Refactored and commented SRSUE's Intra measure component

lib/src/phy/sync/refsignal_dl_sync.c

@@ -30,19 +30,19 @@
  * Constants
  * --------------
  * These constants have been optimized for passing scell_search_test for a number of scenarios.
- * - 6 PRB. 6 cells distributed uniformly 10ms delay
+ * - 6 PRB. 6 cells distributed uniformly 10ms delay. Brut-forced search.
  *     srsue/test/phy/scell_search_test --duration=5 --cell.nof_prb=6 --active_cell_list=all
- *       --simulation_cell_list=1,2,3,4,5,6 --channel_period_s=30 --channel.hst.fd=750 --channel.delay_max=1000
+ *       --simulation_cell_list=1,2,3,4,5,6 --channel_period_s=30 --channel.hst.fd=750 --channel.delay_max=10000
  *
- * - 6 PRB. 6 cells distributed uniformly 10ms delay
+ * - 6 PRB. 6 cells distributed uniformly 10ms delay. With PCI set list.
  *     srsue/test/phy/scell_search_test --duration=30 --cell.nof_prb=6 --active_cell_list=2,3,4,5,6
  *       --simulation_cell_list=1,2,3,4,5,6 --channel_period_s=30 --channel.hst.fd=750 --channel.delay_max=10000
  *
- * - 6 PRB. 6 cell PSS, SSS overlapped:
+ * - 6 PRB. 6 cell PSS, SSS overlapped. Brut-forced search.
  *     srsue/test/phy/scell_search_test --duration=30 --cell.nof_prb=6 --active_cell_list=all
  *       --simulation_cell_list=1,2,3,4,5,6 --channel_period_s=30 --channel.hst.fd=750 --channel.delay_max=0
  *
- * - 100 PRB, 6 cell, distributed around 1ms
+ * - 100 PRB, 6 cell, distributed around 1ms. With PCI set list.
  *     srsue/test/phy/scell_search_test --duration=30 --cell.nof_prb=100 --active_cell_list=2,3,4,5,6
  *       --simulation_cell_list=1,2,3,4,5,6 --channel_period_s=30 --channel.hst.fd=750 --channel.delay_max=1000
  */

srsue/hdr/phy/scell/intra_measure.h

@@ -34,45 +34,163 @@ namespace scell {
 // Class to perform intra-frequency measurements
 class intra_measure : public thread
 {
+  /*
+   * The intra-cell measurment has 5 different states:
+   *  - idle: it has been initiated and it is waiting to get configured to start capturing samples. From any state
+   *          except quit can transition to idle.
+   *  - wait: waits for at least intra_freq_meas_period_ms since last receive start and goes to receive.
+   *  - receive: captures base-band samples for intra_freq_meas_len_ms and goes to measure.
+   *  - measure: enables the inner thread to start the measuring function and goes to wait.
+   *  - quit: stops the inner thread and quits. Transition from any state measure state.
+   *
+   * FSM abstraction:
+   *
+   *  +------+   set_cells_to_meas   +------+   intra_freq_meas_period_ms   +---------+
+   *  | Idle | --------------------->| Wait |------------------------------>| Receive |
+   *  +------+                       +------+                               +---------+
+   *     ^                              ^                                        |          stop  +------+
+   *     |                              |                                        |          ----->| Quit |
+   *   init                        +---------+    intra_freq_meas_len_ms         |                +------+
+   * meas_stop                     | Measure |<----------------------------------+
+   *                               +---------+
+   */
 public:
+  /**
+   * Constructor
+   */
   intra_measure();
+
+  /**
+   * Destructor
+   */
   ~intra_measure();
-  void     init(phy_common* common, rrc_interface_phy_lte* rrc, srslte::log* log_h);
-  void     stop();
-  void     set_primary_cell(uint32_t earfcn, srslte_cell_t cell);
-  void     set_cells_to_meas(const std::set<uint32_t>& pci);
-  void     meas_stop();
-  void     write(uint32_t tti, cf_t* data, uint32_t nsamples);
+
+  /**
+   * Initiation function, necessary to configure main parameters
+   * @param common SRSUE phy_common instance pointer for providing intra_freq_meas_len_ms and intra_freq_meas_period_ms
+   * @param rrc SRSUE PHY->RRC interface for supplying the RRC with the measurements
+   * @param log_h Physical layer Logging filter pointer
+   */
+  void init(phy_common* common, rrc_interface_phy_lte* rrc, srslte::log* log_h);
+
+  /**
+   * Stops the operation of this component
+   */
+  void stop();
+
+  /**
+   * Sets the primmary cell, configures the cell bandwidth and sampling rate
+   * @param earfcn Frequency the component is receiving base-band from. Used only for reporting the EARFCN to the RRC
+   * @param cell Actual cell configuration
+   */
+  void set_primary_cell(uint32_t earfcn, srslte_cell_t cell);
+
+  /**
+   * Sets the PCI list of the cells this components needs to measure and starts the FSM for measuring
+   * @param pci is the list of PCIs to measure
+   */
+  void set_cells_to_meas(const std::set<uint32_t>& pci);
+
+  /**
+   * Stops the measurment FSM, setting the inner state to idle.
+   */
+  void meas_stop();
+
+  /**
+   * Inputs the baseband IQ samples into the component, internal state dictates whether it will be written or not.
+   * @param tti The current physical layer TTI, used for calculating the buffer write
+   * @param data buffer with baseband IQ samples
+   * @param nsamples number of samples to write
+   */
+  void write(uint32_t tti, cf_t* data, uint32_t nsamples);
+
+  /**
+   * Get EARFCN of this component
+   * @return EARFCN
+   */
   uint32_t get_earfcn() { return current_earfcn; };
-  void     wait_meas()
+
+  /**
+   * Synchronous wait mechanism, used for testing purposes, it waits for the inner thread to return a measurement.
+   */
+  void wait_meas()
   { // Only used by scell_search_test
     meas_sync.wait();
   }
 
