Optimal Polyphase Coded Signal Design

Abstract

In the war prone global arena where every target of an enemy, on and off the land to be kept on eagle’s eye watch and to deceive enemy’s counter measure technologies, there is a strong requirement for most secured signal design which domicile maximum detection range along with high range resolution, to flare them up .The efficiency of the system mainly depends on how much power the generated pulse may possess in the main lobe to that of the side lobes and how independent they are from one another. The measure of Autocorrelation and cross correlation exhibited by polyphase coded sequence is determined mathematically. Multi input and multi output possesses best potential in mitigating the effects of fading, enhancing the resolution, suppressing the signal jamming and interference, which are all very useful in improving the target detection and recognition performance of the system. Recently, most optimization researches of polyphase codes are carried out by genetic algorithm (GA), Particle swarm optimization (PSO) and simulated annealing (SA) but this technique require more parameters for optimization. In order to overcome these difficulties modified PSO algorithm is adopted in the present research to optimize the polyphase coded sequence. The obtained codes are also put for Doppler resilience by including Doppler shift in the process of generation of the codes.