diff --git a/lib/include/srslte/common/common.h b/lib/include/srslte/common/common.h
index c450fc1d0..41a89fb36 100644
--- a/lib/include/srslte/common/common.h
+++ b/lib/include/srslte/common/common.h
@@ -50,6 +50,8 @@
 #define TTI_TX(tti)     ((tti+HARQ_DELAY_MS)%10240)
 #define TTI_RX_ACK(tti) ((tti+(2*HARQ_DELAY_MS))%10240)
 
+#define UL_PIDOF(tti)   (tti%(2*HARQ_DELAY_MS))
+
 #define TTIMOD_SZ       (((2*HARQ_DELAY_MS) < 10)?10:20)
 #define TTIMOD(tti)     (tti%TTIMOD_SZ)
 
diff --git a/lib/src/phy/ue/ue_ul.c b/lib/src/phy/ue/ue_ul.c
index 853937f7c..ec2809dfe 100644
--- a/lib/src/phy/ue/ue_ul.c
+++ b/lib/src/phy/ue/ue_ul.c
@@ -453,7 +453,7 @@ int srslte_ue_ul_pusch_encode_rnti_softbuffer(srslte_ue_ul_t *q,
     
     if (srslte_pusch_encode(&q->pusch, &q->pusch_cfg, softbuffer, data, uci_data, rnti, q->sf_symbols)) {
       fprintf(stderr, "Error encoding TB\n");
-      return ret; 
+      return SRSLTE_ERROR;
     }
 
     if (q->signals_pregenerated) {
diff --git a/srsenb/hdr/phy/phch_worker.h b/srsenb/hdr/phy/phch_worker.h
index dd95aaa93..523fefeec 100644
--- a/srsenb/hdr/phy/phch_worker.h
+++ b/srsenb/hdr/phy/phch_worker.h
@@ -95,7 +95,7 @@ private:
   srslte_enb_dl_t enb_dl;
   srslte_enb_ul_t enb_ul;
   
-  srslte_timestamp_t tx_time; 
+  srslte_timestamp_t tx_time;
 
   // Class to store user information 
   class ue {
@@ -112,6 +112,11 @@ private:
     void metrics_read(phy_metrics_t *metrics);
     void metrics_dl(uint32_t mcs);
     void metrics_ul(uint32_t mcs, float rssi, float sinr, uint32_t turbo_iters);
+
+    int last_dl_tbs[2*HARQ_DELAY_MS][SRSLTE_MAX_CODEWORDS];
+    int last_ul_tbs[2*HARQ_DELAY_MS];
+    srslte_mod_t last_ul_mod[2*HARQ_DELAY_MS];
+
   private:
     phy_metrics_t metrics; 
   }; 
diff --git a/srsenb/src/mac/scheduler.cc b/srsenb/src/mac/scheduler.cc
index 81ed0882e..f477895b5 100644
--- a/srsenb/src/mac/scheduler.cc
+++ b/srsenb/src/mac/scheduler.cc
@@ -709,7 +709,7 @@ int sched::ul_sched(uint32_t tti, srsenb::sched_interface::ul_sched_res_t* sched
   
     /* Indicate PHICH acknowledgment if needed */
     if (h->has_pending_ack()) {
-      sched_result->phich[nof_phich_elems].phich = h->get_ack()?ul_sched_phich_t::ACK:ul_sched_phich_t::NACK; 
+      sched_result->phich[nof_phich_elems].phich = h->get_ack()?ul_sched_phich_t::ACK:ul_sched_phich_t::NACK;
       sched_result->phich[nof_phich_elems].rnti = rnti;
       nof_phich_elems++;
     }
@@ -767,7 +767,7 @@ int sched::ul_sched(uint32_t tti, srsenb::sched_interface::ul_sched_res_t* sched
     {   
       ul_harq_proc::ul_alloc_t alloc = h->get_alloc(); 
       bool is_newtx = h->is_empty(); 
-      bool needs_pdcch = !h->is_adaptive_retx() && !is_rar;
+      bool needs_pdcch = h->is_adaptive_retx() && !is_rar;
 
