Sidelink config MAC->PHY, PSBCH scheduler and supporting functions

	- Phy config update and Sidelink frame parameters initialisation
	- PSBCH scheduler to trigger TX PSBCH/RX PSBCH actions
	- Sidelink indication with rx ind to trigger send SL-MIB to MAC

executables/nr-uesoftmodem.c

@@ -312,13 +312,15 @@ void set_options(int CC_id, PHY_VARS_NR_UE *UE){
 
 }
 
-void init_openair0(void) {
+void init_openair0(uint8_t is_sidelink) {
   int card;
   int freq_off = 0;
   NR_DL_FRAME_PARMS *frame_parms = &PHY_vars_UE_g[0][0]->frame_parms;
+  if (is_sidelink)
+    frame_parms = &PHY_vars_UE_g[0][0]->SL_UE_PHY_PARAMS.sl_frame_params;
 
   for (card=0; card<MAX_CARDS; card++) {
-    uint64_t dl_carrier, ul_carrier, sl_carrier;
+    uint64_t dl_carrier, ul_carrier;
     openair0_cfg[card].configFilename    = NULL;
     openair0_cfg[card].threequarter_fs   = frame_parms->threequarter_fs;
     openair0_cfg[card].sample_rate       = frame_parms->samples_per_subframe * 1e3;
@@ -344,15 +346,14 @@ void init_openair0(void) {
       openair0_cfg[card].rx_num_channels,
       duplex_mode[openair0_cfg[card].duplex_mode]);
 
+    if (is_sidelink) {
+      dl_carrier = frame_parms->dl_CarrierFreq;
+      ul_carrier = frame_parms->ul_CarrierFreq;
+    } else
       nr_get_carrier_frequencies(PHY_vars_UE_g[0][0], &dl_carrier, &ul_carrier);
 
     nr_rf_card_config_freq(&openair0_cfg[card], ul_carrier, dl_carrier, freq_off);
 
-    if (get_softmodem_params()->sl_mode == 2) {
-      nr_get_carrier_frequencies_sl(PHY_vars_UE_g[0][0], &sl_carrier);
-      nr_rf_card_config_freq(&openair0_cfg[card], sl_carrier, sl_carrier, freq_off);
-    }
-
     nr_rf_card_config_gain(&openair0_cfg[card], rx_gain_off);
 
     openair0_cfg[card].configFilename = get_softmodem_params()->rf_config_file;
@@ -503,10 +504,6 @@ int main( int argc, char **argv ) {
   if (!get_softmodem_params()->nsa && get_softmodem_params()->emulate_l1)
     start_oai_nrue_threads();
 
-  if (get_softmodem_params()->sl_mode) {
-    nr_UE_configure_Sidelink(0, get_softmodem_params()->sync_ref);
-  }
-
   if (!get_softmodem_params()->emulate_l1) {
     for (int CC_id=0; CC_id<MAX_NUM_CCs; CC_id++) {
       PHY_vars_UE_g[0][CC_id] = (PHY_VARS_NR_UE *)malloc(sizeof(PHY_VARS_NR_UE));
@@ -536,10 +533,26 @@ int main( int argc, char **argv ) {
         *mac->scc->downlinkConfigCommon->frequencyInfoDL->frequencyBandList.list.array[0]);
       }
 
+      UE[CC_id]->sl_mode = get_softmodem_params()->sl_mode;
       init_nr_ue_vars(UE[CC_id], 0, abstraction_flag);
+
+      if (UE[CC_id]->sl_mode) {
+        AssertFatal(UE[CC_id]->sl_mode == 2, "Only Sidelink mode 2 supported. Mode 1 not yet supported\n");
+        nr_UE_configure_Sidelink(0, get_softmodem_params()->sync_ref);
+        DevAssert(mac->if_module != NULL && mac->if_module->sl_phy_config_request != NULL);
+        sl_nr_ue_phy_params_t *sl_phy = &UE[CC_id]->SL_UE_PHY_PARAMS;
+        mac->if_module->sl_phy_config_request(&mac->SL_MAC_PARAMS->sl_phy_config);
+        nr_init_frame_parms_ue_sl(&sl_phy->sl_frame_params,&sl_phy->sl_config,
+                                  get_nrUE_params()->threequarter_fs,
+                                  get_nrUE_params()->ofdm_offset_divisor);
+        sl_ue_phy_init(UE[CC_id]);
       }
 
-    init_openair0();
+    }
+
+    uint8_t is_sl = (get_softmodem_params()->sl_mode) ? 1 : 0;
+
+    init_openair0(is_sl);
     // init UE_PF_PO and mutex lock
     pthread_mutex_init(&ue_pf_po_mutex, NULL);
     memset (&UE_PF_PO[0][0], 0, sizeof(UE_PF_PO_t)*NUMBER_OF_UE_MAX*MAX_NUM_CCs);

openair1/PHY/INIT/nr_init_ue.c

@@ -297,8 +297,12 @@ int init_nr_ue_signal(PHY_VARS_NR_UE *ue, int nb_connected_gNB)
   // init RX buffers
   common_vars->rxdata = malloc16(fp->nb_antennas_rx * sizeof(c16_t *));
 
+  int num_samples = 2 * fp->samples_per_frame + fp->ofdm_symbol_size;
+  if (ue->sl_mode == 2)
+    num_samples = (SL_NR_PSBCH_REPETITION_IN_FRAMES * fp->samples_per_frame) + fp->ofdm_symbol_size;
+
   for (i=0; i<fp->nb_antennas_rx; i++) {
-    common_vars->rxdata[i] = malloc16_clear((2 * (fp->samples_per_frame) + fp->ofdm_symbol_size) * sizeof(c16_t));
+    common_vars->rxdata[i] = malloc16_clear(num_samples * sizeof(c16_t));
   }
 
   // ceil(((NB_RB<<1)*3)/32) // 3 RE *2(QPSK)
@@ -646,7 +650,8 @@ void init_N_TA_offset(PHY_VARS_NR_UE *ue){
 
   NR_DL_FRAME_PARMS *fp = &ue->frame_parms;
 
