Refactored worker_end mechanism for concurrent workers

lib/include/srsran/interfaces/phy_common_interface.h

@@ -18,19 +18,40 @@
 
 namespace srsran {
 
+/**
+ * @brief Descibes a physical layer common interface
+ */
 class phy_common_interface
 {
 public:
+  /**
+   * @brief Describes a worker context
+   */
+  struct worker_context_t {
+    uint32_t               sf_idx     = 0;       ///< Subframe index
+    void*                  worker_ptr = nullptr; ///< Worker pointer for wait/release semaphore
+    bool                   last       = false;   ///< Indicates this worker is the last one in the sub-frame processing
+    srsran::rf_timestamp_t tx_time    = {};      ///< Transmit time, used only by last worker
+
+    void copy(const worker_context_t& other)
+    {
+      sf_idx     = other.sf_idx;
+      worker_ptr = other.worker_ptr;
+      last       = other.last;
+      tx_time.copy(other.tx_time);
+    }
+
+    worker_context_t() = default;
+    worker_context_t(const worker_context_t& other) { copy(other); }
+  };
+
   /**
    * @brief Common PHY interface for workers to indicate they ended
-   * @param h Worker pointer used as unique identifier for synchronising Tx
+   * @param w_ctx Worker context
    * @param tx_enable Indicates whether the buffer has baseband samples to transmit
    * @param buffer Baseband buffer
-   * @param tx_time Transmit timestamp
-   * @param is_nr Indicates whether the worker is NR or not
    */
-  virtual void
-  worker_end(void* h, bool tx_enable, srsran::rf_buffer_t& buffer, srsran::rf_timestamp_t& tx_time, bool is_nr) = 0;
+  virtual void worker_end(const worker_context_t& w_ctx, const bool& tx_enable, srsran::rf_buffer_t& buffer) = 0;
 };
 
 } // namespace srsran

lib/include/srsran/radio/rf_buffer.h

@@ -112,6 +112,26 @@ public:
   {
     sample_buffer.at(logical_ch * nof_antennas + port_idx) = ptr;
   }
+  void set_combine(const uint32_t& channel_idx, cf_t* ptr)
+  {
+    if (sample_buffer.at(channel_idx) == nullptr) {
+      sample_buffer.at(channel_idx) = ptr;
+    } else if (ptr != nullptr) {
+      srsran_vec_sum_ccc(ptr, sample_buffer.at(channel_idx), sample_buffer.at(channel_idx), nof_samples);
+    }
+  }
+  void set_combine(const uint32_t& logical_ch, const uint32_t& port_idx, const uint32_t& nof_antennas, cf_t* ptr)
+  {
+    set_combine(logical_ch * nof_antennas + port_idx, ptr);
+  }
+  void set_combine(const rf_buffer_interface& other)
+  {
+    // Take the other number of samples always
+    set_nof_samples(other.get_nof_samples());
+    for (uint32_t ch = 0; ch < SRSRAN_MAX_CHANNELS; ch++) {
+      set_combine(ch, other.get(ch));
+    }
+  }
   void**   to_void() override { return (void**)sample_buffer.data(); }
   cf_t**   to_cf_t() override { return sample_buffer.data(); }
   uint32_t size() override { return nof_subframes * SRSRAN_SF_LEN_MAX; }

srsenb/hdr/phy/lte/sf_worker.h

@@ -32,7 +32,7 @@ public:
   void init(phy_common* phy);
 
   cf_t* get_buffer_rx(uint32_t cc_idx, uint32_t antenna_idx);
-  void  set_time(uint32_t tti_, const srsran::rf_timestamp_t& tx_time_);
+  void  set_context(const srsran::phy_common_interface::worker_context_t& w_ctx);
 
   int      add_rnti(uint16_t rnti, uint32_t cc_idx);
   void     rem_rnti(uint16_t rnti);
@@ -60,9 +60,8 @@ private:
   std::mutex            work_mutex;
 
   uint32_t                                       tti_rx = 0, tti_tx_dl = 0, tti_tx_ul = 0;
-  srsran::rf_timestamp_t tx_time       = {};
-
   std::vector<std::unique_ptr<cc_worker> >       cc_workers;
+  srsran::phy_common_interface::worker_context_t context = {};
 
   srsran_softbuffer_tx_t temp_mbsfn_softbuffer = {};
 };

srsenb/hdr/phy/nr/slot_worker.h

@@ -36,6 +36,7 @@ public:
     uint32_t nof_max_prb        = SRSRAN_MAX_PRB_NR;
     uint32_t nof_tx_ports       = 1;
     uint32_t nof_rx_ports       = 1;
+    uint32_t rf_port            = 0;
     uint32_t pusch_max_nof_iter = 10;
   };
 
