无线网络语音传输质量监测仿真研究

摘要

Wireless network voice is a very important means of communication.In order to achieve the quality of voice transmission monitoring,it is necessary to measure one-way delay of the network path.However,the clock skew and clock offset make the one-way delay measurement results inaccurate.Aimed at solving the above problem,a new one-way delay measurement method based on maximum likelihood estimation is proposed.The sender and receiver periodically sent the probe packets at the same interval according to their local clocks.The maximum likelihood estimators of clock skew and clock offset were derived by detecting the packet reception time and its variation.Simulation experiments validate that the proposed one-way delay measurement method based on maximum likelihood estimation can eliminate the influence of nonsynchronous clocks and improve the precision of one-way delay measurement.%无线网络语音是目前非常重要的通信方式,为了实现语音传输质量的监测,需要测量网络路径的单向时延;然而,收发端时钟频差和时钟偏移使得单向时延测量结果误差较大.为了解决上述问题,提出了一种基于最大似然估计的单向时延测量方法,收发端主机根据本地时钟以相同间隔周期性发送探测包,通过探测包的接收时间及其变化实现时钟频率比和时钟偏移的最大似然估计.仿真验证了所提出的单向时延测量方法能够消除时钟不同步带来的影响,提高了单向时延测量精度.