Fix to prevent USRP from disabling TX when transmitting zeros

srsue/src/phy/phch_common.cc

@@ -61,6 +61,10 @@ phch_common::phch_common(uint32_t max_mutex_) : tx_mutex(max_mutex_)
   cur_pusch_power = 0;
   bzero(zeros, 50000*sizeof(cf_t));
 
+  // FIXME: This is an ungly fix to avoid the TX filters to empty
+  for (int i=0;i<50000;i++) {
+    zeros[i] = 0.01*cexpf(((float) i/50000)*0.1*_Complex_I);
+  }
   bzero(&dl_metrics, sizeof(dl_metrics_t));
   dl_metrics_read = true;
   dl_metrics_count = 0;