rrc/phy/nr: calculate tuning freq of NR carrier from RRC signaling params

skip initial tuning to hard-coded NR frequency and use RRC-provided
values to calculate center frequency

lib/include/srsran/phy/common/phy_common_nr.h

@@ -280,6 +280,7 @@ typedef struct SRSRAN_API {
   uint32_t                    pci;
   uint32_t                    absolute_frequency_ssb;
   uint32_t                    absolute_frequency_point_a;
+  uint32_t                    offset_to_carrier; ///< Offset between point A and the lowest subcarrier of the lowest RB
   srsran_subcarrier_spacing_t scs;
   uint32_t                    nof_prb; ///< @brief See TS 38.101-1 Table 5.3.2-1 for more details
   uint32_t                    start;

lib/src/asn1/rrc_nr_utils.cc

@@ -1182,13 +1182,11 @@ bool make_phy_carrier_cfg(const freq_info_dl_s& asn1_freq_info_dl, srsran_carrie
     asn1::log_warning("Option absolute_freq_ssb not present");
     return false;
   }
-  uint32_t absolute_frequency_point_a = asn1_freq_info_dl.absolute_freq_point_a;
   if (asn1_freq_info_dl.scs_specific_carrier_list.size() != 1) {
     asn1::log_warning("Option absolute_freq_ssb not present");
     return false;
   }
 
-  uint32_t                    nof_prb = asn1_freq_info_dl.scs_specific_carrier_list[0].carrier_bw;
   srsran_subcarrier_spacing_t scs = srsran_subcarrier_spacing_15kHz;
   switch (asn1_freq_info_dl.scs_specific_carrier_list[0].subcarrier_spacing) {
     case subcarrier_spacing_opts::options::khz15:
@@ -1211,8 +1209,9 @@ bool make_phy_carrier_cfg(const freq_info_dl_s& asn1_freq_info_dl, srsran_carrie
   }
   // As the carrier structure requires parameters from different objects, set fields separately
   out_carrier_nr->absolute_frequency_ssb     = absolute_frequency_ssb;
-  out_carrier_nr->absolute_frequency_point_a = absolute_frequency_point_a;
+  out_carrier_nr->absolute_frequency_point_a = asn1_freq_info_dl.absolute_freq_point_a;
-  out_carrier_nr->nof_prb                    = nof_prb;
+  out_carrier_nr->offset_to_carrier          = asn1_freq_info_dl.scs_specific_carrier_list[0].offset_to_carrier;
+  out_carrier_nr->nof_prb                    = asn1_freq_info_dl.scs_specific_carrier_list[0].carrier_bw;
   out_carrier_nr->scs                        = scs;
   return true;
 }

lib/src/common/test/band_helper_test.cc

@@ -18,6 +18,8 @@ int bands_test_nr()
   srsran::srsran_band_helper bands;
 
   TESTASSERT(bands.nr_arfcn_to_freq(632628) == 3489.42e6);
+  TESTASSERT(bands.nr_arfcn_to_freq(633928) == 3508.92e6); // default refPointA
+  TESTASSERT(bands.nr_arfcn_to_freq(634240) == 3513.6e6);  // default ARFCN with freq divisible by 11.52 MHz
 
   const uint32_t max_valid_nr_arfcn = 3279165;
 

lib/src/phy/ch_estimation/test/csi_rs_test.c

@@ -21,6 +21,7 @@ static srsran_carrier_nr_t carrier = {
     1,                               // pci
     0,                               // absolute_frequency_ssb
     0,                               // absolute_frequency_point_a
+    0,                               // offset_to_carrier
     srsran_subcarrier_spacing_15kHz, // scs
     50,                              // nof_prb
     0,                               // start

lib/src/phy/ch_estimation/test/dmrs_pdsch_test.c

@@ -20,11 +20,11 @@
 #include <strings.h>
 #include <unistd.h>
 
-
 static srsran_carrier_nr_t carrier = {
     1,                               // pci
     0,                               // absolute_frequency_ssb
     0,                               // absolute_frequency_point_a
+    0,                               // offset_to_carrier
     srsran_subcarrier_spacing_15kHz, // scs
     50,                              // nof_prb
     0,                               // start

lib/src/phy/phch/test/pdcch_nr_test.c

@@ -19,6 +19,7 @@ static srsran_carrier_nr_t carrier = {
     1,                               // pci
     0,                               // absolute_frequency_ssb
     0,                               // absolute_frequency_point_a
+    0,                               // offset_to_carrier
     srsran_subcarrier_spacing_15kHz, // scs
     50,                              // nof_prb
     0,                               // start

lib/src/phy/phch/test/pdsch_nr_test.c

@@ -24,13 +24,13 @@ static srsran_carrier_nr_t carrier = {
     1,                               // pci
     0,                               // absolute_frequency_ssb
     0,                               // absolute_frequency_point_a
+    0,                               // offset_to_carrier
     srsran_subcarrier_spacing_15kHz, // scs
     SRSRAN_MAX_PRB_NR,               // nof_prb
     0,                               // start
     1                                // max_mimo_layers
 };
 