 private:
+  class internal_state ///< Internal state class, provides thread safe state management
+  {
+  public:
+    typedef enum {
+      idle = 0, ///< Initial state, internal thread runs, it does not capture data
+      wait,     ///< Wait for the period time to pass
+      receive,  ///< Accumulate samples in ring buffer
+      measure,  ///< Module is busy measuring
+      quit      ///< Quit thread, no transitions are allowed
+    } state_t;
+
+  private:
+    state_t                 state = idle;
+    std::mutex              mutex;
+    std::condition_variable cvar;
+
+  public:
+    /**
+     * Get the internal state
+     * @return protected state
+     */
+    state_t get_state() { return state; }
+
+    /**
+     * Transitions to a different state, all transitions are allowed except from quit
+     * @param new_state
+     */
+    void set_state(state_t new_state)
+    {
+      std::unique_lock<std::mutex> lock(mutex);
+      // Do not allow transition from quit
+      if (state != quit) {
+        state = new_state;
+      }
+
+      // Notifies to the inner thread about the change of state
+      cvar.notify_all();
+    }
+
+    /**
+     * Waits for a state transition change, used for blocking the inner thread
+     */
+    void wait_change()
+    {
+      std::unique_lock<std::mutex> lock(mutex);
+      cvar.wait(lock);
+    }
+  };
+
+  internal_state state;
+
   void             run_thread() override;
   const static int INTRA_FREQ_MEAS_PRIO = DEFAULT_PRIORITY + 5;
 
-  scell_recv             scell            = {};
-  rrc_interface_phy_lte* rrc              = nullptr;
-  srslte::log*           log_h            = nullptr;
-  phy_common*            common           = nullptr;
-  uint32_t               current_earfcn   = 0;
-  uint32_t               current_sflen    = 0;
-  srslte_cell_t          serving_cell     = {};
-  std::set<uint32_t>     active_pci       = {};
-  std::mutex             active_pci_mutex = {};
-
-  srslte::tti_sync_cv tti_sync;
-  srslte::tti_sync_cv meas_sync; // Only used by scell_search_test
+  scell_recv             scell                     = {};
+  rrc_interface_phy_lte* rrc                       = nullptr;
+  srslte::log*           log_h                     = nullptr;
+  uint32_t               current_earfcn            = 0;
+  uint32_t               current_sflen             = 0;
+  srslte_cell_t          serving_cell              = {};
+  std::set<uint32_t>     active_pci                = {};
+  std::mutex             active_pci_mutex          = {};
+  uint32_t               last_measure_tti          = 0;
+  uint32_t               intra_freq_meas_len_ms    = 20;
+  uint32_t               intra_freq_meas_period_ms = 200;
+  uint32_t               rx_gain_offset_db         = 0;
+  srslte::tti_sync_cv    meas_sync; // Only used by scell_search_test
 
   cf_t* search_buffer = nullptr;
 
