发射机的设计是采用m序列来扩展二进制数据流，将其扩频为宽频信号，并采用QPSK调制方式将信号调制后发送出去。信号经过AWGN信道传输到接收端。接收机采用相干解调原理解调信号，采用的解扩码序列与发射机扩频码序列完全相同，信号经解扩调制后，带宽恢复原始宽度。-Transmitter design is the use of m sequence to expand the binary data stream, the spread spectrum is a broadband signal, and the use of QPSK modulation mode to send out the signal modulation. The signal is transmitted to the receiving end via the AWGN channel. The receiver uses the coherent demodulation principle and demodulation signal, and the sequence of the code sequence is identical with that of the transmitter.