NR UE PHY Refactor

This MR is a major refactor in the physical layer of the UE. Samples of one OFDM symbol are received from the radio and processed before receiving the next symbol. All RX PHY channel functions are segmented to first process frequency domain data, then in the last symbol the remaining processing is done.

The refactor gives more time to process PUSCH as the TX thread is started immediately after the last PDCCH symbol. Also, at the end of the slot only the PDSCH decoding is done in contrast to develop where all the PHY channel processing is done at the end of the slot. This improved the real time performance with DURATION_RX_TO_TX = 2 and k1, k2 = 2 compared to develop. There is also a 20% reduction in PDSCH processing time compared to develop.

New PDSCH stats:

         L1 TX processing:           50.914 us;           37968;         135.803 us;
           ULSCH encoding:           13.566 us;           18572;          46.810 us;
            UL Indication:            7.857 us;           37968;          15.356 us;
    PDSCH symbol receiver:           17.747 us;           39687;           0.501 us;    <===
PDSCH last symbol receiver:          245.668 us;           39687;         849.306 us;   <===
           PDSCH decoding:          176.516 us;           39687;         724.542 us;
          -> Deinterleive:            5.737 us;           86255;         142.174 us;
          -> Rate Unmatch:            6.325 us;           86255;          27.547 us;
          ->  LDPC Decode:          144.148 us;           86255;         692.277 us;
       PDSCH unscrambling:            1.599 us;           39687;           5.810 us;

Develop PDSCH stats:

         L1 TX processing:           52.088 us;           28968;         176.877 us;
           ULSCH encoding:           12.302 us;           15940;          78.455 us;
         L1 RX processing:          332.034 us;           77249;        1261.602 us;
            UL Indication:            8.147 us;           28968;          22.080 us;
           PDSCH receiver:          301.437 us;           32856;         870.468 us;    <===
           PDSCH decoding:          210.813 us;           32856;         669.498 us;
          -> Deinterleive:            6.506 us;           71553;         141.580 us;
          -> Rate Unmatch:            7.558 us;           71553;         138.606 us;
          ->  LDPC Decode:          170.131 us;           71553;         781.438 us;
       PDSCH unscrambling:            1.644 us;           32856;           4.095 us;

openair2/LAYER2/NR_MAC_UE/nr_ue_procedures.c

@@ -917,7 +917,7 @@ static int nr_ue_process_dci_dl_10(NR_UE_MAC_INST_t *mac,
   const uint16_t feedback_ti = 1 + dci->pdsch_to_harq_feedback_timing_indicator.val + ntn_ue_koffset;
 
   if (rnti_type != TYPE_RA_RNTI_ && rnti_type != TYPE_SI_RNTI_) {
-    AssertFatal(feedback_ti > DURATION_RX_TO_TX,
+    AssertFatal(feedback_ti >= DURATION_RX_TO_TX,
                 "PDSCH to HARQ feedback time (%d) needs to be higher than DURATION_RX_TO_TX (%d).\n",
                 feedback_ti,
                 DURATION_RX_TO_TX);
@@ -1255,7 +1255,7 @@ static int nr_ue_process_dci_dl_11(NR_UE_MAC_INST_t *mac,
   const int ntn_ue_koffset = get_NTN_UE_Koffset(mac->sc_info.ntn_Config_r17, dlsch_pdu->SubcarrierSpacing);
   const uint16_t feedback_ti = pucch_Config->dl_DataToUL_ACK->list.array[dci->pdsch_to_harq_feedback_timing_indicator.val][0] + ntn_ue_koffset;
 
-  AssertFatal(feedback_ti > DURATION_RX_TO_TX,
+  AssertFatal(feedback_ti >= DURATION_RX_TO_TX,
               "PDSCH to HARQ feedback time (%d) needs to be higher than DURATION_RX_TO_TX (%d). Min feedback time set in config "
               "file (min_rxtxtime).\n",
               feedback_ti,