From 10cbb9ad920191f9c74e44123e059e92747e9f55 Mon Sep 17 00:00:00 2001 From: Ismael Gomez Date: Thu, 25 Aug 2016 19:01:47 -0700 Subject: [PATCH] ue_sync: set default offset correction interval to 0. chest_dl: added option to average estimates per subframe --- matlab/tests/equalizer_test.m | 21 +++++------- matlab/tests/pdsch_equal.m | 3 +- srslte/examples/pdsch_ue.c | 2 ++ srslte/lib/ch_estimation/chest_dl.c | 52 +++++++++++++++++++++-------- srslte/lib/ue/ue_sync.c | 22 ++++++------ 5 files changed, 62 insertions(+), 38 deletions(-) diff --git a/matlab/tests/equalizer_test.m b/matlab/tests/equalizer_test.m index 1391d5e53..5cd7e3353 100644 --- a/matlab/tests/equalizer_test.m +++ b/matlab/tests/equalizer_test.m @@ -6,13 +6,13 @@ clear plot_noise_estimation_only=false; -SNR_values_db=100;%linspace(20,35,8); -Nrealizations=1; +SNR_values_db=linspace(0,20,8); +Nrealizations=10; w1=0.1; w2=0.3; -enb.NDLRB = 6; % Number of resource blocks +enb.NDLRB = 25; % Number of resource blocks enb.CellRefP = 1; % One transmit antenna port enb.NCellID = 0; % Cell ID @@ -181,8 +181,8 @@ for i=1:10 rxGrid_sf = rxGrid(:,(i-1)*14+1:i*14); %% Channel Estimation with Matlab - [hest{1}(:,(1:14)+(i-1)*14), tmpnoise{1}(i), hls(:,(1:4*P)+(i-1)*4*P)] = ... - lteDLChannelEstimate2(enb,cec,rxGrid_sf); + [hest{1}(:,(1:14)+(i-1)*14), tmpnoise{1}(i)] = ... + lteDLChannelEstimate(enb,cec,rxGrid_sf); tmpnoise{1}(i)=tmpnoise{1}(i)*sqrt(2)*enb.CellRefP; %% LS-Linear estimation with srsLTE @@ -227,17 +227,12 @@ if (length(SNR_values_db) == 1) tmp{Ntests+1}='Real'; legend(tmp) - xlabel('SNR (dB)') + xlabel('Sample') ylabel('Channel Gain') grid on; - fprintf('Mean MMSE Robust %.2f dB\n', 10*log10(MSE(4,nreal,snr_idx))) - fprintf('Mean MMSE matlab %.2f dB\n', 10*log10(MSE(1,nreal,snr_idx))) -<<<<<<< HEAD - -======= - ->>>>>>> master +% fprintf('Mean MMSE Robust %.2f dB\n', 10*log10(MSE(4,nreal,snr_idx))) +% fprintf('Mean MMSE matlab %.2f dB\n', 10*log10(MSE(1,nreal,snr_idx))) end end diff --git a/matlab/tests/pdsch_equal.m b/matlab/tests/pdsch_equal.m index 665ff8047..08722b3bd 100644 --- a/matlab/tests/pdsch_equal.m +++ b/matlab/tests/pdsch_equal.m @@ -116,7 +116,7 @@ for snr_idx=1:length(SNR_values) rmccFgOut.TotSubframes=1; % Perform channel estimation - [hest, nest,estimates] = lteDLChannelEstimate2(rmccFgOut, cec, subframe_rx); + [hest, nest] = lteDLChannelEstimate(rmccFgOut, cec, subframe_rx); [cws,symbols] = ltePDSCHDecode(rmccFgOut,rmccFgOut.PDSCH,subframe_rx,hest,nest); [trblkout,blkcrc,dstate] = lteDLSCHDecode(rmccFgOut,rmccFgOut.PDSCH, ... @@ -156,6 +156,7 @@ if (length(SNR_values)>1) axis([min(SNR_values) max(SNR_values) 1/Npackets/(Nsf+1) 1]) else scatter(real(symbols{1}),imag(symbols{1})) + plot( fprintf('Matlab: %d OK\nsrsLTE: %d OK\n',decoded, decoded_srslte); end diff --git a/srslte/examples/pdsch_ue.c b/srslte/examples/pdsch_ue.c index b0a9c5fd6..8c986ab75 100644 --- a/srslte/examples/pdsch_ue.c +++ b/srslte/examples/pdsch_ue.c @@ -583,11 +583,13 @@ int main(int argc, char **argv) { sfn++; if (sfn == 1024) { sfn = 0; + /* printf("\n"); ue_dl.pkt_errors = 0; ue_dl.pkts_total = 0; ue_dl.nof_detected = 0; nof_trials = 0; + */ } } diff --git a/srslte/lib/ch_estimation/chest_dl.c b/srslte/lib/ch_estimation/chest_dl.c index beb7518d2..7ac4444a0 100644 --- a/srslte/lib/ch_estimation/chest_dl.c +++ b/srslte/lib/ch_estimation/chest_dl.c @@ -39,6 +39,8 @@ #include "srslte/utils/vector.h" #include "srslte/utils/convolution.h" +#define AVERAGE_SUBFRAME + //#define DEFAULT_FILTER_LEN 3 #ifdef DEFAULT_FILTER_LEN @@ -165,7 +167,18 @@ void srslte_chest_dl_free(srslte_chest_dl_t *q) /* Uses the difference between the averaged and non-averaged pilot estimates */ static float estimate_noise_pilots(srslte_chest_dl_t *q, uint32_t port_id) { + float norm = sqrt(2); +#ifdef AVERAGE_SUBFRAME + int nref=2*q->cell.nof_prb; +#else int nref=SRSLTE_REFSIGNAL_NUM_SF(q->cell.nof_prb, port_id); + if (q->smooth_filter_len == 3) { + float a = q->smooth_filter[0]; + float norm3 = 6.143*a*a+0.04859*a-0.002774; + norm /= norm3; + } +#endif + /* Substract noisy pilot estimates */ srslte_vec_sub_ccc(q->pilot_estimates_average, q->pilot_estimates, q->tmp_noise, nref); @@ -179,12 +192,6 @@ static float estimate_noise_pilots(srslte_chest_dl_t *q, uint32_t port_id) #endif /* Compute average power. Normalized for filter len 3 using matlab */ - float norm = 1; - if (q->smooth_filter_len == 3) { - float a = q->smooth_filter[0]; - float norm3 = 6.143*a*a+0.04859*a-0.002774; - norm /= norm3; - } float power = norm*q->cell.nof_ports*srslte_vec_avg_power_cf(q->tmp_noise, nref); return power; } @@ -225,19 +232,29 @@ static float estimate_noise_empty_sc(srslte_chest_dl_t *q, cf_t *input) { static void interpolate_pilots(srslte_chest_dl_t *q, cf_t *pilot_estimates, cf_t *ce, uint32_t port_id) { - /* interpolate the symbols with references in the freq domain */ - uint32_t l; + +#ifdef AVERAGE_SUBFRAME + // Interpolate symbol 0 in the frequency domain + uint32_t fidx_offset = srslte_refsignal_cs_fidx(q->cell, 0, port_id, 0); + srslte_interp_linear_offset(&q->srslte_interp_lin, pilot_estimates, + &ce[srslte_refsignal_cs_nsymbol(0,q->cell.cp, port_id) * q->cell.nof_prb * SRSLTE_NRE], + fidx_offset, SRSLTE_NRE/2-fidx_offset); + // All channel estimates in the subframe are the same + for (int l=1;l<2*SRSLTE_CP_NSYMB(q->cell.cp);l++) { + memcpy(&ce[l*q->cell.nof_prb*SRSLTE_NRE], ce, q->cell.nof_prb*SRSLTE_NRE*sizeof(cf_t)); + } +#else + uint32_t l=0; uint32_t nsymbols = srslte_refsignal_cs_nof_symbols(port_id); - - /* Interpolate in the frequency domain */ + + // Interpolate in the frequency domain for (l=0;lcell, l, port_id, 0); srslte_interp_linear_offset(&q->srslte_interp_lin, &pilot_estimates[2*q->cell.nof_prb*l], &ce[srslte_refsignal_cs_nsymbol(l,q->cell.cp, port_id) * q->cell.nof_prb * SRSLTE_NRE], fidx_offset, SRSLTE_NRE/2-fidx_offset); } - - /* Now interpolate in the time domain between symbols */ + // Interpolate in the