Revert zeros around DC REs in NR PDSCH

lib/include/srsran/phy/phch/pdsch_nr.h

@@ -37,8 +37,6 @@ typedef struct SRSRAN_API {
   srsran_sch_nr_args_t sch;
   bool                 measure_evm;
   bool                 measure_time;
-  bool                 disable_zero_re_around_dc; ///< PDSCH NR sets the LLR around the DC to zero to avoid noise
-  uint32_t             nof_zero_re_around_dc; ///< Number of RE to set to zero around DC. It uses default value if 0.
 } srsran_pdsch_nr_args_t;
 
 /**
@@ -59,8 +57,6 @@ typedef struct SRSRAN_API {
   uint32_t             meas_time_us;
   srsran_re_pattern_t  dmrs_re_pattern;
   uint32_t             nof_rvd_re;
-  uint32_t nof_zero_re_around_dc; ///< Sets a number of RE surrounding the center of the resource grid to zero. Set to 0
-                                  ///< for disabling.
 } srsran_pdsch_nr_t;
 
 /**

lib/src/phy/phch/pdsch_nr.c

@@ -17,9 +17,6 @@
 #include "srsran/phy/mimo/precoding.h"
 #include "srsran/phy/modem/demod_soft.h"
 
-///@brief Default number of zero RE around DC
-#define PDSCH_NR_DEFAULT_NOF_ZERO_RE_AROUND_DC 3
-
 int pdsch_nr_init_common(srsran_pdsch_nr_t* q, const srsran_pdsch_nr_args_t* args)
 {
   SRSRAN_MEM_ZERO(q, srsran_pdsch_nr_t, 1);
@@ -34,14 +31,6 @@ int pdsch_nr_init_common(srsran_pdsch_nr_t* q, const srsran_pdsch_nr_args_t* arg
     }
   }
 
-  if (!args->disable_zero_re_around_dc) {
-    if (args->nof_zero_re_around_dc == 0) {
-      q->nof_zero_re_around_dc = PDSCH_NR_DEFAULT_NOF_ZERO_RE_AROUND_DC;
-    } else {
-      q->nof_zero_re_around_dc = args->nof_zero_re_around_dc;
-    }
-  }
-
   return SRSRAN_SUCCESS;
 }
 
@@ -249,27 +238,11 @@ static int srsran_pdsch_nr_cp(const srsran_pdsch_nr_t*     q,
       // Put or get
       if (put) {
         count += pdsch_nr_put_rb(&sf_symbols[re_idx], &symbols[count], &rvd_mask[rb * SRSRAN_NRE]);
-      } else {
-        uint32_t k_begin    = rb * SRSRAN_NRE;
-        uint32_t k_end      = (rb + 1) * SRSRAN_NRE;
-        uint32_t k_dc_begin = q->carrier.nof_prb * SRSRAN_NRE / 2 - q->nof_zero_re_around_dc / 2;
-        uint32_t k_dc_end   = q->carrier.nof_prb * SRSRAN_NRE / 2 + SRSRAN_CEIL(q->nof_zero_re_around_dc, 2);
-        if (k_begin <= k_dc_end && k_end >= k_dc_begin && q->nof_zero_re_around_dc > 0) {
-          for (uint32_t k = k_begin; k < k_end; k++) {
-            if (!rvd_mask[k]) {
-              if (k >= k_dc_begin && k < k_dc_end) {
-                symbols[count++] = 0.0f;
-              } else {
-                symbols[count++] = sf_symbols[q->carrier.nof_prb * l * SRSRAN_NRE + k];
-              }
-            }
-          }
       } else {
         count += pdsch_nr_get_rb(&symbols[count], &sf_symbols[re_idx], &rvd_mask[rb * SRSRAN_NRE]);
       }
     }
   }
-  }
 
   return count;
 }

lib/test/phy/phy_dl_nr_test.c

@@ -214,7 +214,6 @@ int main(int argc, char** argv)
   ue_dl_args.pdsch.sch.disable_simd          = false;
   ue_dl_args.pdsch.sch.decoder_use_flooded   = false;
   ue_dl_args.pdsch.measure_evm               = true;
-  ue_dl_args.pdsch.disable_zero_re_around_dc = true;
   ue_dl_args.pdcch.disable_simd              = false;
   ue_dl_args.pdcch.measure_evm               = true;
   ue_dl_args.nof_max_prb                     = carrier.nof_prb;