matlab-GPS-多径估计延迟锁相环算法(MEDLL)

%构造LOS+多径的综合相关曲线，做MEDLL多径分解 %使用相关间距1/16chip，仿真实际32个相关器的接收机的相关曲线，做MEDLL多径分解 %构造LOS+2Mpath，3路循环优化 MUX_LOOP_NUM>500结束 %构造LOS+2Mpath，4路循环优化, LOS峰值左限控制LOS_index_est_min， 多径峰值左右限窗口 %用余量估计法来控制估计的信号数目 SRR_Threshold=10000; load MEDLL_R_Reference.mat; d_chip=4./(length(R_ref)-1);%0.005chip tt=-2:d_chip:2; %%%%%%%%%%%%SIMULINK 参数 fs = 16e6; fIF = 4.092e+6; Ms=1.023e6; % Mpath_gain = [0 -5 -10 -15 -20 ]; %channel multipaths in dB; here: 2 paths % Mpath_delay = [0 2/fs 4/fs 8/fs 12/fs ]; %multipath delays in seconds % Mpath_gain = [0 -8 -10 -15 -200 ]; %channel multipaths in dB; here: 2 paths % Mpath_delay = [0 4/fs 7/fs 10/fs 16/fs ]; %multipath delays in seconds % Mpath_gain = [0 -5 -1000 -1500 -2000 ]; %channel multipaths in dB; here: 2 paths % Mpath_delay = [0 3/fs 6/fs 12/fs 16/fs ]; %multipath delays in seconds % Mpath_gain = [0 -8 -10 -15 -200 ]; %channel multipaths in dB; here: 2 paths % Mpath_delay = [0/fs 4/fs 7/fs 10/fs 16/fs ]; %multipath delays in seconds % Mpath_phase = [0 0 0 0 0 ]; Mpath_gain = [0 -5 -10 -200 -300 ]; %channel multipaths in dB; here: 2 paths Mpath_delay = [0/fs 3/fs 9/fs 10/fs 16/fs ]; %multipath delays in seconds Mpath_phase = [0 pi/6 -3*pi/4 -pi/3 pi ]; AA = 10.^(Mpath_gain./20) TT = Mpath_delay.*Ms PH = Mpath_phase %%%%%%%%%%%%合成多径 %幅度 时延 相位 a0=AA(1); t0= TT(1) ; ph0= PH(1); a1=AA(2); t1= TT(2) ; ph1= PH(2); a2=AA(3); t2= TT(3) ; ph2= PH(3); a3=AA(4); t3= TT(4) ; ph3= PH(4); a4=AA(5); t4= TT(5) ; ph4= PH(5); R0=a0*MEDLL_R_shift(R_ref,t0).*exp(1j*ph0); R1=a1*MEDLL_R_shift(R_ref,t1).*exp(1j*ph1); R2=a2*MEDLL_R_shift(R_ref,t2).*exp(1j*ph2); R3=a3*MEDLL_R_shift(R_ref,t3).*exp(1j*ph3); R4=a4*MEDLL_R_shift(R_ref,t4).*exp(1j*ph4); R_all = R0+R1+R2 +R3 ; % los + multpath1 %%%%实际采用32个相关器，1/16=0.065chips d_chip1_16=1/16; ttt=-2:d_chip1_16:2; R_all_samp=R_all(1:d_chip1_16/d_chip:end);%%实际采集的信号 %%%%加噪声 R_all_samp = awgn(R_all_samp,35,'measured');% SNR=25dB %%插值成0.005chip间隔 R_all_test = interp1(ttt,R_all_samp,tt,'spline') ;%插值 'pchip':三次Hermite; 'spline':三次样条;linear R_all_test= awgn(R_all,45,'measured');%%全400个相关器 %%%%绘图 figure; plot(tt,real(R0),'-k',tt,real(R1),'-b',tt,real(R2),'-c',tt,real(R3),'-g',tt,real(R4),'-y',tt,real(R_all),'-r+'); legend('LOS','Multpath1','Multpath2','Multpath3','Multpath4','Synthesis') grid on; figure; plot3(tt,real(R0),imag(R0),'-k',... tt,real(R1),imag(R1),'-b',... tt,real(R2),imag(R2),'-c',... tt,real(R3),imag(R3),'-g',... tt,real(R4),imag(R4),'-y',... tt,real(R_all),imag(R_all),'-r+'); xlabel('Code Phase Shift(Chips)');ylabel('Normalized Correlation Value (Re)');zlabel('Im'); legend('LOS','Multpath1','Multpath2','Multpath3','Multpath4','Synthesis') grid on; %%%%%%%%%%%%%%%%%%%%%%%%%%%%合成多径结束 % tic; MAX_Mpath_NUM=4; %LOS +3Mpath Value=zeros(1,MAX_Mpath_NUM); SRR=zeros(1,MAX_Mpath_NUM); SRR_Threshold=10000; %%%%%%%%%%% 1路LOS Rin=R_all_test; LOS_index_est_range=MEDLL_LOSpeakdect(Rin,tt,-0.3,1); tt(LOS_index_est_range) %%%%%重建出LOS相关函数 [phase,D_tmax,D_a,R_0]=MEDLL_Rebuild(Rin,R_ref,tt,LOS_index_est_range,MEDLL_D_ref,MEDLL_D_err,MEDLL_D_d); Res=R_all_test-R_0; % figure; % plot(tt,real(R_0),tt,R_all_test-R_0); Value(1)=mean((abs(Res((length(tt)-1)/4:3*(length(tt)-1)/4))).^2); SRR(1)=1/Value(1) if(SRR(1)>SRR_Threshold) Path_num=1 else %%%%%%%%%%% 2路循环优化 Rin=R_all_test; [phase,D_tmax,D_a,T,R_0,R_1]=MEDLL_Twopathloop(R_all_test,Rin,R_ref,tt,LOS_index_est_range,MEDLL_D_ref,MEDLL_D_err,MEDLL_D_d ,R0,R1); Value(2)=mean((abs(R_all_test-R_0-R_1)).^2); SRR(2)=1/Value(2) if(SRR(2)>SRR_Threshold) Path_num=2 else %%%%%%%%%%% 3路循环优化 Rin=R_all_test; [phase,D_tmax,D_a,T,R_0,R_1,R_2]=MEDLL_Threepathloop(R_all_test,Rin,R_ref,tt,LOS_index_est_range,MEDLL_D_ref,MEDLL_D_err,MEDLL_D_d ,R_0,R_1 ,R0,R1,R2); Res=R_all_test-R_0-R_1-R_2; Value(3)=mean((abs( Res((length(tt)-1)/4:3*(length(tt)-1)/4) )).^2); SRR(3)=1/Value(3) if(SRR(3)> SRR_Threshold) Path_num=3 else %%%%%%%%%%% 4路循环优化 Rin=R_all_test; [phase,D_tmax,D_a,T,R_0,R_1,R_2,R_3]=MEDLL_Fourpathloop(R_all_test,Rin,R_ref,tt,LOS_index_est_range,MEDLL_D_ref,MEDLL_D_err,MEDLL_D_d ,R_0,R_1,R_2 ,R0,R1,R2,R3); Res=R_all_test-R_0-R_1-R_2-R_3; Value(4)=mean((abs(Res((length(tt)-1)/4:3*(length(tt)-1)/4))).^2); SRR(4)=1/Value(4) if(SRR(4)>SRR_Threshold) Path_num=4 else Path_num=5 end end end end % toc;