The main work and originality in this thesis can be summarized as following : 1 . analysis of acoustic characteristics of ship ' s radiated noise both in time and frequency domain , especially its deviation from the ordinary statistical signal . studies on two modern signal processing methods - higher - order statistics ( hos ) and wavelet transform 分析了舰船辐射噪声的通过特性、调制特性、谱特性与线谱的特征及应用，特别分析了辐射噪声谱的“三非”特性；研究了基于高阶谱分析和小波变换的舰船辐射噪声特征。
The new algorithm has three characters : first is that the new algorithm is on the basis of super frame which include 3 continuous simple frames in melp algorithm , the algorithm deal with parameters of a super frame by the mode of the super frame . secondly , two algorithms are introduced for improving vector quantization quality of line spectral frequency ( lsf ) parameter . one is swithed - adaptive inter - frame vector prediction ( sivp ) , which can get rid of the correlation between neighboring frames effectively , the other is joint codebook optimization for multi stage vector quantization ( jco - msvq ) , which can improve performance of codebook 第二是在制作线谱对参数( lsf )矢量量化码本时,引入了目前提高lsf码本性能的两个方法:在利用重点帧对非重点帧作预测时,借鉴自适应帧间矢量量化( sivp )去除相关性算法的优点,提出了以固定矩阵去除相关性的方法,有效的控制了预测后残差的动态范围,提高了对残差矢量量化的精度;采用联合码本优化多级矢量量化算法( jco - msvq ) ,改良多级矢量量化码本的性能。
