From 5a032c4316308fcd30c3079c98afd6e620357623 Mon Sep 17 00:00:00 2001
From: ismagom <gomezi@tcd.ie>
Date: Thu, 11 Dec 2014 09:06:58 +0000
Subject: [PATCH] Using short correlation for peak tracking

---
 lte/examples/cell_measurement.c           | 29 ++++++-----
 lte/examples/pdsch_ue.c                   | 43 +++++++++-------
 lte/phy/include/liblte/phy/sync/pss.h     |  2 -
 lte/phy/include/liblte/phy/utils/vector.h |  1 +
 lte/phy/lib/ch_estimation/src/chest_dl.c  |  1 +
 lte/phy/lib/sync/src/pss.c                | 60 ++++++++++++++++-------
 lte/phy/lib/sync/src/sync.c               |  1 -
 lte/phy/lib/sync/test/pss_usrp.c          | 14 ++++--
 lte/phy/lib/ue/src/ue_celldetect.c        |  1 +
 lte/phy/lib/ue/src/ue_sync.c              |  7 +--
 lte/phy/lib/utils/src/convolution.c       | 18 ++++---
 11 files changed, 113 insertions(+), 64 deletions(-)

diff --git a/lte/examples/cell_measurement.c b/lte/examples/cell_measurement.c
index 1e6b2e212..40f905375 100644
--- a/lte/examples/cell_measurement.c
+++ b/lte/examples/cell_measurement.c
@@ -48,7 +48,7 @@ float gain_offset = B210_DEFAULT_GAIN_CORREC;
 
 cell_detect_cfg_t cell_detect_config = {
   100, // nof_frames_total 
-  3.0 // early-stops cell detection if mean PSR is above this value 
+  6.0 // early-stops cell detection if mean PSR is above this value 
 };
 
 /**********************************************************************
@@ -149,16 +149,11 @@ int main(int argc, char **argv) {
   uint8_t bch_payload[BCH_PAYLOAD_LEN], bch_payload_unpacked[BCH_PAYLOAD_LEN];
   uint32_t sfn_offset; 
   float rssi_utra=0,rssi=0, rsrp=0, rsrq=0, snr=0;
-  cf_t *nullce[MAX_PORTS]; 
   uint32_t si_window_length; 
   scheduling_info_t sinfo[MAX_SINFO];
   scheduling_info_t *sinfo_sib4 = NULL;
   uint32_t neighbour_cell_ids[MAX_NEIGHBOUR_CELLS]; 
-  
-  
-  for (int i=0;i<MAX_PORTS;i++) {
-    nullce[i] = NULL;
-  }
+  cf_t *ce[MAX_PORTS];
 
   parse_args(&prog_args, argc, argv);
 
@@ -174,6 +169,10 @@ int main(int argc, char **argv) {
   cuhd_set_rx_freq(uhd, (double) prog_args.uhd_freq);
   cuhd_rx_wait_lo_locked(uhd);
   printf("Tunning receiver to %.3f MHz\n", (double ) prog_args.uhd_freq/1000000);
+  
+  
+  
+
 
   if (detect_and_decode_cell(&cell_detect_config, uhd, prog_args.force_N_id_2, &cell)) {
     fprintf(stderr, "Cell not found\n");
@@ -215,12 +214,17 @@ int main(int argc, char **argv) {
   int sf_re = SF_LEN_RE(cell.nof_prb, cell.cp);
 
   cf_t *sf_symbols = vec_malloc(sf_re * sizeof(cf_t));
+
+  for (int i=0;i<MAX_PORTS;i++) {
+    ce[i] = vec_malloc(sizeof(cf_t) * sf_re);
+  }
   
   cuhd_start_rx_stream(uhd);
 
   bool sib4_window_start = false;
   uint32_t sib4_window_cnt = 0; 
   
+  
   /* Main loop */
   while (sf_cnt < prog_args.nof_subframes || prog_args.nof_subframes == -1) {
     
