From 682bc151177d89d4cd0293c4dacd5f2c708f5192 Mon Sep 17 00:00:00 2001 From: Francesco Mani Date: Thu, 7 Feb 2019 17:06:46 +0100 Subject: [PATCH] FFO estimation and compensation optional via command line --- openair1/PHY/NR_REFSIG/pss_nr.h | 1 + .../PHY/NR_UE_TRANSPORT/nr_initial_sync.c | 16 ++++---- openair1/PHY/NR_UE_TRANSPORT/pss_nr.c | 41 +++++++++++-------- openair1/PHY/defs_nr_UE.h | 2 + openair1/SIMULATION/NR_PHY/pbchsim.c | 3 ++ targets/RT/USER/nr-uesoftmodem.c | 2 + targets/RT/USER/nr-uesoftmodem.h | 2 + 7 files changed, 42 insertions(+), 25 deletions(-) diff --git a/openair1/PHY/NR_REFSIG/pss_nr.h b/openair1/PHY/NR_REFSIG/pss_nr.h index 279f9e417a..dc20ab24d7 100644 --- a/openair1/PHY/NR_REFSIG/pss_nr.h +++ b/openair1/PHY/NR_REFSIG/pss_nr.h @@ -137,6 +137,7 @@ int set_pss_nr(int ofdm_symbol_size); int pss_synchro_nr(PHY_VARS_NR_UE *PHY_vars_UE, int rate_change); int pss_search_time_nr(int **rxdata, ///rx data in time domain NR_DL_FRAME_PARMS *frame_parms, + int fo_flag, int *eNB_id, int *f_off); diff --git a/openair1/PHY/NR_UE_TRANSPORT/nr_initial_sync.c b/openair1/PHY/NR_UE_TRANSPORT/nr_initial_sync.c index 78a2f0c82d..e5f079ebc3 100644 --- a/openair1/PHY/NR_UE_TRANSPORT/nr_initial_sync.c +++ b/openair1/PHY/NR_UE_TRANSPORT/nr_initial_sync.c @@ -202,19 +202,21 @@ int nr_initial_sync(PHY_VARS_NR_UE *ue, runmode_t mode) LOG_I(PHY,"sync_pos %d ssb_offset %d sync_pos_slot %d \n",sync_pos,ue->ssb_offset,sync_pos_slot); #endif - // digital compensation of FFO for SSB symbols - double s_time = 1/(1.0e3*fp->samples_per_subframe); // sampling time - double off_angle = -2*M_PI*s_time*(ue->common_vars.freq_offset); // offset rotation angle compensation per sample + // digital compensation of FFO for SSB symbols + if (ue->UE_fo_compensation){ + double s_time = 1/(1.0e3*fp->samples_per_subframe); // sampling time + double off_angle = -2*M_PI*s_time*(ue->common_vars.freq_offset); // offset rotation angle compensation per sample - int start = ue->ssb_offset; // start for offset correction is at ssb_offset (pss time position) - int end = start + 4*(fp->ofdm_symbol_size + fp->nb_prefix_samples); // loop over samples in 4 symbols (ssb size), including prefix + int start = ue->ssb_offset; // start for offset correction is at ssb_offset (pss time position) + int end = start + 4*(fp->ofdm_symbol_size + fp->nb_prefix_samples); // loop over samples in 4 symbols (ssb size), including prefix - for(int n=start; nnb_antennas_rx; ar++) { + for(int n=start; nnb_antennas_rx; ar++) { re = ((double)(((short *)ue->common_vars.rxdata[ar]))[2*n]); im = ((double)(((short *)ue->common_vars.rxdata[ar]))[2*n+1]); ((short *)ue->common_vars.rxdata[ar])[2*n] = (short)(round(re*cos(n*off_angle) - im*sin(n*off_angle))); ((short *)ue->common_vars.rxdata[ar])[2*n+1] = (short)(round(re*sin(n*off_angle) + im*cos(n*off_angle))); + } } } diff --git a/openair1/PHY/NR_UE_TRANSPORT/pss_nr.c b/openair1/PHY/NR_UE_TRANSPORT/pss_nr.c index 30fb4bfc0f..9b09a846bb 100644 --- a/openair1/PHY/NR_UE_TRANSPORT/pss_nr.c +++ b/openair1/PHY/NR_UE_TRANSPORT/pss_nr.c @@ -663,6 +663,7 @@ int pss_synchro_nr(PHY_VARS_NR_UE *PHY_vars_UE, int rate_change) NR_DL_FRAME_PARMS *frame_parms = &(PHY_vars_UE->frame_parms); int synchro_position; int **rxdata = NULL; + int fo_flag = PHY_vars_UE->UE_fo_compensation; // flag