-  bool                running         = false;
-  bool                receive_enabled = false;
-  bool                receiving       = false;
-  uint32_t            receive_cnt     = 0;
-  srslte_ringbuffer_t ring_buffer     = {};
+  uint32_t            receive_cnt = 0;
+  srslte_ringbuffer_t ring_buffer = {};
 
   srslte_refsignal_dl_sync_t refsignal_dl_sync = {};
 };

srsue/src/phy/scell/intra_measure.cc

@@ -45,52 +45,52 @@ intra_measure::~intra_measure()
   free(search_buffer);
 }
 
-void intra_measure::init(phy_common* common_, rrc_interface_phy_lte* rrc_, srslte::log* log_h_)
+void intra_measure::init(phy_common* common, rrc_interface_phy_lte* rrc_, srslte::log* log_h_)
 {
-  this->rrc       = rrc_;
-  this->log_h     = log_h_;
-  this->common    = common_;
-  receive_enabled = false;
+  rrc   = rrc_;
+  log_h = log_h_;
+
+  if (common) {
+    intra_freq_meas_len_ms    = common->args->intra_freq_meas_len_ms;
+    intra_freq_meas_period_ms = common->args->intra_freq_meas_period_ms;
+    rx_gain_offset_db         = common->args->rx_gain_offset;
+  }
 
   // Initialise Reference signal measurement
   srslte_refsignal_dl_sync_init(&refsignal_dl_sync);
 
   // Start scell
-  scell.init(log_h, common->args->intra_freq_meas_len_ms);
+  scell.init(log_h, intra_freq_meas_len_ms);
 
-  search_buffer =
-      (cf_t*)srslte_vec_malloc(common->args->intra_freq_meas_len_ms * SRSLTE_SF_LEN_PRB(SRSLTE_MAX_PRB) * sizeof(cf_t));
+  search_buffer = srslte_vec_cf_malloc(intra_freq_meas_len_ms * SRSLTE_SF_LEN_PRB(SRSLTE_MAX_PRB));
 
-  if (srslte_ringbuffer_init(
-          &ring_buffer, sizeof(cf_t) * common->args->intra_freq_meas_len_ms * 2 * SRSLTE_SF_LEN_PRB(SRSLTE_MAX_PRB))) {
+  if (srslte_ringbuffer_init(&ring_buffer, sizeof(cf_t) * intra_freq_meas_len_ms * SRSLTE_SF_LEN_PRB(SRSLTE_MAX_PRB))) {
     return;
   }
 
-  running = true;
+  state.set_state(internal_state::idle);
   start(INTRA_FREQ_MEAS_PRIO);
 }
 
 void intra_measure::stop()
 {
-  running = false;
+  state.set_state(internal_state::quit);
   srslte_ringbuffer_stop(&ring_buffer);
-  tti_sync.increase();
   wait_thread_finish();
   srslte_refsignal_dl_sync_free(&refsignal_dl_sync);
 }
 
 void intra_measure::set_primary_cell(uint32_t earfcn, srslte_cell_t cell)
 {
-  this->current_earfcn = earfcn;
-  current_sflen        = (uint32_t)SRSLTE_SF_LEN_PRB(cell.nof_prb);
-  this->serving_cell   = cell;
+  current_earfcn = earfcn;
+  current_sflen  = (uint32_t)SRSLTE_SF_LEN_PRB(cell.nof_prb);
+  serving_cell   = cell;
 }
 
 void intra_measure::meas_stop()
 {
-  receive_enabled = false;
-  receiving       = false;
-  receive_cnt     = 0;
+  state.set_state(internal_state::idle);
+  receive_cnt = 0;
   srslte_ringbuffer_reset(&ring_buffer);
   if (log_h) {
     log_h->info("INTRA: Disabled neighbour cell search for EARFCN %d\n", get_earfcn());
@@ -102,30 +102,41 @@ void intra_measure::set_cells_to_meas(const std::set<uint32_t>& pci)
   active_pci_mutex.lock();
   active_pci = pci;
   active_pci_mutex.unlock();
-  receive_enabled = true;
+  state.set_state(internal_state::receive);
   log_h->info("INTRA: Received list of %lu neighbour cells to measure in EARFCN %d.\n", pci.size(), current_earfcn);
 }
 
