% Lab 2 Digicom
close all

% Read in sample file (example here)
fd = fopen('usrp_samples.dat','r') ; 
s = fread(fd,153600*2,'int16') ; 
fclose(fd) ; 
s2 = s(1:2:end) + sqrt(-1)*s(2:2:end) ; 





% close all
%test = N_f;
N_f = ind2; %needs to be changed for every new ind
sss_e = [];
ss0 = s2((N_f-72-1024-1023):(N_f-72-1024));
pss0 = s2((N_f - 72-1023): (N_f - 72));
p_f = fft(pss0, 1024);
p_f2(1:36) =   p_f(1:36);
p_f2(37:72)=  p_f(1024 + (-35:0) );
s_f  = (fft(ss0,1024));
figure;
stem(abs(fftshift(s_f)))
title 's_f'
sss_e(1:36)= s_f((1024-35):1024);
sss_e(37:72)= s_f(2:37);
figure;
stem(abs(sss_e));
   figure;
   plot(sss_e,'o')
   axis([-10*power(10,5) 10*power(10,5) -10*power(10,5) 10*power(10,5)])
   pss2_f_extracted = []; 
   i=6;
   pss2_f_extracted = zeros(1,72);
   for j=1:1:1024
        if (abs(pss2_f(j))~= 0)
            
            pss2_f_extracted(i) = pss2_f(j);
            i=i+1;
        end 
   end 
   %pss2_f_extracted(end:end+5) = 0
   H_n = abs(conj(pss2_f_extracted).* sss_e); 
   figure; stem(20*log10(abs(H_n))); axis([0 72 0 250])
   
   

% c) 

%h_pss = cconv(conj(pss_2f),