针对移动通信网络中AMR-WB编解码器在话音分组传输中的抗丢包问题,提出了一种与VoLTE系统中语音编码速率相匹配的AMR-WB抗丢包实现方案.通过实验分析AMR-WB编解码器中经过错误隐藏恢复的各个参数对语音质量的影响,利用多描述编码(multiple description coding,MDC)技术设计了AMR-WB抗丢包方案,并进一步结合删余卷积编码提出了双重差错保护的增强型抗丢包算法,实现了多码率下的差错保护和速率匹配,该方案可兼容原有AMR-WB编码模式下的语音编码速率.仿真结果表明,提出的新方案能够增强AMR-WB的抗丢包能力,并且不需要增加额外的信令开销,兼容现有系统网络中的多速率语音编码.
Speech enhancement is an effective method to solve noise pollution,the main target is to extract pure voice from the noisy speech as much as possible,and it has been an important research field in speech processing and has an important value in practice.Actually,the mainly often used algorithms include Spectral Subtraction,Wiener Filter,the algorithms based on statistical model(e.g.MMSE) and Subspace Decomposition.This paper mainly discusses the basic principles of spectral subtraction,MMSE,two-step noise reduction(TSNR) and subspace decomposition and also makes comparisons and analysis on the performance of noise reduction among the four algorithms by using objective assessment index.
<span id="ChDivSummary" name="ChDivSummary" class="abstract-text"><正> 在一个社会的框架中,在“个体行为理性”的前提下,纳税人与征税主体、纳税人与纳税人之间,围绕纳税与征税、纳税与漏税所展开的一系列较量,构成了一个完整的博弈。本文试图用博弈论的方法,通过对两纳税人纳税博弈的分析,论证了为实现良好的“市场类型”,税收体系所必须做出的策略选择。</span>
