beckgom's fabula in Textcube

- Abstract
In this paper, we investigate the use of existing audio codecs for the purpose of a high quality color ring-back-tone service. First of all, we exploit the limitations of the enhanced variable rate codec (EVRC) in a view of music quality because EVRC is a standard speech coder employed in a code division multiple access (CDMA)
system. In order to figure it out which current existing audio codec is suitable to deliver music over CDMA or wideband CDMA (W-CDMA), several audio codecs such as two di®erent versions of MPEG AAC and the Enhanced AAC+ codec are reviewed. Next, the music quality of the audio codecs is compared with that of
EVRC, where the bit-rates of the audio codecs are set to be around 10 kbit/s because the color ring-back-tone service using one of the audio codecs should be realized by replacing EVRC with it. The quality comparison is performed by an informal listening test as well as an objective quality test. It is shown from the experiments that the audio codecs provide better music quality than EVRC and among them, the Enhance AAC+ codec operated at a bit-rate of 10 kbit/s with a sampling rate of 32 kHz can be considered as a new candidate for the high quality color ring-back-tone service.

-Keyword

Color ring-back-tone, audio codec, EVRC, CDMA, audio quality