-
 static uint32_t            n_prb     = 0;  // Set to 0 for steering
 static uint32_t            mcs       = 30; // Set to 30 for steering
 static srsran_sch_cfg_nr_t pdsch_cfg = {};

lib/src/phy/phch/test/pucch_nr_test.c

@@ -26,6 +26,7 @@ static srsran_carrier_nr_t carrier = {
     1,                               // pci
     0,                               // absolute_frequency_ssb
     0,                               // absolute_frequency_point_a
+    0,                               // offset_to_carrier
     srsran_subcarrier_spacing_15kHz, // scs
     6,                               // nof_prb
     0,                               // start

lib/src/phy/phch/test/pusch_nr_test.c

@@ -23,6 +23,7 @@ static srsran_carrier_nr_t carrier = {
     1,                               // pci
     0,                               // absolute_frequency_ssb
     0,                               // absolute_frequency_point_a
+    0,                               // offset_to_carrier
     srsran_subcarrier_spacing_15kHz, // scs
     SRSRAN_MAX_PRB_NR,               // nof_prb
     0,                               // start

lib/src/phy/phch/test/sch_nr_test.c

@@ -22,6 +22,7 @@ static srsran_carrier_nr_t carrier = {
     1,                               // pci
     0,                               // absolute_frequency_ssb
     0,                               // absolute_frequency_point_a
+    0,                               // offset_to_carrier
     srsran_subcarrier_spacing_15kHz, // scs
     SRSRAN_MAX_PRB_NR,               // nof_prb
     0,                               // start

lib/test/phy/phy_dl_nr_test.c

@@ -23,6 +23,7 @@ static srsran_carrier_nr_t carrier = {
     501,                             // pci
     0,                               // absolute_frequency_ssb
     0,                               // absolute_frequency_point_a
+    0,                               // offset_to_carrier
     srsran_subcarrier_spacing_15kHz, // scs
     52,                              // nof_prb
     0,                               // start

srsue/src/phy/phy.cc

@@ -13,6 +13,7 @@
 #include <string>
 #include <sys/mman.h>
 
+#include "srsran/common/band_helper.h"
 #include "srsran/common/standard_streams.h"
 #include "srsran/srsran.h"
 #include "srsue/hdr/phy/phy.h"
@@ -634,6 +635,22 @@ void phy::set_earfcn(std::vector<uint32_t> earfcns)
 
 bool phy::set_config(const srsran::phy_cfg_nr_t& cfg)
 {
+  // Derive actual RF frequencies for NR carrier
+  double abs_freq_point_a_freq = srsran::srsran_band_helper().nr_arfcn_to_freq(cfg.carrier.absolute_frequency_point_a);
+
+  // for FR1 unit of resources blocks for freq calc is always 180kHz regardless for actual SCS of carrier
+  // TODO: add offset_to_carrier
+  double carrier_center_freq =
+      abs_freq_point_a_freq +
+      (cfg.carrier.nof_prb / 2 * SRSRAN_SUBC_SPACING_NR(srsran_subcarrier_spacing_t::srsran_subcarrier_spacing_15kHz) *
+       SRSRAN_NRE);
+
+  for (uint32_t i = 0; i < common.args->nof_nr_carriers; i++) {
+    logger_phy.info("Tuning channel %d to %.2f GHz", i + common.args->nof_lte_carriers, carrier_center_freq / 1e6);
+    radio->set_rx_freq(i + common.args->nof_lte_carriers, carrier_center_freq);
+    radio->set_tx_freq(i + common.args->nof_lte_carriers, carrier_center_freq);
+  }
+
   return nr_workers.set_config(cfg);
 }
 

srsue/src/phy/sync.cc

@@ -861,11 +861,6 @@ bool sync::set_frequency()
     radio_h->set_rx_freq(0, set_dl_freq);
     radio_h->set_tx_freq(0, set_ul_freq);
 
-    for (uint32_t i = 0; i < worker_com->args->nof_nr_carriers; i++) {
-      radio_h->set_rx_freq(i + worker_com->args->nof_lte_carriers, worker_com->args->nr_freq_hz);
-      radio_h->set_tx_freq(i + worker_com->args->nof_lte_carriers, worker_com->args->nr_freq_hz);
-    }
-
     ul_dl_factor = (float)(set_ul_freq / set_dl_freq);
 
     srsran_ue_sync_reset(&ue_sync);

srsue/src/ue.cc

@@ -12,7 +12,6 @@
 
 #include "srsue/hdr/ue.h"
 #include "srsran/build_info.h"
-#include "srsran/common/band_helper.h"
 #include "srsran/common/string_helpers.h"
 #include "srsran/radio/radio.h"
 #include "srsran/radio/radio_null.h"
@@ -251,8 +250,6 @@ int ue::parse_args(const all_args_t& args_)
     }
   }
 
-  srsran_band_helper bands_helper;
-
   // populate NR DL ARFCNs
   if (args.phy.nof_nr_carriers > 0) {
     if (not args.stack.rrc_nr.supported_bands_nr_str.empty()) {