离散LTI系统的时域分析，适用于初学者，学习仿真信号与系统这门课程-Time-domain analysis of discrete LTI systems, suitable for beginners to learn the simulation of signals and systems this course

离散信号的卷积和运算，适用于初学者，学习仿真信号与系统这门课程-Discrete signal convolution and operation, suitable for beginners to learn the simulation of signals and systems this course