Frequency Domain Design Method of Wavelet Basis Based on Pulsar Signal
Frequency Domain Design Method of Wavelet Basis Based on Pulsar Signal
复制标题
DOI：
10.1017/s0373463320000211
复制
发表时间：
2020-06
影响因子：
2.4
通讯作者：
S. You;Hongli Wang;Yiyang He;Qiang Xu;Lei Feng
中科院分区：
文献类型：
--
作者：
S. You;Hongli Wang;Yiyang He;Qiang Xu;Lei Feng
在脉冲星导航过程中，脉冲星轮廓信号携带的高频噪声降低了脉冲到达时间（TOA）估计的精度。目前，利用小波变换去除信号噪声的主要方法是重新设计小波变换的阈值和电平函数。但滤波后信号的信噪比等指标还需要进一步优化，因此需要设计更合适的小波基。提出了一种基于频域分析的小波基设计方法，以提高脉冲星信号的去噪效果。该方法首先对脉冲星轮廓信号进行频域分析，然后根据脉冲星轮廓信号的频域特性设计一个Crab脉冲星小波基（CPn，n为小波基长度）。为了提高算法的实时性，实现了小波提升算法。通过仿真，对国内外脉冲星轮廓信号数据进行了分析。实验结果表明，该方法可使信噪比提高4dB，均方误差降低61%，峰值误差降低45%。因此，该方法具有较好的滤波效果。
During pulsar navigation, the high-frequency noise carried by the pulsar profile signal reduces the accuracy of the pulse TOA (Time of Arrival) estimation. At present, the main method to remove signal noise by using wavelet transform is to redesign the function of the threshold and level of wavelet transform. However, the signal-to-noise ratio and other indicators of the filtered signal need to be further optimised, so a more appropriate wavelet basis needs to be designed. This paper proposes a wavelet basis design method based on frequency domain analysis to improve the denoising effect of pulsar signals. This method first analyses the pulsar contour signal in the frequency domain and then designs a Crab pulsar wavelet basis (CPn, where n represents the wavelet basis length) based on its frequency domain characteristics. In order to improve the real-time performance of the algorithm, a wavelet lifting scheme is implemented. Through simulation, this method analyses the pulsar contour signal data at home and abroad. Results show the signal-to-noise ratio can be increased by 4 dB, the mean square error is reduced by 61% and the peak error is reduced by 45%. Therefore, this method has better filtering effect.