Combining Radon-ambiguity transform with second-order difference to improve detection probability of LFM signals in low SNR  

作　　者：Tan Xiaogang Wei Ping Li Liping 

机构地区：[1]School of Electronic Engineering, Univ. of Electronic Science and Technology of China, Chengdu 610054, P. R. China

出　　处：《Journal of Systems Engineering and Electronics》2009年第1期13-19,共7页系统工程与电子技术（英文版）

基　　金：supported by the Program for New Century Excellent Talents in University, Ministry of Education (NCET-05-0803)

摘　　要：The Radon-ambiguity transform （RAT）, although efficient for detecting the linear frequency modulated signals （LFMs）, is troubled by the energy accumulation of noise in low signal-to-noise ratio （SNR）. A secondorder difference （SOD） method is proposed to treat with this problem. In the SOD method, the optimal search step and difference step are derived from the LFM rate resolution formula. The sharpness of the peaks of RAT is measured by curvature, and the sharpness, but not the magnitude of the peaks, is used to detect the LFMs. The SOD method removes the noise energy accumulation and reserves the drastically changing components integrally; thus, it improves the detection probability of LFMs in low SNR. The expected performance of the new method is verified by 100 Monte Carlo simulations.The Radon-ambiguity transform （RAT）, although efficient for detecting the linear frequency modulated signals （LFMs）, is troubled by the energy accumulation of noise in low signal-to-noise ratio （SNR）. A secondorder difference （SOD） method is proposed to treat with this problem. In the SOD method, the optimal search step and difference step are derived from the LFM rate resolution formula. The sharpness of the peaks of RAT is measured by curvature, and the sharpness, but not the magnitude of the peaks, is used to detect the LFMs. The SOD method removes the noise energy accumulation and reserves the drastically changing components integrally; thus, it improves the detection probability of LFMs in low SNR. The expected performance of the new method is verified by 100 Monte Carlo simulations.

关 键 词：linear frequency modulated signals Radon-axnbiguity transform detection probability low signal-to-noise ratio. 

分 类 号：TN957.51[电子电信—信号与信息处理] P631.443[电子电信—信息与通信工程]