Radar Waveform Generation and Optimization based on Rossler Chaotic System

Abstract

The concept of Multiple-Input Multiple-Output (MIMO) radars has drawn considerable attention recently. Unlike the traditional Single-Input Multiple-Output (SIMO) radar which emits coherent waveforms to form a focused beam, the MIMO radar can transmit orthogonal (incoherent) waveforms. These waveforms can be used to increase the system spatial resolution. The challenge is on how to generate the large set of incoherent waveforms. Contemporary research has focused on using chaotic systems to generate these waveforms. With Chaotic waveforms obtained from a dynamical system, different radar waveforms can be generated from a single dynamical system; one only needs to change the control parameters and the initial conditions of the system. This scheme for radar waveform generation reduces the need for a comprehensive library of waveforms in a radar system and generates waveforms with good properties for both secure communications and high spatial resolution.

This paper proposes the use of Rossler system– a type of a dynamical system to generate radar waveforms. Through Matlab/Simulink Simulations, it is shown that the Rossler waveforms, which are characterized by control variables and initial conditions are comparable to the Linear Frequency Modulated (LFM) waveforms, the most commonly used class of radar waveforms in terms of the ambiguity diagram and the frequency components and yet versatile enough to generate a large number of independent waveforms. An ambiguity diagram is a plot of an ambiguity function of a transmitted waveform and is a metric that characterizes the compromise between range and Doppler resolutions. It is a major tool for analyzing and studying radar waveforms. Impulsive synchronization theory is used to develop the ambiguity diagram.

Keywords: Chaos, Rossler system, ambiguity function, impulsive synchronization theory