-  if (fp->frame_type == FDD) {
+  // No timing offset for Sidelink, refer to 3GPP 38.211 Section 8.5
+  if (fp->frame_type == FDD || ue->sl_mode == 2) {
     ue->N_TA_offset = 0;
   } else {
     int N_TA_offset = fp->ul_CarrierFreq < 6e9 ? 400 : 431; // reference samples  for 25600Tc @ 30.72 Ms/s for FR1, same @ 61.44 Ms/s for FR2
@@ -940,6 +945,4 @@ void sl_ue_phy_init(PHY_VARS_NR_UE *UE) {
   // Generate PSS time domain samples used for correlation during SLSS reception.
   sl_generate_pss_ifft_samples(&UE->SL_UE_PHY_PARAMS, &UE->SL_UE_PHY_PARAMS.init_params);
 
-  init_symbol_rotation(sl_fp);
-  init_timeshift_rotation(sl_fp);
 }
\ No newline at end of file

openair1/PHY/INIT/nr_phy_init.h

@@ -29,7 +29,10 @@ int nr_get_ssb_start_symbol(NR_DL_FRAME_PARMS *fp,uint8_t i_ssb);
 int nr_init_frame_parms(nfapi_nr_config_request_scf_t *config, NR_DL_FRAME_PARMS *frame_parms);
 int nr_init_frame_parms_ue(NR_DL_FRAME_PARMS *frame_parms, fapi_nr_config_request_t *config, uint16_t nr_band);
 void nr_init_frame_parms_ue_sa(NR_DL_FRAME_PARMS *frame_parms, uint64_t downlink_frequency, int32_t uplink_frequency_offset, uint8_t mu, uint16_t nr_band);
-void nr_init_frame_parms_ue_sl(NR_DL_FRAME_PARMS *frame_parms, uint64_t sidelink_frequency, uint16_t nr_band);
+int nr_init_frame_parms_ue_sl(NR_DL_FRAME_PARMS *fp,
+                              sl_nr_phy_config_request_t* config,
+                              int threequarter_fs,
+                              uint32_t ofdm_offset_divisor);
 int init_nr_ue_signal(PHY_VARS_NR_UE *ue,int nb_connected_eNB);
 void term_nr_ue_signal(PHY_VARS_NR_UE *ue, int nb_connected_gNB);
 void init_nr_ue_transport(PHY_VARS_NR_UE *ue);
@@ -58,5 +61,4 @@ void phy_init_nr_top(PHY_VARS_NR_UE *ue);
 void phy_term_nr_top(void);
 void sl_ue_phy_init(PHY_VARS_NR_UE *UE);
 
-void sl_ue_phy_init(PHY_VARS_NR_UE *UE);
 #endif

openair1/PHY/MODULATION/nr_modulation.c

@@ -601,7 +601,7 @@ void init_symbol_rotation(NR_DL_FRAME_PARMS *fp) {
   uint64_t dl_CarrierFreq = fp->dl_CarrierFreq;
   uint64_t ul_CarrierFreq = fp->ul_CarrierFreq;
   uint64_t sl_CarrierFreq = fp->sl_CarrierFreq;
-  double f[2] = {(double)dl_CarrierFreq, (double)ul_CarrierFreq};
+  double f[3] = {(double)dl_CarrierFreq, (double)ul_CarrierFreq, (double)sl_CarrierFreq};
 
   const int nsymb = fp->symbols_per_slot * fp->slots_per_frame/10;
   const double Tc=(1/480e3/4096);
@@ -609,15 +609,12 @@ void init_symbol_rotation(NR_DL_FRAME_PARMS *fp) {
   const double Ncp0=16*64 + (144*64*(1/(float)(1<<fp->numerology_index)));
   const double Ncp1=(144*64*(1/(float)(1<<fp->numerology_index)));
 
-  for (uint8_t ll = 0; ll < 2; ll++){
+  for (uint8_t ll = 0; ll < 3; ll++){
 
     double f0 = f[ll];
+    if (f0 == 0) continue;
     LOG_D(PHY, "Doing symbol rotation calculation for gNB TX/RX, f0 %f Hz, Nsymb %d\n", f0, nsymb);
     c16_t *symbol_rotation = fp->symbol_rotation[ll];
-    if (get_softmodem_params()->sl_mode == 2) {
-      f0 = (double)sl_CarrierFreq;
-      symbol_rotation = fp->symbol_rotation[link_type_sl];
-    }
 
     double tl = 0.0;
     double poff = 0.0;

openair1/PHY/NR_UE_ESTIMATION/nr_ue_measurements.c

@@ -362,7 +362,7 @@ void nr_sl_psbch_rsrp_measurements(sl_nr_ue_phy_params_t *sl_phy_params,
                               dB_fixed(fp->ofdm_symbol_size);
 
 
-  LOG_I(PHY, "PSBCH RSRP (DMRS REs): numREs:%d RSRP :%d dB/RE ,RSRP:%d dBm/RE\n",
+  LOG_D(PHY, "PSBCH RSRP (DMRS REs): numREs:%d RSRP :%d dB/RE ,RSRP:%d dBm/RE\n",
                               num_re, psbch_rx->rsrp_dB_per_RE, psbch_rx->rsrp_dBm_per_RE);
 
 }
\ No newline at end of file

openair1/PHY/NR_UE_TRANSPORT/nr_ue_rf_helpers.c

@@ -47,15 +47,7 @@ void nr_get_carrier_frequencies(PHY_VARS_NR_UE *ue, uint64_t *dl_carrier, uint64
 }
 
