pll.rar_锁相环

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 = 3; %仿真数据长度 Simulation_Length=1000; %基带信号 if PLL_Mode == 1 I_Data=ones(Simulation_Length,1);%单载波调制 Q_Data=I_Data; else if PLL_Mode == 2 %BPSK调制 I_Data=randint(Simulation_Length,1)*2-1; Q_Data=zeros(Simulation_Length,1); else %QPSK调制 I_Data=randint(Simulation_Length,1)*2-1; Q_Data=randint(Simulation_Length,1)*2-1; end end Signal_Source=I_Data + j*Q_Data;%生成载波信号 %载波信号 Freq_Sample=2400;%采样率，Hz Delta_Freq=-60; %频偏，Hz Time_Sample=1/Freq_Sample;%周期 Delta_Phase=rand(1)*2*pi; %随机初相，Rad Carrier=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=0.00024722; for i=2:Simulation_Length Signal_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 == 1 Discriminator_Out(i)=atan2(Q_PLL(i),I_PLL(i)); else if PLL_Mode == 2 Discriminator_Out(i)=sign(I_PLL(i))*Q_PLL(i)/abs(Signal_PLL(i)); else Discriminator_Out(i)=(sign(I_PLL(i))*Q_PLL(i)-sign(Q_PLL(i))*I_PLL(i))... /(sqrt(2)*abs(Signal_PLL(i))); end end PLL_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 figure subplot(2,2,1) plot(-PLL_Freq_Part(2:Simulation_Length)*Freq_Sample); grid on; title('PLL频率响应曲线图'); axis([1 Simulation_Length -100 100]); subplot(2,2,2) plot(PLL_Phase_Part(2:Simulation_Length)*180/pi); title('PLL相位响应曲线图'); axis([1 Simulation_Length -2 2]); grid on; %设定显示范围 Show_D=300; %起始位置 Show_U=900; %终止位置 Show_Length=Show_U-Show_D; subplot(2,2,3) plot(Signal_Channel(Show_D:Show_U),'*'); title('输入PLL的数据星座图'); axis([-2 2 -2 2]); grid on; hold on; subplot(2,2,3) plot(Signal_PLL(Show_D:Show_U),'r*'); grid on; subplot(2,2,4) plot(Signal_PLL(Show_D:Show_U),'r*'); title('PLL锁定和稳定后的数据星座图'); axis([-2 2 -2 2]); grid on; figure %设定显示范围 Show_D=300; %起始位置 Show_U=350; %终止位置 Show_Length=Show_U-Show_D; subplot(2,2,1) plot(I_Data(Show_D:Show_U)); grid on; title('I路信息数据'); axis([1 Show_Length -2 2]); subplot(2,2,2) plot(Q_Data(Show_D:Show_U)); grid on; title('Q路信息数据'); axis([1 Show_Length -2 2]); subplot(2,2,3) plot(I_PLL(Show_D:Show_U)); grid on; title('PLL输出I路信息数据'); axis([1 Show_Length -2 2]); subplot(2,2,4) plot(Q_PLL(Show_D:Show_U)); grid on; title('PLL输出Q路信息数据'); axis([1 Show_Length -2 2]);