局部投影降噪算法参数的确定及其应用

Parameters Determination of Local Projective Algorithm and Its Application

针对水声信号的非线性特征,采用局部投影降噪算法研究了舰船辐射噪声的非线性降噪问题。在分析局部投影降噪算法有关参数的选择对降噪效果影响的基础上,研究了局部投影邻域半径参数的估计。提出一种适合水声信号降噪的邻域半径估计算法,即通过估算信号的噪声强度确定局部投影的邻域半径。对Logistic模型和实际舰船信号进行降噪处理,结果表明采用噪声强度估计邻域半径的局部投影降噪算法不仅结构简单,具有较好的收敛性,而且对舰船辐射噪声具有很好的降噪效果。

In this paper, the application of well-known local projective noise reduction method to underwater acoustic signals is focused on. What and how parameters select in using local projective noise reduction method are discussed, especially for the parameter of local neighborhood size, which greatly affects the result of noise reduction. In order to improve both the efficiency and the convergence of the local projective noise reduction method, a new way to estimate local neighborhood size is proposed. The new method is based on the estimation of noise level of underwater acoustic signal which is easier to calculate than other algorithm. As an example, Logistic map and three types of real ship radiated noise as samples are used to evaluate the efficiency of the algorithm. The results show that the new algorithm is superior to old one. Besides, the new algorithm is relatively simple and converges quickly.