Error using ==> times Matrix dimensions must agree

i cant find the error guys please help..

clear
clc

fs=50e6;
ts=1/fs;
n=fs/1000;

chprt=511e3;
x=0:1/chprt:0.001;
xi=0:1/fs:0.001-1/fs;

fdlo=-10e3;
fdhi=10e3;
f= [fdlo:1000:fdhi];
M = length(f);
g = 50000;
gg = 1:g;
loop=100;

nn=[0:n-1];

t=0:ts:0.001-ts;
startpt=0;
datatype='ubit1';

load CAcode_511;
record = mseq;
record = [record 0];
recordI= fopen('C:/Users/Frangos/Desktop/14h 22m 36s 046ms/ChannelI.misl', 'rb');

recordQ=fopen('C:/Users/Frangos/Desktop/14h 22m 36s 046ms/ChannelQ.misl', 'rb');

sig = interp1(x,record,xi);

sig=sign(sig);

    w = zeros (loop,2);

for z=1:loop;

   dataI = fread(recordI,[1 50000],'ubit1'); %x6
  dataI = 2.*dataI-1;

dataQ = fread(recordQ,[1 50000], 'ubit1');
dataQ = 2.*dataQ-1; 

imf = zeros(M,length(t));  

   for k=1:M

     signal1= fft(sig.*exp(1i*2*pi*f(k).*t));

      signal2= fft(dataI+dataQ*1i);

      mf=signal2.*conj(signal1);

      imf(k,:)= abs(ifft(mf));

%     plot(t,imf(k,:));
 end

[r,c] = find(imf==max(max(imf)));

freq = (r-11)*1000;
d = c;

w(z,:) = [freq,d];

%surf(t,f,imf);
end

   fseek(recordI, 0, 'bof');    %Move to specified position in file
   status = fseek(recordI, 0, 'bof');   

    fseek(recordQ, 0, 'bof');    %Move to specified position in file
    status = fseek(recordQ, 0, 'bof');   

    mf1=zeros(1);  
    mfrq0 = zeros(1);
    mfrq1 = zeros(1);
    c0= zeros(1);
    f0=zeros(1); 
    frr=zeros(1);
    for z2= 1:loop

         f0(z2) = w(z2,1);
         c0(z2) = w(z2,2);

         dataI = fread(recordI,6*50000,'ubit1');
         dataI = 2.*dataI-1;
         dataQ = fread(recordQ,6*50000,'ubit1');
         dataQ = 2.*dataQ-1;

         z1 = dataI + 1i*dataQ;
         za2 = z1(c0(z2):c0(z2)+5*n-1);
        zaa2 = za2' .* [sig sig sig sig sig];

        for z3 = [1:3];
           fr = f0(z2) -400+400*(z3-1);
    ==>mfrq0(z3) = sum(zaa2(1:250000) .* exp(1i*2*pi*(fr)*ts*nn));
           mfrq1(z3) = abs(mfrq0(z3));
        end

      [mamp mrw] = max(mfrq1);
      mf1(z2) = mrw-2;
       mfrq(z2) = f0(z2) + 200 * (mrw-2);
       mfrt=mfrq(z2);
      plot(mfrq);
      xlabel('time(ms)');
      ylabel('frequency(Hz)');
     end

the error is there ==> 10 lines above

[Fragkos Maragkou]

the problem im pretty sure is caused by nn. but cant see why?

Answer 1

[Walter Roberson]

You have fs = 50e6 and n = fs/1000 so n will be 50e3 which is 50000 . Then nn is 0:n-1 so nn will be 50000 elements long. You then, in the line having trouble, try to multiply the vector 50000 elements long by 250000 elements of zaa2 .

If the number of elements in nn is calculated, the number of elements to extract from zaa2 should also be calculated.