time domain between symbols if (SRSLTE_CP_ISNORM(q->cell.cp)) { if (nsymbols == 4) { srslte_interp_linear_vector(&q->srslte_interp_linvec, &cesymb(0), &cesymb(4), &cesymb(1), 4, 3); @@ -261,6 +278,7 @@ static void interpolate_pilots(srslte_chest_dl_t *q, cf_t *pilot_estimates, cf_t srslte_interp_linear_vector(&q->srslte_interp_linvec, &cesymb(1), &cesymb(7), &cesymb(8), 6, 4); } } +#endif } void srslte_chest_dl_set_smooth_filter(srslte_chest_dl_t *q, float *filter, uint32_t filter_len) { @@ -293,9 +311,17 @@ static void average_pilots(srslte_chest_dl_t *q, cf_t *input, cf_t *output, uint uint32_t nsymbols = srslte_refsignal_cs_nof_symbols(port_id); uint32_t nref = 2*q->cell.nof_prb; - for (int l=0;lsmooth_filter, &output[l*nref], nref, q->smooth_filter_len); +#endif } +#ifdef AVERAGE_SUBFRAME + srslte_vec_sc_prod_cfc(output, (float) 1.0/nsymbols, output, nref); +#endif } float srslte_chest_dl_rssi(srslte_chest_dl_t *q, cf_t *input, uint32_t port_id) { diff --git a/srslte/lib/ue/ue_sync.c b/srslte/lib/ue/ue_sync.c index d04c5c303..a81004ef0 100644 --- a/srslte/lib/ue/ue_sync.c +++ b/srslte/lib/ue/ue_sync.c @@ -44,7 +44,7 @@ cf_t dummy[MAX_TIME_OFFSET]; #define TRACK_MAX_LOST 4 #define TRACK_FRAME_SIZE 32 #define FIND_NOF_AVG_FRAMES 4 -#define DEFAULT_SAMPLE_OFFSET_CORRECT_PERIOD 5 +#define DEFAULT_SAMPLE_OFFSET_CORRECT_PERIOD 0 #define DEFAULT_SFO_EMA_COEFF 0.1 cf_t dummy_offset_buffer[1024*1024]; @@ -358,7 +358,6 @@ static int track_peak_ok(srslte_ue_sync_t *q, uint32_t track_idx) { { INFO("Warning: Expected SF idx %d but got %d! (%d frames)\n", q->sf_idx, srslte_sync_get_sf_idx(&q->strack), q->frame_no_cnt); - q->sf_idx = srslte_sync_get_sf_idx(&q->strack); q->frame_no_cnt++; if (q->frame_no_cnt >= TRACK_MAX_LOST) { INFO("\n%d frames lost. Going back to FIND\n", (int) q->frame_no_cnt); @@ -382,18 +381,19 @@ static int track_peak_ok(srslte_ue_sync_t *q, uint32_t track_idx) { // Compute cumulative moving average time offset */ if (!frame_idx) { - // Adjust RF sampling time based on the mean sampling offset - q->next_rf_sample_offset = (int) round(q->mean_sample_offset); - - // Reset PSS averaging if correcting every a period longer than 1 - if (q->sample_offset_correct_period > 1) { - srslte_sync_reset(&q->strack); - } - - // Compute SFO based on mean sample offset if (q->sample_offset_correct_period) { + // Adjust RF sampling time based on the mean sampling offset + q->next_rf_sample_offset = (int) round(q->mean_sample_offset); + // Reset PSS averaging if correcting every a period longer than 1 + if (q->sample_offset_correct_period > 1) { + srslte_sync_reset(&q->strack); + } + // Compute SFO based on mean sample offset q->mean_sample_offset /= q->sample_offset_correct_period; + } else { + q->next_rf_sample_offset = q->last_sample_offset; } + q->mean_sfo = SRSLTE_VEC_EMA(q->mean_sample_offset, q->mean_sfo, q->sfo_ema); INFO("Time offset adjustment: %d samples (%.2f), mean SFO: %.2f Hz, %.5f samples/5-sf, ema=%f, length=%d\n",