摘要
针对多段差频正弦信号,提出一种基于加权融合的频率估计算法,用以提高低信噪比条件下短时正弦信号的频率估计精度,扩展多段信号融合法的适用范围。为消除各段信号频率不等对频谱分析的影响,根据各段信号间频率差生成差频修正矩阵,对多段差频正弦信号频谱进行同频化处理;为消除各段信号相位不连续对频谱分析的影响,构造具有相位连续特性和降噪特性的加权因子,对同频化的多段差频正弦信号频谱进行加权融合,得到最优加权融合频谱;最后,谱峰搜索最优加权融合频谱,实现高精度频率估计.仿真实验表明,与现有算法相比本文算法估计精度高、抗噪性好、普适性好,特别在低信噪比、短时时宽下性能优良.
Based on weight-fusion of multi-section sinusoids with the known frequency-difference（MS-sinusoids-KFD）,a frequency estimation algorithm was proposed to improve frequency estimation of the short sinusoid in low signal-to-noise ratio（SNR）,and to extend the scope of application of the multi-section signal fusion method.Firstly,the frequency-difference modified matrix was created based on the known frequency-difference.To eliminate the influence caused by the known frequency-difference,spectra of MS-sinusoids-KFD were made the same as those of multi-section co-frequency-sinusoids by this matrix.Secondly,the weighted factor which can make phases continuous and decrease noise was constructed,and the optimization weighted-accumulation spectrum（OW-A spectrum） was gained through weighted-accumulating spectra of MS-Sinusoids-KFD by this weighted factor.Consequently,precise frequency estimation can be obtained through spectral peak searching of the OW-A spectrum.Simulation results show that compared with the current algorithms,the proposed one works better in precision,noise immunity and universality,and is particularly superior for short sinusoids in low SNR.
基金
国家自然科学基金(60871098)
重庆市重点自然科学基金(CSCT
2011BA2015)资助
关键词
频率估计
加权融合
多段差频正弦信号
降噪
frequency estimation
weight-fusion
Multi-section sinusoids with the known frequency-different（MS-Sinusoids-KFD）
noise reduction
