close all clear all enable_plots=1; %eanbles figures %% preload and init data addpath('../../../openair1/PHY/LTE_REFSIG'); primary_synch; %loads the primary sync signal pss_t = upsample(primary_synch0_time,4); %load('E:\EMOS\corridor\ofdm_pilots_sync_2048_v7.mat'); load('ofdm_pilots_sync_30MHz.mat'); ofdm_symbol_length = num_carriers + prefix_length; frame_length = ofdm_symbol_length*num_symbols_frame; useful_carriers = num_carriers-num_zeros-1; %filename = 'E:\EMOS\corridor\lab tests\eNB_data_20140321_184441.EMOS'; filename = 'D:\trials1 train extracted\eNB_data_20140331_UHF_run1.EMOS'; destdir = 'E:\EMOS\corridor\trials1 train'; samples_slot = 7680/2; slots_per_frame = 20; nframes = 100; nant_rx=3; nant_tx=4; d = dir(filename); nblocks = floor(d.bytes/(samples_slot*slots_per_frame*nframes*nant_rx*4)); PDP_total = zeros(nblocks*nframes,useful_carriers/4,nant_tx,nant_rx); %% main loop fid = fopen(filename,'r'); % advance 1 minute of measurements (the synchronization algorithm does not % work so well for low SNR yet) fseek(fid,samples_slot*slots_per_frame*nframes*nant_rx*60*2,'bof'); vStorage = []; block = 1; while ~feof(fid) fprintf(1,'Processing block %d of %d',block,nblocks); [v,c]=fread(fid, samples_slot*slots_per_frame*nframes*nant_rx*2, 'int16',0,'ieee-le'); if (c==0) break end v1 = double(v(1:2:end))+1j*double(v(2:2:end)); v2 = zeros(samples_slot*slots_per_frame*nframes,nant_rx); for slot=1:slots_per_frame*nframes for a=1:nant_rx v2((slot-1)*samples_slot+1:slot*samples_slot,a) = ... v1((slot-1)*samples_slot*nant_rx+(a-1)*samples_slot+1:... (slot-1)*samples_slot*nant_rx+ a *samples_slot,1); end end v2 = [vStorage; v2] ; %handle boundaries between blocks if size(v2,1) > frame_length*nframes ; nframes = floor(size(v2,1) / frame_length) ; vStorage = v2(frame_length*nframes+1:end,:) ; v2(frame_length*nframes + 1 : end,:) = [] ; start = 1 ; end if enable_plots>=2 figure(1) plot(20*log10(abs(fftshift(fft(v2))))) end %% frame start detection if block==1 [corr,lag] = xcorr(v2(:,1),pss_t); %[m,idx]=max(abs(corr)); %[m,idx]=peaksfinder(corr,frame_length); tmp = corr(nframes*slots_per_frame*samples_slot:end); tmp2 = reshape(tmp,slots_per_frame*samples_slot,nframes); [m,idx] = max(abs(tmp2),[],1); frame_offset = round(mean(idx(1:10))) - prefix_length; if enable_plots>=2 figure(2); hold off plot(lag,abs(corr)); hold on plot(frame_offset,m(1),'ro') end else % after the first block we are synchronized frame_offset = prefix_length/8; end %% for i=1:nframes; fprintf(1,'.'); frame_start = (slots_per_frame*samples_slot)*(i-1)+frame_offset+1; %frame_start = lag(idx(i))-prefix_length; % frame_start = lag(i) - prefix_length; if i<nframes %% ofdm receiver received_f = OFDM_RX(v2(frame_start:frame_start+frame_length,:),num_carriers,useful_carriers,prefix_length,num_symbols_frame); else vStorage = [v2(frame_start:end,:) ; vStorage]; % handle block boundaries end %% MIMO channel estimation H = zeros(num_symbols_frame/2,useful_carriers/4,nant_tx,nant_rx); for itx=1:nant_tx % f_start and t_start indicate the start of the pilots in time % and frequency according to the specifications (see .doc file). % t_start has to be >=2, since the first symbol is the PSS. f_start = mod(itx-1,2)*2+1; t_start = floor((itx-1)/2)+1; for irx=1:nant_rx H(:,:,itx,irx)=conj(squeeze(f3(itx,t_start:2:end,f_start:4:end))).*received_f(t_start:2:end,f_start:4:end,irx); end end Ht = ifft(H,[],2); PDP = mean(abs(Ht).^2,1); PDP_all = squeeze(mean(mean(PDP,3),4)); PDP_total((block-1)*nframes+i+1,:,:,:) = PDP; % adjust frame offset base on channel estimate to compensate for % timing drift. We try to keep the peak of the impulse response at % sample prefix_length/8. [m,idx] = max(fft(ifft(PDP_all),num_carriers)); offset = idx - prefix_length/8; if offset > prefix_length offset = offset - num_carriers; end if abs(offset) > 5 frame_offset = frame_offset + round(offset/4); end if enable_plots>=1 figure(3) for itx=1:nant_tx for irx=1:nant_rx subplot(nant_tx,nant_rx,(itx-1)*nant_rx + irx); surf(20*log10(abs(Ht(:,:,itx,irx)))) %xlabel('time [OFDM symbol]') %ylabel('delay time [samples]') %zlabel('power [dB]') shading interp end end figure(4) for itx=1:nant_tx for irx=1:nant_rx subplot(nant_tx,nant_rx,(itx-1)*nant_rx + irx); plot(10*log10(PDP(:,:,itx,irx))) ylim([50 80]) xlim([0 75]) %xlabel('delay time [samples]') %ylabel('power [dB]') end end drawnow end end fprintf(1,'\n'); block = block+1; end fclose(fid); %% save processed data [path,name,ext]=fileparts(filename); save([destdir filesep name '.mat'],'PDP_total');