to enable freq offset estimation and compensation #ifdef DBG_PSS_NR @@ -706,6 +707,7 @@ int pss_synchro_nr(PHY_VARS_NR_UE *PHY_vars_UE, int rate_change) synchro_position = pss_search_time_nr(rxdata, frame_parms, + fo_flag, (int *)&PHY_vars_UE->common_vars.eNb_id, (int *)&PHY_vars_UE->common_vars.freq_offset); @@ -817,14 +819,15 @@ static inline double angle64(int64_t x) int pss_search_time_nr(int **rxdata, ///rx data in time domain NR_DL_FRAME_PARMS *frame_parms, + int fo_flag, int *eNB_id, int *f_off) { unsigned int n, ar, peak_position, pss_source; int64_t peak_value; - int64_t result,result1,result2; + int64_t result; int64_t avg[NUMBER_PSS_SEQUENCE]; - double ffo_est; + double ffo_est=0; unsigned int length = (NR_NUMBER_OF_SUBFRAMES_PER_FRAME*frame_parms->samples_per_subframe); /* 1 frame for now, it should be 2 TODO_NR */ @@ -894,34 +897,36 @@ int pss_search_time_nr(int **rxdata, ///rx data in time domain } } - - // fractional frequency offser computation according to Cross-correlation Synchronization Algorithm Using PSS - // Shoujun Huang, Yongtao Su, Ying He and Shan Tang, "Joint time and frequency offset estimation in LTE downlink," 7th International Conference on Communications and Networking in China, 2012. + if (fo_flag){ + // fractional frequency offser computation according to Cross-correlation Synchronization Algorithm Using PSS + // Shoujun Huang, Yongtao Su, Ying He and Shan Tang, "Joint time and frequency offset estimation in LTE downlink," 7th International Conference on Communications and Networking in China, 2012. - // Computing cross-correlation at peak on half the symbol size for first half of data - result1 = dot_product64((short*)primary_synchro_time_nr[pss_source], + int64_t result1,result2; + // Computing cross-correlation at peak on half the symbol size for first half of data + result1 = dot_product64((short*)primary_synchro_time_nr[pss_source], (short*) &(rxdata[0][peak_position]), frame_parms->ofdm_symbol_size>>1, shift); - // Computing cross-correlation at peak on half the symbol size for data shifted by half symbol size - // as it is real and complex it is necessary to shift by a value equal to symbol size to obtain such shift - result2 = dot_product64((short*)primary_synchro_time_nr[pss_source]+(frame_parms->ofdm_symbol_size), + // Computing cross-correlation at peak on half the symbol size for data shifted by half symbol size + // as it is real and complex it is necessary to shift by a value equal to symbol size to obtain such shift + result2 = dot_product64((short*)primary_synchro_time_nr[pss_source]+(frame_parms->ofdm_symbol_size), (short*) &(rxdata[0][peak_position])+(frame_parms->ofdm_symbol_size), frame_parms->ofdm_symbol_size>>1, shift); - int64_t re1,re2,im1,im2; - re1=((int*) &result1)[0]; - re2=((int*) &result2)[0]; - im1=((int*) &result1)[1]; - im2=((int*) &result2)[1]; + int64_t re1,re2,im1,im2; + re1=((int*) &result1)[0]; + re2=((int*) &result2)[0]; + im1=((int*) &result1)[1]; + im2=((int*) &result2)[1]; - // estimation of fractional frequency offset: angle[(result1)'*(result2)]/pi - ffo_est=atan2(re1*im2-re2*im1,re1*re2+im1*im2)/M_PI; + // estimation of fractional frequency offset: angle[(result1)'*(result2)]/pi + ffo_est=atan2(re1*im2-re2*im1,re1*re2+im1*im2)/M_PI; #ifdef DBG_PSS_NR - printf("ffo %lf\n",ffo_est); + printf("ffo %lf\n",ffo_est); #endif + } // computing absolute value of frequency offset *f_off = ffo_est*frame_parms->subcarrier_spacing; diff --git a/openair1/PHY/defs_nr_UE.h b/openair1/PHY/defs_nr_UE.h index c11ba8933f..54aed7adb1 100644 --- a/openair1/PHY/defs_nr_UE.h +++ b/openair1/PHY/defs_nr_UE.h @@ -983,6 +983,8 @@ typedef struct { int UE_scan; /// \brief Indicator that UE should perform coarse scanning around carrier int UE_scan_carrier; + /// \brief Indicator that UE should enable estimation and compensation of frequency offset + int UE_fo_compensation; /// \brief Indicator that UE is synchronized to an eNB int is_synchronized; /// Data structure for UE process scheduling diff --git a/openair1/SIMULATION/NR_PHY/pbchsim.c b/openair1/SIMULATION/NR_PHY/pbchsim.c index 386b0b3140..214a33fb73 100644 --- a/openair1/SIMULATION/NR_PHY/pbchsim.c +++ b/openair1/SIMULATION/NR_PHY/pbchsim.c @@ -462,6 +462,9 @@ int main(int argc, char **argv) UE->perfect_ce = 0; + if(eps!=0.0) + UE->UE_fo_compensation = 1; // if a frequency offset is set then perform fo estimation and compensation + if (init_nr_ue_signal(UE, 1, 0) != 0) { printf("Error at UE NR initialisation\n"); diff --git a/targets/RT/USER/nr-uesoftmodem.c b/targets/RT/USER/nr-uesoftmodem.c index 81f46d31b3..d3d660e7f5 100644 --- a/targets/RT/USER/nr-uesoftmodem.c +++ b/targets/RT/USER/nr-uesoftmodem.c @@ -130,6 +130,7 @@ static char *itti_dump_file = NULL; int UE_scan = 0; int UE_scan_carrier = 0; +int UE_fo_compensation = 0; runmode_t mode = normal_txrx; FILE *input_fd=NULL; @@ -978,6 +979,7 @@ int main( int argc, char **argv ) { UE[CC_id]->UE_scan = UE_scan; UE[CC_id]->UE_scan_carrier = UE_scan_carrier; + UE[CC_id]->UE_fo_compensation = UE_fo_compensation; UE[CC_id]->mode = mode; printf("UE[%d]->mode = %d\n",CC_id,mode); diff --git a/targets/RT/USER/nr-uesoftmodem.h b/targets/RT/USER/nr-uesoftmodem.h index 816e753086..7f96480b2b 100644 --- a/targets/RT/USER/nr-uesoftmodem.h +++ b/targets/RT/USER/nr-uesoftmodem.h @@ -55,6 +55,7 @@ #define CONFIG_HLP_UENANTR "set UE number of rx antennas\n" #define CONFIG_HLP_UENANTT "set UE number of tx antennas\n" #define CONFIG_HLP_UESCAN "set UE to scan around carrier\n" +#define CONFIG_HLP_UEFO "set UE to enable estimation and compensation of frequency offset\n" #define CONFIG_HLP_DUMPFRAME "dump UE received frame to rxsig_frame0.dat and exit\n" #define CONFIG_HLP_DLSHIFT "dynamic shift for LLR compuation for TM3/4 (default 0)\n" #define CONFIG_HLP_UELOOP "get softmodem (UE) to loop through memory instead of acquiring from HW\n" @@ -135,6 +136,7 @@ {"ue-nb-ant-rx", CONFIG_HLP_UENANTR, 0, u8ptr:&nb_antenna_rx, defuintval:1, TYPE_UINT8, 0}, \ {"ue-nb-ant-tx", CONFIG_HLP_UENANTT, 0, u8ptr:&nb_antenna_tx, defuintval:1, TYPE_UINT8, 0}, \ {"ue-scan-carrier", CONFIG_HLP_UESCAN, PARAMFLAG_BOOL, iptr:&UE_scan_carrier, defintval:0, TYPE_INT, 0}, \ +{"ue-fo-compensation", CONFIG_HLP_UEFO, PARAMFLAG_BOOL, iptr:&UE_fo_compensation, defintval:0, TYPE_INT, 0}, \ {"ue-max-power", NULL, 0, iptr:&(tx_max_power[0]), defintval:90, TYPE_INT, 0}, \ {"r" , CONFIG_HLP_PRB, 0, iptr:&(frame_parms[0]->N_RB_DL), defintval:25, TYPE_UINT, 0}, \ {"dlsch-demod-shift", CONFIG_HLP_DLSHIFT, 0, iptr:(int32_t *)&dlsch_demod_shift, defintval:0, TYPE_INT, 0}, \