EEET 0770 Digital Filter Design Digital Filters Design

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EEET 0770 Digital Filter Design ���������� Digital Filters Design Chapter 4 Finite Impulse Response

EEET 0770 Digital Filter Design ���������� Digital Filters Design Chapter 4 Finite Impulse Response Filter Design Asst. Prof. Dr. Peerapol Yuvapoositanon, Ph. D, DIC Department of Electronic Engineering and Graduate School of Electrical Engineering Centre of Electronic Mahanakorn Systems and University of Technology Digital Signal Processing 1

EEET 0770 Digital Filter Design ขอดของ FIR • มความเสถยร (stable) • สามารถออกแบบใหผลตอบสนองทางเฟส เปนเชงเสน (Linear

EEET 0770 Digital Filter Design ขอดของ FIR • มความเสถยร (stable) • สามารถออกแบบใหผลตอบสนองทางเฟส เปนเชงเสน (Linear phase) ไดงาย Centre of Electronic Systems and Digital Signal Processing 2

EEET 0770 Digital Filter Design เฟสทเปนเชงเสน (linear phase) ������ a=������� FIR ��������� �� Centre

EEET 0770 Digital Filter Design เฟสทเปนเชงเสน (linear phase) ������ a=������� FIR ��������� �� Centre of Electronic Systems and Digital Signal Processing 3

EEET 0770 Digital Filter Design ��������� �� • ���������� h(n) 0 1 N ������

EEET 0770 Digital Filter Design ��������� �� • ���������� h(n) 0 1 N ������ 2 3 4 ������ (symmetric) N ������ 0 1 2 3 4 5 N ������ 0 1 2 3 4 ���������� 0 1 N ������ (Antisymmetric) Centre of Electronic Systems and 2 3 4 5 Digital Signal Processing 4

EEET 0770 Digital Filter Design Low pass filter (LPF ) Band pass filter (BPF)

EEET 0770 Digital Filter Design Low pass filter (LPF ) Band pass filter (BPF) Centre of Electronic Systems and Digital Signal Processing High pass filter (HPF) Band stop filter (BSF) 7

EEET 0770 Digital Filter Design ผลตอบสนองอมพลสของตวกรองตำผาน LPF Centre of Electronic Systems and Digital Signal

EEET 0770 Digital Filter Design ผลตอบสนองอมพลสของตวกรองตำผาน LPF Centre of Electronic Systems and Digital Signal Processing 8

EEET 0770 Digital Filter Design ��������� ���� ��� d(n) �������� d(n) noncausal ( �������)

EEET 0770 Digital Filter Design ��������� ���� ��� d(n) �������� d(n) noncausal ( �������) ������ ��� (approximation) Centre of Electronic Systems and Digital Signal Processing 9

EEET 0770 Digital Filter Design ��������� =����� (Cut-off frequency) Centre of Electronic Systems and

EEET 0770 Digital Filter Design ��������� =����� (Cut-off frequency) Centre of Electronic Systems and Digital Signal Processing 10

ผลตอบสนองอมพลสของตวกรองต ำผาน ทมการ เลอน M ลำดบ EEET 0770 Digital Filter Design Centre of Electronic

ผลตอบสนองอมพลสของตวกรองต ำผาน ทมการ เลอน M ลำดบ EEET 0770 Digital Filter Design Centre of Electronic Systems and Digital Signal Processing 11

EEET 0770 Digital Filter Design �������� = n n n ������� h(n) ����������� w(n)

EEET 0770 Digital Filter Design �������� = n n n ������� h(n) ����������� w(n) ���� N = ������ (order) ����� M=(N-1)/2 Centre of Electronic Systems and Digital Signal Processing 13

EEET 0770 Digital Filter Design �������� = �������� Centre of Electronic Systems and Digital

EEET 0770 Digital Filter Design �������� = �������� Centre of Electronic Systems and Digital Signal Processing 14

EEET 0770 Digital Filter Design ����������� ----- ��������������� ��� 1������ 2��������� Centre of Electronic

EEET 0770 Digital Filter Design ����������� ----- ��������������� ��� 1������ 2��������� Centre of Electronic Systems and Digital Signal Processing 15

EEET 0770 Digital Filter Design ขอกำหนดในการออกแบบตวกรอง (Filter specification) ������� �� ������� Centre of Electronic

EEET 0770 Digital Filter Design ขอกำหนดในการออกแบบตวกรอง (Filter specification) ������� �� ������� Centre of Electronic Systems and Digital Signal Processing 16

EEET 0770 Digital Filter Design ��������� (Main lobe) ������� (sidelobe) ��������� Centre of Electronic

EEET 0770 Digital Filter Design ��������� (Main lobe) ������� (sidelobe) ��������� Centre of Electronic Systems and Digital Signal Processing 17