       // Set number of retx
       if (is_newtx) {
diff --git a/srsenb/src/mac/scheduler_harq.cc b/srsenb/src/mac/scheduler_harq.cc
index f5209b374..88ae6b74d 100644
--- a/srsenb/src/mac/scheduler_harq.cc
+++ b/srsenb/src/mac/scheduler_harq.cc
@@ -198,13 +198,13 @@ ul_harq_proc::ul_alloc_t ul_harq_proc::get_alloc()
 
 void ul_harq_proc::set_alloc(ul_harq_proc::ul_alloc_t alloc)
 {
-  is_adaptive = false; 
+  is_adaptive = true;
   memcpy(&allocation, &alloc, sizeof(ul_alloc_t));
 }
 
 void ul_harq_proc::same_alloc()
 {
-  is_adaptive = true; 
+  is_adaptive = false;
 }
 
 bool ul_harq_proc::is_adaptive_retx()
@@ -243,8 +243,7 @@ void ul_harq_proc::reset_pending_data()
   }
 }
 
-
-  uint32_t ul_harq_proc::get_pending_data()
+uint32_t ul_harq_proc::get_pending_data()
 {
   return pending_data; 
 }
diff --git a/srsenb/src/mac/scheduler_ue.cc b/srsenb/src/mac/scheduler_ue.cc
index 7a810e2cc..87949179e 100644
--- a/srsenb/src/mac/scheduler_ue.cc
+++ b/srsenb/src/mac/scheduler_ue.cc
@@ -444,7 +444,8 @@ int sched_ue::generate_format0(ul_harq_proc *h,
   int tbs = 0; 
   
   ul_harq_proc::ul_alloc_t allocation = h->get_alloc();
-  
+
+  bool is_newtx = true;
   if (h->get_rar_mcs(&mcs)) {
     tbs = srslte_ra_tbs_from_idx(srslte_ra_tbs_idx_from_mcs(mcs), allocation.L)/8;
     h->new_tx(tti, mcs, tbs); 
@@ -463,7 +464,8 @@ int sched_ue::generate_format0(ul_harq_proc *h,
     
     h->new_tx(tti, mcs, tbs);  
 
-  } else {    
+  } else {
+    is_newtx = false;
     h->new_retx(tti, &mcs, NULL);  
     tbs = srslte_ra_tbs_from_idx(srslte_ra_tbs_idx_from_mcs(mcs), allocation.L)/8;
   }
@@ -474,9 +476,13 @@ int sched_ue::generate_format0(ul_harq_proc *h,
   if (tbs > 0) {
     dci->type2_alloc.L_crb = allocation.L;
     dci->type2_alloc.RB_start = allocation.RB_start;
-    dci->mcs_idx     = mcs; 
-    dci->rv_idx      = sched::get_rvidx(h->nof_retx()); 
-    dci->ndi         = h->get_ndi(); 
+    dci->rv_idx      = sched::get_rvidx(h->nof_retx());
+    if (!is_newtx && h->is_adaptive_retx()) {
+      dci->mcs_idx     = 28+dci->rv_idx;
+    } else {
+      dci->mcs_idx     = mcs;
+    }
+    dci->ndi         = h->get_ndi();
     dci->cqi_request = cqi_request; 
     dci->freq_hop_fl = srslte_ra_ul_dci_t::SRSLTE_RA_PUSCH_HOP_DISABLED; 
     dci->tpc_pusch   = next_tpc_pusch; 
diff --git a/srsenb/src/phy/phch_worker.cc b/srsenb/src/phy/phch_worker.cc
index 103017fcc..c023c13e0 100644
--- a/srsenb/src/phy/phch_worker.cc
+++ b/srsenb/src/phy/phch_worker.cc
@@ -412,6 +412,22 @@ int phch_worker::decode_pusch(srslte_enb_ul_pusch_t *grants, uint32_t nof_pusch)
       srslte_ra_ul_grant_t phy_grant;
       int res = -1;
       if (!srslte_ra_ul_dci_to_grant(&grants[i].grant, enb_ul.cell.nof_prb, n_rb_ho, &phy_grant)) {
+
+        // Handle Format0 adaptive retx
+        // Use last TBS for this TB in case of mcs>28
+        if (phy_grant.mcs.idx > 28) {
+          phy_grant.mcs.tbs = ue_db[rnti].last_ul_tbs[TTI_RX(tti_rx)%(2*HARQ_DELAY_MS)];
+          Info("RETX: mcs=%d, old_tbs=%d pid=%d\n", phy_grant.mcs.idx, phy_grant.mcs.tbs, TTI_TX(tti_rx)%(2*HARQ_DELAY_MS));
+        }
+        ue_db[rnti].last_ul_tbs[TTI_RX(tti_rx)%(2*HARQ_DELAY_MS)] = phy_grant.mcs.tbs;
+
+        if (phy_grant.mcs.mod == SRSLTE_MOD_LAST) {
+          phy_grant.mcs.mod = ue_db[rnti].last_ul_mod[TTI_RX(tti_rx)%(2*HARQ_DELAY_MS)];
+          phy_grant.Qm      = srslte_mod_bits_x_symbol(phy_grant.mcs.mod);
+        }
+        ue_db[rnti].last_ul_mod[TTI_RX(tti_rx)%(2*HARQ_DELAY_MS)] = phy_grant.mcs.mod;
+
+
         if (phy_grant.mcs.mod == SRSLTE_MOD_64QAM) {
           phy_grant.mcs.mod = SRSLTE_MOD_16QAM;
         }
diff --git a/srsue/hdr/mac/ul_harq.h b/srsue/hdr/mac/ul_harq.h
index 50143a571..72b691c00 100644
--- a/srsue/hdr/mac/ul_harq.h
+++ b/srsue/hdr/mac/ul_harq.h
@@ -44,39 +44,35 @@
 namespace srsue {
 
