响变化,得出结论,并从现网网优工作中验证该实验的结果。
本文的研究方法是分别对目前日常网络优化数据中的常见路测数据如最小接入电平(ACCMIN)、信道编码方式、切换次数、不连续发射控制、覆盖场强和信号质量以及无线信道干扰等六方面进行单独测试,其中信道编码方式、切换次数、不连续发射控制、覆盖场强和信号质量以及无线信道干扰等五方面的测试是在封闭式的机房,通过机房内的微蜂窝系统的参数调教,且无外系统的相对理想的无线环境下进行的,而最小接入电平则在室外(山区)基站密度相对较低的无线环境下进行测试。在测试完成后记录相关的测试数据进行分析,判断该参数对于PESQ算法所得的MOS值的影响。
测试结果表明,切换次数和无线信道干扰对于MOS值的影响最为严重,切换次数越多;干扰越大,信号质量(误码率)越高,载干比(C/I)越低,MOS值越低(即话音质量越差)其次是覆盖场强和信道编码方式对MOS值的影响相对较低,使用增强全速率和全速率的信道编码方式要比使用半速率的信道编码方式要好,另外覆盖场强的高低并不直接影响MOS值,而是通过影响信号质量(误码率)的高低来影响着MOS值的高低;最后是最小接入电平和不连续发射的控制,在本次实验中并未发现该参数对MOS值参数明显的影响。
关键词:话音质量;感知话音;话音评估
Abstract
PESQ is a kind of speech assessment method which is based on hearing model,it canprovide the sound objective evaluation which has the higher correlation of the subjective andobjective.The method has consider the acoustic properties of the Ears,and use the hearingmodel to assess the sound quality,so,the test results is more close to the call feeling of thecustomer,and then,the method will be the mainstream assessment method of Communicationsystem.This paper is study on the Network optimization Data for PESQ influence,through theobservation and analysis of data,find out conclusion,and verify the results from the reality innetwork optimization.
In this test,we will test the ACCMIN,Channel Coding,The times of handover,DTXcontrol, Cover level,Signal quality and the radio channel interference.In those parameterexcept ACCMIN,were test in one enclosed room,which have the microcells.But ACCMIN istest in the ouside room.At the last,we record all the test data and analysis the influence of theMOS value base on the test data.
The result of study:Base on the test,we can find out the times of handover and radiochannel interference which had a strong impact on the MOS value.The cover level,signalquality and the Channel Coding also had influence to MOS value,but the influence isrelatively low.And then,the ACCMIN and DTX control has the lowest influence to MOSvalue.
Keywords:Speech quality;perceptual speech;evaluation of speech
目 录