PRACH working correctly for ZCZ>4. Fixed TA computation. PRACH matches Matlab.

matlab/tests/prach_test.m

@@ -27,8 +27,8 @@ for n_rb=1:length(NULRB)
                         lib=srslte_prach(ueConfig,prachConfig);
                         
                         [mat, info]=ltePRACH(ueConfig,prachConfig);
-                        err=mean(abs(mat-lib));
-                        if (err > 10^-3)
+                        err=max(abs(mat-lib));
+                        if (err > 2*10^-3)
                             disp(err)    
                             a=1:100;
                             plot(a,real(lib(a)),a,real(mat(a)))

srsapps/ue/mac/src/mux.cc

@@ -239,7 +239,6 @@ bool mux::assemble_pdu(uint32_t pdu_sz_nbits) {
   }
   // MAC control element for PHR
      // TODO
-    printf("1 nof_subh=%d, rem_size=%d\n", pdu_msg.nof_subh(), pdu_msg.rem_size());
 
   // data from any Logical Channel, except data from UL-CCCH;  
   // first only those with positive Bj
@@ -252,15 +251,12 @@ bool mux::assemble_pdu(uint32_t pdu_sz_nbits) {
       }
     }
   }
-  printf("2 nof_subh=%d, rem_size=%d\n", pdu_msg.nof_subh(), pdu_msg.rem_size());
 
   // If resources remain, allocate regardless of their Bj value
   for (int i=0;i<mac_io::NOF_UL_LCH;i++) {
     while (allocate_sdu(lchid_sorted[i], &pdu_msg));   
   }
 
-  printf("3 nof_subh=%d, rem_size=%d\n", pdu_msg.nof_subh(), pdu_msg.rem_size());
-
   bool send_bsr = bsr_procedure->generate_bsr_on_ul_grant(pdu_msg.rem_size(), &bsr);
   // Insert Padding BSR if not inserted Regular/Periodic BSR 
   if (!bsr_payload_sz && send_bsr) {

srsapps/ue/mac/test/mac_test.cc

@@ -202,7 +202,7 @@ void process_connsetup(LIBLTE_RRC_CONNECTION_SETUP_STRUCT *msg, srslte::ue::mac
   
   // FIXME: There's an error parsing the connectionSetup message. This value is hard-coded: 
  
-  phy->set_param(srslte::ue::phy_params::SR_PUCCH_RESINDEX, 
+  phy->set_param(srslte::ue::phy_params::PUCCH_N_PUCCH_SR, 
                  msg->rr_cnfg.phy_cnfg_ded.sched_request_cnfg.sr_pucch_resource_idx);
   phy->set_param(srslte::ue::phy_params::SR_CONFIG_INDEX, 
                  msg->rr_cnfg.phy_cnfg_ded.sched_request_cnfg.sr_cnfg_idx);

srsapps/ue/phy/src/phy.cc

@@ -74,7 +74,8 @@ bool phy::init_(srslte::radio* radio_handler_, srslte::ue::tti_sync* ttisync_, l
   dl_buffer_queue = new queue(6, sizeof(dl_buffer));
   do_agc = do_agc_;
   last_gain = 1e4; 
-  time_adv_sec = 0; 
+  time_adv_sec = 0;
+  sr_tx_tti = 0;  
   
   // Set default params  
   params_db.set_param(phy_params::CELLSEARCH_TIMEOUT_PSS_NFRAMES, 100);
@@ -109,15 +110,14 @@ radio* phy::get_radio() {
 }
 
 void phy::set_timeadv_rar(uint32_t ta_cmd) {
-  ta_cmd=7;
   n_ta = srslte_N_ta_new_rar(ta_cmd);
-  time_adv_sec = ((float) n_ta)/(15000.0*srslte_symbol_sz(cell.nof_prb));
+  time_adv_sec = ((float) n_ta)*SRSLTE_LTE_TS;
   Info("Set TA RAR: ta_cmd: %d, n_ta: %d, ta_usec: %.1f\n", ta_cmd, n_ta, time_adv_sec*1e6);
 }
 
 void phy::set_timeadv(uint32_t ta_cmd) {
   n_ta = srslte_N_ta_new(n_ta, ta_cmd);
-  time_adv_sec = ((float) n_ta)/(15000.0*srslte_symbol_sz(cell.nof_prb));  
+  time_adv_sec = ((float) n_ta)*SRSLTE_LTE_TS;  
   Info("Set TA: ta_cmd: %d, n_ta: %d, ta_usec: %.1f\n", ta_cmd, n_ta, time_adv_sec*1e6);
 }
 
@@ -150,7 +150,7 @@ bool phy::send_prach(uint32_t preamble_idx, int allowed_subframe, int target_pow
   return false; 
 }
 
-/* Send SR as soon as possible as defined in Section 10.2 of 36.213 */
+/* Instruct the PHY to send a SR as soon as possible */
 void phy::send_sr(bool enable)
 {
   sr_enabled = enable;
@@ -502,6 +502,7 @@ void phy::run_rx_tx_state()
     if (prach_buffer.is_ready_to_send(current_tti)) {
       // send prach if we have to 
       prach_buffer.send(radio_handler, cfo, last_rx_time);
+      radio_handler->tx_end();
       radio_handler->set_tx_gain(old_gain);
       srslte_agc_lock(&ue_sync.agc, false);
       Info("Restoring AGC. Set TX gain to %.1f dB\n", old_gain);

srslte/lib/phch/src/prach.c

@@ -357,7 +357,7 @@ int srslte_prach_init(srslte_prach_t *p,
     p->rsi = root_seq_index;
     p->hs = high_speed_flag;
     p->zczc = zero_corr_zone_config;
-
+    
     // Determine N_zc and N_cs
     if(4 == preamble_format){
       p->N_zc = 139;
@@ -370,6 +370,8 @@ int srslte_prach_init(srslte_prach_t *p,
         p->N_cs = prach_Ncs_unrestricted[p->zczc];
       }
     }
+
+    printf("Ncs=%d, zczc=%d, root_seq_index=%d, format=%d\n", p->N_cs, zero_corr_zone_config, root_seq_index, preamble_format);
     
     // Set up containers
     p->prach_bins = srslte_vec_malloc(sizeof(cf_t)*p->N_zc);
@@ -500,7 +502,7 @@ int srslte_prach_detect(srslte_prach_t *p,
     uint32_t N_rb_ul = prach_get_rb_ul(p->N_ifft_ul);
     uint32_t k_0 = freq_offset*N_RB_SC - N_rb_ul*N_RB_SC/2 + p->N_ifft_ul/2;
     uint32_t K = DELTA_F/DELTA_F_RA;
-    uint32_t begin = PHI + (K*k_0) + (K/2) + 1;
+    uint32_t begin = PHI + (K*k_0) + (K/2);
 
     for(int i=0;i<p->N_zc;i++){
       p->prach_bins[i] = signal[begin+i];