crosscorr_ce_40.m

calculation of the autocorrelation peak sidelobe levels and corsscorrelation. CE sequence, frank aut

%Autocorrelation peak sidelobe levels and cross-correlation peak for CE
%optimized polyphase sequences of length =L, M=M, f=4
clear, close all;
L=128;
M=3;
S=CE_seq(L);

nfft=2*L-1;
srfft=zeros(M,nfft);
for m=1:M
srfft(m,:)=fft(S(m,:),nfft);
end

Corr=zeros(M,M,nfft);
Cmax=zeros(M,M);
SL=zeros(M,M,nfft-1);
for m=1:M
    for n=1:M
        if m==n
            Corr(m,n,:)=fftshift(abs(ifft(srfft(m,:).* conj(srfft(n,:))))/(L));
            SL(m,n,1:(nfft-1)/2)=Corr(m,n,1:(nfft-1)/2);
            SL(m,n,(nfft+1)/2:nfft-1)=Corr(m,n,(nfft+1)/2+1:nfft);
            Cmax(m,n)=20*log10( max( SL(m,n,:) ) );
        else
            Corr(m,n,:)=fftshift(abs(ifft(srfft(m,:).* conj(srfft(n,:))))/(L));
            Cmax(m,n)=20*log10(max(Corr(m,n,:)));
        end
    end     
end

% Mean autocorrelation peak sidelobe level(AC PSL), Mean
% cross-correlation(XC) and mean cross-correlation peaks(XC peak) CE
% sequences of length=128 using 4design sub-sequences
% during optimization (L=128,M=3,f=4)

SUM_AC_PSL=0;
for m=1:M
    for n=1:M
        if m==n
            SUM_AC_PSL=SUM_AC_PSL+10^(Cmax(m,n)/20);
        else
            SUM_AC_PSL=SUM_AC_PSL;
        end
    end
end
Mean_AC_PSL=20*log10( SUM_AC_PSL/3 );
SUM_XC=0;
for m=1:M
    for n=1:M
        if m==n
            SUM_XC=SUM_XC;
        else
            SUM_XC=SUM_XC+sum(Corr(m,n,:));
        end
    end
end
Mean_XC=20*log10( SUM_XC/(nfft*(M*M-M)) );

SUM_XCP=0;
for m=1:M
    for n=1:M
        if m==n
            SUM_XCP=SUM_XCP;
        else
            SUM_XCP=SUM_XCP+10^(Cmax(m,n)/20);
        end
    end
end
Mean_XCP=20*log10( SUM_XCP/(M*M-M) );