tailieunhanh - Lecture Digital signal processing: Lecture 5 - Zheng-Hua Tan

In this chapter you will learn: Frequency response, system functions, relationship between magnitude and phase, all-pass systems, minimum-phase systems, linear systems with generalized linear phase. | Digital Signal Processing Fall 2006 Lecture 5 System analysis Zheng-Hua Tan Department of Electronic Systems Aalborg University Denmark zt@ d . 1 Digital Signal Processing V Zheng-Hua Tan 2006 AALBORG UNIVERSITY Course at a glance MM3 MM9 MM10 MM7 MM8 ___________ 1 Mt 2 Digital Signal Processing V Zheng-Hua Tan 2006 AALBORG UNIVERSITY 1 System analysis Three domains Time domain impulse response convolution sum y n x n h n ị x k h n - k k - Frequency domain frequency response Y e m X eja H eja z-transform system function Y z X z H z LTI system is completed characterized by . 3 Digital Signal Processing V Zheng-Hua Tan 2006 AALBORG UNIVERSITY Part I Frequency response Frequency response System functions Relationship between magnitude and phase All-pass systems Minimum-phase systems Linear systems with generalized linear phase 4 Digital Signal Processing V Zheng-Hua Tan 2006 2 Frequency response Relationship btw Fourier transforms of input and output Y ej X ejm H j In polar form Magnitude magnitude response gain distortion Y e X e H e Phase phase response phase shift distortion XY e XX e XH e 5 Digital Signal Processing V Zheng-Hua Tan 2006 AALBORG UNIVERSITY Ideal lowpass filter - an example Frequency response H e a 1 o M o c ữc a n Frequency selective filter Impulse response sin cn h nJ --- - n X nn Noncausal cannot be implemented h n 0 n 0 How to make a noncausal system causal 6 Digital Signal Processing V Zheng-Hua Tan 2006