Title :
Selection of dimensional normalization parameter in digital computation of the fractional Fourier Transform
Author :
Xu, Huifa ; Liu, Feng
Author_Institution :
Dept. of Electron. Eng., Naval Aeronaut. Eng. Inst., Yantai, China
Abstract :
In the digital computation of the fractional Fourier Transform, the dimensional normalization is needed. The initial frequency and chirp rate of a chirp signal are changed by the dimensional normalization parameter, and the position of the chirp signal´s peak on the two-dimensional parameter (p, u) plane is also changed. This influences the detection of the multi-component chirp signals. In order to decrease the influence, a method is presented to choose the dimensional normalization parameter, based on the distance between two chirp signals´ peaks. First, the coordinates of the chirp signal´s peak is educed on the (p, u) plane. And the relationships between the dimensional normalization parameter and the distances between two chirp signals´ peaks on p axis and on u axis are analyzed. It is discovered that the distances varies with the dimensional normalization parameter and they both have their own maximums. By changing signals´ observation time and sampling frequency, selecting a reasonable dimensional normalization parameter can increase the distances between two signals´ peaks. It can improve multi-component chirp signals´ resolution ability and reduce the shading effect between strong signals and weak signals. The effectiveness of the method is verified by the computer simulations.
Keywords :
Fourier transforms; signal detection; signal processing; chirp signal rate; computer simulations; digital computation; dimensional normalization parameter; fractional Fourier transform; multicomponent chirp signal resolution; signal sampling frequency; Aerospace engineering; Automation; Chirp; Fourier transforms; Parameter estimation; Sampling methods; Signal analysis; Signal processing algorithms; Signal resolution; Time frequency analysis; dimensional normalization parameter; fractional Fourier transform; selection;
Conference_Titel :
Information and Automation (ICIA), 2010 IEEE International Conference on
Conference_Location :
Harbin
Print_ISBN :
978-1-4244-5701-4
DOI :
10.1109/ICINFA.2010.5512370