@@ -50,7 +51,7 @@ public:
   cf_t*    get_buffer_rx(uint32_t antenna_idx);
   cf_t*    get_buffer_tx(uint32_t antenna_idx);
   uint32_t get_buffer_len();
-  void     set_time(const uint32_t& tti, const srsran::rf_timestamp_t& timestamp);
+  void     set_context(const srsran::phy_common_interface::worker_context_t& w_ctx);
 
 private:
   /**
@@ -76,10 +77,11 @@ private:
 
   uint32_t                                       sf_len      = 0;
   uint32_t                                       cell_index  = 0;
+  uint32_t                                       rf_port     = 0;
   srsran_slot_cfg_t                              dl_slot_cfg = {};
   srsran_slot_cfg_t                              ul_slot_cfg = {};
+  srsran::phy_common_interface::worker_context_t context     = {};
   srsran_pdcch_cfg_nr_t                          pdcch_cfg   = {};
-  srsran::rf_timestamp_t tx_time     = {};
   srsran_gnb_dl_t                                gnb_dl      = {};
   srsran_gnb_ul_t                                gnb_ul      = {};
   std::vector<cf_t*>                             tx_buffer; ///< Baseband transmit buffers

srsenb/hdr/phy/phy_common.h

@@ -57,11 +57,7 @@ public:
    * @param tx_time timestamp to transmit samples
    * @param is_nr flag is true if it is called from NR
    */
-  void worker_end(void*                   tx_sem_id,
-                  bool                    tx_enable,
-                  srsran::rf_buffer_t&    buffer,
-                  srsran::rf_timestamp_t& tx_time,
-                  bool                    is_nr) override;
+  void worker_end(const worker_context_t& w_ctx, const bool& tx_enable, srsran::rf_buffer_t& buffer) override;
 
   // Common objects
   phy_args_t params = {};
@@ -236,10 +232,9 @@ private:
   uint8_t                 mch_table[40]    = {};
   uint8_t                 mcch_table[10]   = {};
   uint32_t                mch_period_stop  = 0;
+  srsran::rf_buffer_t     tx_buffer        = {};
   bool                    is_mch_subframe(srsran_mbsfn_cfg_t* cfg, uint32_t phy_tti);
   bool                    is_mcch_subframe(srsran_mbsfn_cfg_t* cfg, uint32_t phy_tti);
-  srsran::rf_buffer_t     nr_tx_buffer;
-  bool                    nr_tx_buffer_ready = false;
 };
 
 } // namespace srsenb

srsenb/src/phy/lte/sf_worker.cc

@@ -101,16 +101,16 @@ cf_t* sf_worker::get_buffer_rx(uint32_t cc_idx, uint32_t antenna_idx)
   return cc_workers[cc_idx]->get_buffer_rx(antenna_idx);
 }
 
-void sf_worker::set_time(uint32_t tti_, const srsran::rf_timestamp_t& tx_time_)
+void sf_worker::set_context(const srsran::phy_common_interface::worker_context_t& w_ctx)
 {
-  tti_rx    = tti_;
+  tti_rx    = w_ctx.sf_idx;
   tti_tx_dl = TTI_ADD(tti_rx, FDD_HARQ_DELAY_UL_MS);
   tti_tx_ul = TTI_RX_ACK(tti_rx);
 
-  tx_time.copy(tx_time_);
+  context.copy(w_ctx);
 
   for (auto& w : cc_workers) {
-    w->set_tti(tti_);
+    w->set_tti(w_ctx.sf_idx);
   }
 }
 
@@ -147,14 +147,10 @@ void sf_worker::work_imp()
 
   // Get Transmission buffers
   srsran::rf_buffer_t tx_buffer = {};
-  for (uint32_t cc = 0; cc < phy->get_nof_carriers_lte(); cc++) {
-    for (uint32_t ant = 0; ant < phy->get_nof_ports(0); ant++) {
-      tx_buffer.set(cc, ant, phy->get_nof_ports(0), cc_workers[cc]->get_buffer_tx(ant));
-    }
-  }
+  tx_buffer.set_nof_samples(SRSRAN_SF_LEN_PRB(phy->get_nof_prb(0)));
 
   if (!running) {
-    phy->worker_end(this, true, tx_buffer, tx_time, false);
+    phy->worker_end(context, true, tx_buffer);
     return;
   }
 
