5、绘制散点图。

对发射和接收信号利用scatterplot函数可显示信号星座图的样子及噪声对信号造成的失真程度。在该图中，横轴代表了信号的同相分量而纵轴代表了正交分量。下面的代码还利用了

对接收信号利用modem.deqammod对象的demodulate方法进行解调。解调结果为包含0到15之间整数的列向量。

-5, draw a scatter plot. The transmitted and received signals can be displayed using a function of the degree of distortion scatterplot like and noise signals caused by the signal constellation of FIG. In this figure, the horizontal axis represents the in-phase component signal and the vertical axis represents the quadrature component. The following code is also used to demodulate the received signal using the method of demodulating modem.deqammod object. Demodulation result is an integer from 0 to 15 comprising a column vector.