1.单位脉冲序列（单位采样序列）\(\sigma(n)=\{...,0,\underline{1},0,...\}\)
即
\(\sigma(n)=\begin{cases}1, & n=0\\0, & n \neq 0 \end{cases}\)
\(a\sigma(n)=\begin{cases}a, & n=0\\0, & n \neq 0 \end{cases}\)
\(\sigma(n-k)=\begin{cases}1, & n=k\\0, & n \neq k \end{cases}\)
任意序列都可用单位脉冲序列的位移和加权和表示
2.单位阶跃序列\(\mu(n) = \{...,0,\underline{1},1,1,1...\}\)
即
\(\sigma(n)=\begin{cases}1, & n \ge 0\\0, & n < 0 \end{cases}\)
3.矩形序列\(R_N(n)=\{0,0,...\underline{1},1,1...\}\)
\(R_N(n)=\begin{cases}1,& 0\le n \le N-1\\0 & else \end{cases}\)
4.实指数序列\(\alpha^n\mu(n)\)
5.复指数序列\(e^{(\sigma+j{\omega}_{0})n}\)
\(e^{(\sigma+j{\omega}_{0})n}=e^{\sigma n}e^{j\omega_0n}\)
\(e^{\sigma n}\)：实指数序列
\(e^{j\omega_0n}\)：虚指数序列
\(e^{j\omega_0n}=cos\omega_0n+jsin\omega_0n\)
6.正弦序列\(Asin(\omega_0n+\phi)\)
7.周期序列\(x(n)=x(n+N)\)
