基于LabVIEW设计了相位差的检测程序，采用相关法、过零法、FFT法、频谱分析法四种方法，适合毕业设计。-LabVIEW design phase of the testing procedures, the use of correlation, zero-crossing method, FFT method, spectral analysis of four methods for graduation design.

The magnitude and power spectrum are non-negative variables, and any negative estimates of these variables should be mapped into non-negative values. This nonlinear rectification process distorts the distribution of the restored signal. The