 void intra_measure::write(uint32_t tti, cf_t* data, uint32_t nsamples)
 {
-  if (receive_enabled) {
-    if ((tti % common->args->intra_freq_meas_period_ms) == 0) {
-      receiving   = true;
-      receive_cnt = 0;
-      srslte_ringbuffer_reset(&ring_buffer);
-    }
-    if (receiving) {
+  uint32_t elapsed_tti = ((tti + 10240) - last_measure_tti) % 10240;
+
+  switch (state.get_state()) {
+
+    case internal_state::idle:
+    case internal_state::measure:
+    case internal_state::quit:
+      // Do nothing
+      break;
+    case internal_state::wait:
+      if (elapsed_tti >= intra_freq_meas_period_ms) {
+        state.set_state(internal_state::receive);
+        receive_cnt      = 0;
+        last_measure_tti = tti;
+        srslte_ringbuffer_reset(&ring_buffer);
+      }
+      break;
+    case internal_state::receive:
       if (srslte_ringbuffer_write(&ring_buffer, data, nsamples * sizeof(cf_t)) < (int)(nsamples * sizeof(cf_t))) {
-        Warning("Error writting to ringbuffer\n");
-        receiving = false;
+        Warning("Error writing to ringbuffer\n");
+        state.set_state(internal_state::idle);
       } else {
         receive_cnt++;
-        if (receive_cnt == common->args->intra_freq_meas_len_ms) {
-          tti_sync.increase();
-          receiving = false;
+        if (receive_cnt == intra_freq_meas_len_ms) {
+          // Buffer ready for measuring, start
+          state.set_state(internal_state::measure);
         }
       }
-    }
+      break;
   }
 }
 
@@ -133,32 +144,31 @@ void intra_measure::run_thread()
 {
   std::set<uint32_t> cells_to_measure = {};
 
-  while (running) {
-    if (running) {
-      tti_sync.wait();
-    }
-
-    if (running) {
-
+  while (state.get_state() != internal_state::quit) {
+    if (state.get_state() == internal_state::measure) {
+      // Start measuring
       active_pci_mutex.lock();
       cells_to_measure = active_pci;
       active_pci_mutex.unlock();
 
       // Read data from buffer and find cells in it
-      srslte_ringbuffer_read(
-          &ring_buffer, search_buffer, common->args->intra_freq_meas_len_ms * current_sflen * sizeof(cf_t));
+      srslte_ringbuffer_read(&ring_buffer, search_buffer, intra_freq_meas_len_ms * current_sflen * sizeof(cf_t));
+
+      // Go to receive before finishing, so new samples can be enqueued before the thread finishes
+      if (state.get_state() == internal_state::measure) {
+        // Prevents transition to wait if state has changed while reading the ring-buffer
+        state.set_state(internal_state::wait);
+      }
 
       // Detect new cells using PSS/SSS
-      std::set<uint32_t> detected_cells =
-          scell.find_cells(search_buffer, serving_cell, common->args->intra_freq_meas_len_ms);
+      std::set<uint32_t> detected_cells = scell.find_cells(search_buffer, serving_cell, intra_freq_meas_len_ms);
 
       // Add detected cells to the list of cells to measure
       for (auto& c : detected_cells) {
         cells_to_measure.insert(c);
       }
 
-      receiving = false;
-
+      // Initialise empty neighbour cell list
       std::vector<rrc_interface_phy_lte::phy_meas_t> neighbour_cells = {};
 
       // Use Cell Reference signal to measure cells in the time domain for all known active PCI
@@ -171,14 +181,13 @@ void intra_measure::run_thread()
         cell.id            = id;
 
         srslte_refsignal_dl_sync_set_cell(&refsignal_dl_sync, cell);
-        srslte_refsignal_dl_sync_run(
-            &refsignal_dl_sync, search_buffer, common->args->intra_freq_meas_len_ms * current_sflen);
+        srslte_refsignal_dl_sync_run(&refsignal_dl_sync, search_buffer, intra_freq_meas_len_ms * current_sflen);
 
         if (refsignal_dl_sync.found) {
           rrc_interface_phy_lte::phy_meas_t m = {};
           m.pci                               = cell.id;
           m.earfcn                            = current_earfcn;
-          m.rsrp                              = refsignal_dl_sync.rsrp_dBfs - common->rx_gain_offset;
+          m.rsrp                              = refsignal_dl_sync.rsrp_dBfs - rx_gain_offset_db;
           m.rsrq                              = refsignal_dl_sync.rsrq_dB;
           neighbour_cells.push_back(m);
 
