说明：  ex1_1 单位冲激序列 ex1_2 右移20的单位冲激序列 ex1_3 单位阶跃序列 ex1_4 实指数序列 ex1_5 复指数序列 ex1_6 随机序列 ex1_7 系统冲激响应（impz函数） ex1_8 系统传递函数（freqz函数） ex1_9 零极点增益 ex1_10 residuez函数应用 ex1_11 Lattice结构全极点IIR系统 ex1_12 Lattice结构全零点FIR系统 ex1_13 Lattice结构零极点结构
(unit impulse sequence ex1_1 shifted to right ex1_2 unit 20 unit step impulse ex1_3 sequence sequence sequence ex1_4 index is ex1_5 complex exponential sequence ex1_7 random sequence ex1_6 system impulse response (impz function) ex1_8 system transfer function (freqz function) ex1_9 zeros and poles gain function ex1_10 residuez application ex1_11 Lattice all-pole IIR system structure ex1_12 Lattice structure of the whole system against ex1_13 Lattice Structure of FIR zero-pole structure)