一种引入多脉冲提高AMR_WB丢包处理质量的前向纠错技术

A Multipulse-Based Forward Error Correction Technique for Improving the Quality of AMR_WB in Lossy Network

GSM AMR_WB是唯一可以作为有线和无线通用的语音编码标准,提高AMR_WB在丢包环境下的语音质量至关重要。本文提出了一种改进的AMR_WB丢包处理方法,发送端利用基于多脉冲的前向纠错技术,解决丢包时自适应码本带来的错误传播问题。接收端采用基音轮廓修改方法消除语音帧不同步在帧边界带来的恼人噪声。提出的方法在AMR_WB 12.56kb/s模式下实现,PESQ客观评测结果表明,此方法仅增加了0.26kb/s冗余比特率却明显提高了丢包情况下AMR_WB 12.56kb/s的语音质量。

GSM AMRWB speech codec being used for both Internet and mobile networks, robustness to both frame erasures and random bit errors assumes significance. This paper presents a high-performance concealment algorithm for AMR_WB speech. The proposed algorithm includes using Mutipulse -based Forward Error correction technique at encoder to address the error propagation cased by the Adaptive codebook. And at the decoded side, to alleviate audible artifacts at the boundary between the previous and the current frame by modificating the pitch contour of the current frame. The algorithm has been implemented in the AMR_WB 12.56kb/s standard. Subjective tests have demonstrated that this improves perceived quality in the presences of frame erasures.