 template <std::size_t N, typename Tgrant, typename Taction, typename Tphygrant>
-class ul_harq_entity
-{
+class ul_harq_entity {
 public:
-  static uint32_t pidof(uint32_t tti)
-  {
-    return (uint32_t) tti%N;
+  static uint32_t pidof(uint32_t tti) {
+    return (uint32_t) tti % N;
   }
-  
-  ul_harq_entity() : proc(N)
-  {
+
+  ul_harq_entity() : proc(N) {
     contention_timer = NULL;
 
-    pcap        = NULL;
-    mux_unit    = NULL;
-    log_h       = NULL; 
-    params      = NULL;
-    rntis       = NULL; 
-    average_retx = 0; 
-    nof_pkts     = 0;
+    pcap = NULL;
+    mux_unit = NULL;
+    log_h = NULL;
+    params = NULL;
+    rntis = NULL;
+    average_retx = 0;
+    nof_pkts = 0;
   }
 
-  bool init(srslte::log *log_h_, 
+  bool init(srslte::log *log_h_,
             mac_interface_rrc_common::ue_rnti_t *rntis_,
             mac_interface_rrc_common::ul_harq_params_t *params_,
-            srslte::timers::timer* contention_timer_,
-            mux *mux_unit_)
-  {
-    log_h     = log_h_;
-    mux_unit  = mux_unit_;
-    params    = params_;
-    rntis     = rntis_;
+            srslte::timers::timer *contention_timer_,
+            mux *mux_unit_) {
+    log_h = log_h_;
+    mux_unit = mux_unit_;
+    params = params_;
+    rntis = rntis_;
     contention_timer = contention_timer_;
-    for (uint32_t i=0;i<N;i++) {
+    for (uint32_t i = 0; i < N; i++) {
       if (!proc[i].init(i, this)) {
         return false;
       }
@@ -84,29 +80,29 @@ public:
     return true;
   }
 
-  void reset()
-  {
-    for (uint32_t i=0;i<N;i++) {
+  void reset() {
+    for (uint32_t i = 0; i < N; i++) {
       proc[i].reset();
     }
     ul_sps_assig.clear();
   }
 
-  void reset_ndi()
-  {
-    for (uint32_t i=0;i<N;i++) {
+  void reset_ndi() {
+    for (uint32_t i = 0; i < N; i++) {
       proc[i].reset_ndi();
     }
   }
 
-  void start_pcap(srslte::mac_pcap* pcap_)
-  {
+  void start_pcap(srslte::mac_pcap *pcap_) {
     pcap = pcap_;
   }
 
