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URN etd-0906112-114416 Statistics This thesis had been viewed 1803 times. Download 784 times. Author ChunJui Su Author's Email Address No Public. Department Communication Engineering Year 2011 Semester 2 Degree Master Type of Document Master's Thesis Language zh-TW.Big5 Chinese Page Count 41 Title AN IMBE VOCODER WITH REDUCED COMPUTATION AND DELAY Keyword IMBE (Improved Multi-Band Excitation Vocoder) IMBE (Improved Multi-Band Excitation Vocoder) Abstract ABSTRACT
The IMBE (Improved Multi-Band Excitation) vocoder has been widely used in wireless speech communication, since it is very cost-effective by having high noise immunity and being capable of synthesizing high-quality speech with quite low bit rate. One of the evidence is that the IMBE vocoder not only has been selected by the Telecommunications Industry Association as a voice coding standard (TIA-102.BABA), but also has been adopted by the Association of Public Safety Communications Officials International.
The main objective of this research is to develop a modified IMBE vocoder with reduced computation and coding-delay. Through our experiments and simulations, two results were achieved. First, in the coding end, by omitting the process of look-ahead pitch tracking, we can significantly save the computation amount, reduce 40ms of coding-delay as well. Secondly, in the decoding end, we canceled the randomness of phase function for voiced speech synthesis to save computation further. Our experimental results showed that there is no noticeable difference between the synthetic speeches derived by our simplified IMBE vocoder and the standard IMBE vocoder. This confirms effectiveness and feasibility of the proposed manner for saving computation and reducing coding-delay for the IMBE vocoder.
Advisor Committee Ching-Kuen Lee - advisor
none - co-chair
none - co-chair
Files Date of Defense 2012-07-25 Date of Submission 2012-09-06