中文说明：1、信号频率、幅值和相位估计(1)频率(周期)检测对周期信号来说，可以用时域波形分析来确定信号的周期，也就是计算相邻的两个信号波峰的时间差、或过零点的时间差。这里采用过零点(ti)的时间差T(周期)。频率即为f = 1/T，由于能够求得多个T值(ti有多个)，故采用它们的平均值作为周期的估计值。(2)幅值检测在一个周期内，求出信号最大值ymax与最小值ymin的差的一半，即A = (ymax - ymin)/2，同样，也会求出多个A值，但第1个A值对应的ymax和ymin不是在一个周期内搜索得到的，故以除第1个以外的A值的平均作为幅值的估计值。(3)相位检测采用过零法，即通过判断与同频零相位信号过零点时刻，计算其时间差，然后换成相应的相位差。φ=2π(1-ti/T)，{x}表示x的小数部分，同样，以φ的平均值作为相位的估计值。
English Description：
1, the signal frequency, amplitude, and phase estimation (1) frequency (cycles) for detection of periodic signals, time-domain waveform analysis to determine the signal cycle, that is, calculate adjacent signal wave time difference, or zero time lag. Using zero-crossing point (TI) time t (cycle). The frequency is f = 1/T, because it can obtain more t values (TI has more than one), so their estimate of the average cycle. (2) site value detection in a cycle within, seeking out signal maximum value ymax and minimum value ymin of poor of half, that a, = (ymax-ymin)/2, also, also will seeking out multiple a, value, but 1th a a, value corresponds to of ymax and ymin not in a cycle within search get of, so to except 1th a yiwai of a, value of average as site value of estimated value. (3) the phase detection using zero-crossing method, namely by judging the zero phase signal zero-crossing point with the same frequency, calculate the time difference, and then repla