Title :
Combined source and channel coding based on multimode coding
Author :
Taniguchi, T. ; Amano, F. ; Unagami, S.
Author_Institution :
Fujitsu Lab. Ltd., Kawasaki, Japan
Abstract :
A multimode source/channel coder which can dynamically control the balance of source and channel coding according to the channel quality is introduced. As an example of such a system, a 4.8-kb/s code excited linear predictive coder with three coding modes (A, B1, and B2), each of which has different bit assignments to source and channel coding, is presented. The optimum coding mode is selected in each frame, based on an evaluation of the spectral distortion (SNLAR) in reproduced speech. The threshold value of SNLAR for mode decision is varied according to the channel error rate. Computer simulation shows that 2 dB and 3 dB of SNRseg improvement is achieved at a bit error rate of 3×10-3 and 3×10 -2 respectively, over conventional CELP without channel coding
Keywords :
digital simulation; encoding; error correction codes; speech analysis and processing; telecommunication channels; vocoders; 4.8 kbit/s; 4.8-kb/s code excited linear predictive coder; CELP coder; bit error rate; channel coding; channel error rate; channel quality; error correcting code; multimode source/channel coder; spectral distortion; speech coding; Bit error rate; Bit rate; Channel coding; Computer simulation; Error analysis; Error correction codes; Land mobile radio; Linear predictive coding; Mobile communication; Source coding; Speech analysis; Speech coding; Speech processing; Tin;
Conference_Titel :
Acoustics, Speech, and Signal Processing, 1990. ICASSP-90., 1990 International Conference on
Conference_Location :
Albuquerque, NM
DOI :
10.1109/ICASSP.1990.115753
