Tailored disruption of phase-locked loops via evolutionary algorithms

摘要

Numerical simulations are used to improve in-band disruption of a phase-locked loop (PLL). Disruptive inputs are generated by integrating a system of nonlinear ordinary differential equations (ODEs) for a given set of parameters. Each integration yields a set of time series, of which one is used to modulate a carrier input to the PLL. The modulation is disruptive if the PLL is unable to accurately reproduce the modulation waveform. We view the problem as one of optimization and employ an evolutionary algorithm to search the parameter space of the excitation ODE for those inputs that increase the phase error of the PLL subject to restrictions on excitation amplitude or power. Restricting amplitude (frequency deviation) yields a modulation that approximates a square wave. Constraining modulation power leads to a chaotic excitation that requires less power to disrupt loop operation than either the sinusoid or square wave modulations.