From 9e08ca8712960bb61645b369bb52f4777022412b Mon Sep 17 00:00:00 2001 From: Florian Kaltenberger Date: Tue, 18 Mar 2014 09:47:11 +0000 Subject: [PATCH] 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 | 13 +++ targets/PROJECTS/CORRIDOR/emos_read.m | 112 ++++++++++++++-------- targets/PROJECTS/CORRIDOR/peaksfinder.m | 40 ++++++++ 3 files changed, 124 insertions(+), 41 deletions(-) create mode 100644 targets/PROJECTS/CORRIDOR/LanczosKernel.m create mode 100644 targets/PROJECTS/CORRIDOR/peaksfinder.m diff --git a/targets/PROJECTS/CORRIDOR/LanczosKernel.m b/targets/PROJECTS/CORRIDOR/LanczosKernel.m new file mode 100644 index 0000000000..ee6359498b --- /dev/null +++ b/targets/PROJECTS/CORRIDOR/LanczosKernel.m @@ -0,0 +1,13 @@ +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 diff --git a/targets/PROJECTS/CORRIDOR/emos_read.m b/targets/PROJECTS/CORRIDOR/emos_read.m index 4f36823a7e..6642d60bf5 100644 --- a/targets/PROJECTS/CORRIDOR/emos_read.m +++ b/targets/PROJECTS/CORRIDOR/emos_read.m @@ -1,58 +1,88 @@ 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); +enable_plots=1; %eanbles figures -figure(1) -plot(abs(fftshift(fft(v2)))) - -%% 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; -%% 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]); - ifblock(1:prefix_length)=[]; - fblock=fft(ifblock); - received_f(i+1,:) = [fblock(2:useful_carriers/2+1); fblock(end-useful_carriers/2+1:end)]; +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)))) + + 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(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); + 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 -%% 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]') - - +fclose(fid); diff --git a/targets/PROJECTS/CORRIDOR/peaksfinder.m b/targets/PROJECTS/CORRIDOR/peaksfinder.m new file mode 100644 index 0000000000..80139405e7 --- /dev/null +++ b/targets/PROJECTS/CORRIDOR/peaksfinder.m @@ -0,0 +1,40 @@ +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); + + + + +