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Trang 76 Hàm freqs MATLAB decibels.. bài 6.4 bilinear cho phép này.

Biên

www.hutech.edu.vn

*1.2021.ELS314*

tailieuhoctap@hutech.edu.vn

I III

AB 1

1.1 MATLAB 1

1.2 CÁC 5

5

6

6

1.3 TRÌNH TRONG MATLAB 7

7

1.3.2 Sw itch 7

1.3.3 While 8

1.3.4 For 8

1.3.5 Break: 8

1.4 MA 8

8

1.4.2 Vector 13

13

1.5 14

14

15

15

16

-D 16

17

c 18

23

25

26

1.6 CÁC FILE VÀ HÀM 28

28

1.6.2 File hàm .29

30

1.6.4 Các phép toán trên hàm .31

32

41

2.1 CÁC TÍN 41

2.2 CÁC PHÉP TOÁN 42

2.3 TRA TÍNH TÍNH VÀ 43

2.4 H LTI 45

47

3.1 CÁC VÀ KHÔNG 47

3.2 PHÂN TÍCH DÙNG PHÁP 49

3.3 Z VÀ Z 49

52

4.1 TÍNH DTFT 52

4.2 FFT VÀ CÁC TÍNH 54

56

5.1 CÁC 56

5.2 PHÁP 58

5.3 PHÁP 62

5.4 PHÁP 64

68

6.1 68

6.2 73

TÀI THAM 78

- 5

MATLAB:

1.3.2 Switch

case n1

case n2

case nn

BÀI 1: 11

1.4.1.6 Xoá hàng và c t

1.4.1.7 Các l nh x lý ma tr n

- B Nhân : X = A*B

>> A(2,3) Bài 1.1

{\

BÀI 1: 21

\bf Bold font

\it Italic font

\sl Oblique font (rarely available)

sin(\om ega_0 \tau)')

K t qu :

>>text('units','inch' , 'po sitio n',[.2 5],

'fontsize',14, 'inter prete r', ' latex', 'string' ,

['$$\hb ox {magic(3) is } \left( {\ma trix{ 8 & 1 & 6 \cr ' '3 & 5 & 7 \cr 4 & 9 & 2 } } \ri ght)$$']);

>>text('units','inch' , 'po sitio n',[.2 4],

'fontsize ',14, 'in terpr eter','latex', 'stri ng',

['$$\le ft[ {\matrix{\cos(\phi) & -\sin(\phi) \cr'

'\sin(\phi) & \co s(\ph i) \cr}} \right ]'

'\left[ \matrix{x \cr y} \right] $$']);

>>text('unit s','inch' , 'po sition',[.2 3],

'fontsize ',14, 'in terpr eter','latex', 'stri ng',

['$$L\{f(t)\} \equiv F(s) = \in t_0^\infty \!\!{ e^{-st}'

'f(t)dt}$$']);

>>text('units','inch' , 'po sitio n',[.2 2],

'fontsize ',14, 'in terpr eter','latex', 'stri ng',

'$$e = \sum_{k=0} ^\infty {1 \over {k!} } $ $');

>>text('units','inch' , 'po sitio n',[.2 1],

'fontsize ',14, 'in terpr eter','latex', 'stri ng',

['$$m \ddot y = -m g + C_D \cdot {1 \over 2}'

'\rho {\dot y}^2 \cdot A$$' ]);

>>text('unit s','inch' , 'po sition',[.2 0],

'fontsize ',14, 'in terpr eter','latex', 'stri ng',

\frac{\sqrt{ \pi}}{4}$$');

-project.org/

>>grid on %hien thi l uoi

>>hold on %giu hinh, mac n hien la hold off

>>y2=sin(x.^2); %luy thua tung phan tu

>>axis([0 4*pi 1.25 1.25] ) %dinh lai toa do h ien thi

>>legenBài 1.11 Th c hi

th cho plot

>>theta=0:0.05:2*pi;

BÀI 1: 27

>>r=sin(5*theta);

>>polar(theta,r)Bài 1.14 V hàm s r = 2sin( ) + 3cos( )

>> [x,y]=meshgrid(t); %din h luo i ve

i = i + 1;

end plot(f)

BÀI 1: 33

MATLAB Editor:

>>edit script file có

% Doan script file nay hien thi loi chao trong 2s Sau do hien thi logo cua MATLAB roi th oat

'Color','w',

'Positi on',[0 5],

'Fontsize',32,

'FontAngle','italic') ; axis off;

pause(2); % dung tron g 2 g iay

% Hien thi logo cua MATLAB - - - logo

clear all close

% ket thuc script fil e

help <ten toolbox> % chuc nang toolbox

>>help control % liet ke h am cu a control toolbox

lookfor

MATLAB

lookfor <tu khoa tim kiem>

function [x1,x2]=gptb 2(a,b ,c)

% Giai phuong trinh b ac ha i ax^ 2+bx+c=0

% [x1,x2]=gptb2(a,b,c )

% Trong do: x1,x2 la nghie m

% a, b, c la 3 he so cua p huong trinh

BÀI 1: 37

if nargin<3 error('Error! Nhap 3 he so cua phuong trinh') elseif a==0

x1=-c/b;

x2=[];

else delta = b^2 - 4* a*c;

