diff --git a/doc/RUNMODEM.md b/doc/RUNMODEM.md
index a85f0d9b0c844a1fb590f46b7c35c2caec6dde09..2544dce84560aeae368e8b9a073100fa01ea2b1e 100644
--- a/doc/RUNMODEM.md
+++ b/doc/RUNMODEM.md
@@ -280,4 +280,6 @@ The DL logical antenna port configuration can be selected through configuration
Finally the number of TX physical antenna in the RU part of the configuration file, `nb_tx`, should be equal or larger than the total number of PDSCH logical antenna ports.
+It is possible to limit the number supported DL MIMO layers via RRC configuration, e.g. to a value lower than the number of logical antenna ports configured, by using the configuration file parameter `maxMIMO_layers`.
+
[Example of configuration file with parameters for 2-layer MIMO](https://gitlab.eurecom.fr/oai/openairinterface5g/-/blob/develop/targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.sa.band77.fr1.273PRB.2x2.usrpn300.conf)
diff --git a/openair2/GNB_APP/gnb_config.c b/openair2/GNB_APP/gnb_config.c
index e4e93c36a266765747b468343ff9791d1fab95af..c1d15d810b7a0c550aa905999ec8ee4b186b2dba 100644
--- a/openair2/GNB_APP/gnb_config.c
+++ b/openair2/GNB_APP/gnb_config.c
@@ -718,6 +718,7 @@ void RCconfig_verify(configmodule_interface_t *cfg, ngran_node_t node_type)
verify_gnb_param_notset(gnbp, GNB_DO_CSIRS_IDX, GNB_CONFIG_STRING_DOCSIRS);
verify_gnb_param_notset(gnbp, GNB_DO_SRS_IDX, GNB_CONFIG_STRING_DOSRS);
verify_gnb_param_notset(gnbp, GNB_FORCE256QAMOFF_IDX, GNB_CONFIG_STRING_FORCE256QAMOFF);
+ verify_gnb_param_notset(gnbp, GNB_MAXMIMOLAYERS_IDX, GNB_CONFIG_STRING_MAXMIMOLAYERS);
// check for some general sections
verify_section_notset(cfg, NULL, CONFIG_STRING_L1_LIST);
@@ -1304,12 +1305,16 @@ void RCconfig_nr_macrlc(configmodule_interface_t *cfg)
config.force_256qam_off = *GNBParamList.paramarray[0][GNB_FORCE256QAMOFF_IDX].iptr;
config.force_UL256qam_off = *GNBParamList.paramarray[0][GNB_FORCEUL256QAMOFF_IDX].iptr;
config.use_deltaMCS = *GNBParamList.paramarray[0][GNB_USE_DELTA_MCS_IDX].iptr != 0;
+ config.maxMIMO_layers = *GNBParamList.paramarray[0][GNB_MAXMIMOLAYERS_IDX].iptr;
LOG_I(GNB_APP,
- "CSI-RS %d, SRS %d, 256 QAM %s, delta_MCS %s\n",
+ "CSI-RS %d, SRS %d, 256 QAM %s, delta_MCS %s, maxMIMO_Layers %d\n",
config.do_CSIRS,
config.do_SRS,
config.force_256qam_off ? "force off" : "may be on",
- config.use_deltaMCS ? "on" : "off");
+ config.use_deltaMCS ? "on" : "off",
+ config.maxMIMO_layers);
+ int tot_ant = config.pdsch_AntennaPorts.N1 * config.pdsch_AntennaPorts.N2 * config.pdsch_AntennaPorts.XP;
+ AssertFatal(config.maxMIMO_layers != 0 && config.maxMIMO_layers <= tot_ant, "Invalid maxMIMO_layers %d\n", config.maxMIMO_layers);
NR_ServingCellConfigCommon_t *scc = get_scc_config(cfg, config.minRXTXTIME);
//xer_fprint(stdout, &asn_DEF_NR_ServingCellConfigCommon, scc);
diff --git a/openair2/GNB_APP/gnb_paramdef.h b/openair2/GNB_APP/gnb_paramdef.h