@@ -307,9 +311,7 @@ int main(int argc, char **argv) {
           /* We are looking for SI Blocks, search only in appropiate places */
           if (sib4_window_start && !(ue_sync_get_sfidx(&ue_sync) == 5 && (sfn%2)==0))
           {
-/*            printf("[%d/%d]: Trying SIB4 in SF: %d, SFN: %d\n", sib4_window_cnt, si_window_length, 
-                   ue_sync_get_sfidx(&ue_sync), sfn);
-*/            n = ue_dl_decode_sib(&ue_dl, sf_buffer, data, ue_sync_get_sfidx(&ue_sync), 
+            n = ue_dl_decode_sib(&ue_dl, sf_buffer, data, ue_sync_get_sfidx(&ue_sync), 
                                    ((int) ceilf((float)3*sib4_window_cnt/2))%4);
             if (n < 0) {
               fprintf(stderr, "Error decoding UE DL\n");fflush(stdout);
@@ -340,7 +342,7 @@ int main(int argc, char **argv) {
         /* Run FFT for all subframe data */
         lte_fft_run_sf(&fft, sf_buffer, sf_symbols);
         
-        chest_dl_estimate(&chest, sf_symbols, nullce, ue_sync_get_sfidx(&ue_sync));
+        chest_dl_estimate(&chest, sf_symbols, ce, ue_sync_get_sfidx(&ue_sync));
                 
         rssi = VEC_CMA(vec_avg_power_cf(sf_buffer,SF_LEN(lte_symbol_sz(cell.nof_prb))),rssi,nframes);
         rssi_utra = VEC_CMA(chest_dl_get_rssi(&chest),rssi_utra,nframes);
@@ -357,7 +359,10 @@ int main(int argc, char **argv) {
                 10*log10(rssi*1000)-gain_offset, 
                 10*log10(rssi_utra*1000)-gain_offset, 
                 10*log10(rsrp*1000)-gain_offset, 
-              10*log10(rsrq), 10*log10(snr));                
+                10*log10(rsrq), 10*log10(snr));                
+          if (verbose != VERBOSE_NONE) {
+            printf("\n");
+          }
         }
         break;
       }
diff --git a/lte/examples/pdsch_ue.c b/lte/examples/pdsch_ue.c
index e88e889c3..07b6e587c 100644
--- a/lte/examples/pdsch_ue.c
+++ b/lte/examples/pdsch_ue.c
@@ -43,7 +43,7 @@
 
 #ifndef DISABLE_GRAPHICS
 void init_plots();
-void do_plots(ue_dl_t *q, uint32_t sf_idx);
+void do_plots(ue_dl_t *q, uint32_t sf_idx, ue_sync_t *qs);
 #endif
 
 
@@ -175,12 +175,6 @@ int main(int argc, char **argv) {
   uint32_t sfn_offset; 
   parse_args(&prog_args, argc, argv);
 
-  #ifndef DISABLE_GRAPHICS
-  if (!prog_args.disable_plots) {
-    init_plots();    
-  }
-  #endif
-  
   printf("Opening UHD device...\n");
   if (cuhd_open(prog_args.uhd_args, &uhd)) {
     fprintf(stderr, "Error opening uhd\n");
@@ -225,11 +219,19 @@ int main(int argc, char **argv) {
   // Register Ctrl+C handler
   signal(SIGINT, sig_int_handler);
 
+  #ifndef DISABLE_GRAPHICS
+  if (!prog_args.disable_plots) {
+    init_plots();    
+  }
+  #endif
+  
+
+  
   cuhd_start_rx_stream(uhd);
   
   // Variables for measurements 
   uint32_t nframes=0;
-  float rsrp=0, rsrq=0, snr=0;
+  float rsrp=1.0, rsrq=1.0, snr=1.0;
 
