Error protection for a 4.8 kbps VQ based CELP coder

Author

Yang, G. ; Ho, P. ; Cuperman, V.

Author_Institution

Sch. of Eng. Sci., Simon Fraser Univ., Burnaby, BC, Canada

fYear

1990

fDate

6-9 May 1990

Firstpage

726

Lastpage

723

Abstract

An error protection scheme for a vector-quantization (VQ)-based code excited linear predictive (CELP) coder for mobile radio applications is proposed. To arrive at an appropriate error protection strategy, the sensitivity of the different parameters in the CELP coder are studied, and then unequal error protection is designed according to parameter sensitivities. Different levels of error protection are provided by the use of punctured convolutional codes. The mobile radio channel is modeled as a Rayleigh fading channel. A convolutional interleaving technique is used to combat fading. The combined source and channel codec for this application has a total bit rate of 6.4 kb/s, of which 1.6 kb/s is used for channel coding. Simulation result show that the resulting codec can provide good quality speech at a Doppler frequency of 48 Hz and a channel bit error rate as high as 10^-2

Keywords

codecs; encoding; error correction codes; fading; mobile radio systems; speech analysis and processing; telecommunication channels; 1.6 kbit/s; 4.8 kbit/s; 48 Hz; 6.4 kbit/s; Rayleigh fading channel; VQ based CELP coder; codec; error protection; mobile radio applications; punctured convolutional codes; speech coding; vector-quantization; Bit rate; Channel coding; Codecs; Convolutional codes; Error correction codes; Fading; Interleaved codes; Land mobile radio; Protection; Rayleigh channels;

fLanguage

English

Publisher

ieee

Conference_Titel

Vehicular Technology Conference, 1990 IEEE 40th

Conference_Location

Orlando, FL

ISSN

1090-3038

Type

conf

DOI

10.1109/VETEC.1990.110411

Filename

110411