changed names. Added tutorial examples. MMSE not working correctly due to erroneous noise estimation under time misalignment

matlab/tests/equalizer_test.m

@@ -4,9 +4,9 @@
 
 clear
 
-plot_noise_estimation_only=true;
+plot_noise_estimation_only=false;
 
-SNR_values_db=linspace(0,30,8);
+SNR_values_db=20;%linspace(0,30,8);
 Nrealizations=1 ;
 
 preEVM = zeros(length(SNR_values_db),Nrealizations);
@@ -80,7 +80,7 @@ for sf = 0:10
     subframe = lteDLResourceGrid(enb);
     
     % Map input symbols to grid
-    %subframe(:) = inputSym;
+    subframe(:) = inputSym;
 
     % Generate synchronizing signals
     pssSym = ltePSS(enb);
@@ -141,13 +141,13 @@ rxWaveform = rxWaveform + noise;
 %% Synchronization
 
 offset = lteDLFrameOffset(enb,rxWaveform);
-rxWaveform = rxWaveform(1+offset:end,:);
+rxWaveform = rxWaveform(1+offset+2:end,:);
 
 %% OFDM Demodulation
 rxGrid = lteOFDMDemodulate(enb,rxWaveform);
 rxGrid = rxGrid(:,1:140);
 
-addpath('../../debug/lte/phy/lib/ch_estimation/test')
+addpath('../../debug/srslte/lib/ch_estimation/test')
 
 %% Channel Estimation
 [estChannel, noiseEst(snr_idx)] = lteDLChannelEstimate(enb,cec,rxGrid);

srslte/CMakeLists.txt

@@ -47,3 +47,5 @@ ADD_CUSTOM_TARGET (add_srslte_headers SOURCES ${HEADERS_ALL})
 ADD_SUBDIRECTORY(lib)
 ADD_SUBDIRECTORY(examples)
 
+
+add_subdirectory(tutorial_examples)

srslte/include/srslte/modem/demod_soft.h

@@ -43,7 +43,7 @@ typedef enum SRSLTE_API {
 typedef struct SRSLTE_API {
   float sigma;      // noise power
   srslte_demod_soft_alg_t alg_type;    // soft demapping algorithm (SRSLTE_DEMOD_SOFT_ALG_EXACT or SRSLTE_DEMOD_SOFT_ALG_APPROX)
-  srslte_srslte_modem_table_t *table;  // symbol mapping table (see modem_table.h)
+  srslte_modem_table_t *table;  // symbol mapping table (see modem_table.h)
   uint32_t *zones; 
   float *dd; 
   uint32_t max_symbols;
@@ -55,7 +55,7 @@ SRSLTE_API int srslte_demod_soft_init(srslte_demod_soft_t *q,
 SRSLTE_API void srslte_demod_soft_free(srslte_demod_soft_t *q); 
 
 SRSLTE_API void srslte_demod_soft_table_set(srslte_demod_soft_t *q, 
-                                            srslte_srslte_modem_table_t *table);
+                                            srslte_modem_table_t *table);
 
 SRSLTE_API void srslte_demod_soft_alg_set(srslte_demod_soft_t *q, 
                                           srslte_demod_soft_alg_t alg_type);
@@ -72,7 +72,7 @@ SRSLTE_API int srslte_demod_soft_demodulate(srslte_demod_soft_t *q,
 /* High-level API */
 typedef struct SRSLTE_API {
   srslte_demod_soft_t obj;
-  srslte_srslte_modem_table_t table;
+  srslte_modem_table_t table;
 
   struct srslte_demod_soft_init{
     srslte_mod_t std;    // symbol mapping standard (see modem_table.h)

srslte/include/srslte/modem/mod.h

@@ -35,14 +35,14 @@
 #include "srslte/config.h"
 #include "modem_table.h"
 
-SRSLTE_API int srslte_mod_modulate(srslte_srslte_modem_table_t* table, 
+SRSLTE_API int srslte_mod_modulate(srslte_modem_table_t* table, 
                                    uint8_t *bits, 
                                    cf_t* symbols, 
                                    uint32_t nbits);
 
