Title :
Optimized error correction of MELP speech parameters via maximum a posteriori (MAP) techniques
Author :
Rahikka, Douglas J. ; Fuja, Thomas E. ; Fazel, Tahereh
Author_Institution :
Nat. Security Agency, Ft. Meade, MD, USA
Abstract :
The U.S. Government has developed and adopted a new Federal standard vocoder which operates at 2400 bps and is called MELP-mixed excitation linear prediction. This algorithm has quite good voice quality under benign error channel conditions. However, when subjected to high error conditions as may be experienced in vehicular applications, correction techniques may be employed which utilize the underlying inter-frame residual redundancy of the MELP parameters. This paper describes experiments conducted on the MELP algorithm when combined with Viterbi convolutional error decoding, and enhanced with maximum a posteriori techniques which capitalize on the redundancy statistics. Both hard and soft Viterbi decoding situations are investigated
Keywords :
Viterbi decoding; convolutional codes; error correction; linear predictive coding; redundancy; speech coding; vocoders; 2.4 kbit/s; Federal standard vocoder; MAP techniques; MELP speech parameters; Viterbi convolutional error decoding; error channel conditions; hard Viterbi decoding; inter-frame residual redundancy; maximum a posteriori techniques; mixed excitation linear prediction; optimized error correction; redundancy statistics; soft Viterbi decoding; vehicular applications; Decoding; Error analysis; Error correction; Prediction algorithms; Redundancy; Speech; Standards development; US Government; Viterbi algorithm; Vocoders;
Conference_Titel :
Speech Coding Proceedings, 1999 IEEE Workshop on
Conference_Location :
Porvoo
Print_ISBN :
0-7803-5651-9
DOI :
10.1109/SCFT.1999.781490
