how can I find coherence of a measurement matrix?

coherence =A

[Stephen23]

@Anthony Uwaechia: You might like to accept John's Answer, if it solved your problem.

Answer 1

[John BG]

Hi Anthony

have a look:

P=16 
N =512 
L=50 
M=16 
d=floor(N/L)

for k=1:1:d

      P=ones(1,M)+d*[0:1:M-1]  % you may want this line outside the main for loop
      P2=Pk

      for m=1:1:M

%         [k k+d k+2d .. =<N]
%             k=1 [1 1+d 1+2d .. =<512]  =  [1 11 21 31 .. 501 511]
%             k=2 [2 2+d 2+2d .. =<512]  =  [2 12 22 32 .. 502 512]
%             k=3 [3 3+d 3+2d .. =<512]  =  [3 13 23 33 .. 503]
%             ..
%                    k*ones(1,floor((N-k)/d)+1) +  [0 d 2d .. =<(N-k)]

           n_range=k*ones(1,floor((N-k)/d)+1) + d*[0:1:floor((N-k)/d)]

           for n=n_range

               if (sum(ismember(n,Pk))==0)

                   % change Pk upper limit from (M-1)*d-1 to (n-1)*d-1 and redefine P2
                     P3=ones(1,n)+d*[0:1:n-1]  % you may want this line outside the main for loop

                     if cov(P3)<cov(P2)  
                         % or C is Carrier2Noise ratio and Ci(P2)<Ci(Pk) means all P2 carriers below Pk carriers
                         % then perhaps if max(P3)<min(Pk) ..

                         Pk=P3

                     end

               end

           end

% repeatition % for m=[M:-1:1] % % end

      end

end

2 things :

1.- when Pk is generated again with n instead of M as upper limit, either the comment expression circled

should be [1,2, ... Pm] or it means replace the initial elements, leaving the upper ones, whatever left as initially defined

2.- Without further information, C() may mean covariance cov() or it's Carrier2Noise ratio and Ci(P2)<Ci(Pk) means all P2 carriers are below Pk carriers, only then replace

Are you using this loop to generate OFDM (ADSL, DVB-T, WAN, ..) carrier indices?

Just for the time taken, if the lines above are of any help, would you click on the thumbs-up vote above? thanks in advance

John

[e-mail]