fixed PUCCH correlation estimator

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

@@ -108,7 +108,6 @@ typedef struct SRSLTE_API {
   bool group_hopping_en;
 
   float threshold_format1;
-  float threshold_format1a;
   float last_corr;
   uint32_t last_n_prb;
   uint32_t last_n_pucch;
@@ -126,8 +125,7 @@ SRSLTE_API bool srslte_pucch_set_cfg(srslte_pucch_t* q,
                                      bool group_hopping_en); 
 
 SRSLTE_API void srslte_pucch_set_threshold(srslte_pucch_t *q,
-                                           float format1, 
+                                           float format1_threshold);
-                                           float format1a); 
 
 SRSLTE_API int srslte_pucch_set_crnti(srslte_pucch_t *q, 
                                       uint16_t c_rnti); 

lib/include/srslte/phy/utils/vector.h

@@ -152,6 +152,9 @@ SRSLTE_API void srslte_vec_conj_cc(cf_t *x, cf_t *y, uint32_t len);
 /* average vector power */
 SRSLTE_API float srslte_vec_avg_power_cf(cf_t *x, uint32_t len);
 
+/* Correlation between complex vectors x and y */
+SRSLTE_API float srslte_vec_corr_ccc(cf_t *x, cf_t *y, uint32_t len);
+
 /* return the index of the maximum value in the vector */
 SRSLTE_API uint32_t srslte_vec_max_fi(float *x, uint32_t len);
 SRSLTE_API uint32_t srslte_vec_max_abs_ci(cf_t *x, uint32_t len);

lib/src/phy/enb/enb_ul.c

@@ -91,7 +91,7 @@ int srslte_enb_ul_init(srslte_enb_ul_t *q, srslte_cell_t cell,
       srslte_prach_set_detect_factor(&q->prach, 60);    
     }
     
-    srslte_pucch_set_threshold(&q->pucch, 0.5, 0.5);
+    srslte_pucch_set_threshold(&q->pucch, 0.8);
     
     if (srslte_chest_ul_init(&q->chest, cell)) {
       fprintf(stderr, "Error initiating channel estimator\n");

lib/src/phy/phch/pucch.c

@@ -411,9 +411,8 @@ static int pucch_get(srslte_pucch_t *q, srslte_pucch_format_t format, uint32_t n
   return pucch_cp(q, format, n_pucch, input, z, true);
 }
 
-void srslte_pucch_set_threshold(srslte_pucch_t *q, float format1, float format1a) {
+void srslte_pucch_set_threshold(srslte_pucch_t *q, float format1_threshold) {
-  q->threshold_format1  = format1; 
+  q->threshold_format1  = format1_threshold;
-  q->threshold_format1a = format1a; 
 }
 
 /** Initializes the PDCCH transmitter and receiver */
@@ -452,6 +451,8 @@ int srslte_pucch_init(srslte_pucch_t *q, srslte_cell_t cell) {
     q->z_tmp = srslte_vec_malloc(sizeof(cf_t)*SRSLTE_PUCCH_MAX_SYMBOLS);
     q->ce = srslte_vec_malloc(sizeof(cf_t)*SRSLTE_PUCCH_MAX_SYMBOLS);
 
+    q->threshold_format1  = 0.8;
+
     ret = SRSLTE_SUCCESS;
   }
   return ret;
@@ -612,6 +613,10 @@ static int uci_mod_bits(srslte_pucch_t *q, srslte_pucch_format_t format, uint8_t
 // Declare this here, since we can not include refsignal_ul.h
 void srslte_refsignal_r_uv_arg_1prb(float *arg, uint32_t u);
 