@@ -192,14 +188,14 @@ void sf_worker::work_imp()
   if (sf_type == SRSRAN_SF_NORM) {
     if (stack->get_dl_sched(tti_tx_dl, dl_grants) < 0) {
       Error("Getting DL scheduling from MAC");
-      phy->worker_end(this, false, tx_buffer, tx_time, false);
+      phy->worker_end(context, true, tx_buffer);
       return;
     }
   } else {
     dl_grants[0].cfi = mbsfn_cfg.non_mbsfn_region_length;
     if (stack->get_mch_sched(tti_tx_dl, mbsfn_cfg.is_mcch, dl_grants)) {
       Error("Getting MCH packets from MAC");
-      phy->worker_end(this, false, tx_buffer, tx_time, false);
+      phy->worker_end(context, true, tx_buffer);
       return;
     }
   }
@@ -207,7 +203,7 @@ void sf_worker::work_imp()
   // Get UL scheduling for the TX TTI from MAC
   if (stack->get_ul_sched(tti_tx_ul, ul_grants_tx) < 0) {
     Error("Getting UL scheduling from MAC");
-    phy->worker_end(this, false, tx_buffer, tx_time, false);
+    phy->worker_end(context, true, tx_buffer);
     return;
   }
 
@@ -232,9 +228,15 @@ void sf_worker::work_imp()
   // Save grants
   phy->set_ul_grants(tti_tx_ul, ul_grants_tx);
 
+  // Set or combine RF ports
+  for (uint32_t cc = 0; cc < phy->get_nof_carriers_lte(); cc++) {
+    for (uint32_t ant = 0; ant < phy->get_nof_ports(0); ant++) {
+      tx_buffer.set_combine(phy->get_rf_port(cc), ant, phy->get_nof_ports(0), cc_workers[cc]->get_buffer_tx(ant));
+    }
+  }
+
   Debug("Sending to radio");
-  tx_buffer.set_nof_samples(SRSRAN_SF_LEN_PRB(phy->get_nof_prb(0)));
-  phy->worker_end(this, true, tx_buffer, tx_time, false);
+  phy->worker_end(context, true, tx_buffer);
 
 #ifdef DEBUG_WRITE_FILE
   fwrite(signal_buffer_tx, SRSRAN_SF_LEN_PRB(phy->cell.nof_prb) * sizeof(cf_t), 1, f);

srsenb/src/phy/nr/slot_worker.cc

@@ -18,7 +18,9 @@ namespace nr {
 slot_worker::slot_worker(srsran::phy_common_interface& common_,
                          stack_interface_phy_nr&       stack_,
                          srslog::basic_logger&         logger_) :
-  common(common_), stack(stack_), logger(logger_)
+  common(common_),
+  stack(stack_),
+  logger(logger_)
 {
   // Do nothing
 }
@@ -30,8 +32,7 @@ bool slot_worker::init(const args_t& args)
 
   // Copy common configurations
   cell_index = args.cell_index;
-  // FIXME:
-  // pdcch_cfg  = args.pdcch_cfg;
+  rf_port    = args.rf_port;
 
   // Allocate Tx buffers
   tx_buffer.resize(args.nof_tx_ports);
@@ -124,12 +125,12 @@ uint32_t slot_worker::get_buffer_len()
   return sf_len;
 }
 
-void slot_worker::set_time(const uint32_t& tti, const srsran::rf_timestamp_t& timestamp)
+void slot_worker::set_context(const srsran::phy_common_interface::worker_context_t& w_ctx)
 {
-  logger.set_context(tti);
-  ul_slot_cfg.idx = tti;
-  dl_slot_cfg.idx = TTI_ADD(tti, FDD_HARQ_DELAY_UL_MS);
-  tx_time.copy(timestamp);
+  logger.set_context(w_ctx.sf_idx);
+  ul_slot_cfg.idx = w_ctx.sf_idx;
+  dl_slot_cfg.idx = TTI_ADD(w_ctx.sf_idx, FDD_HARQ_DELAY_UL_MS);
+  context.copy(w_ctx);
 }
 
 bool slot_worker::work_ul()
@@ -326,27 +327,26 @@ void slot_worker::work_imp()
   stack.slot_indication(dl_slot_cfg);
 