 /* High-level API */
 typedef struct SRSLTE_API {
-  srslte_srslte_modem_table_t obj;
+  srslte_modem_table_t obj;
   struct mod_init {
     srslte_mod_t std;  // symbol mapping standard (see modem_table.h)
   } init;

srslte/include/srslte/modem/modem_table.h

@@ -49,22 +49,22 @@ typedef struct SRSLTE_API {
   srslte_soft_table_t soft_table;   	// symbol-to-bit mapping (used in soft demodulating)
   uint32_t nsymbols;        	// number of modulation symbols
   uint32_t nbits_x_symbol;      // number of bits per symbol
-}srslte_srslte_modem_table_t;
+}srslte_modem_table_t;
 
 
-SRSLTE_API void srslte_modem_table_init(srslte_srslte_modem_table_t* q);
+SRSLTE_API void srslte_modem_table_init(srslte_modem_table_t* q);
 
-SRSLTE_API void srslte_modem_table_free(srslte_srslte_modem_table_t* q);
+SRSLTE_API void srslte_modem_table_free(srslte_modem_table_t* q);
 
-SRSLTE_API void srslte_modem_table_reset(srslte_srslte_modem_table_t* q);
+SRSLTE_API void srslte_modem_table_reset(srslte_modem_table_t* q);
 
-SRSLTE_API int srslte_modem_table_set(srslte_srslte_modem_table_t* q, 
+SRSLTE_API int srslte_modem_table_set(srslte_modem_table_t* q, 
                                       cf_t* table, 
                                       srslte_soft_table_t *soft_table, 
                                       uint32_t nsymbols, 
                                       uint32_t nbits_x_symbol);
 
-SRSLTE_API int srslte_modem_table_lte(srslte_srslte_modem_table_t* q, 
+SRSLTE_API int srslte_modem_table_lte(srslte_modem_table_t* q, 
                                       srslte_mod_t modulation, 
                                       bool compute_soft_demod);
 

srslte/include/srslte/phch/pbch.h

@@ -69,7 +69,7 @@ typedef struct SRSLTE_API {
   uint32_t frame_idx;
 
   /* tx & rx objects */
-  srslte_srslte_modem_table_t mod;
+  srslte_modem_table_t mod;
   srslte_demod_soft_t demod;
   srslte_sequence_t seq;
   srslte_viterbi_t decoder;

srslte/include/srslte/phch/pcfich.h

@@ -64,7 +64,7 @@ typedef struct SRSLTE_API {
   float data_f[PCFICH_CFI_LEN]; 
 
   /* tx & rx objects */
-  srslte_srslte_modem_table_t mod;
+  srslte_modem_table_t mod;
   srslte_demod_soft_t demod;
   srslte_sequence_t seq[SRSLTE_NSUBFRAMES_X_FRAME];
   srslte_precoding_t precoding; 

srslte/include/srslte/phch/pdcch.h

@@ -69,7 +69,7 @@ typedef struct SRSLTE_API {
   float *llr;
 
   /* tx & rx objects */
-  srslte_srslte_modem_table_t mod;
+  srslte_modem_table_t mod;
   srslte_demod_soft_t demod;
   srslte_sequence_t seq[SRSLTE_NSUBFRAMES_X_FRAME];
   srslte_viterbi_t decoder;

srslte/include/srslte/phch/pdsch.h

@@ -62,7 +62,7 @@ typedef struct SRSLTE_API {
   void *e;
 
   /* tx & rx objects */
-  srslte_srslte_modem_table_t mod[4];
+  srslte_modem_table_t mod[4];
   srslte_demod_soft_t demod;
   srslte_sequence_t seq[SRSLTE_NSUBFRAMES_X_FRAME];
   srslte_precoding_t precoding; 

srslte/include/srslte/phch/phich.h

@@ -76,7 +76,7 @@ typedef struct SRSLTE_API {
   uint8_t data[SRSLTE_PHICH_NBITS];
 
   /* tx & rx objects */
-  srslte_srslte_modem_table_t mod;
+  srslte_modem_table_t mod;
   srslte_demod_hard_t demod;
   srslte_sequence_t seq[SRSLTE_NSUBFRAMES_X_FRAME];
   srslte_precoding_t precoding; 

srslte/include/srslte/phch/pusch.h

@@ -81,7 +81,7 @@ typedef struct SRSLTE_API {
   void *g;
 
