以非線性訊號處理延伸頻寬及其應用

Abstract

音樂在於人類的生活上早已隨處可見，然而近年來電腦發展日新月異加上行動電話及i-pod的普及，消費者對音樂品質的要求似乎也與日俱增，因此許多人開始利用電腦的便利性，開始創造所要產生的音樂來開創更多的聽覺享受。以往或許需要搭配一些樂器的硬體才能產生的音效，如今可能只需要靠演算法的處理即能達成，因此電腦音樂的處理對現代的音樂創作可說是扮演重要的地位。 在這篇論文主要分成三個段落，主要都是利用原本的頻寬經過Nonlinear Process之後產生我們所需要的新的頻寬來彌補原來音樂訊號的不足。第一個段落為vitual bass，敘述的是往低頻的部份拓展頻寬;相反的，第二跟第三個段落敘述的是音訊往高頻拓展頻寬，分別是voice clarity和SBR。

Music takes an important rool in human life. Recently, computers develope quickly as cellphone, i-pod and walkman are very common, comsumers gradually aren’t satisfied with quality of old musical sound. Music composers nowadays can easily take advantages of powerful and user-friendly personal computers to produce more and more audio effects which would be created by some electric instruments, and now they maybe realized easily by writing some algorithms on computers. This paper is divided into three main parts, they both modulate information of original bandwidth to the other bandwidth. We use the new information to repair or enhance the original signal. First section, called “virtual bass”, describes the bandwidth expansion toward the low-frequency bandwidth; second and three sections, oppositely, decribe the bandwidth expansion toward the high-frequency bandwidth, there are respectively “voice clarity” and “SBR”.