MPSK的仿真代码，这里我们模拟一个45×旋转的QPSK系统。一旦符号映射，对QPSK调制的功率信号需要1 /平方根归一化（2）。 码(In the previous section, we saw how QPSK modulation and demodulation in passband can be done.Here we are simulating a 45* rotated QPSK system. Once the symbols are mapped, the power of the QPSK modulated signal needs to be normalized by 1/sqrt(2).)