For sampling signal x()=x()∑(t-n)=∑x(nT)6(t-n) n=-00 n=-00 the laplace transform LIx,(t)=x,(t)e"dt S=+ jQ2 ∑x:(n)」(-mT) if s=jQ2, =Q2T =∑x(n)em=X(e)=X(e n=-00 Jon z-transform 令zae ,(0+19)7 of discrete x[n]z=X(z) e T time signal n=-0o11 For sampling signal， ( ) ( ) st c n x nT t nT e dt   − − = −   ( )  − =− =  sTn c n x nT e [ ] ( ) ( ) st s s x t x t e dt  − − = L  ( + ) = sT j T 令 z e e @ [ ] ( ) n n x n z X z  − =− = =  z-transform of discrete￾time signal the Laplace transform s c c ( ) ( ) ( ) ( ) ( ) n n x t x t t nT x nT t nT     =− =− = − = −  ( ) ST = X e if s j , =   = T = x n[ ] j re  = s j = +   − j n  e ( ) j X e T r e  =