IDR @ IIT Bhubaneswar
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Item Suppression of grating lobes in stepped frequency LFM pulse train using PSO(2014) Sahoo A.K.; Panda G.Frequency stepping technique is used in radar to achieve high range resolution and this technique requires inexpensive transmitter hardware. However, its matched filter output introduces undesired peaks known as grating lobes. In this letter efficient particle swarm optimization (PSO) based technique is proposed which judiciously determines the parameters of a linear frequency modulated (LFM) pulse train that enables effective suppression of grating lobes. Simulation results have been provided to demonstrate the efficacy of the proposed method. � 2014 Published by Elsevier Masson SAS.Item A multiobjective optimization approach to determine the parameters of stepped frequency pulse train(2013) Sahoo A.K.; Panda G.Frequency stepping techniques are commonly used in modern radar system to get high range resolution with the disadvantage that its autocorrelation function (ACF) yield undesirable "grating lobes". Wider mainlobe deteriorates the range resolution capability of the waveform and higher peak sidelobe either hides the small targets or causes the false target detection. Several techniques have been used to choose the parameters of linear frequency modulated (LFM) pulse train to suppress the grating lobes without paying much attention to the mainlobe width and peak sidelobe level. In this paper a multiobjective optimization (Nondominated Sorting Genetic Algorithm-II (NSGA-II)) approach is proposed to optimize the parameters of the LFM pulse train to achieve reduced grating lobes, low peak sidelobe level and narrow mainlobe width. The optimization problem has been studied in two different ways: first one is associated with the reduction of grating lobes and the minimization of peak sidelobe level of the ACF with constraints and second one is related to the minimization of the peak sidelobe level and mainlobe width of the ACF with constraints. Simulation studies have been carried out to justify the potentiality of the proposed approach. � 2011 Elsevier Masson SAS. All rights reserved.Item Sidelobe suppression using convolutional windows in radar(2012) Sahoo A.K.; Panda G.The matched filter output of pulse compression radar is associated with range sidelobes along with the mainlobe. To reduce these sidelobes, different types of windows are used as weighing function at the receiver. When the target is in motion, the reflected signal is Doppler-shifted version of the original transmitted signal. If this Doppler-shifted signal is passed through the receiver matched filter, it produces very low Peak to Sidelobe Ratio (PSR). In this paper, we have proposed the use of convolutional windows at the receiver along with amplitude tapered or phase distorted transmitted Linearly Frequency Modulated (LFM) signal to get high PSR value in Doppler shift condition. Exhaustive simulation studies are carried out for Time-Bandwidth (TB) product of 50 and 100 and it is found that convolutional windows provide superior PSR performance over conventional windows. � 2012 Inderscience Enterprises Ltd.