(6 1.1 1.2 1.3 Z1.4 1.5

1,

2

3

4

5////

1.1{x(n)}

x(n)x(n)nx(n)n

1.1.11.()

(t)

2. u(n)

u(t)

3.

4.

a

5.

00=/8T=16

6.

Matlabn0=0;nf=10;ns=3;n1=n0:nf;x1=[(n1-ns)==0]; % n2=n0:nf;x2=[(n2-ns)>=0]; %n3=n0:nf;x3=(0.75).^n3; %n4=n0:nf;x4=exp((-0.4+pi/3j)*n4); %subplot(2,2,1),stem(n1,x1);subplot(2,2,2),stem(n2,x2);subplot(2,2,3),stem(n3,x3);figuresubplot (2,2,1),stem(n4,real(x4)); %subplotsubplot (2,2,2),stem(n4,imag(x4)); Subplot (2,2,3),stem(n4,angle(x4)); subplot (2,2,4),stem(n4,abs(x4));

7. nNx(n)N

8

9.

9.x(n)

1.1.2 1.mx(n-m)mx(n+m)m

2.x(-n)n=0x(n)

3. (n)

4.

(n)

x1=[0 1 2 3 4 3 2 1 0];ns1=-2;x2=[2 2 0 0 0 -2 -2];ns2=2;nf1=ns1+length(x1)-1;nf2=ns2+length(x2)-1;ny=min(ns1,ns2):max(nf1,nf2);xa1=zeros(1,length(ny));xa2=xa1;xa1(find((ny>=ns1)&(ny=ns2)&(ny

5.a)x(n),h(n),y(n)

(),,,

f(0)=1f(1)=2f(2)=3f(3)=4f(4)=5f(5)=3f(6)=1f(7)=-1f(8)=-3f(9)=-5f(10)=-4f(11)=-3f(12)=-2f(13)=-1

b)Matlabconv()

1.2 1.pT(t),xa(t)x(n)

2

M(t)TM(t)

T()TM(t),xa(t),

,

,s(), 1/T1/T,

1.2.1/T3.

500Hz

1-2 kHz

1kHz

-kHz

kHz

4-10 kHz

kHz

8-16 kHz

kHz

40-96 kHz

MHz

8-10 MHz

_1097605554.unknown

_1097605693.unknown

5

:

*=

nT1;0

123

1.3 DTFTz1.3.1 ->->Z

2.2 DTFT2.2.1 1.DTFT

Matlab:dft1()

2.IDTFT

2.2.2 DTFT

1.3.2 z1.Z

ZMatlab: F=ztrans()ZMatlab: F=itrans()

2. ZDTFTZ

3.1: x(n)zX(z)zX(z).2 X(z)

X(z)

Z

1

R=1

2)

3)

z=b

4

z

1.3.3 Z1.X(z),x(n)Z

Z

2. Z

3.Z ck cm Res[ ]

ZrZrl()NN-1CCC

2n-2X(z)zn-1zn+1n+1Cz=1/4(), z=0(n+1)C z=4():

1.3.4 Z**1.

[] ,z

2) [2-8] x(n)=u(n)-u(n-3)z

3)

4)

5)()

[]

1.4 x(n)y(n)y(n)=T[x(n)]

1.4.1 **=

1.4.2 T[x(n)]=y(n),T[x(n-m)]=y(n-m)

*x(n)

1.4.3 1.LSILinear Shift Invariant h(n)

2. LSIh(n)h(n)

*x(n)Nh(n)MLL=N+M-1

1.4.4 1. nnnn LSI

2. LSI

LSI

n N

1.4.5

yn=ayn-1+xn

y(n) yn=0n0 n0yn=0

yn=0n0 n=0n=0

yn-1=2[ yn-1.5xn] y0=2[ y1-1.5x(1) ]=0

; Z.

MATLABfilter

y=filter(a,b,x)

xab

aibiy

MATLAB

_1137593445.unknown

_1137593793.unknown

_1137593310.unknown

MATLAB

N=41;

a=[0.8 -0.44 0.36 0.22];

b=[1 0.7 -0.45 -0.6];

x=[1 zeros(1,N-1)];

k=0:1:N-1;

y=filter(a,b,x);

stem(k,y)

xlabel('n');ylabel('')

1.5 1.5.1 1.h(n)Z

2.H(z)

1h(n)=0,n

h(n)

h(n)z

2H(z)Z=1

H(z) zH(z)3

1

2.6.3

1.2--21.7--41.3---21.16---21.22