摘要
离散快速傅里叶变换算法在频谱分析中得到了广泛的应用,这种算法得到的计算结果是在整个频段上的频谱信息.在一些应用中,需要了解的仅仅是某一窄带内的频谱精细结构,要求频谱的分辨率较高.而要得到一个较高分辨率的频谱,直接采用快速傅里叶变换计算则会导致参加快速傅里叶变换运算的数据点数的增加,从而引起计算量和存储量的急剧增大,这样,快速傅里叶变换算法就不能满足要求了.本文介绍了基于复调制的频率细化技术的原理及其在超低频/极低频电磁接收机研制中的应用,阐述了采用这种技术如何实现高分辨率频谱的计算,并给出了理论数据和实际观测数据的计算结果.
Discrete fast Fourier transform （FFT） has been widely applied to signal spectral analysis and can figure out the entire bandwidth spectrum of a signal. However, the fine structure of high resolution spectrum in a narrow bandwidth is required in some applications. If regular FFT is still used to figure out the high resolution spectrum, it will result in addition of data and at last sharp increase of computation and storage. Therefore, FFT is inefficient and a new method must be put forward. In the paper, the principle of zoom FFT technique based on complex modulation, its application to development of SLF/ELF receiver and how to obtain high resolution spectrum using the new technique are introduced in detail and also the theoretical and test results are presented.
出处
《地震学报》
CSCD
北大核心
2007年第1期59-66,共8页
Acta Seismologica Sinica
基金
科技部"十五"科技攻关子课题<甚低频电磁接收机研究>(2001BA601B03-01-03)资助.