Bài 1.23

ng Becnulli:

function vdcongdb(a,m ,meth od)

% Ve duong cong trong toa do cu c: vdcongdb(a,m ,method)

% method = 'Becnulli' - Ve duong Lemnisca t Bec nulli:

% r=a*sqrt(abs(2*cos( 2*the ta)))

% 'Astroit' - Ve duong Astroit:

theta=0:0.01:2*pi; me thod= upper (method);

switch method case 'BECNULLI' r=a*sqrt(abs(2*cos(2* theta )));

case 'ASTROIT' r=a*sqrt(abs(1-sin(3* theta)/4));

case 'XOANOC' r=a*cos(theta)+1;

otherwise error('Chon: ''Becnul i'', ''Ast roit'' hoa c ''Xoano c''') end % end of switch

% ve do thi close all; figure('Co lor', 'w');

for k=1:m hold on r1=r*k;

mau=[rand(1,1) rand(1 ,1) r and(1 ,1)];

tiep = 'y'; sai=0; du ng=0;

disp('Chao mung ban den vo i chuong trinh du do an xuc xa c!') while(lower(tiep)=='y ')

doan=input('Moi ban d u doa n ket qua (1-6) :');

kqua=tungxx;

if (doan ~= kqua)

disp('Xin loi, ban da doan sai! ') sai=sai+1;

else disp('Xin chuc mung!' ) dung=dung+1;

end tiep=input('Ban muon choi tiep( ''y'' /''n''):');

end

num2str(sai+dung) ' l an do an'])

% subfunction - function mat = tungxx ()

mat=floor(6*rand(1,1) )+1;

% end

Bài 1.26

Bài 2.3 Tín n -10,10); (0,1000); (0,1e6)

>>y = n.*(a1*x1 + a2* x2);

>>subplot(211), stem( n,a1* y1+a2 *y2);

>>subplot(212), stem( n,y);

y(n) = x(n2)

Bi c:

h các th a s th

end

BÀI 5: 59

function hd = ideal_l p(wc, M) alpha = (M-1)/2;

function [db,mag,pha, grd,w ] = f reqz_m(b,a)

% db = Do lon tuong d oi th eo dB tren doan tu 0 den pi

% mag = Do lon tuyet doi t ren d oan tu 0 den pi

% pha = Dap ung pha t ren d oan t u 0 den pi

% grd = Tre nhom tren doan tu 0 den pi

% w = Cac mau tan so doan tu 0 den pi

% b = Cac he so da th uc tu so c ua H(z) (voi FIR: b=h)

% a = Cac he so da th uc ma u so cua H(z)(voi FIR: a=[1]) [H,w] = freqz(b,a,1000,'whole' );

p = 0.2 ; s = 0.3 ; Rp = 0.25 dB; As = 50 dB

-

p

hamming, blackman, Kaiser

>>Rp = -(min(db(1:1:w p/del ta_w+ 1)))

>>As = -round(max(db( ws/de lta_w +1:1:501)))

H(k) = [1,1,1,1,1,1,1,T1,T2 2,T1,1 ,1,1,1 ,1,1]

>>M = 6 0; al pha = (M-1)/2; L = 0:M-1; wl = (2*pi/M )*L;

>>Hk = [ones(1, 7),0.5925,0.1099,zeros(1 ,43), 0.1099, 0.5925, ones(1,6)];

% Dap ung ta n so mau ly tu ong

>>Hdr = [1,1,0,0]; wd l = [ 0,0.2 ,0.3,1];

% Dap ung tan so ly t uong de bi eu dien do thi

BÀI 5: 63

>>k1 = 0:flo or((M-1)/2); k2 = f loor( (M-1) /2)+1:M-1;

>>angH = [-alpha*(2*p i)/M* k1, alpha*(2*pi )/M*( M-k2 )];

>>title ('Cac mau tan so: M=60, T2 = 0.592 5, T1 = 0.1099 ');

>>xlabe l(f[* \pi]'); y label ('Hr(k)');

>>title ('Bien do cua dap u ng tan so');

>>xlabe l('f[ *\pi ]'); ylabe l('Hr (w)') ;

>>subpl ot(22 4); plot(w/pi, db);

>>axis( [0,1, -100,10]); gri d

>>title ('Bien do cua dap u ng ta n so ');

>>xlabe l('f[ *\pi ]'); ylabe l('dB ');

delta2 = (1+delta1)*( 10^(-As/20 ));

deltaH = max(delta1,d elta2 );

deltaL = min(delta1,d elta2 );

weights = [delta2/del ta1 1 ];

Asd = -max(d b(wsi:1:5 01)) while Asd<As

M = M+1 [h,ERR,RES] = firpm(M -1,f,m,wei ghts) ; [db,mag,pha,grd,w] = freqz _m(h, [1]);

