Application of time-variant soft threshold method in denoising nanosecond pulse signal

Based on the comparison of several commonly used wavelets in the engineering, biorthogonal wavelet is considered to be the most suitable mother wavelet for the nanosecond pulse analysis. A time variant soft threshold is proposed in the signal denoising on the basis of the characteristic of the noise. A Doppler wave in Matlab and a square pulse generated by square wave generator are chosen to validate the effect of the method. The results prove that the time-variant soft threshold method proposed in this paper is better than the traditionally used threshold-fixed method.