CELP编码器中自适应码本快速搜索算法

A Fast Algorithm for Adaptive Code-book Search of CELP Coder

ＣＥＬＰ以其高质量的合成语音及优良的抗噪声和多次转接性能，在移动通信，保密电话和语音中继等中低速率上获得了广泛应用。由于ＣＥＬＰ的运算量庞大，减少其运算量一直是研究的热点。自适应码本是多数ＣＥＬＰ方案中的重要环节。本文对自适应码本的快速搜索算法进行了研究，并在端点递归法的基础上提出了一种双层搜索法。实验表明，此方法既保持了复原语音的高质量的特点，又明显地降低了运算量。

CELP coders,due to its high quality of reconstructed speech and robustness against channel noise,have many applications in mobile communication,encrypted telephone and voice relay service etc .In order to overcome the difficulty in its implementation,A hot topic of research in recent years has been the reduction of computational complexity.Adaptive code-book search(or long-term prediction)plays an important role in most CELP schemes.This paper proposes a fast algorithm called Double Layer Recursive End-point Correction,This algorithm can significantly simplify the computation of code-book search.