index 46dae3622ef027d552314cb7b9bf01bd86fbd90f..6491ddb755b138eb4c0c851deef202ea765939fe 100644
--- a/openair2/GNB_APP/gnb_paramdef.h
+++ b/openair2/GNB_APP/gnb_paramdef.h
@@ -125,6 +125,7 @@ typedef enum {
#define GNB_CONFIG_STRING_ULPRBBLACKLIST "ul_prbblacklist"
#define GNB_CONFIG_STRING_UMONDEFAULTDRB "um_on_default_drb"
#define GNB_CONFIG_STRING_FORCE256QAMOFF "force_256qam_off"
+#define GNB_CONFIG_STRING_MAXMIMOLAYERS "maxMIMO_layers"
#define GNB_CONFIG_STRING_ENABLE_SDAP "enable_sdap"
#define GNB_CONFIG_STRING_DRBS "drbs"
#define GNB_CONFIG_STRING_USE_DELTA_MCS "use_deltaMCS"
@@ -136,6 +137,7 @@ typedef enum {
#define GNB_CONFIG_HLP_STRING_ENABLE_SDAP "enable the SDAP layer\n"
#define GNB_CONFIG_HLP_FORCE256QAMOFF "suppress activation of 256 QAM despite UE support"
+#define GNB_CONFIG_HLP_MAXMIMOLAYERS "limit on maxMIMO-layers for DL"
#define GNB_CONFIG_HLP_STRING_DRBS "Number of total DRBs to establish, including the mandatory for PDU SEssion (default=1)\n"
#define GNB_CONFIG_HLP_GNB_DU_ID "defines the gNB-DU ID (only applicable for DU)"
#define GNB_CONFIG_HLP_GNB_CU_UP_ID "defines the gNB-CU-UP ID (only applicable for CU-UP)"
@@ -177,6 +179,7 @@ typedef enum {
{GNB_CONFIG_STRING_GNB_CU_UP_ID, GNB_CONFIG_HLP_GNB_CU_UP_ID, 0, .u64ptr=NULL, .defint64val=1, TYPE_UINT64, 0}, \
{GNB_CONFIG_STRING_USE_DELTA_MCS, GNB_CONFIG_HLP_USE_DELTA_MCS, 0, .iptr=NULL, .defintval=0, TYPE_INT, 0}, \
{GNB_CONFIG_STRING_FORCEUL256QAMOFF, GNB_CONFIG_HLP_FORCEUL256QAMOFF, 0, .iptr=NULL, .defintval=0, TYPE_INT, 0}, \
+{GNB_CONFIG_STRING_MAXMIMOLAYERS, GNB_CONFIG_HLP_MAXMIMOLAYERS, 0, .iptr=NULL, .defintval=-1, TYPE_INT, 0}, \
}
// clang-format on
@@ -212,6 +215,7 @@ typedef enum {
#define GNB_GNB_CU_UP_ID_IDX 28
#define GNB_USE_DELTA_MCS_IDX 29
#define GNB_FORCEUL256QAMOFF_IDX 30
+#define GNB_MAXMIMOLAYERS_IDX 31
#define TRACKING_AREA_CODE_OKRANGE {0x0001,0xFFFD}
#define GNBPARAMS_CHECK { \
diff --git a/openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h b/openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h
index eeeff6543c79f93ad605570c6ccb7579ee396269..59a33556913db67c68646ba9ce92e32a74626dce 100644
--- a/openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h
+++ b/openair2/LAYER2/NR_MAC_gNB/nr_mac_gNB.h
@@ -138,6 +138,7 @@ typedef struct nr_mac_config_t {
bool force_256qam_off;
bool force_UL256qam_off;
bool use_deltaMCS;
+ int maxMIMO_layers;
//int pusch_TargetSNRx10;
//int pucch_TargetSNRx10;
} nr_mac_config_t;
diff --git a/openair2/RRC/NR/nr_rrc_config.c b/openair2/RRC/NR/nr_rrc_config.c
index 941f81d81c05d3e51c48aa84ec48c6b4050a98d3..3b1791ad55c2582a4de42d6e56a4c32e6042797a 100644
--- a/openair2/RRC/NR/nr_rrc_config.c
+++ b/openair2/RRC/NR/nr_rrc_config.c
@@ -512,7 +512,8 @@ static void config_csiim(int do_csirs,
void set_dl_maxmimolayers(NR_PDSCH_ServingCellConfig_t *pdsch_servingcellconfig,
