摘要
将噪声消除系统应用在3G手机的下行链路时,在消除环境背景噪声的同时,发现下行信号音失真。这是因为噪声消除系统中的VAD算法对功率剧烈变化的信号音敏感造成的。经过详细研究信号音的时频特性,以及网络传输的误差因素,提出了一种新的适用于下行噪声抑制系统的信号音检测算法,这种算法利用每帧信号的频域功率变化和时域信号周期变化来检测信号音,经过理论的评估和实际的验证,该算法在不影响噪声消除系统的功能前提下,能准确检测出信号音信号,从而避免了失真的发生。
While the NC（Noise Cancellation） system is applied to the downlink of 3G mobile telephone,the signal tone distortion is found at the same time of canceling the noise.This is because the VAD algorithm of the NC system is sensitive to dramatic changes in the power of signal tone.In view of the time and frequency domain characteristics and the error factor of the network transfers,a new algorithm of the signal tone detection fit for the downlink NC system is proposed,which uses the frequency domain power and the time domain period change to detect signal tone.The academic evaluations and practice tests prove that the algorithm can more precisely detect signal tone,without degrading the performance of the NC system,so as to avoid the occurrence of distortion.
出处
《计算机工程与应用》
CSCD
北大核心
2011年第13期131-133,156,共4页
Computer Engineering and Applications
关键词
噪声消除
信号音检测
回铃音
忙音
空号音
语音激活检测
频谱图
周期图
noise cancellation
signal tone detection
feedback ringing
busyness ringing
empty number ringing
voice activitydetection
frequency spectrogram
periodic plot
