中文说明：
应用LSE 算法估计载波频率和相位，又称为锁相环。使用初值和迭代算法，估计频率和相位值，并根据估计出的频率和相位值画出估计得正弦波。将正弦波真值和估计值画在同一个图中，每更新一次，重新绘制两个波形，最终需要画出演示视频中的效果：估计出的波形逐步靠近真正的波形。
English Description：
Using LSE algorithm to estimate carrier frequency and phase is also called phase locked loop. The initial value and iterative algorithm are used to estimate the frequency and phase values, and the estimated sine wave is drawn according to the estimated frequency and phase values. Draw the true value and estimated value of sine wave in the same graph, and draw two waveforms again every time. Finally, we need to draw the effect in the demonstration video: the estimated waveform gradually approaches the real waveform.