const NR_ServingCellConfigCommon_t *scc,
- const NR_UE_NR_Capability_t *uecap)
+ const NR_UE_NR_Capability_t *uecap,
+ int maxMIMO_layers)
{
if(!pdsch_servingcellconfig->ext1)
@@ -536,7 +537,10 @@ void set_dl_maxmimolayers(NR_PDSCH_ServingCellConfig_t *pdsch_servingcellconfig,
supported_bw_comparison(bw_mhz, &dl_fs->supportedBandwidthDL, dl_fs->channelBW_90mhz) &&
dl_fs->maxNumberMIMO_LayersPDSCH) {
long ue_supported_layers = (2 << *dl_fs->maxNumberMIMO_LayersPDSCH);
- *pdsch_servingcellconfig->ext1->maxMIMO_Layers = NR_MAX_SUPPORTED_DL_LAYERS < ue_supported_layers ? NR_MAX_SUPPORTED_DL_LAYERS : ue_supported_layers;
+ if (maxMIMO_layers == -1)
+ *pdsch_servingcellconfig->ext1->maxMIMO_Layers = NR_MAX_SUPPORTED_DL_LAYERS < ue_supported_layers ? NR_MAX_SUPPORTED_DL_LAYERS : ue_supported_layers;
+ else
+ *pdsch_servingcellconfig->ext1->maxMIMO_Layers = maxMIMO_layers < ue_supported_layers ? maxMIMO_layers : ue_supported_layers;
return;
}
}
@@ -2397,7 +2401,7 @@ static NR_SpCellConfig_t *get_initial_SpCellConfig(int uid,
pdsch_servingcellconfig->nrofHARQ_ProcessesForPDSCH = calloc(1, sizeof(*pdsch_servingcellconfig->nrofHARQ_ProcessesForPDSCH));
*pdsch_servingcellconfig->nrofHARQ_ProcessesForPDSCH = NR_PDSCH_ServingCellConfig__nrofHARQ_ProcessesForPDSCH_n16;
pdsch_servingcellconfig->pucch_Cell = NULL;
- set_dl_maxmimolayers(pdsch_servingcellconfig, scc, NULL);
+ set_dl_maxmimolayers(pdsch_servingcellconfig, scc, NULL, configuration->maxMIMO_layers);
// Downlink BWPs
int n_dl_bwp = 0;
@@ -2600,7 +2604,7 @@ void update_cellGroupConfig(NR_CellGroupConfig_t *cellGroupConfig,
NR_SpCellConfig_t *SpCellConfig = cellGroupConfig->spCellConfig;
NR_PDSCH_ServingCellConfig_t *pdsch_servingcellconfig = SpCellConfig->spCellConfigDedicated->pdsch_ServingCellConfig->choice.setup;
- set_dl_maxmimolayers(pdsch_servingcellconfig, scc, uecap);
+ set_dl_maxmimolayers(pdsch_servingcellconfig, scc, uecap, configuration->maxMIMO_layers);
NR_CSI_MeasConfig_t *csi_MeasConfig = SpCellConfig->spCellConfigDedicated->csi_MeasConfig->choice.setup;
for (int report = 0; report < csi_MeasConfig->csi_ReportConfigToAddModList->list.count; report++) {
@@ -2979,7 +2983,7 @@ NR_CellGroupConfig_t *get_default_secondaryCellGroup(const NR_ServingCellConfigC
pdsch_servingcellconfig->nrofHARQ_ProcessesForPDSCH = calloc(1, sizeof(*pdsch_servingcellconfig->nrofHARQ_ProcessesForPDSCH));
*pdsch_servingcellconfig->nrofHARQ_ProcessesForPDSCH = NR_PDSCH_ServingCellConfig__nrofHARQ_ProcessesForPDSCH_n16;
pdsch_servingcellconfig->pucch_Cell = NULL;
- set_dl_maxmimolayers(pdsch_servingcellconfig, servingcellconfigcommon, uecap);
+ set_dl_maxmimolayers(pdsch_servingcellconfig, servingcellconfigcommon, uecap, configuration->maxMIMO_layers);
pdsch_servingcellconfig->ext1->processingType2Enabled = NULL;
secondaryCellGroup->spCellConfig->spCellConfigDedicated->csi_MeasConfig = NULL;
