phasetrack.asv

该程序包含一般数字PLL仿真maltab程序和数字COSTAS环程序

%This program validates the tracking character of pll by
%phase step signal, frequency step signal and frequency damp signal
%by PLL phase mode
clear all;clc;close all;
fo=10000;
thetao=0;
fi=10000;
thetai=0;

dtheta=pi/2;
t1=[0:0.001:2];
theta=2*pi*t1;
Thetai=zeros(1,length(t1));
Thetao=zeros(1,length(t1));
Thetai(500:1200)=Thetai(500:1200)+dtheta;

%parameter of the loop
T=0.001;
zeta=0.7;
omiga=2*pi*10;

delThe(1)=0;
uf(1)=0;
for i=2:length(t1)-1
    delThe(i)=Thetai(i)-Thetao(i);
    uf(i)=uf(i-1)+(2*zeta/omiga+T/2)*delThe(i)-(2*zeta/omiga-T/2)*delThe(i-1);
    Thetao(i+1)=Thetao(i)+omiga^2*T/2*(uf(i)+uf(i-1));
end
figure;plot(t1,sin(theta+Thetai),'r-',t1,sin(theta+Thetao),'b:');
legend('输入信号','输出信号');
figure;plot(uf);title('');