摘要
首先建立AM-FM数学模型,用多个相近载波的调幅信号组合描述它。利用最小二乘法对幅度调制和频率调制两个部分分别进行非线性拟合;拟合以相关系数满足一定条件为精度控制原则,拟合项数以相邻相关系数不再显著变化为判定条件。有效性检验证明该方法切实可行。重力固体潮IMF的拟合结果表明,AM-FM数学模型可以很好地刻画重力固体潮IMF;重力固体潮是多个AM-FM信号合成的复合信号。为后续深入研究重力固体潮的AM-FM信号特征、循环平稳信号特征等性质建立了良好的数学基础。
In this paper,the non-linear least squares data fitting method for the AM-FM model of the the gravity tide IMF signal is proposed.Firstly,the AM-FM model is decomposed amplitude modulation signal and frequency modulation signal which is fitted by using the non-linear least squares method separately.The fitting number is determined by the correlation coefficient.Then the IMF signal of the gravity tide is fitted by the AM-FM model.The experimental results show that the gravity tide IMF signal can be well described by the AM-FM signal.A foundation is established for further discussion its characteristic such as the cyclostationarity.
出处
《计算机工程与应用》
CSCD
北大核心
2009年第30期138-142,共5页
Computer Engineering and Applications
基金
国家自然科学基金 No.40774032~~
