Improved Frame Error Concealment Algorithm Based on Transform- Domain Mobile Audio Codec

In this paper, we propose an improved frame error concealment algorithm for TCX-based audio coders in order to improve the quality of decoded audio at the receiver. Conventional TCX-based frame error concealment algorithms in the AMR-WB+ audio codec are usually unable to adaptively adjust gain control according to changes in the magnitude of the correct frame before lost frames. Thus, we propose a new gain control approach based on stability of LPC filter, and the stream data need to contain the line spectrum frequency data and utilize different continuous attenuation factor formula based on different categories of lost frames. The proposed frame error concealment algorithm is designed for TCX-based audio codec. We make the performance comparison between the proposed method and the original algorithm currently employed in AMR-WB+ audio codec through the objective evaluation test and subjective evaluation test. The results prove that our algorithm can achieve better audio recovery quality than original frame error concealment algorithm employed in AMR-WB+ speech codec.