   /* Main loop */
   while (!go_exit && (sf_cnt < prog_args.nof_subframes || prog_args.nof_subframes == -1)) {
@@ -276,6 +278,10 @@ int main(int argc, char **argv) {
           rsrp = VEC_CMA(chest_dl_get_rsrp(&ue_dl.chest),rsrp,nframes);      
           snr = VEC_CMA(chest_dl_get_snr(&ue_dl.chest),snr,nframes);      
           nframes++;
+
+          if (isnan(rsrq)) {
+            rsrq = 0; 
+          }
           
           // Plot and Printf
           if (ue_sync_get_sfidx(&ue_sync) == 0) {
@@ -298,7 +304,7 @@ int main(int argc, char **argv) {
       }
       #ifndef DISABLE_GRAPHICS
       if (!prog_args.disable_plots && ue_sync_get_sfidx(&ue_sync) == 5) {
-        do_plots(&ue_dl, 5);          
+        do_plots(&ue_dl, 5, &ue_sync);          
       }
       #endif
     } else if (ret == 0) {
@@ -332,12 +338,13 @@ int main(int argc, char **argv) {
 
 
 #include "liblte/graphics/plot.h"
-plot_real_t poutfft;
+plot_real_t poutfft, p_sync;
 plot_real_t pce;
-plot_scatter_t pscatrecv, pscatequal, pscatequal_pdcch;
+plot_scatter_t  pscatequal, pscatequal_pdcch;
 
 float tmp_plot[SLOT_LEN_RE(MAX_PRB, CPNORM)];
 float tmp_plot2[SLOT_LEN_RE(MAX_PRB, CPNORM)];
+float tmp_plot3[SLOT_LEN_RE(MAX_PRB, CPNORM)];
 
 void init_plots() {
   plot_init();
@@ -351,10 +358,9 @@ void init_plots() {
   plot_real_setLabels(&pce, "Index", "dB");
   plot_real_setYAxisScale(&pce, -60, 0);
 
-  plot_scatter_init(&pscatrecv);
-  plot_scatter_setTitle(&pscatrecv, "Received Symbols");
-  plot_scatter_setXAxisScale(&pscatrecv, -4, 4);
-  plot_scatter_setYAxisScale(&pscatrecv, -4, 4);
+  plot_real_init(&p_sync);
+  plot_real_setTitle(&p_sync, "PSS Cross-Corr abs value");
+  plot_real_setYAxisScale(&p_sync, 0, 1);
 
   plot_scatter_init(&pscatequal);
   plot_scatter_setTitle(&pscatequal, "PDSCH - Equalized Symbols");
@@ -368,7 +374,7 @@ void init_plots() {
 
 }
 
-void do_plots(ue_dl_t *q, uint32_t sf_idx) {
+void do_plots(ue_dl_t *q, uint32_t sf_idx, ue_sync_t *qs) {
   int i;
   uint32_t nof_re = SLOT_LEN_RE(q->cell.nof_prb, q->cell.cp);
   uint32_t nof_symbols = q->harq_process[0].prb_alloc.re_sf[sf_idx];
@@ -386,7 +392,10 @@ void do_plots(ue_dl_t *q, uint32_t sf_idx) {
   }
   plot_real_setNewData(&poutfft, tmp_plot, nof_re);        
   plot_real_setNewData(&pce, tmp_plot2, REFSIGNAL_NUM_SF(q->cell.nof_prb,0));        
-  plot_scatter_setNewData(&pscatrecv, q->pdsch.pdsch_symbols[0], nof_symbols);
+  int max = vec_max_fi(qs->strack.pss.conv_output_avg, qs->strack.pss.frame_size+qs->strack.pss.fft_size-1);
+  vec_sc_prod_fff(qs->strack.pss.conv_output_avg, 1/qs->strack.pss.conv_output_avg[max], tmp_plot2, qs->strack.pss.frame_size+qs->strack.pss.fft_size-1);        
+  plot_real_setNewData(&p_sync, tmp_plot2, qs->strack.pss.frame_size);        
+  
   plot_scatter_setNewData(&pscatequal, q->pdsch.pdsch_d, nof_symbols);
   plot_scatter_setNewData(&pscatequal_pdcch, q->pdcch.pdcch_d, 36*q->pdcch.nof_cce);
 }
diff --git a/lte/phy/include/liblte/phy/sync/pss.h b/lte/phy/include/liblte/phy/sync/pss.h
index 1ff0fee5f..9f5b435cf 100644
--- a/lte/phy/include/liblte/phy/sync/pss.h
+++ b/lte/phy/include/liblte/phy/sync/pss.h
@@ -39,8 +39,6 @@
 typedef _Complex float cf_t; /* this is only a shortcut */
 
