suijixinhao.m

对低频段的带通信号进行高精度的时延估计

%用窄带随机信号作测试信号
%采用带通滤波得到中心频率为1.44M的窄带信号
clear all;

M=10;                   %循环次数
TimeDelay=zeros(1,M); 
for k=1:M     Ts=0.5e-7; Tdelay=265e-9;N1=16e+3;N2=800e+3;
%x=1*randn(1,1024); [b,a]=ellip(4,0.1,50,[0.286,0.29]);N1=4e+3;N2=400e+3;Ts=1e-7;Tdelay=100e-9;% 10M 20k
x=1*randn(1,2048); [b,a]=ellip(4,0.1,50,[0.143,0.145]);N1=16e+3;N2=800e+3;Ts=0.5e-7;Tdelay=50e-9;% 10M 20k
%x=1*randn(1,4096); [b,a]=ellip(4,0.005,50,[0.071,0.073]);N1=64e+3;N2=1.6e+6;Ts=0.25e-7;Tdelay=25e-9;%40M
x1n=filter(b,a,x);        %经过带通滤波,得到中心频率为1.44M的宰带信号
N=length(x1n);
L=1; x2n=[zeros(1,L),x1n(1:N-L)];
%-------------------------------------------------
x1n=awgn(x1n,10,'measured');  %awgn：Add white Gaussian noise to a signal
x2n=awgn(x2n,10,'measured');
X1k=MCZT(x1n,N,N1);
X2k=MCZT(x2n,N,N1);
Rn=FICP(X1k,X2k,N2);  %快速FICP算法
Nn=find(Rn==max(Rn(N:N+300)))-N-1;
TimeDelay(k)=Nn*N1*Ts/N2;
end
plot(TimeDelay,'.');grid on;ylim([Tdelay-10e-9,Tdelay+10e-9])
%freqz(b,a,4096);