   /* tx & rx objects */
-  srslte_srslte_modem_table_t mod[4];
+  srslte_modem_table_t mod[4];
   srslte_demod_soft_t demod;
   srslte_sequence_t seq[SRSLTE_NSUBFRAMES_X_FRAME];
   srslte_sequence_t seq_type2_fo; 

srslte/include/srslte/ue/ue_dl.h

@@ -71,6 +71,8 @@ typedef struct SRSLTE_API {
   cf_t *sf_symbols; 
   cf_t *ce[SRSLTE_MAX_PORTS];
   
+  srslte_dci_format_t dci_format;
+  uint32_t cfi;
   uint64_t pkt_errors; 
   uint64_t pkts_total;
   uint64_t nof_detected; 

srslte/include/srslte/ue/ue_sync.h

@@ -94,6 +94,7 @@ typedef struct SRSLTE_API {
   uint32_t sf_idx;
       
   bool decode_sss_on_track; 
+  bool correct_cfo; 
   
   uint32_t peak_idx;
   int time_offset;

srslte/lib/ch_estimation/src/chest_dl.c

@@ -92,7 +92,6 @@ int srslte_chest_dl_init(srslte_chest_dl_t *q, srslte_cell_t cell)
       perror("malloc");
       goto clean_exit;
     }
-    bzero(q->tmp_timeavg_mult, sizeof(cf_t) * 2*cell.nof_prb);
     
     for (int i=0;i<cell.nof_ports;i++) {
       q->pilot_estimates[i] = srslte_vec_malloc(sizeof(cf_t) * SRSLTE_REFSIGNAL_NUM_SF(cell.nof_prb, i));
@@ -123,13 +122,13 @@ int srslte_chest_dl_init(srslte_chest_dl_t *q, srslte_cell_t cell)
     }
     
     /* Set default time/freq filters */
-    //float f[3]={0.1, 0.8, 0.1};
+    //float f[3]={0.2, 0.6, 0.2};
     //srslte_chest_dl_set_filter_freq(q, f, 3);
 
-    float f[5]={0.05, 0.2, 0.5, 0.2, 0.05};
+    float f[5]={0.1, 0.2, 0.4, 0.2, 0.1};
     srslte_chest_dl_set_filter_freq(q, f, 5);
 
-    float t[2]={0.1, 0.9};
+    float t[2]={0.5, 0.5};
     srslte_chest_dl_set_filter_time(q, t, 0);
     
     q->cell = cell; 
@@ -269,14 +268,18 @@ static void average_pilots(srslte_chest_dl_t *q, uint32_t port_id)
       for (i=0;i<q->filter_time_len-1;i++) {
         memcpy(q->tmp_timeavg[i], q->tmp_timeavg[i+1], nref*sizeof(cf_t));                      
       }
-      /* Put last symbol to buffer */
+      /* Save last symbol to buffer */
-      memcpy(q->tmp_timeavg[i], &pilot_tmp(0), nref*sizeof(cf_t));            
+      memcpy(q->tmp_timeavg[q->filter_time_len-1], &pilot_tmp(0), nref*sizeof(cf_t));            
       
       /* Multiply all symbols by filter and add them  */
-      bzero(&pilot_avg(0), nref * sizeof(cf_t));
+      if (l > 0) {
-      for (i=0;i<q->filter_time_len;i++) {
+        bzero(&pilot_avg(0), nref * sizeof(cf_t));
-        srslte_vec_sc_prod_cfc(q->tmp_timeavg[i], q->filter_time[i], q->tmp_timeavg[i], nref);
+        for (i=0;i<q->filter_time_len;i++) {
-        srslte_vec_sum_ccc(q->tmp_timeavg[i], &pilot_avg(0), &pilot_avg(0), nref);            
+          srslte_vec_sc_prod_cfc(q->tmp_timeavg[i], q->filter_time[i], q->tmp_timeavg_mult, nref);
+          srslte_vec_sum_ccc(q->tmp_timeavg_mult, &pilot_avg(0), &pilot_avg(0), nref);            
+        }        
+      } else {
+        memcpy(&pilot_avg(0), &pilot_tmp(0), nref * sizeof(cf_t));
       }
     } else {
       memcpy(&pilot_avg(0), &pilot_tmp(0), nref * sizeof(cf_t));        

srslte/lib/modem/src/demod_soft.c

@@ -71,7 +71,7 @@ void srslte_demod_soft_free(srslte_demod_soft_t *q) {
   bzero((void*)q,sizeof(srslte_demod_soft_t));
 }
 
