From 8b2514ded35e591f469565602dc750a77e6d2ff3 Mon Sep 17 00:00:00 2001
From: Xavier Arteaga <xavier.arteaga@softwareradiosystems.com>
Date: Thu, 23 Sep 2021 19:19:59 +0200
Subject: [PATCH] Added NZP-CSI-RS signals in gNb

---
 lib/include/srsran/phy/gnb/gnb_dl.h |  5 +++++
 lib/src/phy/gnb/gnb_dl.c            | 16 ++++++++++++++++
 srsenb/src/phy/nr/slot_worker.cc    |  7 +++++--
 test/phy/dummy_gnb_stack.h          | 14 ++++++++++++++
 4 files changed, 40 insertions(+), 2 deletions(-)

diff --git a/lib/include/srsran/phy/gnb/gnb_dl.h b/lib/include/srsran/phy/gnb/gnb_dl.h
index 77f0b07d0..909a42a03 100644
--- a/lib/include/srsran/phy/gnb/gnb_dl.h
+++ b/lib/include/srsran/phy/gnb/gnb_dl.h
@@ -13,6 +13,7 @@
 #ifndef SRSRAN_GNB_DL_H
 #define SRSRAN_GNB_DL_H
 
+#include "srsran/phy/ch_estimation/csi_rs.h"
 #include "srsran/phy/common/phy_common_nr.h"
 #include "srsran/phy/dft/ofdm.h"
 #include "srsran/phy/phch/pdcch_cfg_nr.h"
@@ -78,4 +79,8 @@ srsran_gnb_dl_pdcch_dl_info(const srsran_gnb_dl_t* q, const srsran_dci_dl_nr_t*
 SRSRAN_API int
 srsran_gnb_dl_pdcch_ul_info(const srsran_gnb_dl_t* q, const srsran_dci_ul_nr_t* dci, char* str, uint32_t str_len);
 
+SRSRAN_API int srsran_gnb_dl_nzp_csi_rs_put(srsran_gnb_dl_t*                    q,
+                                            const srsran_slot_cfg_t*            slot_cfg,
+                                            const srsran_csi_rs_nzp_resource_t* resource);
+
 #endif // SRSRAN_GNB_DL_H
diff --git a/lib/src/phy/gnb/gnb_dl.c b/lib/src/phy/gnb/gnb_dl.c
index e977007f1..f9554dac1 100644
--- a/lib/src/phy/gnb/gnb_dl.c
+++ b/lib/src/phy/gnb/gnb_dl.c
@@ -309,3 +309,19 @@ int srsran_gnb_dl_pdcch_ul_info(const srsran_gnb_dl_t* q, const srsran_dci_ul_nr
 
   return len;
 }
+
+int srsran_gnb_dl_nzp_csi_rs_put(srsran_gnb_dl_t*                    q,
+                                 const srsran_slot_cfg_t*            slot_cfg,
+                                 const srsran_csi_rs_nzp_resource_t* resource)
+{
+  if (q == NULL) {
+    return SRSRAN_ERROR_INVALID_INPUTS;
+  }
+
+  if (srsran_csi_rs_nzp_put_resource(&q->carrier, slot_cfg, resource, q->sf_symbols[0]) < SRSRAN_SUCCESS) {
+    ERROR("Error putting NZP-CSI-RS resource");
+    return SRSRAN_ERROR;
+  }
+
+  return SRSRAN_SUCCESS;
+}
diff --git a/srsenb/src/phy/nr/slot_worker.cc b/srsenb/src/phy/nr/slot_worker.cc
index 2600940c0..cf49708f2 100644
--- a/srsenb/src/phy/nr/slot_worker.cc
+++ b/srsenb/src/phy/nr/slot_worker.cc
@@ -330,8 +330,11 @@ bool slot_worker::work_dl()
   }
 
   // Put NZP-CSI-RS
-  for (srsran_csi_rs_nzp_resource_t& pdsch : dl_sched.nzp_csi_rs) {
-    // ...
+  for (srsran_csi_rs_nzp_resource_t& nzp_csi_rs : dl_sched.nzp_csi_rs) {
+    if (srsran_gnb_dl_nzp_csi_rs_put(&gnb_dl, &dl_slot_cfg, &nzp_csi_rs) < SRSRAN_SUCCESS) {
+      logger.error("NZP-CSI-RS: Error putting signal");
+      return false;
+    }
   }
 
   // Generate baseband signal
diff --git a/test/phy/dummy_gnb_stack.h b/test/phy/dummy_gnb_stack.h
index 50adf8dfe..a71b5589a 100644
--- a/test/phy/dummy_gnb_stack.h
+++ b/test/phy/dummy_gnb_stack.h
@@ -484,6 +484,20 @@ public:
       return SRSRAN_ERROR;
     }
 
+    // Schedule NZP-CSI-RS, iterate all NZP-CSI-RS sets
+    for (const srsran_csi_rs_nzp_set_t& set : phy_cfg.pdsch.nzp_csi_rs_sets) {
+      // For each NZP-CSI-RS resource available in the set
+      for (uint32_t i = 0; i < set.count; i++) {
+        // Select resource
+        const srsran_csi_rs_nzp_resource_t& nzp_csi_resource = set.data[i];
+
+        // Check if the resource is scheduled for this slot
+        if (srsran_csi_rs_send(&nzp_csi_resource.periodicity, &slot_cfg)) {
+          dl_sched.nzp_csi_rs.push_back(nzp_csi_resource);
+        }
+      }
+    }
+
     return SRSRAN_SUCCESS;
   }