   // Get Transmission buffers
+  uint32_t            nof_ant      = (uint32_t)tx_buffer.size();
   srsran::rf_buffer_t tx_rf_buffer = {};
-  for (uint32_t i = 0; i < (uint32_t)tx_buffer.size(); i++) {
-    tx_rf_buffer.set(i, tx_buffer[i]);
-  }
-
-  // Set number of samples
   tx_rf_buffer.set_nof_samples(sf_len);
+  for (uint32_t a = 0; a < nof_ant; a++) {
+    tx_rf_buffer.set(rf_port, a, nof_ant, tx_buffer[a]);
+  }
 
   // Process uplink
   if (not work_ul()) {
-    common.worker_end(this, false, tx_rf_buffer, tx_time, true);
+    common.worker_end(context, false, tx_rf_buffer);
     return;
   }
 
   // Process downlink
   if (not work_dl()) {
-    common.worker_end(this, false, tx_rf_buffer, tx_time, true);
+    common.worker_end(context, false, tx_rf_buffer);
     return;
   }
 
-  common.worker_end(this, true, tx_rf_buffer, tx_time, true);
+  common.worker_end(context, true, tx_rf_buffer);
 }
 bool slot_worker::set_common_cfg(const srsran_carrier_nr_t& carrier, const srsran_pdcch_cfg_nr_t& pdcch_cfg_)
 {

srsenb/src/phy/nr/worker_pool.cc

@@ -52,6 +52,7 @@ bool worker_pool::init(const args_t& args, const phy_cell_cfg_list_nr_t& cell_li
     w_args.nof_max_prb             = cell_list[cell_index].carrier.nof_prb;
     w_args.nof_tx_ports            = cell_list[cell_index].carrier.max_mimo_layers;
     w_args.nof_rx_ports            = cell_list[cell_index].carrier.max_mimo_layers;
+    w_args.rf_port                 = cell_list[cell_index].rf_port;
     w_args.pusch_max_nof_iter      = args.pusch_max_nof_iter;
 
     if (not w->init(w_args)) {

srsenb/src/phy/phy_common.cc

@@ -104,42 +104,37 @@ void phy_common::set_ul_grants(uint32_t tti, const stack_interface_phy_lte::ul_s
  * Each worker uses this function to indicate that all processing is done and data is ready for transmission or
  * there is no transmission at all (tx_enable). In that case, the end of burst message will be sent to the radio
  */
-void phy_common::worker_end(void*                   tx_sem_id,
-                            bool                    tx_enable,
-                            srsran::rf_buffer_t&    buffer,
-                            srsran::rf_timestamp_t& tx_time,
-                            bool                    is_nr)
+void phy_common::worker_end(const worker_context_t& w_ctx, const bool& tx_enable, srsran::rf_buffer_t& buffer)
 {
   // Wait for the green light to transmit in the current TTI
-  semaphore.wait(tx_sem_id);
+  semaphore.wait(w_ctx.worker_ptr);
 
-  // If this is for NR, save Tx buffers...
-  if (is_nr) {
-    nr_tx_buffer       = buffer;
-    nr_tx_buffer_ready = true;
+  // For combine buffer with previous buffers
+  if (tx_enable) {
+    tx_buffer.set_nof_samples(buffer.get_nof_samples());
+    tx_buffer.set_combine(buffer);
+  }
+
+  // If the current worker is not the last one, skip transmission
+  if (not w_ctx.last) {
+    // Release semaphore and let next worker to get in
     semaphore.release();
     return;
   }
 
-  // ... otherwise, append NR base-band from saved buffer if available
-  if (nr_tx_buffer_ready) {
-    uint32_t j = 0;
-    for (uint32_t i = 0; i < SRSRAN_MAX_CHANNELS; i++) {
-      if (buffer.get(i) == nullptr) {
-        buffer.set(i, nr_tx_buffer.get(j));
-        j++;
-      }
-    }
-    nr_tx_buffer_ready = false;
-  }
+  // Add current time alignment
+  srsran::rf_timestamp_t tx_time = w_ctx.tx_time; // get transmit time from the last worker
+
+  // Use last buffer number of samples
+  tx_buffer.set_nof_samples(buffer.get_nof_samples());
 
   // Run DL channel emulator if created
   if (dl_channel) {
-    dl_channel->run(buffer.to_cf_t(), buffer.to_cf_t(), buffer.get_nof_samples(), tx_time.get(0));
+    dl_channel->run(tx_buffer.to_cf_t(), tx_buffer.to_cf_t(), tx_buffer.get_nof_samples(), tx_time.get(0));
   }
 
   // Always transmit on single radio
-  radio->tx(buffer, tx_time);
+  radio->tx(tx_buffer, tx_time);
 
