phy: move n_ta_offset struct out of PHY under generic ran

this will allow usage in band_helper without depending on lower PHY

Author: andrepuschmann

apps/examples/du/du_example.cpp

@@ -76,7 +76,7 @@ static radio_configuration::over_the_wire_format otw_format = radio_configuratio
 static radio_configuration::clock_sources        clock_src  = {};
 static sampling_rate                             srate      = sampling_rate::from_MHz(61.44);
 static int                                       time_alignmemt_calibration = 0;
-static const lower_phy_ta_offset                 ta_offset                  = lower_phy_ta_offset::n0;
+static const n_ta_offset                         ta_offset                  = n_ta_offset::n0;
 static double                                    tx_gain                    = 60.0;
 static double                                    rx_gain                    = 70.0;
 

apps/examples/phy/radio_ssb.cpp

@@ -345,7 +345,7 @@ lower_phy_configuration create_lower_phy_configuration(float
   phy_config.max_processing_delay_slots = max_processing_delay_slots;
   phy_config.ul_to_dl_subframe_offset   = ul_to_dl_subframe_offset;
   phy_config.time_alignment_calibration = 0;
-  phy_config.ta_offset                  = lower_phy_ta_offset::n0;
+  phy_config.ta_offset                  = n_ta_offset::n0;
   phy_config.tx_scale                   = tx_scale;
   phy_config.cp                         = cp;
   phy_config.dft_window_offset          = 0.5F;

apps/gnb/gnb_appconfig_translators.cpp

@@ -233,9 +233,7 @@ lower_phy_configuration srsran::generate_ru_config(const gnb_appconfig& config)
 
     out_cfg.srate = sampling_rate::from_MHz(config.rf_driver_cfg.srate_MHz);
 
-    out_cfg.ta_offset = lower_phy_ta_offset::n0;
-
-    // Apply time alignment calibration.
+    out_cfg.ta_offset = n_ta_offset::n0;
     if (config.rf_driver_cfg.time_alignment_calibration.has_value()) {
       // Selects the user specific value.
       out_cfg.time_alignment_calibration = config.rf_driver_cfg.time_alignment_calibration.value();

include/srsran/phy/lower/lower_phy_configuration.h

@@ -20,6 +20,7 @@
 #include "srsran/phy/lower/sampling_rate.h"
 #include "srsran/phy/support/resource_grid_pool.h"
 #include "srsran/ran/cyclic_prefix.h"
+#include "srsran/ran/n_ta_offset.h"
 #include "srsran/ran/subcarrier_spacing.h"
 #include "srsran/support/executors/task_executor.h"
 
@@ -45,24 +46,6 @@ struct lower_phy_sector_description {
   std::vector<lower_phy_sector_port_mapping> port_mapping;
 };
 
-/// \brief Time advance offset - parameter \f$N_{TA,offset}\f$ in TS38.211 Section 4.3.3.
-///
-/// This value must be selected from the parameter \e n-TimingAdvanceOffset (TS38.331 Section 6.3.2, Information Element
-/// \e ServingCellConfigCommon) if it is present. Otherwise, it is given by TS38.133 Section 7.1.2 depending on the
-/// duplex mode of the cell and the frequency range.
-///
-/// The values are given in units of \f$T_c\f$ (see TS38.211 Section 4.1).
-enum class lower_phy_ta_offset {
-  /// For FR1 FDD band with LTE-NR coexistence case.
-  n0 = 0,
-  /// For FR1 FDD band without LTE-NR coexistence case or for FR1 TDD band without LTE-NR coexistence case.
-  n25600 = 25600,
-  /// For FR2.
-  n13792 = 13792,
-  /// For FR1 TDD band with LTE-NR coexistence case.
-  n39936 = 39936
-};
-
 /// Lower physical layer configuration.
 struct lower_phy_configuration {
   /// Indicates the log level.
@@ -87,7 +70,7 @@ struct lower_phy_configuration {
   /// Sampling rate.
   sampling_rate srate;
   /// Time alignment offset.
-  lower_phy_ta_offset ta_offset;
+  n_ta_offset ta_offset;
   /// \brief Time alignment calibration in number of samples.
   ///
   /// Models the reception and transmission time misalignment inherent to the RF device. This time adjustment is