-  
+
   /***************** PHY->MAC interface for UL processes **************************/
-  void new_grant_ul(Tgrant grant, Taction *action)
+  void new_grant_ul(Tgrant grant, Taction *action) {
+    new_grant_ul_ack(grant, NULL, action);
+  }
+  void new_grant_ul_ack(Tgrant grant, bool *ack, Taction *action)
   {
     if (grant.rnti_type == SRSLTE_RNTI_USER ||
       grant.rnti_type == SRSLTE_RNTI_TEMP ||
@@ -115,27 +111,20 @@ public:
       if (grant.rnti_type == SRSLTE_RNTI_USER && proc[pidof(grant.tti)].is_sps()) {
         grant.ndi[0] = true;
       }
-      run_tti(grant.tti, &grant, action);
+      run_tti(grant.tti, &grant, ack, action);
     } else if (grant.rnti_type == SRSLTE_RNTI_SPS) {
       if (grant.ndi[0]) {
         grant.ndi[0] = proc[pidof(grant.tti)].get_ndi();
-        run_tti(grant.tti, &grant, action);
+        run_tti(grant.tti, &grant, ack, action);
       } else {
         Info("Not implemented\n");
       }
     }
   }
 
-  void new_grant_ul_ack(Tgrant grant, bool ack, Taction *action)
-  {
-    set_ack(grant.tti, ack, action);
-    new_grant_ul(grant, action);
-  }
-
   void harq_recv(uint32_t tti, bool ack, Taction *action)
   {
-    set_ack(tti, ack, action);
-    run_tti(tti, NULL, action);
+    run_tti(tti, NULL, &ack, action);
   }
 
   int get_current_tbs(uint32_t tti)
@@ -206,10 +195,19 @@ private:
       bzero(&cur_grant, sizeof(Tgrant));
     }
 
-    void reset_ndi() { ndi = false; }
-    
-    void run_tti(uint32_t tti_tx, Tgrant *grant, Taction* action)
+    void reset_ndi() { cur_grant.ndi[0] = false; }
+
+    void run_tti(uint32_t tti_tx, Tgrant *grant, bool *ack, Taction* action)
     {
+      if (ack) {
+        if (grant) {
+          if (grant->ndi[0] == get_ndi()) {
+            *ack = false;
+          }
+        }
+        set_harq_feedback(*ack);
+      }
+
       uint32_t max_retx;
       if (is_msg3) {
         max_retx = harq_entity->params->max_harq_msg3_tx;
@@ -219,9 +217,9 @@ private:
 
       // Receive and route HARQ feedbacks
       if (grant) {
-        if ((!(grant->rnti_type == SRSLTE_RNTI_TEMP) && grant->ndi[0] != get_ndi() && grant->phy_grant.ul.mcs.idx < 29) ||
-          (grant->rnti_type == SRSLTE_RNTI_USER && !has_grant())             ||
-          grant->is_from_rar)
+        if ((!(grant->rnti_type == SRSLTE_RNTI_TEMP) && grant->ndi[0] != get_ndi() && ack) ||
+            (grant->rnti_type == SRSLTE_RNTI_USER && !has_grant())                  ||
+             grant->is_from_rar)
         {
           // New transmission
 
@@ -255,7 +253,7 @@ private:
             generate_retx(tti_tx, grant, action);
           }
         } else {
-          Warning("UL %d: Received mcs=%d but no previous grant available for this PID.\n", pid, grant->phy_grant.ul.mcs.idx);
+          Warning("UL %d: Received retransmission but no previous grant available for this PID.\n", pid);
         }
       } else if (has_grant()) {
         // Non-Adaptive Re-Tx
@@ -294,9 +292,8 @@ private:
     }
 
     bool has_grant() { return is_grant_configured; }
-    bool get_ndi() { return ndi; }
+    bool get_ndi() { return cur_grant.ndi[0]; }
     bool is_sps() { return false; }
-    uint32_t last_tx_tti() { return tti_last_tx; }
     uint32_t get_nof_retx() { return current_tx_nb; }
     int get_current_tbs() { return cur_grant.n_bytes[0]*8; }
    
@@ -307,7 +304,6 @@ private:
     uint32_t                    current_tx_nb;
     uint32_t                    current_irv; 
     bool                        harq_feedback; 
-    bool                        ndi; 
     srslte::log                 *log_h;
     ul_harq_entity              *harq_entity; 
     bool                        is_grant_configured; 
@@ -398,24 +394,12 @@ private:
 
