科斯塔斯锁相环的matlab仿真程序

《科斯塔斯锁相环的matlab仿真程序》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、科斯塔斯锁相环的matlab仿真程序：clearall;closeall;fs=12e6;%采样频率ts=1/fs;num=2.5e6;  %数据长度SNR=-15;real_fc=3563000;%实信号频率data=sin(2*pi*real_fc*(0:num-1)*ts+pi/4)+sqrt(10^(SNR/10))*randn(1,num);%科斯塔斯环的输入信号fc=3563010;%本地频率n=fs/1000;%累积时间为1msnn=[0:n-1];nf=floor(length(data)/n);%将输入数据分成1ms的多个数据块wfc=2*

2、pi*fc;  %本地信号phi_prv=0;temp=0;frame=0;carrier_phase=0;phase=0;%环路滤波器的参数c1=153.7130;c2=6.1498;forframe=1:nf%产生本地的sin和cos函数expcol=exp(j*(wfc*ts*nn+phase));sine=imag(expcol);  cosine=real(expcol);x=data((1:n)+((frame-1)*n));%将数据转换到基带x_sine=x.*sine;x_cosine=x.*cosine;Q=sum(x_sine);    

3、%经过滤波器I=sum(x_cosine);phase_discri(frame)=atan(Q/I);  %得到锁相环的输入%锁相环dfrq=c1*phase_discri(frame)+temp;%经过环路滤波器temp=temp+c2*phase_discri(frame);wfc=wfc-dfrq*2*pi;  %改变本地频率dfrq_frame(frame)=wfc;phase=wfc*ts*n+phase;  %得到不同块的相位endplot(dfrq_frame/(2*pi));holdonplot([1:length(dfrq_frame)]

4、,real_fc,'r');legend('锁相环跟踪','实际的载波频率');gridmean_freq=mean(dfrq_frame/2/pi)p=abs(real_fc-mean_freq)/real_fc%%%%%%%%%%%%%%%function[c1,c2]=calculatePLLCoef(zeta,bandwidth)%Calculatescoefficientsusedinthecarriertrackingloop(PLL)%  zeta  :  tampingfactor%  bandwidth:nosiebandwidthtUpd

5、=0.001;                    %integrationtime积分时间gain=0.0005;                    %gainwT=(2*bandwidth*zeta)/(zeta^2+0.25)*tUpd;  %naturalfrequencyc1=(1/gain)*(8*zeta*wT)/(4+4*zeta*wT+wT^2);c2=(1/gain)*(4*wT^2)/(4+4*zeta*wT+wT^2);**************************华丽的分割线***********************

6、**************%**FLL********clearall;closeall;fs=5e6;        %sampleratets=1/fs;T=1e-3;        %timeofsignalN=fs*T;nn=(0:N-1);fc=0;          %carrierfrequencydoppler_shift=500;  %dopplerfrequencyshiftphi=pi/4;x=cos(2*pi*(fc+doppler_shift)*ts*nn+phi)+3*randn(1,N);  %inputsignalfigur

7、e(1)plot(x(1:200));bandwidth=50;              %equalbandwidthzeta=0.7;                  %dampfactortUpd=0.001;                    %integrationtimegain=0.0002;                    %gainwT=(2*bandwidth*zeta)/(zeta^2+0.25)*tUpd;  %naturalfrequencyc1=(1/gain)*(8*zeta*wT)/(4+4*zeta*wT+wT

8、^2);c2=(1/gain)*(4*wT^2)/(