 #define CONVOLUTION_FFT
-#define DEFAULT_CORRELATION_TH 10000
-#define DEFAULT_NOSYNC_TIMEOUT  5
 
 #define PSS_LEN     62
 #define PSS_RE      6*12
diff --git a/lte/phy/include/liblte/phy/utils/vector.h b/lte/phy/include/liblte/phy/utils/vector.h
index 8ba871f8c..186329b4b 100644
--- a/lte/phy/include/liblte/phy/utils/vector.h
+++ b/lte/phy/include/liblte/phy/utils/vector.h
@@ -37,6 +37,7 @@ typedef _Complex float cf_t;
 
 
 #define MAX(a,b) ((a)>(b)?(a):(b))
+#define MIN(a,b) ((a)<(b)?(a):(b))
 
 // Cumulative moving average
 #define VEC_CMA(data, average, n) ((average) + ((data) - (average)) / ((n)+1)) 
diff --git a/lte/phy/lib/ch_estimation/src/chest_dl.c b/lte/phy/lib/ch_estimation/src/chest_dl.c
index 8a4c5a79e..5a9c2e5b7 100644
--- a/lte/phy/lib/ch_estimation/src/chest_dl.c
+++ b/lte/phy/lib/ch_estimation/src/chest_dl.c
@@ -373,6 +373,7 @@ float chest_dl_get_rssi(chest_dl_t *q) {
 */ 
 float chest_dl_get_rsrq(chest_dl_t *q) {
   return q->cell.nof_prb*q->rsrp[0] / q->rssi[0];
+  
 }
 
 float chest_dl_get_rsrp(chest_dl_t *q) {
diff --git a/lte/phy/lib/sync/src/pss.c b/lte/phy/lib/sync/src/pss.c
index ff8e1d288..b183e24b2 100644
--- a/lte/phy/lib/sync/src/pss.c
+++ b/lte/phy/lib/sync/src/pss.c
@@ -290,20 +290,27 @@ int pss_synch_find_pss(pss_synch_t *q, cf_t *input, float *corr_peak_value)
     memcpy(q->tmp_input, input, q->frame_size * sizeof(cf_t));
 
     /* Correlate input with PSS sequence */
-  #ifdef CONVOLUTION_FFT
-    conv_output_len = conv_fft_cc_run(&q->conv_fft, q->tmp_input,
-        q->pss_signal_freq[q->N_id_2], q->conv_output);
-  #else
-    conv_output_len = conv_cc(input, q->pss_signal_freq[q->N_id_2], q->conv_output, q->frame_size, q->fft_size);
-  #endif
+    if (q->frame_size >= q->fft_size) {
+    #ifdef CONVOLUTION_FFT
+      conv_output_len = conv_fft_cc_run(&q->conv_fft, q->tmp_input,
+          q->pss_signal_freq[q->N_id_2], q->conv_output);
+    #else
+      conv_output_len = conv_cc(input, q->pss_signal_freq[q->N_id_2], q->conv_output, q->frame_size, q->fft_size);
+    #endif
+    } else {
+        for (int i=0;i<q->frame_size;i++) {
+          q->conv_output[i] = vec_dot_prod_ccc(q->pss_signal_freq[q->N_id_2], &input[i], q->fft_size);
+        }
+        conv_output_len = q->frame_size; 
+    }
 
