SRSUE: Zero transmit buffer if the slot is not UL

srsue/src/phy/nr/cc_worker.cc

@@ -271,6 +271,8 @@ bool cc_worker::work_ul()
 {
   // Check if it is a DL slot, if not skip
   if (!srslte_tdd_nr_is_ul(&phy->cfg.tdd, 0, ul_slot_cfg.idx)) {
+    // No NR signal shall be transmitted
+    srslte_vec_cf_zero(tx_buffer[0], ue_ul.ifft.sf_sz);
     return true;
   }