摘要
对于频率缓变的单一分量信号叠加噪声的情况,根据其瞬时频率中真实瞬时频率占主导趋势的特点,先使用平滑相位差分法——极大似然法估计噪声信号的瞬时频率,用局域波分解法求极大似然法估计瞬时频率的趋势项,从而得到与理论瞬时频率相符的结果,与其他的瞬时频率估计方法相比,本方法具有精度高、计算量小的优点.
When a monocomponent signal with slowly changing instantaneous frequency is burred by noise, its instantaneous frequency is usually added by many high crest and low trough. But real instantaneous frequency is a trend in estimated instantaneous frequency if signal to noise ratio is not very high. Though Maximum likelihood method can smooth some higher crest and lower trough, real instartaneous frequency is still not very obvious. A new non-parameter instantaneous frequency estimation method is established based on a new method： Local-wave method. Firstly, smoothed versions of the Phase Difference Estimator ,Maximum likelihood method is adopted to estimate the instantaneous frequency. Then more accurate instantaneous frequency can be shifted as a trend by the local-wave method. A simulation is used to test this new method. The result shows the method described in the paper is proved to be more accurate and less computation.
出处
《电子学报》
EI
CAS
CSCD
北大核心
2005年第7期1303-1306,共4页
Acta Electronica Sinica
基金
国家自然科学基金(No.50475155)
关键词
极大似然
瞬时频率
局域波法
instantaneous frequency
maximum likelihood estimation
local-wave method
