updated scheduler ue mcs computation to account for new 256QAM tables

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

@@ -161,6 +161,6 @@ SRSLTE_API int srslte_cqi_hl_get_no_subbands(int nof_prb);
 
 SRSLTE_API uint8_t srslte_cqi_from_snr(float snr);
 
-SRSLTE_API float srslte_cqi_to_coderate(uint32_t cqi);
+SRSLTE_API float srslte_cqi_to_coderate(uint32_t cqi, bool use_alt_table);
 
 #endif // SRSLTE_CQI_H

lib/src/phy/phch/cqi.c

@@ -537,7 +537,7 @@ bool srslte_cqi_periodic_send(const srslte_cqi_report_cfg_t* cfg, uint32_t tti,
   return cfg->periodic_configured && cqi_send(cfg->pmi_idx, tti, frame_type == SRSLTE_FDD);
 }
 
-// CQI-to-Spectral Efficiency:  36.213 Table 7.2.3-1  */
+// CQI-to-Spectral Efficiency:  36.213 Table 7.2.3-1
 static float cqi_to_coderate[16] = {0,
                                     0.1523,
                                     0.2344,
@@ -555,10 +555,28 @@ static float cqi_to_coderate[16] = {0,
                                     5.1152,
                                     5.5547};
 
-float srslte_cqi_to_coderate(uint32_t cqi)
+// CQI-to-Spectral Efficiency:  36.213 Table 7.2.3-2
+static float cqi_to_coderate_table2[16] = {0,
+                                           0.1523,
+                                           0.3770,
+                                           0.8770,
+                                           1.4766,
+                                           1.9141,
+                                           2.4063,
+                                           2.7305,
+                                           3.3223,
+                                           3.9023,
+                                           4.5234,
+                                           5.1152,
+                                           5.5547,
+                                           6.2266,
+                                           6.9141,
+                                           7.4063};
+
+float srslte_cqi_to_coderate(uint32_t cqi, bool use_alt_table)
 {
   if (cqi < 16) {
-    return cqi_to_coderate[cqi];
+    return use_alt_table ? cqi_to_coderate_table2[cqi] : cqi_to_coderate[cqi];
   } else {
     return 0;
   }

srsenb/src/stack/mac/scheduler_ue.cc

@@ -1208,10 +1208,10 @@ int cc_sched_ue::cqi_to_tbs(uint32_t nof_prb, uint32_t nof_re, bool use_tbs_inde
 
   uint32_t cqi     = is_ul ? ul_cqi : dl_cqi;
   uint32_t max_mcs = is_ul ? max_mcs_ul : (cfg->use_tbs_index_alt) ? max_mcs_dl_alt : max_mcs_dl;
-  uint32_t max_Qm  = is_ul and not ul_64qam_enabled ? 4 : 6; //< TODO: Allow PUSCH 64QAM
+  uint32_t max_Qm  = is_ul and not ul_64qam_enabled ? 4 : (not is_ul and use_tbs_index_alt ? 8 : 6);
 
   // Take the upper bound code-rate
-  float    max_coderate = srslte_cqi_to_coderate(cqi < 15 ? cqi + 1 : 15);
+  float    max_coderate = srslte_cqi_to_coderate(std::min(cqi + 1u, 15u), use_tbs_index_alt);
   int      sel_mcs      = max_mcs + 1;
   float    coderate     = 99;
   int      tbs          = 0;
@@ -1345,7 +1345,7 @@ void cc_sched_ue::finish_tti(srslte::tti_point tti_rx)
 uint32_t cc_sched_ue::get_aggr_level(uint32_t nof_bits)
 {
   uint32_t l            = 0;
-  float    max_coderate = srslte_cqi_to_coderate(dl_cqi);
+  float    max_coderate = srslte_cqi_to_coderate(dl_cqi, cfg->use_tbs_index_alt);
   float    coderate     = 99;
   float    factor       = 1.5;
   uint32_t l_max        = 3;
@@ -1382,7 +1382,7 @@ int cc_sched_ue::alloc_tbs(uint32_t nof_prb, uint32_t nof_re, uint32_t req_bytes
     int req_tbs_idx = srslte_ra_tbs_to_table_idx(req_bytes * 8, nof_prb);
     int req_mcs     = srslte_ra_mcs_from_tbs_idx(req_tbs_idx, cfg->use_tbs_index_alt, is_ul);
 
-    if (req_mcs < (int)sel_mcs) {
+    if (req_mcs >= 0 and req_mcs < (int)sel_mcs) {
       sel_mcs   = req_mcs;
       tbs_bytes = srslte_ra_tbs_from_idx(req_tbs_idx, nof_prb) / 8;
     }