added George's peak finder to emos_read.m

git-svn-id: http://svn.eurecom.fr/openair4G/trunk@5179 818b1a75-f10b-46b9-bf7c-635c3b92a50f

targets/PROJECTS/CORRIDOR/LanczosKernel.m

+function La = LanczosKernel(a,x0,samples)
+
+
+min = floor(x0) - a;
+max = ceil(x0) + a;
+
+min(min<1)=1;
+max(max>size(samples,2))=size(samples,2);
+
+La=zeros(size(x0,2),1);
+for i=1:size(x0,2)
+La(i)=sinc((-x0(i)+(min(i):max(i)))).*sinc(((-x0(i)+(min(i):max(i)))/a))*samples(min(i):max(i))';
+end
\ No newline at end of file

targets/PROJECTS/CORRIDOR/emos_read.m

 close all
 clear all
 
-%% read data
-fid = fopen('E:\EMOS\corridor\eNB_data_20140108_185919.EMOS','r');
-[v,c]=fread(fid, 76800*4*100, 'int16',0,'ieee-le');
-v2 = double(v(1:2:end))+1j*double(v(2:2:end));
-fclose(fid);
-
-figure(1)
-plot(abs(fftshift(fft(v2))))
+enable_plots=1; %eanbles figures
 
-%% sync
+%% preload and init data
 addpath('../../../openair1/PHY/LTE_REFSIG');
 primary_synch; %loads the primary sync signal
-
 pss_t = upsample(primary_synch0_time,4*4);
-[corr,lag] = xcorr(v2,pss_t);
-figure(2);
-plot(lag,abs(corr));
 
-%% frame start detection
 %load('../LOCALIZATION/ofdm_pilots_sync_2048.mat');
 load('E:\EMOS\corridor\ofdm_pilots_sync_2048_v7.mat');
 ofdm_symbol_length = num_carriers + prefix_length;
 frame_length = ofdm_symbol_length*num_symbols_frame;
 useful_carriers = num_carriers-num_zeros-1;
 
-% TODO: do a proper peak detection. for now just take the max
-[m,i]=max(abs(corr));
-frame_start = lag(i) - prefix_length;
+filename = 'E:\EMOS\corridor\eNB_data_20140108_185919.EMOS';
+samples_slot = 7680*2;
+slots_per_frame = 20;
+nframes = 100;
+
+d = dir(filename);
+nblocks = floor(d.bytes/(samples_slot*slots_per_frame*nframes*4));
+PDP_total = zeros(nblocks*nframes,useful_carriers);
+
+%% main loop
+fid = fopen(filename,'r');
+block = 1;
+while ~feof(fid)
+    fprintf(1,'Processing block %d of %d',block,nblocks);
+    
+    [v,c]=fread(fid, samples_slot*slots_per_frame*nframes*2, 'int16',0,'ieee-le');
+    v2 = double(v(1:2:end))+1j*double(v(2:2:end));
+    
+    [corr,lag] = xcorr(v2,pss_t);
+
+    if enable_plots>=2
+        figure(1)
+        plot(abs(fftshift(fft(v2))))
 
-%% ofdm receiver
-received = v2(frame_start:frame_start+frame_length);
-received_f = zeros(num_symbols_frame,useful_carriers);
-for i=0:num_symbols_frame-1;
-    ifblock=received(i*ofdm_symbol_length+[1:ofdm_symbol_length]);
+        figure(2);
+        plot(lag,abs(corr));
+    end
+    
+    %% frame start detection
+    %[m,i]=max(abs(corr));
+    [m,idx]=peaksfinder(corr,frame_length);
+    
+    for i=1:size(idx,2)-1; % the last frame is not complite
+        fprintf(1,'.');
+        frame_start = lag(idx(i))-prefix_length;
+        % frame_start = lag(i) - prefix_length;
+        
+        %% ofdm receiver
+        received = v2(frame_start:frame_start+frame_length);
+        received_f = zeros(num_symbols_frame,useful_carriers);
+        for j=0:num_symbols_frame-1;
+            ifblock=received(j*ofdm_symbol_length+(1:ofdm_symbol_length));
             ifblock(1:prefix_length)=[];
             fblock=fft(ifblock);
-    received_f(i+1,:) = [fblock(2:useful_carriers/2+1); fblock(end-useful_carriers/2+1:end)];
-end
+            received_f(j+1,:) = [fblock(2:useful_carriers/2+1); fblock(end-useful_carriers/2+1:end)];
+        end
         
-%% channel estimation
-H=conj(f).*received_f;
-Ht = ifft(H,[],2);
-PDP = mean(abs(Ht(2:end,:).^2),1);
-figure(3)
-surf(20*log10(abs(Ht)))
-xlabel('time [OFDM symbol]')
-ylabel('delay time [samples]')
-zlabel('power [dB]')
-shading interp
-figure(4)
-plot(10*log10(PDP))
-xlabel('delay time [samples]')
-ylabel('power [dB]')
+        %% channel estimation
+        H=conj(f).*received_f;
+        Ht = ifft(H,[],2);
+        PDP = mean(abs(Ht(2:end,:).^2),1);
+        PDP_total((block-1)*nframes+i+1,:) = PDP;
         
+        if enable_plots>=1
+            figure(3)
+            surf(20*log10(abs(Ht)))
+            xlabel('time [OFDM symbol]')
+            ylabel('delay time [samples]')
+            zlabel('power [dB]')
+            shading interp
+            figure(4)
+            plot(10*log10(PDP))
+            xlabel('delay time [samples]')
+            ylabel('power [dB]')
+        end
         
+    end
+    fprintf(1,'\n');
+    block = block+1;
+end
+
+fclose(fid);

targets/PROJECTS/CORRIDOR/peaksfinder.m

+function [m,ind]=peaksfinder(corr,frame_length)
+
+
+
+threshold=45000;
+consecutivePos=[];
+highCorrVal=find(abs(corr)>threshold);
+num_peak=0;
+k=1;
+consecutivePos(1)=highCorrVal(1);
+for i_high=1:size(highCorrVal,1)-1
+    if highCorrVal(i_high+1)-highCorrVal(i_high)==1 
+        consecutivePos(k+1)=highCorrVal(i_high+1);
+        k=k+1;
+    else
+        num_peak=num_peak+1;
+        [m(num_peak),temp_idx]=max(abs(corr(min(consecutivePos):max(consecutivePos))));
+        ind(num_peak)=min(consecutivePos)-1+temp_idx;
+        consecutivePos=[];
+        consecutivePos(1)=highCorrVal(i_high+1);
+        k=1;
+    end
+end
+
+num_peak=num_peak+1;
+[m(num_peak),temp_idx]=max(abs(corr(min(consecutivePos):max(consecutivePos))));
+ind(num_peak)=min(consecutivePos)-1+temp_idx;
+
+
+% a bigining for make code which clculate the best peak in respect to whole frlames
+
+% corrMatrix=vec2mat(corr, frame_length);
+% corrMatrix(end,:)=[];
+% sumCorrMatrix=sum(abs(corrMatrix));
+% [Value Pos]=max(sumCorrMatrix);
+
+
+
+
+