diff --git a/targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.sa.band77.273prb.fhi72.4x4-vvdn.conf b/targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.sa.band77.273prb.fhi72.4x4-vvdn.conf
index ba442af9d73e0208bdeacaeabea55f76a0666744..5984d32b17847fae3659d2a0f393155cc24402f8 100644
--- a/targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.sa.band77.273prb.fhi72.4x4-vvdn.conf
+++ b/targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.sa.band77.273prb.fhi72.4x4-vvdn.conf
@@ -19,6 +19,8 @@ gNBs =
////////// Physical parameters:
pdsch_AntennaPorts_XP = 2;
+ pdsch_AntennaPorts_N1 = 2;
+ maxMIMO_layers = 2;
pusch_AntennaPorts = 4;
do_CSIRS = 1;
do_SRS = 0 ;
diff --git a/targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.sa.band78.273prb.fhi72.4x4-benetel550.conf b/targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.sa.band78.273prb.fhi72.4x4-benetel550.conf
index 7ad71606faea50727e03676e18807205a01f63e7..d5c22b7e5e83d6560ee487662a15299c89bdbd13 100644
--- a/targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.sa.band78.273prb.fhi72.4x4-benetel550.conf
+++ b/targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.sa.band78.273prb.fhi72.4x4-benetel550.conf
@@ -18,6 +18,8 @@ gNBs =
////////// Physical parameters:
pdsch_AntennaPorts_XP = 2;
+ pdsch_AntennaPorts_N1 = 2;
+ maxMIMO_layers = 2;
pusch_AntennaPorts = 4;
do_CSIRS = 1;
do_SRS = 0 ;
diff --git a/targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.sa.band78.273prb.fhi72.4x4-benetel650.conf b/targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.sa.band78.273prb.fhi72.4x4-benetel650.conf
index 919bb45b4c546d704f9515a80a07705eda3eaa5f..ddcb28a331f3ce9369160e5876c8d8c17dfdc9b8 100644
--- a/targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.sa.band78.273prb.fhi72.4x4-benetel650.conf
+++ b/targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.sa.band78.273prb.fhi72.4x4-benetel650.conf
@@ -18,6 +18,8 @@ gNBs =
////////// Physical parameters:
pdsch_AntennaPorts_XP = 2;
+ pdsch_AntennaPorts_N1 = 2;
+ maxMIMO_layers = 2;
pusch_AntennaPorts = 4;
do_CSIRS = 1;
do_SRS = 0 ;
diff --git a/targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.sa.band78.273prb.fhi72.4x4-liteon.conf b/targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.sa.band78.273prb.fhi72.4x4-liteon.conf
index 0df4af5faa737bca2e03e7ef26a8e87e20f44797..1ddba82cdf875c2f4b52e11157173a6d6e2e6d70 100644
--- a/targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.sa.band78.273prb.fhi72.4x4-liteon.conf
+++ b/targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb.sa.band78.273prb.fhi72.4x4-liteon.conf
@@ -18,6 +18,8 @@ gNBs =
////////// Physical parameters:
pdsch_AntennaPorts_XP = 2;
+ pdsch_AntennaPorts_N1 = 2;
+ maxMIMO_layers = 2;
pusch_AntennaPorts = 4;
do_CSIRS = 1;
do_SRS = 0 ;