    
-#ifdef PSS_ABS_SQUARE
-    vec_abs_square_cf(q->conv_output, q->conv_output_abs, conv_output_len-1);
-#else
-    vec_abs_cf(q->conv_output, q->conv_output_abs, conv_output_len-1);
-#endif
-
+  #ifdef PSS_ABS_SQUARE
+      vec_abs_square_cf(q->conv_output, q->conv_output_abs, conv_output_len-1);
+  #else
+      vec_abs_cf(q->conv_output, q->conv_output_abs, conv_output_len-1);
+  #endif
+    
     vec_sc_prod_fff(q->conv_output_abs, q->ema_alpha, q->conv_output_abs, conv_output_len-1);    
     vec_sc_prod_fff(q->conv_output_avg, 1-q->ema_alpha, q->conv_output_avg, conv_output_len-1);    
 
@@ -321,16 +328,35 @@ int pss_synch_find_pss(pss_synch_t *q, cf_t *input, float *corr_peak_value)
       pl_ub ++; 
     }
     // Find end of peak lobe to the left
-    int pl_lb = corr_peak_pos-1;
-    while(q->conv_output_avg[pl_lb-1] <= q->conv_output_avg[pl_lb] && pl_lb > 1) {
-      pl_lb --; 
+    int pl_lb; 
+    if (corr_peak_pos > 0) {
+      pl_lb = corr_peak_pos-1;
+      while(q->conv_output_avg[pl_lb-1] <= q->conv_output_avg[pl_lb] && pl_lb > 1) {
+        pl_lb --; 
+      }      
+    } else {
+      pl_lb = 0; 
     }
+
+    int sl_distance_right = conv_output_len-1-pl_ub; 
+    if (sl_distance_right < 0) {
+      sl_distance_right = 0; 
+    }
+    int sl_distance_left = pl_lb; 
     
-    int sl_right = pl_ub+vec_max_fi(&q->conv_output_avg[pl_ub], conv_output_len-1 - pl_ub);
-    int sl_left = vec_max_fi(q->conv_output_avg, pl_lb);    
+    int sl_right = pl_ub+vec_max_fi(&q->conv_output_avg[pl_ub], sl_distance_right);
+    int sl_left = vec_max_fi(q->conv_output_avg, sl_distance_left);    
     float side_lobe_value = MAX(q->conv_output_avg[sl_right], q->conv_output_avg[sl_left]);    
     if (corr_peak_value) {
       *corr_peak_value = q->conv_output_avg[corr_peak_pos]/side_lobe_value;
+      
+      if (*corr_peak_value < 2.0) {
+        INFO("pl_ub=%d, pl_lb=%d, sl_right: %d (%.2f), sl_left: %d (%.2f), PSR: %.2f/%.2f=%.2f\n", pl_ub, pl_lb, 
+             sl_right, 1000000*q->conv_output_avg[sl_right], 
+             sl_left, 1000000*q->conv_output_avg[sl_left], 
+          1000000*q->conv_output_avg[corr_peak_pos], 1000000*side_lobe_value,*corr_peak_value
+        );
+      }
     }
 #else
     if (corr_peak_value) {
diff --git a/lte/phy/lib/sync/src/sync.c b/lte/phy/lib/sync/src/sync.c
index a9ea8bde1..5048c8f4f 100644
--- a/lte/phy/lib/sync/src/sync.c
+++ b/lte/phy/lib/sync/src/sync.c
@@ -52,7 +52,6 @@ int sync_init(sync_t *q, uint32_t frame_size, uint32_t fft_size) {
   int ret = LIBLTE_ERROR_INVALID_INPUTS; 
   