Asd = -max(d b(wsi:1:5 01)) end

n = [0:1:M-1];

subplot(221); stem(n, h);

title(' Dap u ng tan so ');

xlabel( 'f[*\pi]'); yl abel('Hr(\omega )');

subplot(224); plot(RE S.fgr id,RES.error); grid;

axis([0,1,-0.0150,0.0 150]) ; title(' Dap u ng tan so cua loi') ; xlabel( 'f[*\pi]'); yl abel( 'Er(\omega )');

Bài 5.16

s1 = 0.2 ; p1 = 0.35 ; p2 = 0.65 ; s2 = 0.8 ; Rp = 1 dB; As = 60 dB

impinvar, bilinear

tính

butter, cheby1, cheby2, ellip

tính

Hàm freqs MATLAB

decibels

function [db,mag,pha, w] = freqs _m(b,a,wmax);

% db = Do lon tu ong doi theo dB tren doan tu 0 den wmax

% mag = Do lon tuyet doi t ren d oan tu 0 den wmax

% pha = Dap ung pha t ren d oan t u 0 den wmax

% w = Cac mau tan so tren doan tu 0 den wmax

% b = Cac he so da th uc tu so c ua Ha(s)

% a = Cac he so da th uc ma u so cua H a(s)

% wmax = Tan so cuc d ai th eo do n vi rad/sec tren doan

% tan so mong muon ti m dap ung tan so

% Bo loc thong thap dang C hebyshev-1

% tan so cat khong du oc ch uan h oa

% [b,a] = u_chb1ap(N, Rp,Om egac)

% b = cac he so da th uc tu so c ua Ha(s)

% a = cac he so da th uc ma u so cua Ha(s)

% N = Bac cua bo loc Cheby shev-I

% Rp = Do gon dai tho ng th eo do n vi dB; Rp > 0

% Omega c = tan so cat theo don vi ra dians /sec [z,p,k] = cheb1ap(N,R p);

b0 = k;

b = k*B;

: function [b,a] = afd_ chb1( Wp,Ws ,Rp,As)

% Analog Lowpass Filter De sign: Cheb yshev -1

% [b,a] = afd_chb1(Wp ,Ws,R p,As)

% b = cac he so da th uc tu so c ua Ha(s)

% a = cac he so da th uc ma u so cua Ha(s)

% Wp = tan so cat dai thon g the o don vi rad/sec; Wp >0

% Ws = tan so cat dai chan theo don vi rad/sec; Ws >Wp >0

% Rp = Do gon dai tho ng th eo do n vi dB; (Rp > 0)

% As = Do suy giam da i cha n the o don vi +dB; (Ap > 0)

if Wp <= 0 error('Tan so cat dai thon g pha i lon hon 0') end

if Ws <= Wp error('Tan so cat dai thong phai lon ho n tan so cat da i chan')

end

if (Rp <= 0) | (As<0) error('Do gon dai th ong va/hoac Do suy giam dai chan phai lon hon 0')

end

ep = sqrt(10^(Rp/10)-1);

Bài 6.5 bài 6.4

bilinear cho phép

này

bai605.m

wp =0.2*pi; % digital Pass band freq in Hz

ws =0.3*pi; % digital Stop band freq in Hz

Rp = 1; % Passband ri pple in dB

As = 15; % Stopband a ttenu ation in dB

T = 1; Fs =1/T; % Dat T=1 OmegaP = (2/T)*tan(wp /2);

OmegaS = (2/T)*tan(ws /2);

% Tinh toan bo loc tu ong t u:

[cs, ds] = afd_chb1(O megaP ,Omeg aS,Rp,As);

% Bien doi song tuyen tinh : [b,a] = bilinear(cs,d s,Fs);

[db,mag,pha,grd,w] = freqz _m(b, a);

subplot(221); plot(w/ pi,ma g);

axis([0,1,0,1.2]); gr id title('Dap u ng tan so ');

xlabel('f[*\pi]'); yl abel('|H_r(\omega)|');

subplot(222); plot(w/ pi,db );

axis([0,1,-30,10]); g rid title('Dap u ng tan so theo dB');

xlabel('f[*\pi]'); yl abel('dB');

BÀI 6: 75

c

subplot(223); plot(w/ pi,ph a/pi);

axis([0,1,-1,1]); gri d title(' Dap u ng pha');

xlabel( 'f[*\pi]'); yl abel( 'Angle(H_r(\omega))');

d

subplot(224); plot(w/pi,grd);

axis([0,1,0,15]); gri d title('Group Delay');

xlabel(' f[*\pi]'); y label ('Samples');

bz = zeros(1,bzord+1) ; for k = 0:bzord

pln = [1];

for l = 0:k-1 pln = conv(pln,Nz);

end pld = [1];

for l = 0:bzord-k-1 pld = conv(pld,Dz);

end

bz = bz+bZ(k+1)*conv( pln,p ld); end

az = zeros(1,azord+1) ; for k = 0:azord

pln = [1];

for l = 0:k-1 pln = conv(pln,Nz);

end pld = [1];

for l = 0:azord-k-1 pld = conv(pld,Dz);

end

az = az+aZ(k +1)*conv( pln,p ld); end

az1 = az(1); az = az/ az1; bz=bz/az1;

BÀI 6: 77

c=0.6