include/srsran/ran/n_ta_offset.h

@@ -0,0 +1,33 @@
+/*
+ *
+ * Copyright 2021-2023 Software Radio Systems Limited
+ *
+ * By using this file, you agree to the terms and conditions set
+ * forth in the LICENSE file which can be found at the top level of
+ * the distribution.
+ *
+ */
+
+#pragma once
+
+namespace srsran {
+
+/// \brief Time advance offset - parameter \f$N_{TA,offset}\f$ in TS38.211 Section 4.3.3.
+///
+/// This value must be selected from the parameter \e n-TimingAdvanceOffset (TS38.331 Section 6.3.2, Information Element
+/// \e ServingCellConfigCommon) if it is present. Otherwise, it is given by TS38.133 Section 7.1.2 depending on the
+/// duplex mode of the cell and the frequency range.
+///
+/// The values are given in units of \f$T_c\f$ (see TS38.211 Section 4.1).
+enum class n_ta_offset {
+  /// For FR1 FDD band with LTE-NR coexistence case.
+  n0 = 0,
+  /// For FR1 FDD band without LTE-NR coexistence case or for FR1 TDD band without LTE-NR coexistence case.
+  n25600 = 25600,
+  /// For FR2.
+  n13792 = 13792,
+  /// For FR1 TDD band with LTE-NR coexistence case.
+  n39936 = 39936
+};
+
+} // namespace srsran

lib/phy/lower/lower_phy_impl.h

@@ -194,10 +194,10 @@ class lower_phy_impl : public lower_phy,
   ///                                       maps to \f$N_{\textup{TA, offset}}\f$.
   /// \param[in] srate                      Sampling rate.
   /// \return The reception-to-transmission delay as a number of samples.
-  static inline unsigned get_rx_to_tx_delay(unsigned            ul_to_dl_subframe_offset,
-                                            int                 time_alignment_calibration,
-                                            lower_phy_ta_offset ta_offset,
-                                            sampling_rate       srate)
+  static inline unsigned get_rx_to_tx_delay(unsigned      ul_to_dl_subframe_offset,
+                                            int           time_alignment_calibration,
+                                            n_ta_offset   ta_offset,
+                                            sampling_rate srate)
   {
     // Calculate time between the UL signal reception and the transmission.
     phy_time_unit ul_to_dl_delay = phy_time_unit::from_seconds(0.001 * static_cast<double>(ul_to_dl_subframe_offset));

tests/unittests/phy/lower/lower_phy_test.cpp

@@ -20,18 +20,18 @@
 
 using namespace srsran;
 
-static sampling_rate       srate                      = sampling_rate::from_MHz(61.44);
-static subcarrier_spacing  scs                        = subcarrier_spacing::kHz15;
-static unsigned            max_processing_delay_slots = 4;
-static unsigned            ul_to_dl_subframe_offset   = 1;
-static int                 time_alignment_calibration = 0;
-static lower_phy_ta_offset ta_offset                  = lower_phy_ta_offset::n0;
-static float               tx_scale                   = 1.0F;
-static cyclic_prefix       cp                         = cyclic_prefix::NORMAL;
-static unsigned            bandwidth_rb               = 52;
-static double              dl_freq_hz                 = 2.65e9;
-static double              ul_freq_hz                 = 2.55e9;
-static std::string         log_level                  = "debug";
+static sampling_rate      srate                      = sampling_rate::from_MHz(61.44);
+static subcarrier_spacing scs                        = subcarrier_spacing::kHz15;
+static unsigned           max_processing_delay_slots = 4;
+static unsigned           ul_to_dl_subframe_offset   = 1;
+static int                time_alignment_calibration = 0;
+static n_ta_offset        ta_offset                  = n_ta_offset::n0;
+static float              tx_scale                   = 1.0F;
+static cyclic_prefix      cp                         = cyclic_prefix::NORMAL;
+static unsigned           bandwidth_rb               = 52;
+static double             dl_freq_hz                 = 2.65e9;
+static double             ul_freq_hz                 = 2.55e9;
+static std::string        log_level                  = "debug";
 
 static std::shared_ptr<ofdm_modulator_factory_spy>   modulator_factory         = nullptr;
 static std::shared_ptr<ofdm_demodulator_factory_spy> demodulator_factory       = nullptr;