   if (q                 != NULL         &&
-      frame_size        >= fft_size     &&
       frame_size        <= 307200       &&
       fft_size_isvalid(fft_size))
   {
diff --git a/lte/phy/lib/sync/test/pss_usrp.c b/lte/phy/lib/sync/test/pss_usrp.c
index a2cade849..ea87d887c 100644
--- a/lte/phy/lib/sync/test/pss_usrp.c
+++ b/lte/phy/lib/sync/test/pss_usrp.c
@@ -53,14 +53,16 @@ float uhd_gain=40.0, uhd_freq=-1.0;
 int nof_frames = -1;
 uint32_t fft_size=64;
 float threshold = 0.4; 
-int N_id_2_sync = -1; 
+int N_id_2_sync = -1;
+lte_cp_t cp=CPNORM;
 
 void usage(char *prog) {
-  printf("Usage: %s [adgtvnp] -f rx_frequency_hz -i cell_id\n", prog);
+  printf("Usage: %s [aedgtvnp] -f rx_frequency_hz -i cell_id\n", prog);
   printf("\t-a UHD args [Default %s]\n", uhd_args);
   printf("\t-g UHD Gain [Default %.2f dB]\n", uhd_gain);
   printf("\t-n nof_frames [Default %d]\n", nof_frames);
   printf("\t-l N_id_2 to sync [Default use cell_id]\n");
+  printf("\t-e Extended CP [Default Normal]\n", fft_size);
   printf("\t-s symbol_sz [Default %d]\n", fft_size);
   printf("\t-t threshold [Default %.2f]\n", threshold);
 #ifndef DISABLE_GRAPHICS
@@ -73,7 +75,7 @@ void usage(char *prog) {
 
 void parse_args(int argc, char **argv) {
   int opt;
-  while ((opt = getopt(argc, argv, "adgtvsfil")) != -1) {
+  while ((opt = getopt(argc, argv, "adgetvsfil")) != -1) {
     switch (opt) {
     case 'a':
       uhd_args = argv[optind];
@@ -87,6 +89,9 @@ void parse_args(int argc, char **argv) {
     case 't':
       threshold = atof(argv[optind]);
       break;
+    case 'e':
+      cp = CPEXT;
+      break;
     case 'i':
       cell_id = atoi(argv[optind]);
       break;
@@ -154,6 +159,7 @@ int main(int argc, char **argv) {
     fprintf(stderr, "Error initiating PSS\n");
     exit(-1);
   }
+
   if (pss_synch_set_N_id_2(&pss, N_id_2_sync)) {
     fprintf(stderr, "Error setting N_id_2=%d\n",N_id_2_sync);
     exit(-1);
@@ -233,7 +239,7 @@ int main(int argc, char **argv) {
         }
         
         // Find SSS 
-        int sss_idx = peak_idx-2*fft_size-CP(fft_size, CPNORM_LEN);             
+        int sss_idx = peak_idx-2*fft_size-(CP_ISNORM(cp)?CP(fft_size, CPNORM_LEN):CP(fft_size, CPEXT_LEN));             
         if (sss_idx >= 0 && sss_idx < flen-fft_size) {
           sss_synch_m0m1_partial(&sss, &buffer[sss_idx], 3, NULL, &m0, &m0_value, &m1, &m1_value);
           if (sss_synch_N_id_1(&sss, m0, m1) != N_id_1) {
diff --git a/lte/phy/lib/ue/src/ue_celldetect.c b/lte/phy/lib/ue/src/ue_celldetect.c
index 4ed86d6f6..62ae106e7 100644
--- a/lte/phy/lib/ue/src/ue_celldetect.c
+++ b/lte/phy/lib/ue/src/ue_celldetect.c
@@ -75,6 +75,7 @@ int ue_celldetect_init_max(ue_celldetect_t * q, uint32_t max_frames_total) {
     sync_set_threshold(&q->sfind, 1.0);
     sync_sss_en(&q->sfind, true);
     sync_set_sss_algorithm(&q->sfind, SSS_PARTIAL_3);
+    sync_set_em_alpha(&q->sfind, 0.01);
     
