code.m

A. 产生一个长为1000的二进制随机序列

N=1000;
fs=8;
x=ceil(rand(1,N)-0.8);
AMI=AMI_Code(x);
HDB3=HDB3_Code(x);
Miller=Miller_Code(x);

y=zeros(1,N*fs);
x_t=zeros(1,N*fs);
y_AMI=zeros(1,N*fs);
y_HDB3=zeros(1,N*fs);
y_Miller=zeros(1,N*fs);
for i=1:N*fs
    if(mod(i-1,8)<=5 & mod(i-1,8)>=2)
        y(i)=1;
    else
        y(i)=0;
    end
    %分别给画图序列赋值
    y_AMI(i)=y(i)*AMI(ceil(i/8));
    y_HDB3(i)=y(i)*HDB3(ceil(i/8));
    y_Miller(i)=Miller(ceil(i/4));
    x_t(i)=x(ceil(i/8));
end

figure
subplot(4,1,1)
plot(x_t(1:20*8))
axis([1,20*8,-1.5,1.5]);
title('initial code')

subplot(4,1,2)
plot(y_AMI(1:20*8))
axis([1,20*8,-1.5,1.5]);
title('AMI code')

subplot(4,1,3)
plot(y_HDB3(1:20*8))
axis([1,20*8,-1.5,1.5]);
title('HDB3 code')

subplot(4,1,4)
plot(y_Miller(1:20*8))
axis([1,20*8,-1.5,1.5]);
title('Miller code')

figure
plot_spectrum(x_t,'b');
hold on 
plot_spectrum(y_AMI,'r');
plot_spectrum(y_HDB3,'g');
plot_spectrum(y_Miller,'y');
title('Power spectrum of AMI Code')
legend('NRZ','AMI','HDB3','Miller')