schmidl2.rar_定时同步

%written by shuai shuai close all; clear all; %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 初始化测试数组 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% snr=20; guiyihua_xishu=sqrt(10^(snr/10)); noise75_randn=randn(1,75)/guiyihua_xishu+j*(randn(1,75)/guiyihua_xishu);%与信号的能量统一 p=[1-j 1-j -1-j 1+j 1-j 1-j -1+j 1-j 1-j 1-j 1+j -1-j 1+j 1+j -1-j 1+j -1-j -1-j 1-j -1+j 1-j 1-j -1-j 1+j 1-j 1-j -1+j 1-j 1-j 1-j 1+j -1-j 1+j 1+j -1-j 1+j -1-j -1-j 1-j -1+j 1-j 1-j -1-j 1+j 1-j 1-j -1+j 1-j 1-j 1-j 1+j -1-j 1+j 1+j -1-j 1+j -1-j -1-j 1-j -1+j 1+j 1+j 1-j -1+j 1+j 1+j -1-j 1+j 1+j 1+j -1+j 1-j -1+j -1+j 1-j -1+j 1-j 1-j 1+j -1-j -1-j -1-j -1+j 1-j -1-j -1-j 1+j -1-j -1-j -1-j 1-j -1+j 1-j 1-j -1+j 1-j -1+j -1+j -1-j 1+j 0 -1-j 1+j -1+j -1+j -1-j 1+j 1+j 1+j -1-j 1+j 1-j 1-j 1-j -1+j -1+j -1+j -1+j 1-j -1-j -1-j -1+j 1-j 1+j 1+j -1+j 1-j 1-j]; m=ifft(p); source_data=[m(97:128) m m]; show_result=0;%%%%最终打印结果 circle_n=1;%%%大循环次数 %%%%%%%% 利用m序列优化后 %%%%%%%%% %src1=[1 1 0 0 1 1];%m序列生成多项式 %m1=m_sequence(src1); %m2=ifft(m1); %m_advanced=m.*m2; % source_data=[m_advanced -m_advanced -m_advanced m_advanced m_advanced]; % send_data=[zero10 zero200 m zero150 m m zero100 zero100 zero100 m zero200 zero200];%初始化信道中的数据 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 最外层循环 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% for ii=1:circle_n channel_data=awgn(source_data,snr,'measured'); for a=1:length(channel_data) mod_channel_data(a)=abs(channel_data(a)); end send_data=[noise75_randn channel_data 0.1*ones(1,150)];%初始化信道中的数据 receive_data=send_data; %自相关(schmidl cox算法) for i=1:(length(receive_data)-2*length(m)) for k=1:length(m) data_group1(k)=receive_data(i+k-1); data_group2(k)=receive_data(i+k+length(m)-1); % data_group2(k)=m(k); end r_cor(i)=interfix_adv(data_group1,data_group2); p_cor(i)=interfix_adv(data_group2,data_group2); if p_cor==0 M_result(i)=0; else M_result(i)=(r_cor(i)/p_cor(i))^2; end end show_result=show_result+M_result; end %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 结束最外层循环 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%%%%%%%%%%%%% 配套自相关cox算法的测试 %%%%%%%%%%%%% figure(2), plot(show_result/circle_n); xlabel('采样点'); ylabel('定时测度'); str=['SNR=' num2str(snr)]; title(str); axis([0 350 0 1.2]);