     q->max_frames_total = max_frames_total;
     q->nof_frames_total = CS_DEFAULT_NOFFRAMES_TOTAL; 
diff --git a/lte/phy/lib/ue/src/ue_sync.c b/lte/phy/lib/ue/src/ue_sync.c
index ab7e196ea..3eb62a419 100644
--- a/lte/phy/lib/ue/src/ue_sync.c
+++ b/lte/phy/lib/ue/src/ue_sync.c
@@ -49,6 +49,7 @@ cf_t dummy[MAX_TIME_OFFSET];
 #define FIND_THRESHOLD          4.0
 #define TRACK_THRESHOLD         2.0
 #define TRACK_MAX_LOST          10
+#define TRACK_FRAME_SIZE        32
 
 
 int ue_sync_init(ue_sync_t *q, 
@@ -76,7 +77,7 @@ int ue_sync_init(ue_sync_t *q,
       fprintf(stderr, "Error initiating sync find\n");
       goto clean_exit;
     }
-    if(sync_init(&q->strack, CURRENT_FFTSIZE, CURRENT_FFTSIZE)) {
+    if(sync_init(&q->strack, TRACK_FRAME_SIZE, CURRENT_FFTSIZE)) {
       fprintf(stderr, "Error initiating sync track\n");
       goto clean_exit;
     }
@@ -190,7 +191,7 @@ int track_peak_ok(ue_sync_t *q, uint32_t track_idx) {
       q->sf_idx = sync_get_sf_idx(&q->strack);      
     }
   } else {
-    q->time_offset = ((int) track_idx - (int) CURRENT_FFTSIZE); 
+    q->time_offset = ((int) track_idx - (int) q->strack.frame_size/2); 
     
     /* If the PSS peak is beyond the frame (we sample too slowly), 
       discard the offseted samples to align next frame */
@@ -305,7 +306,7 @@ int ue_sync_get_buffer(ue_sync_t *q, cf_t **sf_symbols) {
           track_idx = 0; 
           
           /* track pss around the middle of the subframe, where the PSS is */
-          ret = sync_find(&q->strack, q->input_buffer, CURRENT_SFLEN/2-CURRENT_FFTSIZE, &track_idx);
+          ret = sync_find(&q->strack, q->input_buffer, CURRENT_SFLEN/2-CURRENT_FFTSIZE-q->strack.frame_size/2, &track_idx);
           if (ret < 0) {
             fprintf(stderr, "Error tracking correlation peak\n");
             return LIBLTE_ERROR;
diff --git a/lte/phy/lib/utils/src/convolution.c b/lte/phy/lib/utils/src/convolution.c
index 2dcac6e5f..6630b7354 100644
--- a/lte/phy/lib/utils/src/convolution.c
+++ b/lte/phy/lib/utils/src/convolution.c
@@ -91,15 +91,17 @@ uint32_t conv_fft_cc_run(conv_fft_cc_t *q, cf_t *input, cf_t *filter, cf_t *outp
 }
 
 uint32_t conv_cc(cf_t *input, cf_t *filter, cf_t *output, uint32_t input_len, uint32_t filter_len) {
-  uint32_t i,j;
-  uint32_t output_len;
-  output_len=input_len+filter_len-1;
-  for (i=0;i<input_len;i++) {
-    for (j=0;j<filter_len;j++) {
-      output[i+j]+=input[i]*filter[j];
-    }
+  uint32_t i;
+  uint32_t M = filter_len; 
+  uint32_t N = input_len; 
+
+  for (i=0;i<M;i++) {
+    output[i]=vec_dot_prod_ccc(&input[i],&filter[i],i);
   }
-  return output_len;
+  for (;i<M+N-1;i++) {
+    output[i] = vec_dot_prod_ccc(&input[i-M], filter, M);
+  }
+  return M+N-1;
 }
 
 /* Centered convolution. Returns the same number of input elements. Equivalent to conv(x,h,'same') in matlab.