Detection of weak signal in laser ranging based on the theory of stochastic resonance

A novel approach based on the theory of stochastic resonance (SR) for detecting weak signals in heavy noise for detecting distance information for laser ranging is presented in this paper. SR in a nonlinear system is a cooperative effect of noise and periodic signal driving in bi-stable systems. Under the proper condition, increasing input noise level results in an increase in the output signal-to-noise ratio (SNR), which means increasing the disorder of the input leads to increasing the order of the output. Driven by a periodic signal and a Gaussian white noise, stochastic resonance exists in the double-well potential system. This stochastic resonance phenomenon can greatly improve the SNR of a periodic signal with additive Gaussian white noise. In this paper the theoretical derivation for bi-stable system at the SR and the computer simulation have been given. Under the generic adiabatic approximation condition, a numerical simulation on such as the out SNR shows that the output SNR in heavy ground noise has been improved evidently. In laser ranging system, the SR theory was applied in electronic circuits and the out SNR improved obviously.