 
-void nr_get_carrier_frequencies_sl(PHY_VARS_NR_UE *ue, uint64_t *sl_carrier) {
 
-  NR_DL_FRAME_PARMS *fp = &ue->frame_parms;
-  if (ue->if_freq!=0) {
-    *sl_carrier = ue->if_freq;
-  } else {
-    *sl_carrier = fp->sl_CarrierFreq;
-  }
-}
 
 void nr_rf_card_config_gain(openair0_config_t *openair0_cfg,
                             double rx_gain_off){

openair1/PHY/defs_nr_sl_UE.h

@@ -75,6 +75,7 @@
 #define SL_NR_NUM_IDs_IN_PSS 2
 #define SL_NR_NUM_IDs_IN_SSS 336
 #define SL_NR_NUM_SLSS_IDs 672
+#define SL_NR_PSBCH_REPETITION_IN_FRAMES 16
 
 typedef enum sl_nr_sidelink_mode {
   SL_NOT_SUPPORTED = 0,

openair1/PHY/impl_defs_nr.h

@@ -98,6 +98,7 @@ SystemInformationBlockType1_nr_t;
 #define NR_DOWNLINK_SLOT                   (0x01)
 #define NR_UPLINK_SLOT                     (0x02)
 #define NR_MIXED_SLOT                      (0x03)
+#define NR_SIDELINK_SLOT                    NR_UPLINK_SLOT
 
 #define FRAME_DURATION_MICRO_SEC           (10000)  /* frame duration in microsecond */
 

openair1/SCHED_NR_UE/defs.h

@@ -198,5 +198,14 @@ void psbch_pscch_processing(PHY_VARS_NR_UE *ue,
 int phy_procedures_nrUE_SL_TX(PHY_VARS_NR_UE *ue,
                             UE_nr_rxtx_proc_t *proc,
                             nr_phy_data_tx_t *phy_data);
+/*! \brief This function prepares the sl indication to pass to the MAC
+ */
+void nr_fill_sl_indication(nr_sidelink_indication_t *sl_ind,
+                           sl_nr_rx_indication_t *rx_ind,
+                           sl_nr_sci_indication_t *sci_ind,
+                           UE_nr_rxtx_proc_t *proc,
+                           PHY_VARS_NR_UE *ue,
+                           void *phy_data);
+
 #endif
 

openair1/SCHED_NR_UE/fapi_nr_ue_l1.c

@@ -391,6 +391,11 @@ int8_t nr_ue_scheduled_response(nr_scheduled_response_t *scheduled_response){
   bool found = false;
   if(scheduled_response != NULL){
 
+    if (scheduled_response->sl_rx_config || scheduled_response->sl_tx_config) {
+      sl_handle_scheduled_response(scheduled_response);
+      return 0;
+    }
+
     module_id_t module_id = scheduled_response->module_id;
     uint8_t cc_id = scheduled_response->CC_id;
     int slot = scheduled_response->slot;
@@ -661,3 +666,84 @@ void nr_ue_synch_request(nr_synch_request_t *synch_request)
   PHY_vars_UE_g[synch_request->Mod_id][synch_request->CC_id]->synch_request.received_synch_request = 1;
 }
 
+int8_t nr_ue_sl_phy_config_request(nr_sl_phy_config_t *phy_config)
+{
+  sl_nr_phy_config_request_t *sl_config = &PHY_vars_UE_g[phy_config->Mod_id][phy_config->CC_id]->SL_UE_PHY_PARAMS.sl_config;
+  if(phy_config != NULL) {
+    memcpy(sl_config,&phy_config->sl_config_req,sizeof(sl_nr_phy_config_request_t));
+  }
+  return 0;
+}
+/*
+* MAC sends the scheduled response with either TX configrequest for Sidelink Transmission requests
+* or RX config request for Sidelink Reception requests.
+* This procedure handles these TX/RX config requests received in this slot and configures PHY
+* with a TTI action to be performed in this slot(TTI)
+*/
+int8_t sl_handle_scheduled_response(nr_scheduled_response_t *scheduled_response) {
+
+  module_id_t module_id = scheduled_response->module_id;
+  uint32_t slot = scheduled_response->slot;
+  uint32_t frame = scheduled_response->frame;
+  const char *sl_rx_action[]={"NONE", "RX_PSBCH", "RX_PSCCH", "RX_SCI2_ON_PSSCH", "RX_SLSCH_ON_PSSCH"};
+  const char *sl_tx_action[]={"TX_PSBCH", "TX_PSCCH_PSSCH", "TX_PSFCH"};
+
+  if(scheduled_response->sl_rx_config != NULL) {
+
+    sl_nr_rx_config_request_t *sl_rx_config = scheduled_response->sl_rx_config;
+    nr_phy_data_t *phy_data = (nr_phy_data_t *)scheduled_response->phy_data;
+
+    AssertFatal(sl_rx_config->number_pdus == SL_NR_RX_CONFIG_LIST_NUM,
+                                      "sl_rx_config->number_pdus incorrect\n");
+
+    switch(sl_rx_config->sl_rx_config_list[0].pdu_type) {
+
+      case SL_NR_CONFIG_TYPE_RX_PSBCH:
+        phy_data->sl_rx_action = SL_NR_CONFIG_TYPE_RX_PSBCH;
+        LOG_D(PHY, "Recvd CONFIG_TYPE_RX_PSBCH\n");
+        break;
+      default:
+        AssertFatal(0,"Incorrect sl_rx config req pdutype \n");
+        break;
+    }
+
+    LOG_D(PHY, "[UE%d] TTI %d:%d, SL-RX action:%s\n",
+                                        module_id,frame,slot,
+                                        sl_rx_action[phy_data->sl_rx_action]);
+
+  } else if(scheduled_response->sl_tx_config != NULL) {
+
+    sl_nr_tx_config_request_t *sl_tx_config = scheduled_response->sl_tx_config;
+    nr_phy_data_tx_t *phy_data_tx = (nr_phy_data_tx_t *)scheduled_response->phy_data;
+
+    AssertFatal(sl_tx_config->number_pdus == SL_NR_TX_CONFIG_LIST_NUM,
+                                      "sl_tx_config->number_pdus incorrect \n");
+
+    switch(sl_tx_config->tx_config_list[0].pdu_type) {
+
+      case SL_NR_CONFIG_TYPE_TX_PSBCH:
+        phy_data_tx->sl_tx_action = SL_NR_CONFIG_TYPE_TX_PSBCH;
+        LOG_D(PHY, "Recvd CONFIG_TYPE_TX_PSBCH\n");
+        *((uint32_t *)phy_data_tx->psbch_vars.psbch_payload) =
+                        *((uint32_t *) sl_tx_config->tx_config_list[0].tx_psbch_config_pdu.psbch_payload);
+        phy_data_tx->psbch_vars.psbch_tx_power =
+                        sl_tx_config->tx_config_list[0].tx_psbch_config_pdu.psbch_tx_power;
+        phy_data_tx->psbch_vars.tx_slss_id =
+                        sl_tx_config->tx_config_list[0].tx_psbch_config_pdu.tx_slss_id;
+        break;
+      default:
+        AssertFatal(0,"Incorrect sl_tx config req pdutype \n");
+        break;
+    }
+
+    LOG_D(PHY, "[UE%d] TTI %d:%d, SL-TX action:%s slss_id:%d, sl-mib:%x, psbch pwr:%d\n",
+                                                       module_id,frame,slot,
+                                                       sl_tx_action[phy_data_tx->sl_tx_action - 6],
+                                                       phy_data_tx->psbch_vars.tx_slss_id,
+                                                       *((uint32_t *)phy_data_tx->psbch_vars.psbch_payload),
+                                                       phy_data_tx->psbch_vars.psbch_tx_power);
+
+  }
+
+  return 0;
+}
\ No newline at end of file

