5 The discrete-time fourier transform 5. The Discrete time Fourier Transform 5.0 Introduction (1)Fourier series (periodic signal xn jk(2I/N)n k= k(2T/N) N ∑ (2) Fourier transform(aperiodic signal) [n]= X(e )endo X(e)=∑xnk
5 The discrete-time Fourier transform 5.0 Introduction (1) Fourier series (periodic signal) 5. The Discrete time Fourier Transform = = = − = n N j k N n k k N j k N n k x n e N a x n a e (2 / ) (2 / ) [ ] 1 [ ] (2) Fourier transform (aperiodic signal) = = − + =− j n N j j j n X e x n e x n X e e d ( ) [ ] [ ] ( ) 2
5 The discrete-time fourier transform Fourier series (periodic signal) Xn k 8l404 中
5 The discrete-time Fourier transform Fourier series (periodic signal) x[n] ak
5 The discrete-time fourier transform Fourier transform(aperiodic signal) ●●●●●●●●●鲁●●●鲁 ●●●●●●●●●鲁● N,0 N X(e 2TT 一T 2丌
5 The discrete-time Fourier transform Fourier transform (aperiodic signal)
