High resolution time-frequency representation for chirp signals using an adaptive system based on duffing oscillators

This paper presents a novel methodology to estimate the frequency shift in chirp signals with SNRs as low as -17 dB through the use of an adaptive array of Duffing oscillators. The system used here is an array of five Duffing oscillators with each oscillator's response enhanced through a correlation with the reference signal. As a final result, a time-frequency depiction is provided by the Duffing array for further analysis of chirp signals. Using computer simulated experiments, it is found that the analysis of chirp signals with low SNR by means of the Duffing oscillator shows a markedly better performance than the conventional methods of time-frequency analysis. To this end, the results obtained from the proposed Duffing method are compared against some recent techniques in time-frequency analysis. Furthermore, to strengthen the proposed representation, Monte Carlo simulation is used. (C) 2016 Elsevier Inc. All rights reserved.