AMR-WB語音編碼器之ISF向量量化編碼的搜尋效能改善研究

• Main Authors: Yi-Chen Huang, 黃奕塵
• Other Authors: Cheng-Yu Yeh
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/ryz6nu

碩士 === 國立勤益科技大學 === 電機工程系 === 104 === The adaptive multi-rate wideband (AMR-WB) speech codec with a sampling rate of 16 kHz is known as one of the speech codecs employed in handheld devices that support 4G mobile communication systems. When applied to smartphones, it provides a superior speech quality relative to conventional speech codecs. This paper adopts a triangular inequality elimination algorithm equipped with a dynamic and an intersection mechanism, DI-TIE for short, as a means to considerably improve the complexity of ISF coefficients quantization in AMR-WB speech codec. Both mechanisms are designed in a way that recursively enhances the performance of TIE algorithm. This proposal is validated by experimental results as a superior search algorithm relative to a conventional TIE and a multiple TIE (MTIE) approach. With a full search algorithm as a benchmark for search load comparison, this work provides a search load reduction above 77%, a figure far beyond 36% in the TIE and 49% in the MTIE approach.