-void srslte_demod_soft_table_set(srslte_demod_soft_t *q, srslte_srslte_modem_table_t *table) {
+void srslte_demod_soft_table_set(srslte_demod_soft_t *q, srslte_modem_table_t *table) {
   q->table = table;
 }
 

srslte/lib/modem/src/mod.c

@@ -35,7 +35,7 @@
 
 /** Low-level API */
 
-int srslte_mod_modulate(srslte_srslte_modem_table_t* q, uint8_t *bits, cf_t* symbols, uint32_t nbits) {
+int srslte_mod_modulate(srslte_modem_table_t* q, uint8_t *bits, cf_t* symbols, uint32_t nbits) {
   uint32_t i,j,idx;
   uint8_t *b_ptr=(uint8_t*) bits;
   j=0;

srslte/lib/modem/src/modem_table.c

@@ -38,26 +38,26 @@
 #include "lte_tables.h"
 
 /** Internal functions */
-static int table_create(srslte_srslte_modem_table_t* q) {
+static int table_create(srslte_modem_table_t* q) {
   q->symbol_table = malloc(q->nsymbols*sizeof(cf_t));
   return q->symbol_table==NULL;
 }
 
-void srslte_modem_table_init(srslte_srslte_modem_table_t* q) {
+void srslte_modem_table_init(srslte_modem_table_t* q) {
-  bzero((void*)q,sizeof(srslte_srslte_modem_table_t));
+  bzero((void*)q,sizeof(srslte_modem_table_t));
 }
-void srslte_modem_table_free(srslte_srslte_modem_table_t* q) {
+void srslte_modem_table_free(srslte_modem_table_t* q) {
   if (q->symbol_table) {
     free(q->symbol_table);
   }
-  bzero(q, sizeof(srslte_srslte_modem_table_t));
+  bzero(q, sizeof(srslte_modem_table_t));
 }
-void srslte_modem_table_reset(srslte_srslte_modem_table_t* q) {
+void srslte_modem_table_reset(srslte_modem_table_t* q) {
   srslte_modem_table_free(q);
   srslte_modem_table_init(q);
 }
 
-int srslte_modem_table_set(srslte_srslte_modem_table_t* q, cf_t* table, srslte_soft_table_t *soft_table, uint32_t nsymbols, uint32_t nbits_x_symbol) {
+int srslte_modem_table_set(srslte_modem_table_t* q, cf_t* table, srslte_soft_table_t *soft_table, uint32_t nsymbols, uint32_t nbits_x_symbol) {
   if (q->nsymbols) {
     return SRSLTE_ERROR;
   }
@@ -71,7 +71,7 @@ int srslte_modem_table_set(srslte_srslte_modem_table_t* q, cf_t* table, srslte_s
   return SRSLTE_SUCCESS;
 }
 
-int srslte_modem_table_lte(srslte_srslte_modem_table_t* q, srslte_mod_t modulation, bool compute_soft_demod) {
+int srslte_modem_table_lte(srslte_modem_table_t* q, srslte_mod_t modulation, bool compute_soft_demod) {
   switch(modulation) {
   case SRSLTE_MOD_BPSK:
     q->nbits_x_symbol = 1;

srslte/lib/modem/test/modem_test.c

@@ -94,7 +94,7 @@ void parse_args(int argc, char **argv) {
 
 int main(int argc, char **argv) {
   int i;
-  srslte_srslte_modem_table_t mod;
+  srslte_modem_table_t mod;
   srslte_demod_hard_t demod_hard;
   srslte_demod_soft_t demod_soft;
   uint8_t *input, *output;

