用AR 模型的自相关法估计信号的功率谱，用AR 模型的Burg 算法估计信号的功率谱，最大熵功率谱估计，用自相关矩阵分解的MUSIC 算法估计信号的功率谱(The power spectrum of the signal is estimated using the AR model autocorrelation method. The power spectrum of the signal is estimated using the Burg model of the AR model. The maximum entropy power spectrum estimation is performed. The power spectrum of the signal is estimated using the autocorrelation matrix decomposition MUSIC algorithm.)