openair1/SCHED_NR_UE/fapi_nr_ue_l1.h

@@ -40,12 +40,14 @@
 /**\brief NR UE FAPI-like P7 messages, scheduled response from L2 indicating L1
    \param scheduled_response including transmission config(dl_config, ul_config) and data transmission (tx_req)*/
 int8_t nr_ue_scheduled_response(nr_scheduled_response_t *scheduled_response);
+int8_t sl_handle_scheduled_response(nr_scheduled_response_t *scheduled_response);
 
 int8_t nr_ue_scheduled_response_stub(nr_scheduled_response_t *scheduled_response);
 
 /**\brief NR UE FAPI-like P5 message, physical configuration from L2 to configure L1
    \param scheduled_response including transmission config(dl_config, ul_config) and data transmission (tx_req)*/
 int8_t nr_ue_phy_config_request(nr_phy_config_t *phy_config);
+int8_t nr_ue_sl_phy_config_request(nr_sl_phy_config_t *phy_config);
 
 /**\brief NR UE FAPI message to schedule a synchronization with target gNB
    \param synch_request including target_Nid_cell*/

openair1/SCHED_NR_UE/phy_frame_config_nr_ue.c

@@ -99,3 +99,66 @@ int nr_ue_slot_select(fapi_nr_config_request_t *cfg, int nr_frame, int nr_slot)
     }
   }
 }
+
+
+/*
+* This function determines if the mixed slot is a Sidelink slot
+*/
+uint8_t sl_determine_if_sidelink_slot(uint8_t sl_startsym, uint8_t sl_lensym, uint8_t num_ulsym) {
+
+  uint8_t ul_startsym = NR_NUMBER_OF_SYMBOLS_PER_SLOT - num_ulsym;
+
+  if ((sl_startsym >= ul_startsym) && (sl_lensym <= NR_NUMBER_OF_SYMBOLS_PER_SLOT)) {
+    LOG_D(MAC,"MIXED SLOT is a SIDELINK SLOT. Sidelink Symbols: %d-%d, Uplink Symbols: %d-%d\n",
+                                                                          sl_startsym,sl_lensym-1,
+                                                                          ul_startsym, ul_startsym+num_ulsym-1);
+    return NR_SIDELINK_SLOT;
+  }
+  else {
+    LOG_D(MAC,"MIXED SLOT is NOT SIDELINK SLOT. Sidelink Symbols: %d-%d, Uplink Symbols: %d-%d\n",
+                                                                              sl_startsym,sl_lensym-1,
+                                                                  ul_startsym, ul_startsym+num_ulsym-1);
+    return 0;
+  }
+}
+
+
+/*
+* This function determines if the Slot is a SIDELINK SLOT
+* Every Uplink Slot is a Sidelink slot
+* Mixed Slot is a sidelink slot if the uplink symbols in Mixed slot
+* overlaps with Sidelink start symbol and number of symbols.
+*/
+int sl_nr_ue_slot_select(sl_nr_phy_config_request_t *cfg,
+                         int nr_frame, int nr_slot,
+                         uint8_t frame_duplex_type)
+{
+
+  int mu = cfg->sl_bwp_config.sl_scs, ul_sym = 0, slot_type = 0;
+
+  //All PC5 bands are TDD bands , hence handling only TDD in this function.
+  AssertFatal(frame_duplex_type == TDD, "No Sidelink operation defined for FDD in 3GPP rel16\n");
+
+  if (cfg->tdd_table.max_tdd_periodicity_list == NULL) { // this happens before receiving TDD configuration 
+    return 0;
+  }
+
+  int slot = (nr_frame%2 == 0) ? nr_slot : ((1<<mu) * NR_NUMBER_OF_SUBFRAMES_PER_FRAME) + nr_slot;
+
+  for(int symbol_count=0; symbol_count<NR_NUMBER_OF_SYMBOLS_PER_SLOT; symbol_count++) {
+    if (cfg->tdd_table.max_tdd_periodicity_list[slot].max_num_of_symbol_per_slot_list[symbol_count].slot_config == 1) {
+      ul_sym++;
+    }
+  }
+
+  if(ul_sym == NR_NUMBER_OF_SYMBOLS_PER_SLOT) {
+    slot_type = NR_SIDELINK_SLOT;
+  } else if (ul_sym){
+    slot_type = sl_determine_if_sidelink_slot(cfg->sl_bwp_config.sl_start_symbol,
+                                              cfg->sl_bwp_config.sl_num_symbols,
+                                              ul_sym);
+  }
+
+  return slot_type;
+
+}
\ No newline at end of file

openair1/SCHED_NR_UE/phy_procedures_nr_ue_sl.c

@@ -49,6 +49,7 @@ void nr_fill_sl_indication(nr_sidelink_indication_t *sl_ind,
   sl_ind->frame_tx  = proc->frame_tx;
   sl_ind->slot_tx   = proc->nr_slot_tx;
   sl_ind->phy_data  = phy_data;
+  sl_ind->slot_type = SIDELINK_SLOT_TYPE_RX;
 
