期刊名称：International Journal of Advanced Research In Computer Science and Software Engineering
印刷版ISSN：2277-6451
电子版ISSN：2277-128X
出版年度：2012
卷号：2
期号：8
出版社：S.S. Mishra
摘要：In Global system for mobile communication (GSM) wireless system, bandwidth is precious goods and telecom service providers are continuously met with the challenge of accommodating more users within a limited allocated bandwidth. Low bit rate sp eech coding offers a way to meet this challenge. If the bit ra te of the speech coding is low then the coder will be deliver quality speech, the more speech channels can be compressed within a given bandwidth. Earlier Code Excited Linear Prediction (CELP) coding has been most preferred coding technique to meet this challenge. CELP uses vector quantization technique to compress the linear prediction (LPC) coefficient of voiced speech. Recently, one tool has been introduced i.e. wavelet transform (WT). Which is used LPC coefficient of voiced speech signal and gives better quality, less coder complexity at same bit rate. In the present paper the performances of both techniques are compared. Finally it has been observed that the wavelet transform technique is much suitable than CELP for performing subjective listening tests. The WT technique does not use vector quantization. The test signals used are clean signals (i.e. with no background noise) and speech signals with artificial noise added. All the CELP and wavelet based transform coding are written in MATLAB.
