Suppressing Autocorrelation Sidelobes of LFM Pulse Trains with Genetic Algorithm

• Published in: Tsinghua science and technology Vol. 13; no. 6; pp. 800 - 806
• Main Authors: Wang, Peng, Meng, Huadong, Wang, Xiqin
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.12.2008; Intelligent Transportation Information Systems Laboratory, Department of ELectronic Engineering, Tsinghua University, Beijing 100084, China
• Subjects: autocorrelation function (ACF); coherent train; genetic algorithm (GA); performance improvement; sidelobes suppression; genetic algorithm (GA); autocorrelation function (ACF); performance improvement; sidelobes suppression; coherent train
• ISSN: 1007-0214; 1878-7606; 1007-0214
• DOI: 10.1016/S1007-0214(08)72203-X

Modulations and diversities, including the Costas-ordered stepped-frequency and nonlinear stepped-frequency waveforms are widely used in linear frequency modulation (LFM) pulse trains to reduce the relatively high autocorrelation function (ACF) sidelobes. An efficient method was developed to optimize the interpulse frequency modulation to remove most of the ACF sidelobes about the mainlobe peak, with only a small increase in the mainlobe width. The genetic algorithm is used to solve the nonlinear optimization problem to find the interpulse frequency modulation sequence. The effects on the ACF sidelobes suppression and mainlobe widening are studied. The results show that the new design is superior to the corresponding stepped-frequency LFM signal and weighted stepped-frequency LFM signal in the terms of the ACF sidelobes reduction and mainlobe spread.