   if (rx_ind) {
     sl_ind->rx_ind = rx_ind; //  hang on rx_ind instance

openair1/SIMULATION/NR_PHY/nr_dummy_functions.c

@@ -49,3 +49,12 @@ int8_t nr_mac_rrc_data_ind_ue(const module_id_t module_id,
                               const channel_t channel,
                               const uint8_t* pduP,
                               const sdu_size_t pdu_len) { return 0; }
+int8_t nr_mac_rrc_sl_mib_ind(const module_id_t module_id,
+                              const int CC_id,
+                              const uint8_t gNB_index,
+                              const frame_t frame,
+                              const int slot,
+                              const int channel,
+                              const uint8_t* pduP,
+                              const sdu_size_t pdu_len,
+                              const uint16_t rx_slss_id) {return 1;}

openair1/SIMULATION/NR_PHY/psbchsim.c

@@ -65,6 +65,10 @@ int8_t nr_mac_rrc_data_req_ue(const module_id_t Mod_idP,
 nr_bler_struct nr_bler_data[NR_NUM_MCS];
 void get_nrUE_params(void) { return;}
 uint8_t check_if_ue_is_sl_syncsource() {return 0;}
+void nr_rrc_mac_config_req_sl_mib(module_id_t module_id,
+                                  NR_SL_SSB_TimeAllocation_r16_t *ssb_ta,
+                                  uint16_t rx_slss_id,
+                                  uint8_t *sl_mib) {}
 //////////////////////////////////////////////////////////////////////////
 static void prepare_mib_bits(uint8_t *buf, uint32_t frame_tx, uint32_t slot_tx) {
 

openair2/LAYER2/NR_MAC_UE/config_ue_sl.c

@@ -86,7 +86,7 @@ static int sl_set_tdd_config_nr_ue(sl_nr_phy_config_request_t *cfg,
     if (nrofDownlinkSymbols) nrofDownlinkSlots -= 1;
   }
 
-  LOG_I(NR_MAC,"Set Phy Sidelink TDD Config: scs:%d,dl:%d-%d, ul:%d-%d, nb_periods_per_frame:%d, nb_slots_to_set:%d\n",
+  LOG_I(NR_MAC,"Set Phy Sidelink TDD Config: scs:%d,dl:%d-%d, ul:%d-%d, nb_periods_per_frame:%d, nb_slots_per_period:%d\n",
                               mu, nrofDownlinkSlots, nrofDownlinkSymbols, nrofUplinkSlots, nrofUplinkSymbols, nb_periods_per_frame, nb_slots_per_period);
 
   if ( (nrofDownlinkSymbols + nrofUplinkSymbols) == 0 )
@@ -436,6 +436,9 @@ int nr_rrc_mac_config_req_sl_preconfig(module_id_t module_id,
     AssertFatal((tdd_uldl_config->pattern2 == NULL), "Sidelink MAC CFG: pattern2 not yet supported");
 
     sl_mac->sl_TDD_config = sl_preconfig->sl_PreconfigGeneral_r16->sl_TDD_Configuration_r16;
+
+    //Sync source is identified, timing needs to be adjusted.
+    sl_mac->adjust_timing = 1;
   }
 
   //Do not copy TDD config yet as SYNC source is not yet found
@@ -538,12 +541,13 @@ void nr_rrc_mac_config_req_sl_mib(module_id_t module_id,
   sl_nr_phy_config_request_t *sl_config = &sl_mac->sl_phy_config.sl_config_req;
 
   //Update configs if Sync source is not set else nothing to be done
-  if (  sl_config->sl_sync_source.sync_source == SL_SYNC_SOURCE_NONE) {
+  if (sl_config->sl_sync_source.sync_source == SL_SYNC_SOURCE_NONE) {
     //Set SYNC source as SYNC REF UE and send the remaining config to PHY
     sl_config->config_mask = 0xF;//all configs done.
     sl_config->sl_sync_source.sync_source = SL_SYNC_SOURCE_SYNC_REF_UE;
     sl_config->sl_sync_source.rx_slss_id = rx_slss_id;
 
+    sl_mac->adjust_timing = 1;
 
     sl_mac->rx_sl_bch.status = 1;
     sl_mac->rx_sl_bch.slss_id = rx_slss_id;
@@ -603,6 +607,8 @@ void nr_rrc_mac_config_req_sl_mib(module_id_t module_id,
                             sl_mac->sl_TDD_config->pattern1.nrofDownlinkSlots, sl_mac->sl_TDD_config->pattern1.nrofUplinkSlots,
                             sl_mac->sl_TDD_config->pattern1.nrofDownlinkSymbols,sl_mac->sl_TDD_config->pattern1.nrofUplinkSymbols);
 
+    DevAssert(mac->if_module != NULL && mac->if_module->sl_phy_config_request != NULL);
+    mac->if_module->sl_phy_config_request(&sl_mac->sl_phy_config);
   }
 
 }
\ No newline at end of file

openair2/LAYER2/NR_MAC_UE/mac_defs_sl.h

@@ -33,10 +33,15 @@
 #define SL_NR_MAC_NUM_TX_RESOURCE_POOLS 1
 #define SL_NUM_BYTES_TIMERESOURCEBITMAP 20
 
+//every 16 frames, SSB is repeated.
+#define SL_NR_SSB_REPETITION_IN_FRAMES 16
+#define SL_FRAME_NUMBER_CYCLE 1024
+
 // Size of Fixed fields prio (3), sci_2ndstage(2),
 // betaoffsetindicator(2), num dmrs ports (1), mcs (5bits)
 #define SL_SCI_FORMAT_1A_LEN_IN_BITS_FIXED_FIELDS 13
 
+
 #define sci_field_t dci_field_t
 
 typedef struct sidelink_sci_format_1a_fields {
@@ -150,6 +155,22 @@ typedef struct sl_nr_ue_mac_params {
   //Holds Broadcast params incase UE receives SL-SSB
   sl_bch_params_t rx_sl_bch;
 
