Study of Weak Signal Detection Based on Second FFT and Chaotic Oscillator

Due to the incapacity of conventional method, while detecting periodic signals buried in the noise and deciding accurate frequency, a novel method is presented. This method is an integration of second FFT, which is an additional DFT after PSD, and the chaotic oscillator. Second FFT can increase the detection ability of weak periodic signals and the chaotic oscillator can improve frequency precision. This method is simple, quick and convenient in hardware realization and instrument design. Furthermore, its effect is demonstrated by detecting a simulation signal and a communication signal. (Nature and Science. 2005;3(2):59-64).