Additive white Gaussian noise（AWGN） channel carrier signal instantaneous frequency probability density distribution model is studied

and the distribution model is verified by hypothesis testing.The effect of different sampling rate and SNR on instantaneous frequency probability of density distribution is analyzed.According to the conclusions of the analysis

a method based on extraction and reconstruction of the instantaneous frequency estimation algorithm is presented

and the performance of the algorithm is analyzed in detail.The multi-carrier signal sampling series instantaneous frequency aliasing are also analyzed and the limit formula of the instantaneous frequency aliasing is derived.The correctness of instantaneous frequency of the probability density distribution is verified

through the Monte-Carlo simulation.