shaoshao.m

混合信号源发生器

%function A=NRZ_L(a,m)
%非归零电平码显示
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a=[1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 0 0 0 0 0];
m=20;
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figure(1);
%a为原码，m为图显密集度
%A为显示序列
n=length(a);%获取原码码元数
pA=ones(1,m);%由图显密集度m产生行向量pA
for i=1:n%读取原码a的数据，产生相应plot显示行向量A
    A(m*(i-1)+1:i*m)=a(i)*pA;
end
mn=m*n;
t=1:mn;%产生和A相同元素个数的行向量t
H=plot(t,A);%绘制图形，并将plot句柄赋值给H
set(H,'linewidth',2);%通过H设置图形线段的宽度
axis([0 mn -1.2 2.2]);%设置x,y轴的范围
title('原始序列显示','FontSize',7.5)
%显示标题，并设置字体的大小
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
figure(2);
%function p_fsk=FSK(a,m)
%FSK频率调制
%a为原码,m为显示密集度
%A=NRZ_L(a,m);%调用NRZ_L函数,得到一维数组A
n=length(a);
mn=m*n;
t=1:mn;
B=1+A;%由A产生新的向量B,供FSK调制计算
p_fsk=sin(1/m*2*pi*(B.*t));% 实现FSK调制
%"1"对应频率为1/m*2*pi*2
%"0"对应频率为1/m*2*pi
H=plot(t,p_fsk-1,'b',t,A+1,'b');%在同一副图中显示
set(H,'Linewidth',2);%设置图形显示属性
axis([0 mn -3 3]);
title('经FSK调制显示','FontSize',7.5)
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figure(3);
%function p_ask=ASK(a,m)
%ASK幅度调制
%a为原码，m 为显示密集度
%A=NRZ_L(a,m);%调用NRZ_L函数，得到行向量A
n=length(a);
mn=m*n;
t=1:mn;
p_ask=A.*sin((1/m)*2*pi*t);%设置频率为1/m*2*pi使正弦信号的一个周期等于一个码元的长度
H2=plot(t,p_ask-1,'b',t,A+1,'b');
%在同一图中显示调制结果
set(H2,'Linewidth',2);%设置图形显示属性
axis([0 mn -3 3]);
title('经ASK调制显示','FontSize',7.5)
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
figure(4);
%function p_fsk=PSK(a,m)
%PSK相位调制
%a为原码,m为显示密集度
%A=NRZ_L(a,m);%调用NRZ_L函数,得到行向量A
n=length(a);
mn=m*n;
B=ones(1,mn);%产生常数"1"行向量B
t=1:mn;
C=A+B;%A+B产生新的向量C,供PSK调制计算
p_psk=sin(1/m*2*pi*t+C*pi);%实现PSK调制
%"1"时,相位改变2*pi,即不改变
%"0"时,相位改变1*pi
H=plot(t,p_psk-1,'b',t,A+1,'b');%在同一副图中显示
set(H,'Linewidth',2);%设置图形显示属性
axis([0 mn -3 3]);
title('经PSK调制显示','FontSize',7.5);