The paper discusses mainly the essential theory of time-frequency analysis method and two important tools: Wigner - Ville distribution , Radon - Wigner transform that applies to the time-frequency analysis method. And it validates that they can applies to the semic signals processing. The processing result indicates that Wigner - Ville distribution has well time-frequency collective feature for single component signal,it applies to single component signal processing. However, Wigner - Ville distribution isn't enough effective applied to multicomponent signals processing for existing crossed items ,sometimes signal items completely can't be distinguished from distribution for serious disturbance of crossed items.In addition,we can utilize the Wigner - Ville distribution to reduce the random noise of signals in that Wigner - Ville distribution isn't enough sensitive to noise.In theory, Radon - Wigner transform of LFM signals produces a distinct maxima(peak) in the Radon-Wigner plane, so it describe effectively the feature of the LFM signals and suppress effectively the crossed items along with Wigner - Ville distribution.we can utilize the Radon - Wigner transform to reduce the random noise of LFM signals in that the noise distrbute as dot at random in the Radon - Wigner plane. |