   // Implements Section 5.4.2.1
   // Called with UL grant
-  void run_tti(uint32_t tti, Tgrant *grant, Taction* action)
+  void run_tti(uint32_t tti, Tgrant *grant, bool *ack, Taction* action)
   {
     uint32_t tti_tx = (tti+action->tti_offset)%10240;
-    proc[pidof(tti_tx)].run_tti(tti_tx, grant, action);
+    proc[pidof(tti_tx)].run_tti(tti_tx, grant, ack, action);
   }
 
-  void set_ack(uint32_t tti, bool ack, Taction *action)
-  {
-    int tti_harq = (int) tti - action->tti_offset;
-    if (tti_harq < 0) {
-      tti_harq += 10240;
-    }
-    uint32_t pid_harq = pidof(tti_harq);
-    if (proc[pid_harq].has_grant() && (proc[pid_harq].last_tx_tti() <= (uint32_t)tti_harq)) {
-      proc[pid_harq].set_harq_feedback(ack);
-    }
-  }
-  
   ul_sps           ul_sps_assig;
 
   srslte::timers::timer  *contention_timer;
diff --git a/srsue/hdr/phy/phch_common.h b/srsue/hdr/phy/phch_common.h
index 39e9e9685..0fe8529da 100644
--- a/srsue/hdr/phy/phch_common.h
+++ b/srsue/hdr/phy/phch_common.h
@@ -64,8 +64,16 @@ namespace srsue {
     float rx_gain_offset;
     float avg_snr_db; 
     float avg_noise; 
-    float avg_rsrp; 
-  
+    float avg_rsrp;
+
+    // Save last TBS for mcs>28 cases
+    int last_dl_tbs[2*HARQ_DELAY_MS][SRSLTE_MAX_CODEWORDS];
+    uint32_t last_dl_tti[2*HARQ_DELAY_MS];
+
+    int last_ul_tbs[2*HARQ_DELAY_MS];
+    uint32_t last_ul_tti[2*HARQ_DELAY_MS];
+    srslte_mod_t last_ul_mod[2*HARQ_DELAY_MS];
+
     phch_common(uint32_t max_mutex = 3);
     void init(phy_interface_rrc::phy_cfg_t *config, 
               phy_args_t  *args, 
@@ -139,7 +147,7 @@ namespace srsue {
       uint32_t n_dmrs;
     } pending_ack_t;
     pending_ack_t pending_ack[TTIMOD_SZ];
-    
+
     bool            is_first_tx;
 
     uint32_t        nof_workers;
diff --git a/srsue/hdr/phy/phch_worker.h b/srsue/hdr/phy/phch_worker.h
index c26966c17..e7030d777 100644
--- a/srsue/hdr/phy/phch_worker.h
+++ b/srsue/hdr/phy/phch_worker.h
@@ -150,11 +150,6 @@ private:
   float                             cfo;
   bool                              rar_cqi_request;
 
-  // Save last TBS for mcs>28 cases
-  int last_dl_tbs[2*HARQ_DELAY_MS][SRSLTE_MAX_CODEWORDS];
-  int last_ul_tbs[2*HARQ_DELAY_MS];
-  srslte_mod_t last_ul_mod[2*HARQ_DELAY_MS];
-
   // Metrics
   dl_metrics_t dl_metrics;
   ul_metrics_t ul_metrics;
diff --git a/srsue/src/mac/mac.cc b/srsue/src/mac/mac.cc
index f8d10bb34..3d1f60f56 100644
--- a/srsue/src/mac/mac.cc
+++ b/srsue/src/mac/mac.cc
@@ -308,7 +308,7 @@ void mac::new_grant_ul(mac_interface_phy::mac_grant_t grant, mac_interface_phy::
 void mac::new_grant_ul_ack(mac_interface_phy::mac_grant_t grant, bool ack, mac_interface_phy::tb_action_ul_t* action)
 {
   int tbs = ul_harq.get_current_tbs(tti);
-  ul_harq.new_grant_ul_ack(grant, ack, action);
+  ul_harq.new_grant_ul_ack(grant, &ack, action);
   if (!ack) {
     metrics.tx_errors++;
   } else {
diff --git a/srsue/src/mac/mux.cc b/srsue/src/mac/mux.cc
index 957c257a1..4e1a3b870 100644
--- a/srsue/src/mac/mux.cc
+++ b/srsue/src/mac/mux.cc
@@ -236,8 +236,7 @@ uint8_t* mux::pdu_get(uint8_t *payload, uint32_t pdu_sz, uint32_t tx_tti, uint32
   // Now allocate the SDUs from the RLC 
   for (uint32_t i=0;i<lch.size();i++) {
     if (lch[i].sched_len != 0) {
-      log_h->info("Allocating scheduled lch=%d len=%d\n", lch[i].id, lch[i].sched_len);
-      allocate_sdu(lch[i].id, &pdu_msg, lch[i].sched_len);    
+      allocate_sdu(lch[i].id, &pdu_msg, lch[i].sched_len);
     }
   }
 