+  //SSB RSRP in dBm
+  int16_t ssb_rsrp_dBm;
+
+  //Bitmap indicating which slots belong to sidelink
+  //Right now supports 30Khz and 15Khz
+  uint32_t sl_slot_bitmap;
+
+  //adjust timing after new timing from sync is acquired.
+  uint8_t adjust_timing;
+
+  //Sidelink slots per frame
+  uint16_t N_SL_SLOTS_perframe;
+
+  uint16_t decoded_DFN;
+  uint16_t decoded_slot;
+
 } sl_nr_ue_mac_params_t;
 
 

openair2/LAYER2/NR_MAC_UE/mac_proto.h

@@ -113,6 +113,8 @@ void nr_ue_dl_scheduler(nr_downlink_indication_t *dl_info);
    @param fapi_nr_dl_config_request_t* pointer to dl_config,
    @param fapi_nr_ul_config_request_t* pointer to ul_config,
    @param fapi_nr_tx_request_t*        pointer to tx_request;
+   @param sl_nr_rx_config_request_t*   pointer to sl_rx_config,
+   @param sl_nr_tx_config_request_t*   pointer to sl_tx_config,
    @param module_id_t mod_id           module ID
    @param int cc_id                    CC ID
    @param frame_t frame                frame number
@@ -122,6 +124,8 @@ void fill_scheduled_response(nr_scheduled_response_t *scheduled_response,
                              fapi_nr_dl_config_request_t *dl_config,
                              fapi_nr_ul_config_request_t *ul_config,
                              fapi_nr_tx_request_t *tx_request,
+                             sl_nr_rx_config_request_t *sl_rx_config,
+                             sl_nr_tx_config_request_t *sl_tx_config,
                              module_id_t mod_id,
                              int cc_id,
                              frame_t frame,
@@ -443,6 +447,7 @@ void nr_rrc_mac_config_req_sl_mib(module_id_t module_id,
                                   NR_SL_SSB_TimeAllocation_r16_t *ssb_ta,
                                   uint16_t rx_slss_id,
                                   uint8_t *sl_mib);
+
 void sl_prepare_psbch_payload(NR_TDD_UL_DL_ConfigCommon_t *TDD_UL_DL_Config,
                               uint8_t *bits_0_to_7, uint8_t *bits_8_to_11,
                               uint8_t mu, uint8_t L, uint8_t Y);
@@ -454,5 +459,26 @@ uint8_t sl_decode_sl_TDD_Config(NR_TDD_UL_DL_ConfigCommon_t *TDD_UL_DL_Config,
 uint8_t sl_determine_sci_1a_len(uint16_t *num_subchannels,
                                 NR_SL_ResourcePool_r16_t *rpool,
                                 sidelink_sci_format_1a_fields_t *sci_1a);
+/** \brief This function checks nr UE slot for Sidelink direction : Sidelink
+ *  @param cfg      : Sidelink config request
+ *  @param nr_frame : frame number
+ *  @param nr_slot  : slot number
+ *  @param frame duplex type  : Frame type
+    @returns int : 0 or Sidelink slot type */
+int sl_nr_ue_slot_select(sl_nr_phy_config_request_t *cfg,
+                         int nr_frame, int nr_slot,
+                         uint8_t frame_duplex_type);
+
+void nr_ue_sidelink_scheduler(nr_sidelink_indication_t *sl_ind);
+
+void nr_mac_rrc_sl_mib_ind(const module_id_t module_id,
+                              const int CC_id,
+                              const uint8_t gNB_index,
+                              const frame_t frame,
+                              const int slot,
+                              const channel_t channel,
+                              uint8_t* pduP,
+                              const sdu_size_t pdu_len,
+                              const uint16_t rx_slss_id);
 #endif
 /** @}*/

openair2/LAYER2/NR_MAC_UE/nr_ue_procedures_sl.c

@@ -19,7 +19,8 @@
  *      contact@openairinterface.org
  */
 
-#include "mac_defs_sl.h"
+#include "mac_defs.h"
+#include "mac_proto.h"
 
 #define SL_DEBUG
 
@@ -474,7 +475,7 @@ uint8_t sl_determine_sci_1a_len(uint16_t *num_subchannels,
   }
 
   LOG_D(NR_MAC,"sci 1A - additional_table:%ld, sci 1a len:%d, additional table nbits:%d\n",
-                                                                *rpool->sl_Additional_MCS_Table_r16,
+                                                                rpool->sl_Additional_MCS_Table_r16 ? *rpool->sl_Additional_MCS_Table_r16 : 0,
                                                                 sci_1a_len,
                                                                 sci_1a->additional_mcs_table_indicator.nbits);
 
