fixing comments from Xavier's review

lib/include/srslte/phy/common/phy_common.h

@@ -38,7 +38,8 @@
 #include "srslte/config.h"
 
 #define SRSLTE_NOF_SF_X_FRAME 10
-#define SRSLTE_NSLOTS_X_FRAME (2 * SRSLTE_NOF_SF_X_FRAME)
+#define SRSLTE_NOF_SLOTS_PER_SF 2
+#define SRSLTE_NSLOTS_X_FRAME (SRSLTE_NOF_SLOTS_PER_SF * SRSLTE_NOF_SF_X_FRAME)
 
 #define SRSLTE_NSOFT_BITS  250368 // Soft buffer size for Category 1 UE
 
@@ -323,6 +324,10 @@ typedef struct SRSLTE_API {
 #define SRSLTE_DEFAULT_MAX_FRAMES_NPSS 20
 #define SRSLTE_DEFAULT_NOF_VALID_NPSS_FRAMES 20
 
+#define SRSLTE_NBIOT_NPBCH_NOF_TOTAL_BITS (1600) ///< Number of bits for the entire NPBCH (See 36.211 Sec 10.2.4.1)
+#define SRSLTE_NBIOT_NPBCH_NOF_BITS_SF                                                                                 \
+  (SRSLTE_NBIOT_NPBCH_NOF_TOTAL_BITS / 8) ///< The NPBCH is transmitted in 8 blocks (See 36.211 Sec 10.2.4.4)
+
 SRSLTE_API bool srslte_cell_isvalid(srslte_cell_t *cell);
 
 SRSLTE_API void srslte_cell_fprint(FILE *stream, 

lib/include/srslte/phy/phch/npbch.h

@@ -81,6 +81,7 @@ typedef struct SRS_API {
   // tx & rx objects
   srslte_modem_table_t mod;
   srslte_sequence_t    seq;
+  srslte_sequence_t    seq_r14[SRSLTE_NPBCH_NUM_BLOCKS];
   srslte_viterbi_t     decoder;
   srslte_crc_t         crc;
   srslte_convcoder_t   encoder;

lib/src/phy/ch_estimation/chest_dl_nbiot.c

@@ -170,7 +170,7 @@ static float estimate_noise_pilots(srslte_chest_dl_nbiot_t* q, uint32_t port_id)
   return power;
 }
 
-#define cesymb(i) ce[SRSLTE_RE_IDX(q->cell.base.nof_prb, i, 0)]
+#define cesymb(i) ce[SRSLTE_RE_IDX(q->cell.base.nof_prb, (i), 0)]
 
 static void interpolate_pilots(srslte_chest_dl_nbiot_t* q, cf_t* pilot_estimates, cf_t* ce, uint32_t port_id)
 {

lib/src/phy/ch_estimation/refsignal_dl_nbiot.c

@@ -131,7 +131,7 @@ int srslte_refsignal_dl_nbiot_set_cell(srslte_refsignal_dl_nbiot_t* q, srslte_nb
 
     srslte_sequence_t seq;
     bzero(&seq, sizeof(srslte_sequence_t));
-    if (srslte_sequence_init(&seq, 2 * 2 * SRSLTE_MAX_PRB)) {
+    if (srslte_sequence_init(&seq, SRSLTE_NOF_SLOTS_PER_SF * SRSLTE_NBIOT_MAX_PORTS * SRSLTE_MAX_PRB)) {
       goto free_and_exit;
     }
 
@@ -145,7 +145,7 @@ int srslte_refsignal_dl_nbiot_set_cell(srslte_refsignal_dl_nbiot_t* q, srslte_nb
           uint32_t c_init = 1024 * (7 * (ns + 1) + lp + 1) * (2 * cell.n_id_ncell + 1) + 2 * cell.n_id_ncell + N_cp;
 
           /* generate sequence for this symbol and slot */
-          srslte_sequence_set_LTE_pr(&seq, 2 * 2 * SRSLTE_MAX_PRB, c_init);
+          srslte_sequence_set_LTE_pr(&seq, SRSLTE_NOF_SLOTS_PER_SF + SRSLTE_NBIOT_MAX_PORTS * SRSLTE_MAX_PRB, c_init);
 
