几个有关通信系统的matlab程序,有关信号，包含：a,对抽样频率为90kHz的信号进行下抽样抗混叠滤波器设计的程序，b,信号抽样率转换的程序，c,通过补零内插对信号进行下抽样，分析抽样对信号频谱的影响的程序-Some matlab programs about communiction system,mainly about signal,a,program about filter to signal sampling without aliasing ,b,transfering sign