tvv.m

用matlab模拟全电视信号

close all;
clear all;
clc;

%%%%%行消隐、 行同步的复合 %%%%%
fs=25e6;  %fs=25M , 1/fs=0.00000004.
t=0:0.00000004:0.05;  %采样点数为1250001
tn=t+0.00016:0.00000004:0.05+0.00016;
yx1=1-((square(2*pi*50*tn,8.06)+1)/2);      %%1612us/20ms

yhx=(square(2*pi*15625*t,18.75)+1)/2;    %%12us/64us
m=(t-0.0000013):0.00000004:(0.05-0.0000013);  
yht=(square(2*pi*15625*m,7.34375)+1)/2;     %%4.7us/64us 
yx2=0.75*yhx+0.25*yht;
y1=yx1.*yx2;
%plot(t,y1),axis([0 0.05 -0.1 1.1]);
%break;



%%%%  场同步信号 %%%%
yv1=(square(2*pi*50*t,0.8)+1)/2;     %%160us/20ms
yv2=(square(2*pi*31250*t,85.3125)+1)/2;      %%(32-4.7)us/32us
yv=yv1.*yv2;
%plot(t,yv1),axis([0 0.05 -0.1 1.1]);
%break;

%%%% 前均衡信号 %%%
n=t+0.00016:0.00000004:0.05+0.00016;
yq1=(square(2*pi*50*n,0.8)+1)/2;     %%160us/20ms
yq2=(square(2*pi*31250*t,7.34375)+1)/2;      %%2.35us/32us
yq=yq1.*yq2;
%plot(t,yq),axis([0 0.05 -0.1 1.1]);
%break;

%%%% 后均衡信号 %%%%
l=t-0.00016:0.00000004:0.05-0.00016;
yh1=(square(2*pi*50*l,0.8)+1)/2;       %%160us/20ms
yh2=(square(2*pi*31250*t,7.34375)+1)/2;      %%2.35us/32us
yh=yh1.*yh2;
%plot(t,yh),axis([0 0.05 -0.1 1.1]);
%break;


%%%%% 前均衡、场同步、后均衡复合信号 %%%%%
y2=yv+yq+yh;
%plot(t,y2),axis([0 0.05 -0.1 1.1]);
%break;


%%%% 场消隐内的行同步信号 %%%%
tm=t-0.00032:0.00000004:0.05-0.00032;
yht1=(square(2*pi*50*tm,5.66)+1)/2;         %%%%(1612-160*3)us/20ms 
yht2=(square(2*pi*15625*t,7.34375)+1)/2;        %%4.7us/64us
y3=yht1.*yht2;
%plot(t,y3),axis([0 0.05 -0.1 1.1]);
%break;

%%%% 场消隐信号 %%%
y4=(square(2*pi*50*tn,8.06)+1)/2;     %%1612us/20ms

y5=0.25*y2+0.25*y3+0.75*y4;



%%%%% 行同步、场同步、行消隐、前均衡、后均衡复合信号(y) %%%%
y=y1+y5;
figure
plot(t,y)
title('行同步、场同步、行消隐、场消隐、前均衡、后均衡复合信号');
axis([0 0.05 -0.1 1.1])

num=length(t);
f1=1:fs/num:fs;
X=abs(fft(y));
X=20*log10(X);
figure
plot(f1,X);
title('电视频谱图');



%%%%%%图象信号%%%%%%%
% noise=0.3*rand(1,num);
% b = FIR1(200,1.5e6/(0.5*fs));   % freqz(b);
% noise = filter(bb,1,noise);
% 
% figure
% plot(t,noise)
% axis([0 0.05 -0.1 1.1])
% X=abs(fft(noise));
% X=20*log10(X);
% figure
% plot(f1,X);
% 
% 
% z=yx1.*(1-yhx);
% z1=z.*noise;
% z2=z1+y;
% 
% figure
% plot(t,z2)
% axis([0 0.05 -0.1 1.1])
% X=abs(fft(z2));
% X=20*log10(X);
% figure
% plot(f1,X);

%%%%%%%%%%%%%%色度信号%%%%%%%%%%%%%%%
% U=0.05*rand(1,num);
% V=0.05*rand(1,num);
% bb = FIR1(200,1.3e6/(0.5*fs));
% U = filter(bb,1,U);
% V = filter(bb,1,V);
% 
% sinfc=sin(2*pi*4.43361875e6*t);
% cosfc=cos(2*pi*4.43361875e6*t);
% k=square(2*pi*7812.5*t,50);
% u=U.*sinfc;
% v=k.*V.*cosfc;
% C=u+v;

% 
% z=yx1.*(1-yhx);
% z1=z.*C;
% z2=z1+y;
% 
% figure
% plot(t,z2)
% axis([0 0.05 -0.1 1.1])
% X=abs(fft(z2));
% X=20*log10(X);
% figure
% plot(f1,X);


%%%%%%%%%%%%色度信号+图象信号(z1)%%%%%%%%%%%%%
noise=0.3*rand(1,num);       %%图象信号noise
b= FIR1(200,1.5e6/(0.5*fs));            %freqz(b);
noise = filter(b,1,noise);

U=0.05*rand(1,num);       %%色度信号C
V=0.05*rand(1,num);
bb = FIR1(200,1.3e6/(0.5*fs));        %freqz(bb);
U = filter(bb,1,U);
V = filter(bb,1,V);
sinfc=sin(2*pi*4.43361875e6*t);
cosfc=cos(2*pi*4.43361875e6*t);
k=square(2*pi*7812.5*t,50);        %%%周期为128us (64us为+1,64us为-1交替)
u=U.*sinfc;
v=k.*V.*cosfc;
C=u+v;

z=yx1.*(1-yhx);            %%%在52us的行正程期间加入色度信号+图象信号
z1=z.*C+z.*noise;
z2=z1+y;

figure
plot(t,z2)
axis([0 0.05 -0.1 1.1])
X=abs(fft(z2));
X=20*log10(X);
figure
plot(f1,X);


%%%%%%%%%%%%%%%色同步信号(s)%%%%%%%%%%%%%%
Cs=-1*(0.15*sinfc)+1*(0.15*(k.*cosfc));           
m1=(t-0.0000069):0.00000004:(0.05-0.0000069);    
yht=(square(2*pi*15625*m1,3.515625)+1)/2;    %%%%%%2.25/64
s1=yx1.*yht.*Cs;

m2=(t-0.0000056):0.00000004:(0.05-0.0000056);  
yht2=(square(2*pi*15625*m2,3.515625)+1)/2;   %%%%%%2.25/64
s2=yht1.*yht2.*Cs;

s=s1+s2;

yyy=s+z2;
figure
plot(t,yyy) 
axis([0 0.05 -0.1 1.1])
X=abs(fft(yyy));
X=20*log10(X);
figure
plot(f1,X)