Title :
Embedded ADPCM with noise spectral shaping for packet voice transmission
Author :
Kim, Hae Dong ; Un, C.K.
Author_Institution :
Korea Advanced Institute of Science & Technology, Communications Research Laboratory, Department of Electrical Engineering, Seoul, Korea
Abstract :
An embedded adaptive differential pulse code modulation (EADPCM) that may be used for speech coding in a packet network is proposed. In this scheme the quantisation nosie of an ADPCM is reduced significantly by employing an instant-aneously adaptive PCM (ADPCM) as a second-stage coder, and is shaped further to reduce the subjectively annoying effects by a noise-shaping filter. By computer simulation using real speech we show a significant performance improvement (3 to 10dB at rates of 16 to 48 kbit/s) with the proposed scheme.
Keywords :
digital simulation; packet switching; pulse-code modulation; voice communication; 16 to 48 kbit/s; APCM; EADPCM; adaptive differential pulse code modulation; computer simulation using real speech; embedded ADPCM; instantaneously adaptive PCM; noise spectral shaping; noise-shaping filter; packet network; packet switching; packet voice transmission; performance improvement; quantisation noise; second-stage coder; speech coding; subjectively annoying effects;
Journal_Title :
Electronics Letters
DOI :
10.1049/el:19870169
