信号进入信道，经过高斯噪声的干扰，经过QPSK调制以后的波形-Signal into the channel, after the Gaussian noise interference after the subsequent QPSK modulation waveform

信号进入信道，经过高斯噪声的干扰，经过QPSK调制以后的时延 -The signal enters the channel, after the interference of the Gaussian noise after a delay after the QPSK modulation