锁相环在通信中使用非常普遍经常看到关于锁相环仿真的帖子-read.doc

锁相环在通信中使用非常普遍，经常看到关于锁相环仿真的帖子。前两天试图帮助microdisk解决他的锁相环仿真问题，但由于编程的习惯和思路不一致，感到看懂并找出问题比较困难。今天正好周末有点时间，自己做了一下仿真，发出来相互讨论，不妥之处请大家多多指教。QQ频偏：-60Hz相偏：在0－－2*pi内随机分布程序及结果如下：clear all;close all;%定义锁相环的工作模式：单载波为“1”、BPSK调制为“2”、QPSK调制为“3”PLL_Mode = 1;%仿真数据长度Simulation_Length=1000;%基带信号if PLL_Mode == 1I_Data=ones(Simulation_Length,1);Q_Data=I_Data;else if PLL_Mode == 2I_Data=randint(Simulation_Length,1)*2-1;Q_Data=zeros(Simulation_Length,1);elseI_Data=randint(Simulation_Length,1)*2-1;Q_Data=randint(Simulation_Length,1)*2-1;endendSignal_Source=I_Data + j*Q_Data;%载波信号Freq_Sample=2400;%采样率，HzDelta_Freq=-60; %频偏，HzTime_Sample=1/Freq_Sample;Delta_Phase=rand(1)*2*pi; %随机初相，RadCarrier=exp(j*(Delta_Freq/Freq_Sample*(1:Simulation_Length)+Delta_Phase));%调制处理Signal_Channel=Signal_Source.*Carrier;%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%以下为锁相环处理过程%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%参数清零Signal_PLL=zeros(Simulation_Length,1);NCO_Phase = zeros(Simulation_Length,1);Discriminator_Out=zeros(Simulation_Length,1);Freq_Control=zeros(Simulation_Length,1);PLL_Phase_Part=zeros(Simulation_Length,1);PLL_Freq_Part=zeros(Simulation_Length,1);%环路处理C1=0.022013;C2=0for i=2:Simulation_LengthSignal_PLL(i)=Signal_Channel(i)*exp(-j*mod(NCO_Phase(i-1),2*pi));I_PLL(i)=real(Signal_PLL(i));Q_PLL(i)=imag(Signal_PLL(i));if PLL_Mode == 1Discriminator_Out(i)=atan2(Q_PLL(i),I_PLL(i));else if PLL_Mode == 2Discriminator_Out(i)=sign(I_PLL(i))*Q_PLL(i)/abs(Signal_PLL(i));elseDiscriminator_Out(i)=(sign(I_PLL(i))*Q_PLL(i)-sign(Q_PLL(i))*I_PLL(i)).../(sqrt(2)*abs(Signal_PLL(i)));endendPLL_Phase_Part(i)=Discriminator_Out(i)*C1;Freq_Control(i)=PLL_Phase_Part(i)+PLL_Freq_Part(i-1);PLL_Freq_Part(i)=Discriminator_Out(i)*C2+PLL_Freq_Part(i-1);NCO_Phase(i)=NCO_Phase(i-1)+Freq_Control(i);end%画图显示结果figuresubplot(2,2,1)plot(-PLL_Freq_Part(2:Simulation_Length)*Freq_Sample);grid on;title(锁相环频率响应曲线);axis([1 Simulation_Length -10