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 * Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
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 * except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.openairinterface.org/?page_id=698
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
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 *-------------------------------------------------------------------------------
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/*! \file nr_l1_helper.c
* \brief PHY helper functions for PRACH adapted to NR
* \author Guido Casati
* \date 2019
* \version 2.0
* \email guido.casati@iis.fraunhofer.de
* @ingroup _mac

*/

#include "PHY/defs_nr_common.h"

#include "mac_defs.h"
#include "LAYER2/NR_MAC_COMMON/nr_mac_extern.h"
#include "LAYER2/NR_MAC_UE/mac_proto.h"

/* TS 38.321 subclause 7.3 - return DELTA_PREAMBLE values in dB */
int8_t nr_get_DELTA_PREAMBLE(module_id_t mod_id, int CC_id, uint16_t prach_format){

  NR_UE_MAC_INST_t *mac = get_mac_inst(mod_id);
  NR_ServingCellConfigCommon_t *scc = mac->scc;
  NR_RACH_ConfigCommon_t *nr_rach_ConfigCommon = scc->uplinkConfigCommon->initialUplinkBWP->rach_ConfigCommon->choice.setup;
  NR_SubcarrierSpacing_t scs = *nr_rach_ConfigCommon->msg1_SubcarrierSpacing;
  int prach_sequence_length = scc->uplinkConfigCommon->initialUplinkBWP->rach_ConfigCommon->choice.setup->prach_RootSequenceIndex.present - 1;
  uint8_t prachConfigIndex, mu;

  AssertFatal(CC_id == 0, "Transmission on secondary CCs is not supported yet\n");

  // SCS configuration from msg1_SubcarrierSpacing and table 4.2-1 in TS 38.211

  switch (scs){
    case NR_SubcarrierSpacing_kHz15:
    mu = 0;
    break;

    case NR_SubcarrierSpacing_kHz30:
    mu = 1;
    break;

    case NR_SubcarrierSpacing_kHz60:
    mu = 2;
    break;

    case NR_SubcarrierSpacing_kHz120:
    mu = 3;
    break;

    case NR_SubcarrierSpacing_kHz240:
    mu = 4;
    break;

    case NR_SubcarrierSpacing_spare3:
    mu = 5;
    break;

    case NR_SubcarrierSpacing_spare2:
    mu = 6;
    break;

    case NR_SubcarrierSpacing_spare1:
    mu = 7;
    break;

    default:
    AssertFatal(1 == 0,"Unknown msg1_SubcarrierSpacing %lu\n", scs);
  }

  // Preamble formats given by prach_ConfigurationIndex and tables 6.3.3.2-2 and 6.3.3.2-2 in TS 38.211

  prachConfigIndex = nr_rach_ConfigCommon->rach_ConfigGeneric.prach_ConfigurationIndex;

  if (prach_sequence_length == 0) {
    switch (prach_format) {
      AssertFatal(prach_format < 4, "Illegal PRACH format %d for sequence length 839\n", prach_format);

      // long preamble formats
      case 0:
      case 3:
      return  0;

      case 1:           
      return -3;

      case 2:
      return -6;
    }
  } else {
    switch (prach_format) { // short preamble formats
      case 0:
      case 3:
      return 8 + 3*mu;

      case 1:
      case 4:
      case 8:
      return 5 + 3*mu;

      case 2:
      case 5:
      return 3 + 3*mu;

      case 6:
      return 3*mu;

      case 7:
      return 5 + 3*mu;

      default:
      AssertFatal(1 == 0, "[UE %d] ue_procedures.c: FATAL, Illegal preambleFormat %d, prachConfigIndex %d\n", mod_id, prach_format, prachConfigIndex);
    }
  }
}

/* TS 38.321 subclause 5.1.3 - RA preamble transmission - ra_PREAMBLE_RECEIVED_TARGET_POWER configuration */
int nr_get_Po_NOMINAL_PUSCH(NR_PRACH_RESOURCES_t *prach_resources, module_id_t mod_id, uint8_t CC_id){
  
  NR_UE_MAC_INST_t *mac = get_mac_inst(mod_id);
  NR_ServingCellConfigCommon_t *scc = mac->scc;
  NR_RACH_ConfigCommon_t *nr_rach_ConfigCommon = scc->uplinkConfigCommon->initialUplinkBWP->rach_ConfigCommon->choice.setup;
  int8_t receivedTargerPower, delta_preamble;
  long preambleReceivedTargetPower;

  AssertFatal(nr_rach_ConfigCommon != NULL, "[UE %d] CCid %d FATAL nr_rach_ConfigCommon is NULL !!!\n", mod_id, CC_id);

  preambleReceivedTargetPower = nr_rach_ConfigCommon->rach_ConfigGeneric.preambleReceivedTargetPower;
  delta_preamble = nr_get_DELTA_PREAMBLE(mod_id, CC_id, prach_resources->prach_format);

  receivedTargerPower = preambleReceivedTargetPower + delta_preamble + (mac->RA_PREAMBLE_POWER_RAMPING_COUNTER - 1) * prach_resources->RA_PREAMBLE_POWER_RAMPING_STEP;

  return receivedTargerPower;
}