已知消息信号为一个长度为8的二进制序列；载波频率为 ，采样频率为4KHz。编程实现一种调制、传输、滤波和解调过程。-Known message signal is a binary sequence with a length of 8　the carrier frequency, the sampling frequency of 4KHz. Programming a modulation, transmission, filtering, and demodulation process.