EEET 0770 Digital Filter Design �������� �� As 8. 9% 21 ������ 0. 63%44

EEET 0770 Digital Filter Design �������� �� As 8. 9% 21 ������ 0. 63%44 ����� �� (Hannin g) 0. 22%53 ����� �� Centre of Electronic Systems and (Hamming) Digital Signal Processing 1 18

EEET 0770 Digital Filter Design ���� 1 (��� ) ���������� ����������� 7. 2 ������������

EEET 0770 Digital Filter Design ���� 1 (��� ) ���������� ����������� 7. 2 ������������ ������� 44. 44 ����� Centre of Electronic Systems and Digital Signal Processing 21

EEET 0770 Digital Filter Design ���� 1 (��� ) Centre of Electronic Systems and

EEET 0770 Digital Filter Design ���� 1 (��� ) Centre of Electronic Systems and Digital Signal Processing 22

EEET 0770 Digital Filter Design ��������� Centre of Electronic Systems and Digital Signal Processing

EEET 0770 Digital Filter Design ��������� Centre of Electronic Systems and Digital Signal Processing 500 Hz ex_7_1. eps 23

EEET 0770 Digital Filter Design ผลตอบสนองอมพลส Centre of Electronic Systems and Digital Signal Processing

EEET 0770 Digital Filter Design ผลตอบสนองอมพลส Centre of Electronic Systems and Digital Signal Processing h(n) ของตวกรอง ex_7_2. eps 24

EEET 0770 Digital Filter Design �������� -21 d. B Centre of Electronic Systems and

EEET 0770 Digital Filter Design �������� -21 d. B Centre of Electronic Systems and Digital Signal Processing 25

EEET 0770 Digital Filter Design ������� -44 d. B Centre of Electronic Systems and

EEET 0770 Digital Filter Design ������� -44 d. B Centre of Electronic Systems and Digital Signal Processing 26

EEET 0770 Digital Filter Design �������� -74 d. B Centre of Electronic Systems and

EEET 0770 Digital Filter Design �������� -74 d. B Centre of Electronic Systems and Digital Signal Processing 27

EEET 0770 Digital Filter Design (DFD) Module 2 3 1 Centre of Electronic Systems

EEET 0770 Digital Filter Design (DFD) Module 2 3 1 Centre of Electronic Systems and Digital Signal Processing 28

EEET 0770 Digital Filter Design Lab. VIEW program Centre of Electronic Systems and Digital

EEET 0770 Digital Filter Design Lab. VIEW program Centre of Electronic Systems and Digital Signal Processing 29

EEET 0770 Digital Filter Design Lab. VIEW program Centre of Electronic Systems and Digital

EEET 0770 Digital Filter Design Lab. VIEW program Centre of Electronic Systems and Digital Signal Processing 30

EEET 0770 Digital Filter Design High. Pass Centre of Electronic Systems and Digital Signal

EEET 0770 Digital Filter Design High. Pass Centre of Electronic Systems and Digital Signal Processing 31

EEET 0770 Digital Filter Design Bandpass Centre of Electronic Systems and Digital Signal Processing

EEET 0770 Digital Filter Design Bandpass Centre of Electronic Systems and Digital Signal Processing 32

EEET 0770 Digital Filter Design Bandstop Centre of Electronic Systems and Digital Signal Processing

EEET 0770 Digital Filter Design Bandstop Centre of Electronic Systems and Digital Signal Processing 33

EEET 0770 Digital Filter Design Hanning Centre of Electronic Systems and Digital Signal Processing

EEET 0770 Digital Filter Design Hanning Centre of Electronic Systems and Digital Signal Processing 34

EEET 0770 Digital Filter Design Hamming Centre of Electronic Systems and Digital Signal Processing

EEET 0770 Digital Filter Design Hamming Centre of Electronic Systems and Digital Signal Processing 35

EEET 0770 Digital Filter Design Blackman-Harris Centre of Electronic Systems and Digital Signal Processing

EEET 0770 Digital Filter Design Blackman-Harris Centre of Electronic Systems and Digital Signal Processing 36

EEET 0770 Digital Filter Design ������ 2 ����������� 2 k. Hz ������������ Centre of

EEET 0770 Digital Filter Design ������ 2 ����������� 2 k. Hz ������������ Centre of Electronic Systems and Digital Signal Processing 37

EEET 0770 Digital Filter Design . 1�������� ������� ��� ����������� ������������� Centre of Electronic

EEET 0770 Digital Filter Design . 1�������� ������� ��� ����������� ������������� Centre of Electronic Systems and Digital Signal Processing 38

