Title :
A robust 384 kbit/s stereo HiFi audio codec for ISDN applications
Author :
Iwadare, Masahiro ; Hazu, Fumie ; Shinichi, A. ; Nishitani, Takao
Author_Institution :
NEC Corp., Kanagawa, Japan
Abstract :
A robust stereo HiFi audio codec designed for 384 kb/s ISDN (integrated services digital network) subrate (H0) channel applications has been developed. The codec is based on subband ADPCM (adaptive differential pulse code modulation). In order to realize high coding quality, a new adaptive bit assignment function is introduced which needs no side-information transmission. Moreover, the coding algorithm brings about the robustness to withstand transmission bit errors in actual transmission environments such as satellite communications, where conventional adaptive bit assignment is inherently inferior. The codec is implemented using floating-point LSI signal processors. Subjective test results show that the coding quality is comparable to that of compact discs. The proposed algorithm can be applied to a basic ISDN channel by limiting the signal bandwidth to 15 kHz and transmitting FM-quality monophonic signals at 128 kb/s
Keywords :
Hi-Fi equipment; ISDN; codecs; pulse-code modulation; 128 kbit/s; 15 kHz; 384 kbit/s; FM-quality monophonic signals; ISDN; adaptive bit assignment; adaptive differential pulse code modulation; coding algorithm; coding quality; floating-point LSI signal processors; integrated services digital network; satellite communications; signal bandwidth; stereo HiFi audio codec; subband ADPCM; subjective test results; Codecs; ISDN; Large scale integration; Modulation coding; Pulse modulation; Robustness; Satellite communication; Signal processing; Signal processing algorithms; Testing;
Conference_Titel :
Global Telecommunications Conference and Exhibition 'Communications Technology for the 1990s and Beyond' (GLOBECOM), 1989. IEEE
Conference_Location :
Dallas, TX
DOI :
10.1109/GLOCOM.1989.64277