@@ -521,3 +522,56 @@ uint8_t sl_determine_sci_1a_len(uint16_t *num_subchannels,
 
   return sci_1a_len;
 }
+
+/* This function determines the number of sidelink slots in 1024 frames - DFN cycle
+* which can be used for determining reserved slots and REsource pool slots according to bitmap.
+* Sidelink slots are the uplink and mixed slots with sidelink support except the SSB slots.
+*/
+uint32_t sl_determine_num_sidelink_slots(uint8_t mod_id, uint16_t *N_SSB_16frames, uint16_t *N_SL_SLOTS_perframe)
+{
+
+  NR_UE_MAC_INST_t *mac = get_mac_inst(mod_id);
+  sl_nr_ue_mac_params_t *sl_mac = mac->SL_MAC_PARAMS;
+  uint32_t N_SSB_1024frames = 0;
+  uint32_t N_SL_SLOTS = 0;
+  *N_SL_SLOTS_perframe = 0;
+  *N_SSB_16frames = 0;
+
+  if (sl_mac->rx_sl_bch.status) {
+    sl_ssb_timealloc_t *ssb_timealloc = &sl_mac->rx_sl_bch.ssb_time_alloc;
+    *N_SSB_16frames += ssb_timealloc->sl_NumSSB_WithinPeriod;
+    LOG_D(MAC, "RX SSB Slots:%d\n", *N_SSB_16frames);
+  }
+
+  if (sl_mac->tx_sl_bch.status) {
+    sl_ssb_timealloc_t *ssb_timealloc = &sl_mac->tx_sl_bch.ssb_time_alloc;
+    *N_SSB_16frames += ssb_timealloc->sl_NumSSB_WithinPeriod;
+    LOG_D(MAC, "TX SSB Slots:%d\n", *N_SSB_16frames);
+  }
+
+  //Total SSB slots in SFN cycle (1024 frames)
+  N_SSB_1024frames = SL_FRAME_NUMBER_CYCLE/SL_NR_SSB_REPETITION_IN_FRAMES * (*N_SSB_16frames);
+
+  sl_nr_phy_config_request_t *sl_cfg = &sl_mac->sl_phy_config.sl_config_req;
+  uint8_t sl_scs = sl_cfg->sl_bwp_config.sl_scs;
+  uint8_t num_slots_per_frame = 10*(1<<sl_scs);
+  uint8_t slot_type = 0;
+  for (int i=0; i<num_slots_per_frame;i++) {
+    slot_type = sl_nr_ue_slot_select(sl_cfg, 0, i, TDD);
+    if (slot_type == NR_SIDELINK_SLOT) {
+      *N_SL_SLOTS_perframe = *N_SL_SLOTS_perframe + 1;
+      sl_mac->sl_slot_bitmap |= (1<<i);
+    }
+  }
+
+  //Determine total number of Valid Sidelink slots which can be used for Respool in a SFN cycle (1024 frames)
+  N_SL_SLOTS = (*N_SL_SLOTS_perframe * SL_FRAME_NUMBER_CYCLE) - N_SSB_1024frames;
+
+  LOG_I(MAC, "[UE%d]SL-MAC:SSB slots in 1024 frames:%d, N_SL_SLOTS_perframe:%d, N_SL_SLOTs in 1024 frames:%d, SL SLOT bitmap:%x\n",
+                                                                  mod_id,N_SSB_1024frames, *N_SL_SLOTS_perframe,
+                                                                  N_SL_SLOTS, sl_mac->sl_slot_bitmap);
+
+
+  return N_SL_SLOTS;
+}
+

openair2/NR_UE_PHY_INTERFACE/NR_IF_Module.c

@@ -1183,7 +1183,7 @@ int nr_ue_dl_indication(nr_downlink_indication_t *dl_info)
         AssertFatal( nr_ue_if_module_inst[module_id] != NULL, "IF module is NULL!\n" );
         AssertFatal( nr_ue_if_module_inst[module_id]->scheduled_response != NULL, "scheduled_response is NULL!\n" );
         fapi_nr_dl_config_request_t *dl_config = get_dl_config_request(mac, dl_info->slot);
-        fill_scheduled_response(&scheduled_response, dl_config, NULL, NULL, dl_info->module_id, dl_info->cc_id, dl_info->frame, dl_info->slot, dl_info->phy_data);
+        fill_scheduled_response(&scheduled_response, dl_config, NULL, NULL, NULL, NULL,dl_info->module_id, dl_info->cc_id, dl_info->frame, dl_info->slot, dl_info->phy_data);
         nr_ue_if_module_inst[module_id]->scheduled_response(&scheduled_response);
         memset(def_dci_pdu_rel15, 0, sizeof(*def_dci_pdu_rel15));
       }
@@ -1262,6 +1262,10 @@ nr_ue_if_module_t *nr_ue_if_module_init(uint32_t module_id){
     nr_ue_if_module_inst[module_id]->current_slot = 0;
     nr_ue_if_module_inst[module_id]->phy_config_request = nr_ue_phy_config_request;
     nr_ue_if_module_inst[module_id]->synch_request = nr_ue_synch_request;
+    if (get_softmodem_params()->sl_mode) {
+      nr_ue_if_module_inst[module_id]->sl_phy_config_request = nr_ue_sl_phy_config_request;
+      nr_ue_if_module_inst[module_id]->sl_indication = nr_ue_sl_indication;
+    }
     if (get_softmodem_params()->emulate_l1)
       nr_ue_if_module_inst[module_id]->scheduled_response = nr_ue_scheduled_response_stub;
     else
@@ -1324,3 +1328,109 @@ void RCconfig_nr_ue_macrlc(void) {
     }
   }
 }
+
+
+static void handle_sl_bch(module_id_t module_id,uint8_t *const sl_mib,
+                          const uint8_t len, uint16_t frame_rx,
+                          uint16_t slot_rx,
+                          uint16_t rx_slss_id)
+{
+
+  LOG_D(NR_MAC," decode SL-MIB %d\n",rx_slss_id);
+
+  NR_UE_MAC_INST_t *mac = get_mac_inst(module_id);
+  sl_nr_ue_mac_params_t *sl_mac = mac->SL_MAC_PARAMS;
+
+  uint8_t sl_tdd_config[2] = {0,0};
+
+  sl_tdd_config[0] = sl_mib[0];
+  sl_tdd_config[1] = sl_mib[1] & 0xF0;
+  uint8_t incov = sl_mib[1] & 0x08;
+  uint16_t frame_0 = (sl_mib[2] & 0xFE) >> 1;
+  uint16_t frame_1 = sl_mib[1] & 0x07;
+  frame_0 |= (frame_1 & 0x01) << 7;
+  frame_1 = ((frame_1 & 0x06) >> 1) << 8;
+  uint16_t frame = frame_1 | frame_0;
+  uint8_t slot =  ((sl_mib[2] & 0x01) << 6) | ((sl_mib[3] & 0xFC) >> 2);
+
+  LOG_I(NR_MAC, "[UE%d]In %d:%d Received SL-MIB:%x .Contents- SL-TDD config:%x, Incov:%d, FN:%d, Slot:%d\n",
+                                      module_id, frame_rx, slot_rx,*((uint32_t *)sl_mib),
+                                       *((uint16_t *)sl_tdd_config), incov,frame, slot);
+
+  sl_mac->decoded_DFN = frame;
+  sl_mac->decoded_slot = slot;
+
+#define NR_SBCCH_SL_BCH 5
+  nr_mac_rrc_sl_mib_ind(module_id,0,0,frame_rx, slot_rx, NR_SBCCH_SL_BCH, sl_mib, len, rx_slss_id);
+
+  return ;
+}
+/*
+if PSBCH rx - handle_psbch()
+  - Extract FN, Slot
+  - Extract TDD configuration from the 12 bits
+  - SEND THE SL-MIB to RRC
+if PSSCH DATa rx - handle slsch()
+*/
+void sl_nr_process_rx_ind(uint16_t mod_id,
+                          uint32_t frame, uint32_t slot,
+                          sl_nr_ue_mac_params_t *sl_mac,
+                          sl_nr_rx_indication_t *rx_ind)
+{
+
+  uint8_t num_pdus = rx_ind->number_pdus;
+  uint8_t pdu_type = rx_ind->rx_indication_body[num_pdus-1].pdu_type;
+
+  switch (pdu_type){
+    case SL_NR_RX_PDU_TYPE_SSB:
+
+      if (rx_ind->rx_indication_body[num_pdus - 1].ssb_pdu.decode_status) {
+        LOG_I(NR_MAC, "[UE%d]SL-MAC Received SL-SSB: RSRP:%d dBm/RE, rx_psbch_payload:%x, rx_slss_id:%d\n",
+                         mod_id,rx_ind->rx_indication_body[num_pdus - 1].ssb_pdu.rsrp_dbm,
+                         *((uint32_t *)rx_ind->rx_indication_body[num_pdus - 1].ssb_pdu.psbch_payload),
+                         rx_ind->rx_indication_body[num_pdus - 1].ssb_pdu.rx_slss_id);
+
+        handle_sl_bch(mod_id, rx_ind->rx_indication_body[num_pdus - 1].ssb_pdu.psbch_payload, 4, frame, slot,
+                      rx_ind->rx_indication_body[num_pdus - 1].ssb_pdu.rx_slss_id);
+        sl_mac->ssb_rsrp_dBm = rx_ind->rx_indication_body[num_pdus - 1].ssb_pdu.rsrp_dbm;
+      } else {
+        LOG_I(NR_MAC, "[UE%d]SL-MAC - NO SL-SSB Received\n",mod_id);
+      }
+
+      break;
+    case SL_NR_RX_PDU_TYPE_SLSCH:
+      break;
+
+    default :
+        AssertFatal(1==0, "Incorrect type received. %s\n", __FUNCTION__);
+      break;
+    }
+}
+
+/*
+* Sidelink indication is sent from PHY->MAC.
+* This interface function handles these
+*  - rx_ind (SSB on PSBCH/SLSCH on PSSCH).
+*  - sci_ind (received scis during rxpool reception/txpool sensing)
+*/
+int nr_ue_sl_indication(nr_sidelink_indication_t *sl_indication)
+{
+
+  //NR_UE_L2_STATE_t ret;
+  module_id_t module_id = sl_indication->module_id;
+  NR_UE_MAC_INST_t *mac = get_mac_inst(module_id);
+
+  uint16_t slot = sl_indication->slot_rx;
+  uint16_t frame = sl_indication->frame_rx;
+
+  sl_nr_ue_mac_params_t *sl_mac = mac->SL_MAC_PARAMS;
+
+  if (sl_indication->rx_ind) {
+    sl_nr_process_rx_ind(module_id, frame, slot, sl_mac, sl_indication->rx_ind);
+  } else {
+    nr_ue_sidelink_scheduler(sl_indication);
+  }
+
+  return 0;
+}
+