srslte/lib/modem/test/soft_demod_test.c

@@ -108,7 +108,7 @@ float mse_threshold() {
 
 int main(int argc, char **argv) {
   int i;
-  srslte_srslte_modem_table_t mod;
+  srslte_modem_table_t mod;
   srslte_demod_soft_t demod_soft;
   uint8_t *input, *output;
   cf_t *symbols;

srslte/lib/phch/src/dci.c

@@ -802,13 +802,13 @@ int srslte_dci_msg_unpack_pusch(srslte_dci_msg_t *msg, srslte_ra_pusch_t *data,
 }
 
 srslte_dci_format_t srslte_dci_format_from_string(char *str) {
-  if (!strcmp(str, "SRSLTE_DCI_FORMAT0")) {
+  if (!strcmp(str, "Format0")) {
     return SRSLTE_DCI_FORMAT0;
-  } else if (!strcmp(str, "SRSLTE_DCI_FORMAT1")) {
+  } else if (!strcmp(str, "Format1")) {
     return SRSLTE_DCI_FORMAT1; 
-  } else if (!strcmp(str, "SRSLTE_DCI_FORMAT1A")) {
+  } else if (!strcmp(str, "Format1A")) {
     return SRSLTE_DCI_FORMAT1A; 
-  } else if (!strcmp(str, "SRSLTE_DCI_FORMAT1C")) {
+  } else if (!strcmp(str, "Format1C")) {
     return SRSLTE_DCI_FORMAT1C; 
   } else {
     return SRSLTE_DCI_FORMAT_ERROR;
@@ -818,13 +818,13 @@ srslte_dci_format_t srslte_dci_format_from_string(char *str) {
 char* srslte_dci_format_string(srslte_dci_format_t format) {
   switch (format) {
   case SRSLTE_DCI_FORMAT0:
-    return "SRSLTE_DCI_FORMAT0";
+    return "Format0";
   case SRSLTE_DCI_FORMAT1:
-    return "SRSLTE_DCI_FORMAT1";
+    return "Format1";
   case SRSLTE_DCI_FORMAT1A:
-    return "SRSLTE_DCI_FORMAT1A";
+    return "Format1A";
   case SRSLTE_DCI_FORMAT1C:
-    return "SRSLTE_DCI_FORMAT1C";
+    return "Format1C";
   default:
     return "N/A"; // fatal error
   }

srslte/lib/sync/src/sync.c

@@ -36,7 +36,7 @@
 #include "srslte/sync/cfo.h"
 
 #define MEANPEAK_EMA_ALPHA      0.2
-#define CFO_EMA_ALPHA           0.01
+#define CFO_EMA_ALPHA           0.1
 #define CP_EMA_ALPHA            0.2
 
 static bool fft_size_isvalid(uint32_t fft_size) {

srslte/lib/ue/src/ue_dl.c

@@ -196,7 +196,7 @@ int srslte_ue_dl_decode_fft_estimate(srslte_ue_dl_t *q, cf_t *input, uint32_t sf
     }
 
     /* Extract all PDCCH symbols and get LLRs */
-    if (srslte_pdcch_extract_llr(&q->pdcch, q->sf_symbols, q->ce, srslte_chest_dl_get_noise_estimate(&q->chest), sf_idx, *cfi)) {
+    if (srslte_pdcch_extract_llr(&q->pdcch, q->sf_symbols, q->ce, 0, sf_idx, *cfi)) {
       fprintf(stderr, "Error extracting LLRs\n");
       return SRSLTE_ERROR;
     }
@@ -228,7 +228,7 @@ int srslte_ue_dl_decode_rnti_rv_packet(srslte_ue_dl_t *q, srslte_dci_msg_t *dci_
   }
   if (q->harq_process[0].mcs.mod > 0 && q->harq_process[0].mcs.tbs >= 0) {
     ret = srslte_pdsch_decode_rnti(&q->pdsch, &q->harq_process[0], q->sf_symbols, 
-                            q->ce, srslte_chest_dl_get_noise_estimate(&q->chest),
+                            q->ce, 0,
                             rnti, data);
     if (ret == SRSLTE_ERROR) {
       q->pkt_errors++;
@@ -262,7 +262,7 @@ int srslte_ue_dl_find_ul_dci(srslte_ue_dl_t *q, srslte_dci_msg_t *dci_msg, uint3
 
