Title :
Development of high performance DCMS with 3-bit and 4-bit coding ADPCM
Author :
Shoji, Yasuo ; Noguchi, Osamu ; Suzuki, Takao
Author_Institution :
Oki Electr. Ind. Co. Ltd., Tokyo, Japan
Abstract :
A digital circuit multiplication system (DCMS), which is equipped with an echo canceller to perform activity detection by applying reciprocal action between an echo canceller and a speech detector, is described. A high-quality speech detector, developed by introducing a hangover controller and linear predictive coding (LPC) analysis, and a trial model of the DCMS using advanced adaptive differential pulse-code modulation (ADPCM) which allowed 4-bit coding for voiceband data (VBD) signals, are presented. Efficiency improved by 10% using 4-bit coding for VBD.<>
Keywords :
codes; digital communication systems; echo suppression; encoding; filtering and prediction theory; pulse-code modulation; speech analysis and processing; 3 bit; 4 bit; LPC analysis; activity detection; advanced adaptive differential pulse-code modulation; codes; coding; digital circuit multiplication system; echo canceller; hangover controller; linear predictive coding; speech detector; voiceband data; Adaptive signal detection; Detectors; Digital circuits; Echo cancellers; Linear predictive coding; Predictive models; Pulse modulation; Signal analysis; Speech analysis; Speech coding;
Conference_Titel :
Communications, 1988. ICC '88. Digital Technology - Spanning the Universe. Conference Record., IEEE International Conference on
Conference_Location :
Philadelphia, PA, USA
DOI :
10.1109/ICC.1988.13818