+
+float tmp_alpha;
+uint32_t tmp_noc, tmp_nprime, tmp_woc;
+
 static int pucch_encode_(srslte_pucch_t* q, srslte_pucch_format_t format, 
                           uint32_t n_pucch, uint32_t sf_idx, uint16_t rnti,
                           uint8_t bits[SRSLTE_PUCCH_MAX_BITS], cf_t z[SRSLTE_PUCCH_MAX_SYMBOLS], bool signal_only) 
@@ -657,6 +662,12 @@ static int pucch_encode_(srslte_pucch_t* q, srslte_pucch_format_t format,
         }
         DEBUG("PUCCH d_0: %.1f+%.1fi, alpha: %.1f, n_oc: %d, n_prime_ns: %d, n_rb_2=%d\n",
               __real__ q->d[0], __imag__ q->d[0], alpha, n_oc, n_prime_ns, q->pucch_cfg.n_rb_2);
+
+        tmp_alpha = alpha;
+        tmp_noc   = n_oc;
+        tmp_nprime = n_prime_ns;
+        tmp_woc   = w_n_oc[N_sf_widx][n_oc%3][m];
+
         for (uint32_t n=0;n<SRSLTE_PUCCH_N_SEQ;n++) {
           z[(ns%2)*N_sf_0*SRSLTE_PUCCH_N_SEQ+m*SRSLTE_PUCCH_N_SEQ+n] = 
             q->d[0]*cexpf(I*(w_n_oc[N_sf_widx][n_oc%3][m]+q->tmp_arg[n]+alpha*n+S_ns));
@@ -767,7 +778,7 @@ int srslte_pucch_decode(srslte_pucch_t* q, srslte_pucch_format_t format,
       case SRSLTE_PUCCH_FORMAT_1:
         bzero(bits, SRSLTE_PUCCH_MAX_BITS*sizeof(uint8_t));
         pucch_encode(q, format, n_pucch, sf_idx, rnti, bits, q->z_tmp);
-        corr = crealf(srslte_vec_dot_prod_conj_ccc(q->z, q->z_tmp, nof_re))/nof_re;
+        corr = srslte_vec_corr_ccc(q->z, q->z_tmp, nof_re);
         if (corr >= q->threshold_format1) {
           ret = 1; 
         } else {
@@ -782,7 +793,7 @@ int srslte_pucch_decode(srslte_pucch_t* q, srslte_pucch_format_t format,
         for (int b=0;b<2;b++) {
           bits[0] = b;
           pucch_encode(q, format, n_pucch, sf_idx, rnti, bits, q->z_tmp);
-          corr = crealf(srslte_vec_dot_prod_conj_ccc(q->z, q->z_tmp, nof_re))/nof_re;          
+          corr = srslte_vec_corr_ccc(q->z, q->z_tmp, nof_re);
           if (corr > corr_max) {
             corr_max = corr; 
             b_max = b; 
@@ -790,7 +801,7 @@ int srslte_pucch_decode(srslte_pucch_t* q, srslte_pucch_format_t format,
           if (corr_max > q->threshold_format1) { // check with format1 in case ack+sr because ack only is binary
             ret = 1; 
           }
-          DEBUG("format1a b=%d, corr=%f, nof_re=%d, th=%f\n", b, corr, nof_re, q->threshold_format1a);
+          DEBUG("format1a b=%d, corr=%f, nof_re=%d\n", b, corr, nof_re);
         }
         q->last_corr = corr_max; 
         bits[0] = b_max; 

lib/src/phy/utils/vector.c

@@ -681,6 +681,15 @@ float srslte_vec_avg_power_cf(cf_t *x, uint32_t len) {
   return crealf(srslte_vec_dot_prod_conj_ccc(x,x,len)) / len;
 }
 
+// Correlation assumes zero-mean x and y
+float srslte_vec_corr_ccc(cf_t *x, cf_t *y, uint32_t len) {
+//  return crealf(srslte_vec_dot_prod_conj_ccc(x,y,len)) / len;
+  float s_x = crealf(srslte_vec_dot_prod_conj_ccc(x, x, len))/len;
+  float s_y = crealf(srslte_vec_dot_prod_conj_ccc(y, y, len))/len;
+  float cov = crealf(srslte_vec_dot_prod_conj_ccc(x, y, len))/len;
+  return cov/(sqrt(s_x*s_y));
+}
+
 void srslte_vec_abs_cf(cf_t *x, float *abs, uint32_t len) {
 #ifndef HAVE_VOLK_MAG_FUNCTION
   int i;

srsenb/src/mac/ue.cc

@@ -248,12 +248,12 @@ bool ue::process_ce(srslte::sch_subh *subh) {
       idx = subh->get_bsr(buff_size);
       if (idx > 0) {
         // Indicate BSR to scheduler 
-        sched->ul_bsr(rnti, idx, buff_size[idx]);
+        sched->ul_bsr(rnti, idx, 2*buff_size[idx]);
         Info("CE:    Received BSR rnti=0x%x, lcid=%d, value=%d\n", rnti, idx, buff_size[idx]);        
       } else if (idx == 0) {
         // TODO: map lcid group to lcid
         for (int i=0;i<4;i++) {
-          sched->ul_bsr(rnti, i, buff_size[i]);
+          sched->ul_bsr(rnti, i, 2*buff_size[i]);
         }
         Info("CE:    Received Long BSR rnti=0x%x, value=%d,%d,%d,%d\n", rnti, 
              buff_size[0], buff_size[1], buff_size[2], buff_size[3]);        

srsenb/src/phy/phch_worker.cc

@@ -109,7 +109,7 @@ void phch_worker::init(phch_common* phy_, srslte::log *log_h_)
     return;
   }
   
-  srslte_pucch_set_threshold(&enb_ul.pucch, 0.5, 0.5);
+  srslte_pucch_set_threshold(&enb_ul.pucch, 0.8);
   srslte_sch_set_max_noi(&enb_ul.pusch.ul_sch, phy->params.pusch_max_its);
   srslte_enb_dl_set_amp(&enb_dl, phy->params.tx_amplitude);