   // Allow next TTI to transmit
   semaphore.release();

srsenb/src/phy/txrx.cc

@@ -172,20 +172,41 @@ void txrx::run_thread()
           timestamp.get(0).frac_secs,
           lte_worker->get_id());
 
-    lte_worker->set_time(tti, timestamp);
-
     // Trigger prach worker execution
     for (uint32_t cc = 0; cc < worker_com->get_nof_carriers_lte(); cc++) {
       prach->new_tti(cc, tti, buffer.get(worker_com->get_rf_port(cc), 0, worker_com->get_nof_ports(0)));
     }
 
-    // Launch NR worker only if available
+    // Set NR worker context and start
     if (nr_worker != nullptr) {
-      nr_worker->set_time(tti, timestamp);
+      srsran::phy_common_interface::worker_context_t context;
+      context.sf_idx     = tti;
+      context.worker_ptr = nr_worker;
+      context.last       = (lte_worker == nullptr); // Set last if standalone
+      context.tx_time.copy(timestamp);
+
+      nr_worker->set_context(context);
+
+      // NR worker needs to be launched first, phy_common::worker_end expects first the NR worker and the LTE worker.
       worker_com->semaphore.push(nr_worker);
       nr_workers->start_worker(nr_worker);
     }
 
+    // Set LTE worker context and start
+    if (lte_worker != nullptr) {
+      srsran::phy_common_interface::worker_context_t context;
+      context.sf_idx     = tti;
+      context.worker_ptr = lte_worker;
+      context.last       = true;
+      context.tx_time.copy(timestamp);
+
+      lte_worker->set_context(context);
+
+      // NR worker needs to be launched first, phy_common::worker_end expects first the NR worker and the LTE worker.
+      worker_com->semaphore.push(lte_worker);
+      lte_workers->start_worker(lte_worker);
+    }
+
     // Trigger phy worker execution
     worker_com->semaphore.push(lte_worker);
     lte_workers->start_worker(lte_worker);

srsue/hdr/phy/lte/sf_worker.h

@@ -42,8 +42,7 @@ public:
   /* Functions used by main PHY thread */
   cf_t*    get_buffer(uint32_t cc_idx, uint32_t antenna_idx);
   uint32_t get_buffer_len();
-  void     set_tti(uint32_t tti);
-  void     set_tx_time(const srsran::rf_timestamp_t& tx_time);
+  void     set_context(const srsran::phy_common_interface::worker_context_t& w_ctx);
   void     set_prach(cf_t* prach_ptr, float prach_power);
   void     set_cfo_unlocked(const uint32_t& cc_idx, float cfo);
 
@@ -89,8 +88,7 @@ private:
   cf_t* prach_ptr   = nullptr;
   float prach_power = 0;
 
-  uint32_t               tti     = 0;
-  srsran::rf_timestamp_t tx_time = {};
+  srsran::phy_common_interface::worker_context_t context = {};
 };
 
 } // namespace lte

srsue/hdr/phy/nr/sf_worker.h

@@ -39,8 +39,7 @@ public:
   /* Functions used by main PHY thread */
   cf_t*    get_buffer(uint32_t cc_idx, uint32_t antenna_idx);
   uint32_t get_buffer_len();
-  void     set_tti(uint32_t tti);
-  void     set_tx_time(const srsran::rf_timestamp_t& tx_time_);
+  void     set_context(const srsran::phy_common_interface::worker_context_t& w_ctx);
   int      read_pdsch_d(cf_t* pdsch_d);
   void     start_plot();
 
@@ -59,6 +58,7 @@ private:
   uint32_t                                       tti_rx      = 0;
   cf_t*                                          prach_ptr   = nullptr;
   float                                          prach_power = 0;
+  srsran::phy_common_interface::worker_context_t context     = {};
 };
 
 } // namespace nr

srsue/hdr/phy/phy_common.h

@@ -130,11 +130,7 @@ public:
                           srsran_pdsch_ack_resource_t resource);
   bool get_dl_pending_ack(srsran_ul_sf_cfg_t* sf, uint32_t cc_idx, srsran_pdsch_ack_cc_t* ack);
 
-  void worker_end(void*                   h,
-                  bool                    tx_enable,
-                  srsran::rf_buffer_t&    buffer,
-                  srsran::rf_timestamp_t& tx_time,
-                  bool                    is_nr) override;
+  void worker_end(const worker_context_t& w_ctx, const bool& tx_enable, srsran::rf_buffer_t& buffer) override;
 
   void set_cell(const srsran_cell_t& c);
 