EEET 0770 Digital Filter Design �������� (0. 02%( ������ 7. 2 ���������� ��������� 300

EEET 0770 Digital Filter Design �������� (0. 02%( ������ 7. 2 ���������� ��������� 300 � Centre of Electronic Systems and Digital Signal Processing 41

EEET 0770 Digital Filter Design %window. m technique demonstrating of the window design fc=500;

EEET 0770 Digital Filter Design %window. m technique demonstrating of the window design fc=500; fs=2000; N=41; M=(N-1)/2; wc=2*pi*fc/fs; n=0: N-1; %%%%%%% we can add a smallest number % 'eps' to avoid dividing by zero d=sin(wc*(n-M+eps)). /(n-M+eps)/pi; %%%% uncomment lines below for different windows w=ones(1, N); % Rectangular % w=. 5 -. 5*cos(2*pi*n. /(N-1)); %Hanning % w=. 42 -. 5*cos(2*pi*n. /(N-1))+. 08*cos(4*pi*n. /(N-1)); %blackman h=d. *w; figure(1); subplot(111); freqres(h, 1, fs, 'db') figure(2); subplot(111); stem(h) grid on xlabel('n') ylabel('h(n)') Centre of Electronic Systems and Digital Signal Processing 42

EEET 0770 Digital Filter Design การออกแบบ FIR เทคนกการสมความถ (Frequency Sampling Techniques) ������������������� 7 ������������

EEET 0770 Digital Filter Design การออกแบบ FIR เทคนกการสมความถ (Frequency Sampling Techniques) ������������������� 7 ������������ 1 Centre of Electronic Systems and Digital Signal Processing 43

EEET 0770 Digital Filter Design ������������������ “FIR: Frequency Sampling” �� DSP 7: ������������ h(n)

EEET 0770 Digital Filter Design ������������������ “FIR: Frequency Sampling” �� DSP 7: ������������ h(n) ������������� Centre of Electronic Systems and Digital Signal Processing 44

EEET 0770 Digital Filter Design ��������� ������ ���������� ��� Centre of Electronic Systems and

EEET 0770 Digital Filter Design ��������� ������ ���������� ��� Centre of Electronic Systems and Digital Signal Processing 45

EEET 0770 Digital Filter Design เลอก N เปนเลขค ครอบคลม 1 0 1 2 3

EEET 0770 Digital Filter Design เลอก N เปนเลขค ครอบคลม 1 0 1 2 3 Centre of Electronic Systems and Digital Signal Processing 10 20 46

EEET 0770 Digital Filter Design ����������� FIR �������� 2 k. Hz ������ (fs) 10

EEET 0770 Digital Filter Design ����������� FIR �������� 2 k. Hz ������ (fs) 10 k. Hz ������� ���������� = �������� = Centre of Electronic Systems and Digital Signal Processing 47

EEET 0770 Digital Filter Design ��������� 1 Centre of Electronic Systems and Digital Signal

EEET 0770 Digital Filter Design ��������� 1 Centre of Electronic Systems and Digital Signal Processing 48

EEET 0770 Digital Filter Design ���� 21 ��� ex_8_8. eps Centre of Electronic Systems

EEET 0770 Digital Filter Design ���� 21 ��� ex_8_8. eps Centre of Electronic Systems and Digital Signal Processing 49

EEET 0770 Digital Filter Design ��������� 61 ��� ����������� = �������� = Centre of

EEET 0770 Digital Filter Design ��������� 61 ��� ����������� = �������� = Centre of Electronic Systems and Digital Signal Processing 50

EEET 0770 Digital Filter Design ���� 61 ���������� 21 ��� ex_8_9. eps Centre of

EEET 0770 Digital Filter Design ���� 61 ���������� 21 ��� ex_8_9. eps Centre of Electronic Systems and Digital Signal Processing 51

EEET 0770 Digital Filter Design %freq_sampl. m demonstrating low-pass design for FIR % fs=10000;

EEET 0770 Digital Filter Design %freq_sampl. m demonstrating low-pass design for FIR % fs=10000; % ������ 10 k. Hz wc= 0. 4*pi; % ��������� N=21; % ����������� Mp= ceil(wc*N/(2*pi)); %�. �. ���������� 0<w<pi Mpp=Mp-1; %�. �. ���������� pi<w<2 pi Ms= N-Mp-Mpp; %�. �. ���������� 0<w<pi H=[ones(1, Mp) zeros(1, Ms) ones(1, Mpp)]; %������� k=0: 1: N-1; % ��N ������� H=H. *exp(-j*pi*(N-1)*k/N); % ������� =���� *��� h=real(ifft(H)); %��������� figure(1) freqres(h, 1, fs) Centre of Electronic Systems and Digital Signal Processing 52