 int srslte_ue_dl_decode_rnti_rv(srslte_ue_dl_t *q, cf_t *input, uint8_t *data, uint32_t sf_idx, uint16_t rnti, uint32_t rvidx) 
 {
-  uint32_t cfi, i;
+  uint32_t i;
   srslte_dci_msg_t dci_msg;
   srslte_dci_location_t locations[MAX_CANDIDATES];
   uint32_t nof_locations;
@@ -271,17 +271,17 @@ int srslte_ue_dl_decode_rnti_rv(srslte_ue_dl_t *q, cf_t *input, uint8_t *data, u
   uint32_t nof_formats; 
   srslte_dci_format_t *formats = NULL; 
 
-  if ((ret = srslte_ue_dl_decode_fft_estimate(q, input, sf_idx, &cfi)) < 0) {
+  if ((ret = srslte_ue_dl_decode_fft_estimate(q, input, sf_idx, &q->cfi)) < 0) {
     return ret; 
   }
   
   /* Generate PDCCH candidates */
   if (rnti == SRSLTE_SIRNTI) {
-    nof_locations = srslte_pdcch_common_locations(&q->pdcch, locations, MAX_CANDIDATES, cfi);
+    nof_locations = srslte_pdcch_common_locations(&q->pdcch, locations, MAX_CANDIDATES, q->cfi);
     formats = common_formats;
     nof_formats = nof_common_formats;
   } else {
-    nof_locations = srslte_pdcch_ue_locations(&q->pdcch, locations, MAX_CANDIDATES, sf_idx, cfi, rnti);    
+    nof_locations = srslte_pdcch_ue_locations(&q->pdcch, locations, MAX_CANDIDATES, sf_idx, q->cfi, rnti);    
     formats = ue_formats; 
     nof_formats = nof_ue_formats;
   }
@@ -299,8 +299,9 @@ int srslte_ue_dl_decode_rnti_rv(srslte_ue_dl_t *q, cf_t *input, uint8_t *data, u
       INFO("Decoded DCI message RNTI: 0x%x\n", srslte_crc_rem);
       
       if (srslte_crc_rem == rnti) {
+        q->dci_format = formats[f];
         found_dci++;        
-        ret = srslte_ue_dl_decode_rnti_rv_packet(q, &dci_msg, data, cfi, sf_idx, rnti, rvidx);
+        ret = srslte_ue_dl_decode_rnti_rv_packet(q, &dci_msg, data, q->cfi, sf_idx, rnti, rvidx);
       }
     }
   }

srslte/lib/ue/src/ue_sync.c

@@ -63,7 +63,7 @@ int srslte_ue_sync_init_file(srslte_ue_sync_t *q, uint32_t nof_prb, char *file_n
       goto clean_exit; 
     }
     
-    q->input_buffer = srslte_vec_malloc(q->sf_len * sizeof(cf_t));
+    q->input_buffer = srslte_vec_malloc(2 * q->sf_len * sizeof(cf_t));
     if (!q->input_buffer) {
       perror("malloc");
       goto clean_exit;
@@ -102,6 +102,7 @@ int srslte_ue_sync_init(srslte_ue_sync_t *q,
     q->fft_size = srslte_symbol_sz(q->cell.nof_prb);
     q->sf_len = SRSLTE_SF_LEN(q->fft_size);
     q->file_mode = false; 
+    q->correct_cfo = true; 
     
     if (cell.id == 1000) {
       /* If the cell is unkown, decode SSS on track state */
@@ -449,7 +450,7 @@ int srslte_ue_sync_get_buffer(srslte_ue_sync_t *q, cf_t **sf_symbols) {
           }
           
           /* Do CFO Correction if not done in track and deliver the frame */
-          if (!q->strack.correct_cfo) {
+          if (!q->strack.correct_cfo && q->correct_cfo) {
             srslte_cfo_correct(&q->sfind.cfocorr, 
                         q->input_buffer, 
                         q->input_buffer,