@@ -371,8 +367,8 @@ private:
   bool is_mcch_subframe(srsran_mbsfn_cfg_t* cfg, uint32_t phy_tti);
 
   // NR carriers buffering synchronization, LTE workers are in charge of transmitting
-  srsran::rf_buffer_t nr_tx_buffer;
-  bool                nr_tx_buffer_ready = false;
+  bool                tx_enabled = false;
+  srsran::rf_buffer_t tx_buffer  = {};
 };
 } // namespace srsue
 

srsue/src/phy/lte/sf_worker.cc

@@ -103,20 +103,15 @@ uint32_t sf_worker::get_buffer_len()
   return cc_workers.at(0)->get_buffer_len();
 }
 
-void sf_worker::set_tti(uint32_t tti_)
+void sf_worker::set_context(const srsran::phy_common_interface::worker_context_t& w_ctx)
 {
-  tti = tti_;
+  context.copy(w_ctx);
 
   for (auto& cc_worker : cc_workers) {
-    cc_worker->set_tti(tti);
+    cc_worker->set_tti(w_ctx.sf_idx);
   }
 
-  logger.set_context(tti);
-}
-
-void sf_worker::set_tx_time(const srsran::rf_timestamp_t& tx_time_)
-{
-  tx_time.copy(tx_time_);
+  logger.set_context(w_ctx.sf_idx);
 }
 
 void sf_worker::set_prach(cf_t* prach_ptr_, float prach_power_)
@@ -153,9 +148,10 @@ void sf_worker::set_config_unlocked(uint32_t cc_idx, const srsran::phy_cfg_t& ph
 
 void sf_worker::work_imp()
 {
+  uint32_t            tti           = context.sf_idx;
   srsran::rf_buffer_t tx_signal_ptr = {};
   if (!cell_initiated) {
-    phy->worker_end(this, false, tx_signal_ptr, tx_time, false);
+    phy->worker_end(context, false, tx_signal_ptr);
     return;
   }
 
@@ -226,7 +222,7 @@ void sf_worker::work_imp()
   }
 
   // Call worker_end to transmit the signal
-  phy->worker_end(this, tx_signal_ready, tx_signal_ptr, tx_time, false);
+  phy->worker_end(context, tx_signal_ready, tx_signal_ptr);
 
   if (rx_signal_ok) {
     update_measurements();

srsue/src/phy/nr/sf_worker.cc

@@ -28,7 +28,9 @@ static int       plot_worker_id = -1;
 namespace srsue {
 namespace nr {
 sf_worker::sf_worker(srsran::phy_common_interface& common_, state& phy_state_, srslog::basic_logger& log) :
-  phy_state(phy_state_), common(common_), logger(log)
+  phy_state(phy_state_),
+  common(common_),
+  logger(log)
 {
   for (uint32_t i = 0; i < phy_state.args.nof_carriers; i++) {
     cc_worker* w = new cc_worker(i, log, phy_state);
@@ -59,18 +61,14 @@ uint32_t sf_worker::get_buffer_len()
   return cc_workers.at(0)->get_buffer_len();
 }
 
-void sf_worker::set_tti(uint32_t tti)
+void sf_worker::set_context(const srsran::phy_common_interface::worker_context_t& w_ctx)
 {
-  tti_rx = tti;
-  logger.set_context(tti);
+  tti_rx = w_ctx.sf_idx;
+  logger.set_context(w_ctx.sf_idx);
   for (auto& w : cc_workers) {
-    w->set_tti(tti);
+    w->set_tti(w_ctx.sf_idx);
   }
-}
-
-void sf_worker::set_tx_time(const srsran::rf_timestamp_t& tx_time_)
-{
-  tx_time.copy(tx_time_);
+  context.copy(w_ctx);
 }
 
 void sf_worker::work_imp()
@@ -100,7 +98,7 @@ void sf_worker::work_imp()
                                 0);
 
     // Transmit NR PRACH
-    common.worker_end(this, true, tx_buffer, tx_time, true);
+    common.worker_end(context, true, tx_buffer);
 
     // Reset PRACH pointer
     prach_ptr = nullptr;
@@ -120,7 +118,7 @@ void sf_worker::work_imp()
   tx_buffer.set_nof_samples(SRSRAN_SF_LEN_PRB_NR(phy_state.cfg.carrier.nof_prb));
 
   // Always call worker_end before returning
-  common.worker_end(this, true, tx_buffer, tx_time, true);
+  common.worker_end(context, true, tx_buffer);
 