@@ -285,7 +284,7 @@ bool mux::sched_sdu(lchid_t *ch, int *sdu_space, int max_sdu_sz)
         sched_len = *sdu_space;
       }        
 
-      log_h->info("SDU:   scheduled lcid=%d, rlc_buffer=%d, allocated=%d/%d\n", 
+      log_h->debug("SDU:   scheduled lcid=%d, rlc_buffer=%d, allocated=%d/%d\n",
                    ch->id, ch->buffer_len, sched_len, sdu_space?*sdu_space:0);
       
       *sdu_space     -= sched_len; 
@@ -317,7 +316,7 @@ bool mux::allocate_sdu(uint32_t lcid, srslte::sch_pdu* pdu_msg, int max_sdu_sz)
         sdu_len = pdu_msg->get()->set_sdu(lcid, sdu_len, rlc);
         if (sdu_len > 0) { // new SDU could be added
           
-          Info("SDU:   allocated lcid=%d, rlc_buffer=%d, allocated=%d/%d, max_sdu_sz=%d, remaining=%d\n", 
+          Debug("SDU:   allocated lcid=%d, rlc_buffer=%d, allocated=%d/%d, max_sdu_sz=%d, remaining=%d\n",
                  lcid, buffer_state, sdu_len, sdu_space, max_sdu_sz, pdu_msg->rem_size());
           return true;               
         } else {
diff --git a/srsue/src/phy/phch_worker.cc b/srsue/src/phy/phch_worker.cc
index ff7412d77..97fad0720 100644
--- a/srsue/src/phy/phch_worker.cc
+++ b/srsue/src/phy/phch_worker.cc
@@ -322,9 +322,9 @@ void phch_worker::work_imp()
   ul_action.tti_offset = HARQ_DELAY_MS;
 
   /* Send UL grant or HARQ information (from PHICH) to MAC */
-  if (ul_grant_available         && ul_ack_available && ul_mac_grant.phy_grant.ul.mcs.idx < 29)  {
+  if (ul_grant_available         && ul_ack_available)  {
     phy->mac->new_grant_ul_ack(ul_mac_grant, ul_ack, &ul_action);      
-  } else if (ul_grant_available  && (!ul_ack_available || ul_mac_grant.phy_grant.ul.mcs.idx < 29)) {
+  } else if (ul_grant_available  && !ul_ack_available) {
     phy->mac->new_grant_ul(ul_mac_grant, &ul_action);
   } else if (!ul_grant_available && ul_ack_available)  {    
     phy->mac->harq_recv(tti, ul_ack, &ul_action);        
@@ -477,19 +477,19 @@ bool phch_worker::decode_pdcch_dl(srsue::mac_interface_phy::mac_grant_t* grant)
       return false;   
     }
 
-    grant->pid = ASYNC_DL_SCHED?dci_unpacked.harq_process:(tti%(2*HARQ_DELAY_MS));
+    grant->pid = ASYNC_DL_SCHED?dci_unpacked.harq_process:(UL_PIDOF(TTI_TX(tti)));
 
     // Set last TBS for this TB (pid) in case of mcs>28 (7.1.7.2 of 36.213)
     for (int i=0;i<SRSLTE_MAX_CODEWORDS;i++) {
       if (grant->phy_grant.dl.mcs[i].idx > 28) {
-        grant->phy_grant.dl.mcs[i].tbs = last_dl_tbs[grant->pid%(2*HARQ_DELAY_MS)][i];
+        grant->phy_grant.dl.mcs[i].tbs = phy->last_dl_tbs[grant->pid][i];
       }
       if(grant->phy_grant.dl.mcs[i].tbs < 0) {
         Info("Invalid TBS size for PDSCH grant\n");
         grant->phy_grant.dl.mcs[i].tbs = 0;
       }
       // save it
-      last_dl_tbs[grant->pid%(2*HARQ_DELAY_MS)][i] = grant->phy_grant.dl.mcs[i].tbs;
+      phy->last_dl_tbs[grant->pid][i] = grant->phy_grant.dl.mcs[i].tbs;
     }
 