           /* Compute signal */
           for (uint32_t i = 0; i < 2; i++) {

lib/src/phy/phch/npbch.c

@@ -151,6 +151,10 @@ void srslte_npbch_free(srslte_npbch_t* q)
   if (q->rm_b) {
     free(q->rm_b);
   }
+  for (uint32_t i = 0; i < SRSLTE_NPBCH_NUM_BLOCKS; i++) {
+    srslte_sequence_free(&q->seq_r14[i]);
+  }
+
   srslte_sequence_free(&q->seq);
   srslte_modem_table_free(&q->mod);
   srslte_viterbi_free(&q->decoder);
@@ -175,6 +179,15 @@ int srslte_npbch_set_cell(srslte_npbch_t* q, srslte_nbiot_cell_t cell)
         fprintf(stderr, "Error initiating NPBCH sequence.\n");
         return SRSLTE_ERROR;
       }
+
+      // pre-compute the 8 rotation sequences for R14
+      if (q->cell.is_r14) {
+        for (uint32_t i = 0; i < SRSLTE_NPBCH_NUM_BLOCKS; i++) {
+          if (srslte_sequence_npbch_r14(&q->seq_r14[i], q->cell.n_id_ncell, i)) {
+            return SRSLTE_ERROR;
+          }
+        }
+      }
     }
 
     ret = SRSLTE_SUCCESS;
@@ -258,7 +271,6 @@ int srslte_npbch_encode(srslte_npbch_t* q,
                         cf_t*           sf[SRSLTE_MAX_PORTS],
                         uint32_t        frame_idx)
 {
-  int   nof_bits;
   int   block_idx = (frame_idx / SRSLTE_NPBCH_NUM_REP) % SRSLTE_NPBCH_NUM_BLOCKS;
   cf_t* x[SRSLTE_MAX_LAYERS];
 
@@ -269,7 +281,7 @@ int srslte_npbch_encode(srslte_npbch_t* q,
       }
     }
     // Set pointers for layermapping & precoding
-    nof_bits = 2 * q->nof_symbols;
+    int nof_bits = 2 * q->nof_symbols;
 
     // number of layers equals number of ports
     for (int i = 0; i < q->cell.nof_ports; i++) {
@@ -310,7 +322,7 @@ int srslte_npbch_encode(srslte_npbch_t* q,
     // Write exactly SRSLTE_NPBCH_NUM_RE (assumes symbols have been modulated before)
     for (int i = 0; i < q->cell.nof_ports; i++) {
       if (q->cell.is_r14) {
-        DEBUG("Applying phase rotattion on port %d in frame %d.\n", i, frame_idx);
+        DEBUG("Applying phase rotation on port %d in frame %d.\n", i, frame_idx);
         srslte_npbch_rotate(q, frame_idx, q->symbols[i], q->symbols[i], q->nof_symbols, false);
       }
       DEBUG("Putting MIB-NB block %d on port %d in frame %d.\n", block_idx, i, frame_idx);
@@ -336,14 +348,9 @@ int srslte_npbch_rotate(srslte_npbch_t* q,
   // Generate frame specific scrambling sequence for symbol rotation
   DEBUG("%sotating NPBCH in SFN=%d\n", back ? "De-R" : "R", nf);
 
-  srslte_sequence_t seq;
-  if (srslte_sequence_npbch_r14(&seq, q->cell.n_id_ncell, nf)) {
-    return SRSLTE_ERROR;
-  }
-
   for (int i = 0; i < num_samples; i++) {
-    int c_2i   = seq.c[2 * i];
+    int c_2i   = q->seq_r14[nf % 8].c[2 * i];
-    int c_2ip1 = seq.c[2 * i + 1];
+    int c_2ip1 = q->seq_r14[nf % 8].c[2 * i + 1];
 
 #if 1
     cf_t phi_f = 0;
@@ -374,7 +381,6 @@ int srslte_npbch_rotate(srslte_npbch_t* q,
     }
   }
 
