diff --git a/targets/PROJECTS/CORRIDOR/emos_read.m b/targets/PROJECTS/CORRIDOR/emos_read.m index 98b5eb00d9..4f36823a7e 100644 --- a/targets/PROJECTS/CORRIDOR/emos_read.m +++ b/targets/PROJECTS/CORRIDOR/emos_read.m @@ -1,3 +1,6 @@ +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'); @@ -5,7 +8,7 @@ v2 = double(v(1:2:end))+1j*double(v(2:2:end)); fclose(fid); figure(1) -plot(abs(fft(v2))) +plot(abs(fftshift(fft(v2)))) %% sync addpath('../../../openair1/PHY/LTE_REFSIG'); @@ -17,27 +20,39 @@ figure(2); plot(lag,abs(corr)); %% frame start detection -% TODO: do a proper peak detection. for now just take the max -[m,i]=max(abs(corr)); -frame_start = lag(i); - -%% ofdm receiver -load('../LOCALIZATION/ofdm_pilots_sync_2048.mat'); +%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; + +%% 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(end-useful_carriers/2+1:end); fblock(2:useful_carriers/2+1)]; + received_f(i+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]')