frame synchronization mechanism and robustification of if4p5 packet handling for out-of-order asynchronous reception (PDLFFT)

openair1/PHY/LTE_TRANSPORT/if4_tools.c

@@ -229,7 +229,7 @@ void recv_IF4p5(PHY_VARS_eNB *eNB, int *frame, int *subframe, uint16_t *packet_t
 
   *packet_type = packet_header->sub_type; 
 
-  //  printf("CC_id %d : frame %d, subframe %d\n",eNB->CC_id,*frame,*subframe);
+  //  LOG_I(PHY,"CC_id %d : frame %d, subframe %d\n",eNB->CC_id,*frame,*subframe);
 
   if (*packet_type == IF4p5_PDLFFT) {          
     *symbol_number = ((packet_header->frame_status)>>26)&0x000f;         

openair1/PHY/defs.h

@@ -238,6 +238,8 @@ typedef struct eNB_proc_t_s {
   openair0_timestamp timestamp_tx;
   /// subframe to act upon for reception
   int subframe_rx;
+  /// symbol mask for IF4p5 reception per subframe
+  uint32_t symbol_mask[10];
   /// subframe to act upon for PRACH
   int subframe_prach;
   /// frame to act upon for reception

targets/ARCH/USRP/USERSPACE/LIB/usrp_lib.cpp

@@ -360,19 +360,34 @@ static bool is_equal(double a, double b)
   return std::fabs(a-b) < std::numeric_limits<double>::epsilon();
 }
 
-/*! \brief Set frequencies (TX/RX)
+void *freq_thread(void *arg) {
+  
+  openair0_device *device=(openair0_device *)arg;
+  usrp_state_t *s = (usrp_state_t*)device->priv;
+  
+  s->usrp->set_tx_freq(device->openair0_cfg[0].tx_freq[0]);
+  s->usrp->set_rx_freq(device->openair0_cfg[0].rx_freq[0]);
+}
+/*! \brief Set frequencies (TX/RX). Spawns a thread to handle the frequency change to not block the calling thread
  * \param device the hardware to use
  * \param openair0_cfg RF frontend parameters set by application
  * \param dummy dummy variable not used
  * \returns 0 in success 
  */
-int trx_usrp_set_freq(openair0_device* device, openair0_config_t *openair0_cfg, int dummy) {
+int trx_usrp_set_freq(openair0_device* device, openair0_config_t *openair0_cfg, int dont_block) {
 
   usrp_state_t *s = (usrp_state_t*)device->priv;
+  pthread_t f_thread;
 
   printf("Setting USRP TX Freq %f, RX Freq %f\n",openair0_cfg[0].tx_freq[0],openair0_cfg[0].rx_freq[0]);
-  s->usrp->set_tx_freq(openair0_cfg[0].tx_freq[0]);
-  s->usrp->set_rx_freq(openair0_cfg[0].rx_freq[0]);
+
+  // spawn a thread to handle the frequency change to not block the calling thread
+  if (dont_block == 1)
+    pthread_create(&f_thread,NULL,freq_thread,(void*)device);
+  else {
+    s->usrp->set_tx_freq(device->openair0_cfg[0].tx_freq[0]);
+    s->usrp->set_rx_freq(device->openair0_cfg[0].rx_freq[0]);
+  }
 
   return(0);
   

targets/RT/USER/lte-enb.c

@@ -744,11 +744,10 @@ void fh_if4p5_asynch_DL(PHY_VARS_eNB *eNB,int *frame,int *subframe) {
   eNB_proc_t *proc       = &eNB->proc;
 
   uint16_t packet_type;
-  uint32_t symbol_number,symbol_mask,symbol_mask_full;
+  uint32_t symbol_number,symbol_mask_full;
   int subframe_tx,frame_tx;
 
   symbol_number = 0;
-  symbol_mask = 0;
   symbol_mask_full = (1<<fp->symbols_per_tti)-1;
 
   do {   // Blocking, we need a timeout on this !!!!!!!!!!!!!!!!!!!!!!!
@@ -765,21 +764,24 @@ void fh_if4p5_asynch_DL(PHY_VARS_eNB *eNB,int *frame,int *subframe) {
 	//	exit_fun("Exiting");
       }
       if (subframe_tx != *subframe) {
-	LOG_E(PHY,"fh_if4p5_asynch_DL: subframe_tx %d is not what we expect %d\n",subframe_tx,*subframe);
-	*subframe = subframe_tx;
-	//	exit_fun("Exiting");
+	LOG_E(PHY,"fh_if4p5_asynch_DL: (frame %d) subframe_tx %d is not what we expect %d\n",frame_tx,subframe_tx,*subframe);
+	//*subframe = subframe_tx;
+	//exit_fun("Exiting");
       }
     }
     if (packet_type == IF4p5_PDLFFT) {
-      symbol_mask = symbol_mask | (1<<symbol_number);
+      proc->symbol_mask[subframe_tx] =proc->symbol_mask[subframe_tx] | (1<<symbol_number);
     }
     else {
       LOG_E(PHY,"Illegal IF4p5 packet type (should only be IF4p5_PDLFFT%d\n",packet_type);
       exit_fun("Exiting");
     }
-  } while (symbol_mask != symbol_mask_full);    
+  } while (proc->symbol_mask[*subframe] != symbol_mask_full);    
+
+  // intialize this to zero after we're done with the subframe
+  proc->symbol_mask[*subframe] = 0;
   
-  do_OFDM_mod_rt(subframe_tx, eNB);
+  do_OFDM_mod_rt(*subframe, eNB);
 } 
 
 /*!
@@ -1463,7 +1465,7 @@ static void* eNB_thread_single( void* param ) {
       eNB->rfdevice.openair0_cfg->rx_freq[i] = temp_freq1;
       eNB->rfdevice.openair0_cfg->tx_freq[i] = temp_freq2;
     }
-    eNB->rfdevice.trx_set_freq_func(&eNB->rfdevice,eNB->rfdevice.openair0_cfg,0);
+    eNB->rfdevice.trx_set_freq_func(&eNB->rfdevice,eNB->rfdevice.openair0_cfg,1);
   } // if RRU and slave
 
 
@@ -1540,6 +1542,8 @@ void init_eNB_proc(int inst) {
     proc->first_rx=1;
     proc->first_tx=1;
 
+    for (i=0;i<10;i++) proc->symbol_mask[i]=0;
+
     pthread_mutex_init( &proc_rxtx[0].mutex_rxtx, NULL);
     pthread_mutex_init( &proc_rxtx[1].mutex_rxtx, NULL);
     pthread_cond_init( &proc_rxtx[0].cond_rxtx, NULL);