A frame erasure concealment algorithm based on gain parameterre-estimation for CELP coders

摘要

In this paper, we propose a frame erasure concealment algorithmnbased on reestimating gain parameters for a code-excited linearnprediction (CELP) coder. When a frame is detected as being erased, thencoding parameters, especially the adaptive codebook gain and fixedncodebook gain, of the erased and subsequent frames, are reestimated by angain-matching procedure. By doing this, we can reduce the abrupt changencaused in the decoded excitation signal by a simple scaling downnprocedure. We have applied this technique to the IS-63-1 speech codernand found that the proposed algorithm improves the speech quality undernvarious channel conditions compared with the conventionalnextrapolation-based concealment algorithm