混沌通信中QCSK调制matlab代码

混沌通信中QCSK调制matlab代码

clear all;

x=randsrc(20,1,[0:1]); %产生二进制随机码stairs(x);

axis([0,20,-0.1,1.1]);

title('二进制随机序列');

clc

clear

close all

% q=99;

%k=[1:99];

%x(k)=sin(k*pi/q);

x(1)=0.212345;

x(k+1) =4 * x(k) * (1 - x(k)); end

plot(x);

legend('混沌信号x');

grid on;%加网格

clc

clear

close all

% q=99;

%k=[1:99];

%x(k)=sin(k*pi/q);

x(1)=0.212345;

x(k+1)=4*x(k)*(1-x(k)); end

y=hilbert(x);

figure(1)

plot(imag(y));

legend('希尔伯特变换y'); grid on

clc

clear

close all

% q=99;

%x(k)=sin(k*pi/q);

x(1)=0.212345;%x的初植

for k=1:99;

x(k+1)=4*x(k)*(1-x(k)); end

y=hilbert(x);%x的希尔伯特变换figure(1)

plot(imag(y));

grid on

legend('加密后的信号ms');

clc

clear

close all

% q=99;

%k=[1:99];

%x(k)=sin(k*pi/q);

x(1)=0.212345;

for k=1:99;

x(k+1)=4*x(k)*(1-x(k));

end

y=hilbert(x);%希尔伯特变换

figure(1)

plot(imag(y));

grid on

legend('加密后的信号ms');

y2=AWGN(imag(y),0.8,1);%imag(y)为已调信号，0.8为信噪比，1为信号功率

figure(2)

plot(y2);

grid on

legend('加噪声后的调制信号y2');

bs=1; Eb=1;

Zb=bs.*Eb;%解调出的信号

stem(Zb,'r');

title('解调出的信号Zb')

clc;

x=0:18;%信噪比的取植范围

xSNR=10.^(x/20);%化成dB形式

for i=1:length(x);

k=2;

y1(i)=1/2*erfc(1/(sqrt(4*1/xSNR(i)+k*((1/xSNR( i))^2))));%求k=2的系统理论的误码率

end

semilogy(x,y1);%绘出x和y1的图

for i=1:length(x)

hold on;

plot(x(i),y1(i),'g*')

end

gtext('QCSK,K=2');%在光标的位置放置给定的文字

for i=1:length(x);

k=16;

y2(i)=1/2*erfc(1/(sqrt(4*1/xSNR(i)+k*((1/xSNR( i))^2))));%求k=16的系统理论的误码率

end

semilogy(x,y2);%绘出x和y2的图

for i=1:length(x)

hold on;

plot(x(i),y2(i),'r.')

end

gtext('QCSK,K=16');

for i=1:length(x);

k=64;

y3(i)=1/2*erfc(1/(sqrt(4*1/xSNR(i)+k*((1/xSNR( i))^2))));%求k=64的系统理论的误码率

end

semilogy(x,y3);%绘出x和y3的图for i=1:length(x)

hold on;

plot(x(i),y3(i),'b+')

end

gtext('QCSK,K=64');

grid on

xlabel('Eb/No[dB]');

ylabel('BER');

title('QCSK的系统误码率');

clc;

x=0:18;%信噪比的取植范围

xSNR=10.^(x/20);%化成dB形式

for i=1:length(x);

k=2;

y1(i)=1/2*erfc(1/(sqrt(4*1/xSNR(i)+k*((1/xSNR( i))^2))));%求QCSK，k=2的系统理论的误码率end

semilogy(x,y1);

for i=1:length(x)

hold on;

plot(x(i),y1(i),'g*')

end

for i=1:length(x);

k=2;

y2(i)=1/2*erfc(1/(sqrt(4*1/xSNR(i)+2*k*((1/xSN R(i))^2))));%求DCSK，k=2的系统理论的误码率

end

semilogy(x,y2);

for i=1:length(x)

hold on;

plot(x(i),y2(i),'r.')

end

gtext('绿色的*表示QCSK K=2;红色的.表示DCSK K=2');

grid on

xlabel('Eb/No[dB]');

ylabel('BER');

title('K=2的系统误码率');