possibility to set identity precoding matrix from config file

openair2/GNB_APP/MACRLC_nr_paramdef.h

@@ -71,6 +71,7 @@
 #define CONFIG_STRING_MACRLC_UL_HARQ_ROUND_MAX             "ul_harq_round_max"
 #define CONFIG_STRING_MACRLC_MIN_GRANT_PRB                 "min_grant_prb"
 #define CONFIG_STRING_MACRLC_MIN_GRANT_MCS                 "min_grant_mcs"
+#define CONFIG_STRING_MACRLC_IDENTITY_PM                   "identity_precoding_matrix"
 
 #define HLP_MACRLC_UL_PRBBLACK "SNR threshold to decide whether a PRB will be blacklisted or not"
 #define HLP_MACRLC_DL_BLER_UP "Upper threshold of BLER to decrease DL MCS"
@@ -83,6 +84,7 @@
 #define HLP_MACRLC_UL_HARQ_MAX "Maximum number of UL HARQ rounds"
 #define HLP_MACRLC_MIN_GRANT_PRB "Minimal Periodic ULSCH Grant PRBs"
 #define HLP_MACRLC_MIN_GRANT_MCS "Minimal Periodic ULSCH Grant MCS"
+#define HLP_MACRLC_IDENTITY_PM "Flag to use only identity matrix in DL precoding"
 
 /*-------------------------------------------------------------------------------------------------------------------------------------------------------*/
 /*                                            MacRLC  configuration parameters                                                                           */
@@ -123,6 +125,7 @@
   {CONFIG_STRING_MACRLC_UL_HARQ_ROUND_MAX,           HLP_MACRLC_UL_HARQ_MAX,   0, .u8ptr=NULL,  .defintval=4,               TYPE_UINT8,   0}, \
   {CONFIG_STRING_MACRLC_MIN_GRANT_PRB,               HLP_MACRLC_MIN_GRANT_PRB, 0, .u8ptr=NULL,  .defintval=5,               TYPE_UINT8,   0}, \
   {CONFIG_STRING_MACRLC_MIN_GRANT_MCS,               HLP_MACRLC_MIN_GRANT_MCS, 0, .u8ptr=NULL,  .defintval=9,               TYPE_UINT8,   0}, \
+  {CONFIG_STRING_MACRLC_IDENTITY_PM,                 HLP_MACRLC_IDENTITY_PM,   PARAMFLAG_BOOL, .u8ptr=NULL, .defintval=0,   TYPE_UINT8,   0}, \
 }
 // clang-format off
 
@@ -159,6 +162,7 @@
 #define MACRLC_UL_HARQ_ROUND_MAX_IDX                           30
 #define MACRLC_MIN_GRANT_PRB_IDX                               31
 #define MACRLC_MIN_GRANT_MCS_IDX                               32
+#define MACRLC_IDENTITY_PM_IDX                                 33
 
 #define MACRLCPARAMS_CHECK { \
   { .s5 = { NULL } }, \
@@ -194,6 +198,7 @@
   { .s2 = { config_check_intrange, {1, 8} } }, /* UL max HARQ rounds */ \
   { .s5 = { NULL } }, \
   { .s5 = { NULL } }, \
+  { .s2 = { NULL } }, \
 }
 
 /*---------------------------------------------------------------------------------------------------------------------------------------------------------*/

openair2/GNB_APP/gnb_config.c

@@ -936,6 +936,7 @@ void RCconfig_nr_macrlc() {
       ul_bler_options->harq_round_max = *(MacRLC_ParamList.paramarray[j][MACRLC_UL_HARQ_ROUND_MAX_IDX].u8ptr);
       RC.nrmac[j]->min_grant_prb = *(MacRLC_ParamList.paramarray[j][MACRLC_MIN_GRANT_PRB_IDX].u8ptr);
       RC.nrmac[j]->min_grant_mcs = *(MacRLC_ParamList.paramarray[j][MACRLC_MIN_GRANT_MCS_IDX].u8ptr);
+      RC.nrmac[j]->identity_pm = *(MacRLC_ParamList.paramarray[j][MACRLC_IDENTITY_PM_IDX].u8ptr);
       RC.nrmac[j]->num_ulprbbl = num_prbbl;
       memcpy(RC.nrmac[j]->ulprbbl, prbbl, 275 * sizeof(prbbl[0]));
     } //  for (j=0;j<RC.nb_nr_macrlc_inst;j++)

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_dlsch.c

@@ -630,9 +630,7 @@ void pf_dl(module_id_t module_id,
       else
         sched_pdsch->mcs = get_mcs_from_bler(bo, stats, &sched_ctrl->dl_bler_stats, max_mcs, frame);
       sched_pdsch->nrOfLayers = get_dl_nrOfLayers(sched_ctrl, current_BWP->dci_format);
-      sched_pdsch->pm_index = get_pm_index(UE,
-                                           sched_pdsch->nrOfLayers,
-                                           mac->xp_pdsch_antenna_ports);
+      sched_pdsch->pm_index = mac->identity_pm ? 0 : get_pm_index(UE, sched_pdsch->nrOfLayers, mac->xp_pdsch_antenna_ports);
       const uint8_t Qm = nr_get_Qm_dl(sched_pdsch->mcs, current_BWP->mcsTableIdx);
       const uint16_t R = nr_get_code_rate_dl(sched_pdsch->mcs, current_BWP->mcsTableIdx);
       uint32_t tbs = nr_compute_tbs(Qm,

openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h

@@ -799,7 +799,7 @@ typedef struct gNB_MAC_INST_s {
   NR_bler_options_t ul_bler;
   uint8_t min_grant_prb;
   uint8_t min_grant_mcs;
-
+  bool identity_pm;
   nr_mac_rrc_ul_if_t mac_rrc;
 
   int16_t frame;