   // Tell the plotting thread to draw the plots
 #ifdef ENABLE_GUI

srsue/src/phy/phy_common.cc

@@ -531,48 +531,48 @@ bool phy_common::get_dl_pending_ack(srsran_ul_sf_cfg_t* sf, uint32_t cc_idx, srs
  * Each worker uses this function to indicate that all processing is done and data is ready for transmission or
  * there is no transmission at all (tx_enable). In that case, the end of burst message will be sent to the radio
  */
-void phy_common::worker_end(void*                   tx_sem_id,
-                            bool                    tx_enable,
-                            srsran::rf_buffer_t&    buffer,
-                            srsran::rf_timestamp_t& tx_time,
-                            bool                    is_nr)
+void phy_common::worker_end(const worker_context_t& w_ctx, const bool& tx_enable, srsran::rf_buffer_t& buffer)
 {
   // Wait for the green light to transmit in the current TTI
-  semaphore.wait(tx_sem_id);
+  semaphore.wait(w_ctx.worker_ptr);
 
-  // If this is for NR, save Tx buffers...
-  if (is_nr) {
-    nr_tx_buffer       = buffer;
-    nr_tx_buffer_ready = true;
-    semaphore.release();
-    return;
-  }
-
-  // ... otherwise, append NR base-band from saved buffer if available
-  if (nr_tx_buffer_ready) {
-    // Load NR carrier base-band
-    for (uint32_t i = 0; i < args->nof_nr_carriers * args->nof_rx_ant; i++) {
-      uint32_t channel_idx = args->nof_lte_carriers * args->nof_rx_ant + i;
-      buffer.set(channel_idx, nr_tx_buffer.get(i));
+  // For each channel set or combine baseband
+  if (tx_enable) {
+    tx_buffer.set_combine(buffer);
   }
 
-    // Remove NR buffer flag
-    nr_tx_buffer_ready = false;
+  // Flag transmit enabled
+  tx_enabled = true;
 
-    // Make sure it transmits in this TTI
-    tx_enable = true;
+  // If the current worker is not the last one, skip transmission
+  if (not w_ctx.last) {
+    // Release semaphore and let next worker to get in
+    semaphore.release();
+    return;
   }
 
-  // Add Time Alignment
+  // Add current time alignment
+  srsran::rf_timestamp_t tx_time = w_ctx.tx_time; // get transmit time from the last worker
   tx_time.sub((double)ta.get_sec());
 
-  // For each radio, transmit
-  if (tx_enable) {
+  // Check if any worker had a transmission
+  if (tx_enabled) {
+    // Set number of samples to the latest transmit buffer
+    tx_buffer.set_nof_samples(buffer.get_nof_samples());
+
+    // Run uplink channel emulator
     if (ul_channel) {
-      ul_channel->run(buffer.to_cf_t(), buffer.to_cf_t(), buffer.get_nof_samples(), tx_time.get(0));
+      ul_channel->run(tx_buffer.to_cf_t(), tx_buffer.to_cf_t(), tx_buffer.get_nof_samples(), tx_time.get(0));
     }
 
-    radio_h->tx(buffer, tx_time);
+    // Actual baseband transmission
+    radio_h->tx(tx_buffer, tx_time);
+
+    // Reset tx buffer
+    tx_enabled = false;
+    for (uint32_t ch = 0; ch < SRSRAN_MAX_CHANNELS; ch++) {
+      tx_buffer.set(ch, nullptr);
+    }
   } else {
     if (radio_h->is_continuous_tx()) {
       if (is_pending_tx_end) {

srsue/src/phy/sync.cc

@@ -519,11 +519,19 @@ void sync::run_camping_in_sync_state(lte::sf_worker*      lte_worker,
     worker_com->update_cfo_measurement(cc, cfo);
   }
 
-  lte_worker->set_tti(tti);
-
   // Compute TX time: Any transmission happens in TTI+4 thus advance 4 ms the reception time
   last_rx_time.add(FDD_HARQ_DELAY_DL_MS * 1e-3);
-  lte_worker->set_tx_time(last_rx_time);
+
+  // Set LTE worker context
+  if (lte_worker != nullptr) {
+    srsran::phy_common_interface::worker_context_t context;
+    context.sf_idx     = tti;
+    context.worker_ptr = lte_worker;
+    context.last       = true;
+    context.tx_time.copy(last_rx_time);
+
+    lte_worker->set_context(context);
+  }
 
   // Advance/reset prach subframe pointer
   if (prach_ptr) {
@@ -534,17 +542,35 @@ void sync::run_camping_in_sync_state(lte::sf_worker*      lte_worker,
     }
   }
 