     /* Fill MAC grant structure */
@@ -743,30 +743,30 @@ bool phch_worker::decode_pdcch_ul(mac_interface_phy::mac_grant_t* grant)
     }
   }
 
-  if (ret) {
 
+  // Handle Format0 adaptive retx
+  if (ret) {
     // Use last TBS for this TB in case of mcs>28
     if (grant->phy_grant.ul.mcs.idx > 28) {
-      grant->phy_grant.ul.mcs.tbs = last_ul_tbs[TTI_RX(tti)%(2*HARQ_DELAY_MS)];
-      Info("RETX: mcs=%d, old_tbs=%d pid=%d\n", grant->phy_grant.ul.mcs.idx, grant->phy_grant.ul.mcs.tbs, TTI_TX(tti)%(2*HARQ_DELAY_MS));
-    }
-    last_ul_tbs[TTI_RX(tti)%(2*HARQ_DELAY_MS)] = grant->phy_grant.ul.mcs.tbs;
-
-    if (grant->phy_grant.ul.mcs.mod == SRSLTE_MOD_LAST) {
-      grant->phy_grant.ul.mcs.mod = last_ul_mod[TTI_RX(tti)%(2*HARQ_DELAY_MS)];
+      // Make sure we received a grant in the previous TTI for this PID
+      grant->phy_grant.ul.mcs.tbs = phy->last_ul_tbs[UL_PIDOF(TTI_TX(tti))];
+      grant->phy_grant.ul.mcs.mod = phy->last_ul_mod[UL_PIDOF(TTI_TX(tti))];
       grant->phy_grant.ul.Qm      = srslte_mod_bits_x_symbol(grant->phy_grant.ul.mcs.mod);
     }
-    last_ul_mod[TTI_RX(tti)%(2*HARQ_DELAY_MS)] = grant->phy_grant.ul.mcs.mod;
   }
-
-  /* Limit UL modulation if not supported by the UE or disabled by higher layers */
-  if (!phy->config->enable_64qam) {
-    if (grant->phy_grant.ul.mcs.mod >= SRSLTE_MOD_64QAM) {
-      grant->phy_grant.ul.mcs.mod = SRSLTE_MOD_16QAM;
-      grant->phy_grant.ul.Qm      = 4;
+  if (ret) {
+    phy->last_ul_tbs[UL_PIDOF(TTI_TX(tti))] = grant->phy_grant.ul.mcs.tbs;
+    phy->last_ul_mod[UL_PIDOF(TTI_TX(tti))] = grant->phy_grant.ul.mcs.mod;
+    phy->last_ul_tti[UL_PIDOF(TTI_TX(tti))] = TTI_RX_ACK(tti);
+    /* Limit UL modulation if not supported by the UE or disabled by higher layers */
+    if (!phy->config->enable_64qam) {
+      if (grant->phy_grant.ul.mcs.mod >= SRSLTE_MOD_64QAM) {
+        grant->phy_grant.ul.mcs.mod = SRSLTE_MOD_16QAM;
+        grant->phy_grant.ul.Qm      = 4;
+      }
     }
   }
-  
+
   /* Make sure the grant is valid */
   if (ret && !srslte_dft_precoding_valid_prb(grant->phy_grant.ul.L_prb) && grant->phy_grant.ul.L_prb <= cell.nof_prb) {
     Warning("Received invalid UL grant. L=%d\n", grant->phy_grant.ul.L_prb);
@@ -783,11 +783,9 @@ bool phch_worker::decode_pdcch_ul(mac_interface_phy::mac_grant_t* grant)
     if (SRSLTE_VERBOSE_ISINFO()) {
       srslte_ra_pusch_fprint(stdout, &dci_unpacked, cell.nof_prb);
     }
-    
-    return true;     
-  } else {
-    return false; 
-  }    
+  }
+
+  return ret;
 }
 
 void phch_worker::reset_uci()