A 7 kHz bandwidth, 32 kbps speech coder for ISDN
- 1 January 1991
- conference paper
- Published by Institute of Electrical and Electronics Engineers (IEEE)
- p. 1-4 vol.1
- https://doi.org/10.1109/icassp.1991.150264
Abstract
The author describes a voice codec with a 20 to 7000 Hz bandwidth that compresses to 2 bits per sample at a sample rate of 16 kHz. The algorithm is based on a transform coder that employs dynamic bit allocation in the frequency domain using a perceptual noise weighting criterion, and by Huffman compression of the quantized transform signal. It is well suited to ISDN (integrated services digital network) channels since it permits two coded voice signals to be carried on a single 64 kbps ISDN B channel. A two-channel coder has been implemented in real-time using three AT&T DSP32C signal processors and runs on the public switched ISDN network. The one-way communication delay of this hardware is 75 msec.Keywords
This publication has 1 reference indexed in Scilit:
- Transform coding of audio signals using perceptual noise criteriaIEEE Journal on Selected Areas in Communications, 1988