-  // Start NR worker only if present
+  // Set NR worker context and start
   if (nr_worker != nullptr) {
+    srsran::phy_common_interface::worker_context_t context;
+    context.sf_idx     = tti;
+    context.worker_ptr = nr_worker;
+    context.last       = (lte_worker == nullptr); // Set last if standalone
+    context.tx_time.copy(last_rx_time);
+
+    nr_worker->set_context(context);
+
     // NR worker needs to be launched first, phy_common::worker_end expects first the NR worker and the LTE worker.
-    nr_worker->set_tti(tti);
     worker_com->semaphore.push(nr_worker);
     nr_worker_pool->start_worker(nr_worker);
   }
 
-  // Start LTE worker
+  // Set LTE worker context and start
+  if (lte_worker != nullptr) {
+    srsran::phy_common_interface::worker_context_t context;
+    context.sf_idx     = tti;
+    context.worker_ptr = lte_worker;
+    context.last       = true;
+    context.tx_time.copy(last_rx_time);
+
+    lte_worker->set_context(context);
+
+    // NR worker needs to be launched first, phy_common::worker_end expects first the NR worker and the LTE worker.
     worker_com->semaphore.push(lte_worker);
     lte_worker_pool->start_worker(lte_worker);
+  }
 }
 void sync::run_camping_state()
 {

test/phy/dummy_phy_common.h

@@ -146,7 +146,9 @@ public:
     uint32_t nof_channels = 1;
 
     args_t(double srate_hz_, uint32_t buffer_sz_ms_, uint32_t nof_channels_) :
-      srate_hz(srate_hz_), buffer_sz_ms(buffer_sz_ms_), nof_channels(nof_channels_)
+      srate_hz(srate_hz_),
+      buffer_sz_ms(buffer_sz_ms_),
+      nof_channels(nof_channels_)
     {}
   };
 
@@ -179,21 +181,20 @@ public:
 
   void push_semaphore(void* worker_ptr) { semaphore.push(worker_ptr); }
 
-  void
-  worker_end(void* h, bool tx_enable, srsran::rf_buffer_t& buffer, srsran::rf_timestamp_t& tx_time, bool is_nr) override
+  void worker_end(const worker_context_t& w_ctx, const bool& tx_enable, srsran::rf_buffer_t& buffer) override
   {
     // Synchronize worker
-    semaphore.wait(h);
+    semaphore.wait(w_ctx.worker_ptr);
 
     // Protect internal buffers and states
     std::unique_lock<std::mutex> lock(ringbuffers_mutex);
 
-    uint64_t tx_ts = srsran_timestamp_uint64(&tx_time.get(0), srate_hz);
+    uint64_t tx_ts = srsran_timestamp_uint64(&w_ctx.tx_time.get(0), srate_hz);
 
     // Check transmit timestamp is not in the past
     if (tx_ts < write_ts) {
       logger.error("Tx time (%f) is %d samples in the past",
-                   srsran_timestamp_real(tx_time.get_ptr(0)),
+                   srsran_timestamp_real(&w_ctx.tx_time.get(0)),
                    (uint32_t)(write_ts - tx_ts));
       semaphore.release();
       return;

test/phy/test_bench.h

@@ -138,7 +138,14 @@ public:
 
     // Set gNb time
     gnb_time.add(TX_ENB_DELAY * 1e-3);
-    gnb_worker->set_time(slot_idx, gnb_time);
+
+    // Set gnb context
+    srsran::phy_common_interface::worker_context_t gnb_context;
+    gnb_context.sf_idx     = slot_idx;
+    gnb_context.worker_ptr = gnb_worker;
+    gnb_context.last       = true; // Set last if standalone
+    gnb_context.tx_time.copy(gnb_time);
+    gnb_worker->set_context(gnb_context);
 
     // Start gNb work
     gnb_phy_com.push_semaphore(gnb_worker);
@@ -158,8 +165,14 @@ public:
 
     // Set UE time
     ue_time.add(TX_ENB_DELAY * 1e-3);
-    ue_worker->set_tti(slot_idx);
-    ue_worker->set_tx_time(ue_time);
+
+    // Set gnb context
+    srsran::phy_common_interface::worker_context_t ue_context;
+    ue_context.sf_idx     = slot_idx;
+    ue_context.worker_ptr = ue_worker;
+    ue_context.last       = true; // Set last if standalone
+    ue_context.tx_time.copy(gnb_time);
+    ue_worker->set_context(ue_context);
 
     // Run UE stack
     ue_stack.run_tti(slot_idx);