-  srslte_sequence_free(&seq);
   return SRSLTE_SUCCESS;
 }
 

lib/src/phy/phch/ra_nbiot.c

@@ -36,8 +36,6 @@
 #define MAX_I_SF_VAL 7
 #define EUTRA_CONTROL_REGION_SIZE 3 // FIXME: Needs to be set by SIB1
 
-#define min(a, b) (a < b ? a : b)
-
 /// Number of repetitions according to Table 16.4.1.3-2 in TS 36.213 13.2.0
 const int n_rep_table[16] = {1, 2, 4, 8, 16, 32, 64, 128, 192, 256, 384, 512, 768, 1024, 1536, 2048};
 
@@ -139,9 +137,9 @@ static int nbiot_dl_dci_to_grant_mcs(srslte_ra_nbiot_dl_dci_t* dci, srslte_ra_nb
   grant->mcs[0].mod = SRSLTE_MOD_QPSK;
 
   // limit config values in DCI
-  dci->alloc.sched_info_sib1 = min(dci->alloc.sched_info_sib1, MAX_I_TBS_VAL_SIB);
+  dci->alloc.sched_info_sib1 = SRSLTE_MIN(dci->alloc.sched_info_sib1, MAX_I_TBS_VAL_SIB);
-  dci->mcs_idx               = min(dci->mcs_idx, MAX_I_TBS_VAL);
+  dci->mcs_idx               = SRSLTE_MIN(dci->mcs_idx, MAX_I_TBS_VAL);
-  dci->alloc.i_sf            = min(dci->alloc.i_sf, MAX_I_SF_VAL);
+  dci->alloc.i_sf            = SRSLTE_MIN(dci->alloc.i_sf, MAX_I_SF_VAL);
 
   if (dci->alloc.has_sib1) {
     i_tbs = dci->alloc.sched_info_sib1;
@@ -173,7 +171,7 @@ int srslte_ra_n_rep_sib1_nb(srslte_mib_nb_t* mib)
 
 int srslte_ra_nbiot_get_sib1_tbs(srslte_mib_nb_t* mib)
 {
-  uint32_t i_tbs = min(mib->sched_info_sib1, MAX_I_TBS_VAL_SIB);
+  uint32_t i_tbs = SRSLTE_MIN(mib->sched_info_sib1, MAX_I_TBS_VAL_SIB);
   return tbs_table_nbiot_sib1[i_tbs];
 }
 

lib/src/phy/phch/sequences.c

@@ -84,7 +84,7 @@ int srslte_sequence_pmch(srslte_sequence_t* seq, uint32_t nslot, uint32_t mbsfn_
  */
 int srslte_sequence_npbch(srslte_sequence_t *seq, srslte_cp_t cp, uint32_t cell_id) {
    bzero(seq, sizeof(srslte_sequence_t));
-   return srslte_sequence_LTE_pr(seq, 1600, cell_id);
+   return srslte_sequence_LTE_pr(seq, SRSLTE_NBIOT_NPBCH_NOF_TOTAL_BITS, cell_id);
 }
 
 /**
@@ -93,7 +93,10 @@ int srslte_sequence_npbch(srslte_sequence_t *seq, srslte_cp_t cp, uint32_t cell_
 int srslte_sequence_npbch_r14(srslte_sequence_t *seq, uint32_t n_id_ncell, uint32_t nf)
 {
   bzero(seq, sizeof(srslte_sequence_t));
-  return srslte_sequence_LTE_pr(seq, 200, (n_id_ncell + 1) * (((nf % 8) + 1) * ((nf % 8) + 1) * ((nf % 8) + 1)) * 512 + n_id_ncell);
+  return srslte_sequence_LTE_pr(seq,
+                                SRSLTE_NBIOT_NPBCH_NOF_BITS_SF,
+                                (n_id_ncell + 1) * (((nf % 8) + 1) * ((nf % 8) + 1) * ((nf % 8) + 1)) * 512 +
+                                    n_id_ncell);
 }
 
 /**