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srsLTE
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Added CP autocorrelation method to sync_test

This commit is contained in:
ismagom 2016-03-23 11:47:18 +01:00
parent f31922f5f5
commit 64515eb602
3 changed files with 16 additions and 13 deletions
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2
matlab/sync/cfo_estimate_cp.m
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@ -1,4 +1,4 @@
function cfo = cfo_estimate_cp(input_slot, Nsyms, sym_len, cp0_len, cp_len)
function [cfo, r] = cfo_estimate_cp(input_slot, Nsyms, sym_len, cp0_len, cp_len)
% Start correlating from the end. Nsyms is the number of symbols to
% correlate starting from the end.

2
matlab/sync/cp_corr.m
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@ -1,4 +1,4 @@
function [ lambda ] = cp_corr( x, theta, N, L, rho)
function [ lambda ] = cp_corr( x, theta, N, L)
l0=sum(x(theta:theta+L-1).*conj(x(theta+N:theta+L+N-1)));
l1=0;

25
matlab/tests/sync_test.m
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@ -1,12 +1,11 @@
clear
enb = lteTestModel('1.1','1.4MHz');
Ntrials = 1;
SNR_values = 100;%linspace(0,10,6);
Ntrials = 100;
SNR_values = linspace(-8,0,6);
flen=1920;
fft_size=128;
tx_offset = 0;%randi(50,1,Ntrials);
cfo_offset = 0;%2*rand(1,Ntrials)-1;
tx_offset = randi(50,1,Ntrials);
tx_signal = lteTestModelTool(enb);
pss_idx = flen/2-fft_size+1:flen/2;
@ -36,7 +35,7 @@ addpath('../sync/')
t = (0:length(tx_signal)-1).'/fft_size;
L=16;
M=3;
M=4;
diff=zeros(length(SNR_values),M);
for snr_idx=1:length(SNR_values)
fprintf('SNR=%.1f dB\n', SNR_values(snr_idx));
@ -44,7 +43,6 @@ for snr_idx=1:length(SNR_values)
rx_offset = zeros(M,length(tx_offset));
for i=1:Ntrials
[rx_signal, chinfo] = lteFadingChannel(cfg,tx_signal);
% rx_signal = rx_signal.*exp(-1i*cfo_offset(i)*2*pi.*t);
%rx_signal = tx_signal;
SNR = 10^(SNRdB/10); % Linear SNR
rx = [zeros(tx_offset(i),1); rx_signal];
@ -60,22 +58,27 @@ for snr_idx=1:length(SNR_values)
% srsLTE in tracking mode
track_offset=2+rx_offset(2,i)+flen/2-fft_size-L/2;
[rx_offset(3,i),corr_lt_track] = srslte_pss(enb,rx(track_offset:end),L);
rx_offset(3,i) = rx_offset(2,i) + (rx_offset(3,i) - fft_size - L/2);
rx_offset(3,i) = rx_offset(2,i) + (rx_offset(3,i) - fft_size - L/2) + 1;
% CP based
[rx_offset(4,i), corr_lt_cp] = srslte_cp_synch(enb, rx);
end
diff(snr_idx,:)=mean(abs(rx_offset-repmat(tx_offset,M,1)),2);
diff(snr_idx,:)=mean(abs(rx_offset-repmat(tx_offset,M,1) - chinfo.ChannelFilterDelay),2);
end
if (Ntrials == 1)
disp(diff)
%plot(1:flen,abs(corr_res(1:flen)),1:flen,abs(corr_lt(1:flen)));
t=940:1000;
plot(t,abs(corr_lt(t)));
t=1:fft_size;
plot(t,abs(corr_lt_cp(t)));
%plot(lambda)
%plot(1:L,abs(corr_lt_track),[L/2, L/2], [0 max(abs(corr_lt_track))])
grid on
else
plot(SNR_values,diff);
legend('Matlab','srs find','srs tracking 16','srs tracking 64')
legend('Matlab','srs find','srs tracking','srs cp')
grid on
xlabel('SNR (dB)')
ylabel('Avg time offset')