信号与系统基础知识包括连续信号与模型、离散信号与模型；常用信号变换包括Z变换、Chirp Z变换、FFT变换、DCT变换和Hilbert变换等；离散系统结构包括IIR、fir和Lattice结构；IIR滤波器设计包括模拟和数字低通、高-Basic knowledge of signals and systems, including continuous signal with the model, discrete signals and model common signal, inclu