openair2/NR_UE_PHY_INTERFACE/NR_IF_Module.h

@@ -42,6 +42,16 @@
 #include "NR_Packet_Drop.h"
 #include "nfapi/open-nFAPI/nfapi/public_inc/sidelink_nr_ue_interface.h"
 
+typedef enum sl_sidelink_slot_type {
+
+    SIDELINK_SLOT_TYPE_NONE = 0,
+    SIDELINK_SLOT_TYPE_RX,
+    SIDELINK_SLOT_TYPE_TX,
+    SIDELINK_SLOT_TYPE_BOTH
+
+} sl_sidelink_slot_type_t;
+
+
 extern slot_rnti_mcs_s slot_rnti_mcs[NUM_NFAPI_SLOT];
 
 typedef struct NR_UL_TIME_ALIGNMENT NR_UL_TIME_ALIGNMENT_t;
@@ -126,6 +136,8 @@ typedef struct {
     frame_t frame_tx;
     /// slot tx
     uint32_t slot_tx;
+    //slot type rx or tx
+    sl_sidelink_slot_type_t slot_type;
 
     /// NR UE FAPI-like P7 message, direction: L1 to L2
     /// data reception indication structure
@@ -244,7 +256,7 @@ typedef int8_t (nr_ue_phy_config_request_f)(nr_phy_config_t *phy_config);
  *  -1: Failed to consume bytes. Abort the mission.
  * Non-negative return values indicate success, and ignored.
  */
-typedef int8_t (nr_sl_ue_phy_config_request_f)(nr_sl_phy_config_t *sl_phy_config);
+typedef int8_t (nr_ue_sl_phy_config_request_f)(nr_sl_phy_config_t *sl_phy_config);
 
 /*
  * Generic type of an application-defined callback to return various
@@ -285,6 +297,7 @@ typedef int (nr_ue_sl_indication_f)(nr_sidelink_indication_t *sl_info);
 typedef struct nr_ue_if_module_s {
   nr_ue_scheduled_response_f *scheduled_response;
   nr_ue_phy_config_request_f *phy_config_request;
+  nr_ue_sl_phy_config_request_f *sl_phy_config_request;
   nr_ue_synch_request_f      *synch_request;
   nr_ue_dl_indication_f      *dl_indication;
   nr_ue_ul_indication_f      *ul_indication;
@@ -333,6 +346,8 @@ int nr_ue_dl_indication(nr_downlink_indication_t *dl_info);
 
 int nr_ue_ul_indication(nr_uplink_indication_t *ul_info);
 
+int nr_ue_sl_indication(nr_sidelink_indication_t *sl_indication);
+
 int nr_ue_dcireq(nr_dcireq_t *dcireq);
 
 //  TODO check