@@ -199,6 +208,9 @@ void intra_measure::run_thread()
       }
 
       meas_sync.increase();
+    } else if (state.get_state() != internal_state::quit) {
+      // Wait for changing state
+      state.wait_change();
     }
   }
 }

srsue/test/phy/scell_search_test.cc

@@ -324,6 +324,7 @@ int parse_args(int argc, char** argv)
   common.add_options()
       ("duration",                  bpo::value<uint32_t>(&duration_execution_s)->default_value(60),                "Duration of the execution in seconds")
       ("cell.nof_prb",              bpo::value<uint32_t>(&cell_base.nof_prb)->default_value(100),                  "Cell Number of PRB")
+      ("cell.nof_ports",            bpo::value<uint32_t>(&cell_base.nof_ports)->default_value(1),                  "Cell Number of Tx ports")
       ("intra_meas_log_level",      bpo::value<std::string>(&intra_meas_log_level)->default_value("none"),         "Intra measurement log level (none, warning, info, debug)")
       ("intra_freq_meas_len_ms",    bpo::value<uint32_t>(&phy_args.intra_freq_meas_len_ms)->default_value(20),     "Intra measurement measurement length")
       ("intra_freq_meas_period_ms", bpo::value<uint32_t>(&phy_args.intra_freq_meas_period_ms)->default_value(200), "Intra measurement measurement period")
@@ -450,6 +451,7 @@ int main(int argc, char** argv)
   phy_args.cfo_loop_pss_conv            = DEFAULT_PSS_STABLE_TIMEOUT;
   phy_args.snr_estim_alg                = "refs";
   phy_args.snr_ema_coeff                = 0.1f;
+  phy_args.rx_gain_offset               = rx_gain + 62.0f;
 
   // Set phy-lib logging level
   srslte_verbose = phy_lib_log_level;
@@ -490,7 +492,7 @@ int main(int argc, char** argv)
   logger.set_level(intra_meas_log_level);
 
   intra_measure.init(&common, &rrc, &logger);
-  intra_measure.set_primary_cell(serving_cell_id, cell_base);
+  intra_measure.set_primary_cell(SRSLTE_MAX(earfcn_dl, 0), cell_base);
 
   if (earfcn_dl >= 0) {
     // Create radio log
@@ -636,17 +638,19 @@ int main(int argc, char** argv)
           enb->work(&sf_cfg_dl, nullptr, nullptr, nullptr, nullptr, baseband_buffer, ts);
         }
       }
+      // If it is time for a measurement, wait previous to finish
+      if (sf_idx > phy_args.intra_freq_meas_period_ms) {
+        if (sf_idx % phy_args.intra_freq_meas_period_ms == 0) {
+          intra_measure.wait_meas();
+        }
+      }
     }
 
+    // Increase Time counter
     srslte_timestamp_add(&ts, 0, 0.001f);
 
-    if (sf_idx > phy_args.intra_freq_meas_period_ms) {
-      if (sf_idx % phy_args.intra_freq_meas_period_ms == 0) {
-        intra_measure.wait_meas();
-      }
-    }
-
-    intra_measure.write(sf_idx, baseband_buffer, SRSLTE_SF_LEN_PRB(cell_base.nof_prb));
+    // Give data to intra measure component
+    intra_measure.write(sf_idx % 10240, baseband_buffer, SRSLTE_SF_LEN_PRB(cell_base.nof_prb));
     if (sf_idx % 1000 == 0) {
       printf("Done %.1f%%\n", (double)sf_idx * 100.0 / ((double)duration_execution_s * 1000.0));
     }
@@ -657,6 +661,10 @@ int main(int argc, char** argv)
 
   ret = rrc.print_stats() ? SRSLTE_SUCCESS : SRSLTE_ERROR;
 
+  if (radio) {
+    radio->stop();
+  }
+
   if (baseband_buffer) {
     free(baseband_buffer);
   }
@@ -673,7 +681,7 @@ int main(int argc, char** argv)
     }
   }
 
-  if (ret) {
+  if (ret && radio == nullptr) {
     printf("Error\n");
   } else {
     printf("Ok\n");