/*
 * 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.
 * The OpenAirInterface Software Alliance licenses this file to You under
 * the OAI Public License, Version 1.1  (the "License"); you may not use this file
 * 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
 * limitations under the License.
 *-------------------------------------------------------------------------------
 * For more information about the OpenAirInterface (OAI) Software Alliance:
 *      contact@openairinterface.org
 */

/*! \file PHY/LTE_TRANSPORT/pbch.c
* \brief Top-level routines for generating and decoding  the PBCH/BCH physical/transport channel V8.6 2009-03
* \author R. Knopp, F. Kaltenberger
* \date 2011
* \version 0.1
* \company Eurecom
* \email: knopp@eurecom.fr,florian.kaltenberger.fr
* \note
* \warning
*/


#include "PHY/defs_UE.h"
#include "PHY/CODING/coding_defs.h"
#include "PHY/CODING/coding_extern.h"
#include "PHY/CODING/lte_interleaver_inline.h"
#include "transport_ue.h"
#include "PHY/phy_extern.h"
#include "PHY/sse_intrin.h"
#include "PHY/LTE_REFSIG/lte_refsig.h"

//#define DEBUG_PBCH 1
//#define DEBUG_PBCH_ENCODING
//#define INTERFERENCE_MITIGATION 1


#define PBCH_A 24

uint16_t pbch_extract(int **rxdataF,
                      int **dl_ch_estimates,
                      int **rxdataF_ext,
                      int **dl_ch_estimates_ext,
                      uint32_t symbol,
                      uint32_t high_speed_flag,
                      LTE_DL_FRAME_PARMS *frame_parms) {
  uint16_t rb,nb_rb=6;
  uint8_t i,j,aarx,aatx;
  int *dl_ch0,*dl_ch0_ext,*rxF,*rxF_ext;
  uint32_t nsymb = (frame_parms->Ncp==0) ? 7:6;
  uint32_t symbol_mod = symbol % nsymb;
  int rx_offset = frame_parms->ofdm_symbol_size-3*12;
  int ch_offset = frame_parms->N_RB_DL*6-3*12;
  int nushiftmod3 = frame_parms->nushift%3;

  for (aarx=0; aarx<frame_parms->nb_antennas_rx; aarx++) {
    /*
    printf("extract_rbs (nushift %d): symbol_mod=%d, rx_offset=%d, ch_offset=%d\n",frame_parms->nushift,symbol_mod,
     (rx_offset + (symbol*(frame_parms->ofdm_symbol_size)))*2,
     LTE_CE_OFFSET+ch_offset+(symbol_mod*(frame_parms->ofdm_symbol_size)));
    */
    rxF        = &rxdataF[aarx][(rx_offset + (symbol*(frame_parms->ofdm_symbol_size)))];
    rxF_ext    = &rxdataF_ext[aarx][symbol_mod*(6*12)];

    for (rb=0; rb<nb_rb; rb++) {
      // skip DC carrier
      if (rb==3) {
        rxF       = &rxdataF[aarx][(1 + (symbol*(frame_parms->ofdm_symbol_size)))];
      }

      if ((symbol_mod==0) || (symbol_mod==1)) {
        j=0;

        for (i=0; i<12; i++) {
          if ((i!=nushiftmod3) &&
              (i!=(nushiftmod3+3)) &&
              (i!=(nushiftmod3+6)) &&
              (i!=(nushiftmod3+9))) {
            rxF_ext[j++]=rxF[i];
          }
        }

        rxF+=12;
        rxF_ext+=8;
      } else {
        for (i=0; i<12; i++) {
          rxF_ext[i]=rxF[i];
        }

        rxF+=12;
        rxF_ext+=12;
      }
    }

    for (aatx=0; aatx<4; aatx++) { //frame_parms->nb_antenna_ports_eNB;aatx++) {
      if (high_speed_flag == 1)
        dl_ch0     = &dl_ch_estimates[(aatx<<1)+aarx][LTE_CE_OFFSET+ch_offset+(symbol*(frame_parms->ofdm_symbol_size))];
      else
        dl_ch0     = &dl_ch_estimates[(aatx<<1)+aarx][LTE_CE_OFFSET+ch_offset];

      dl_ch0_ext = &dl_ch_estimates_ext[(aatx<<1)+aarx][symbol_mod*(6*12)];

      for (rb=0; rb<nb_rb; rb++) {
        // skip DC carrier
        // if (rb==3) dl_ch0++;
        if (symbol_mod>1) {
          memcpy(dl_ch0_ext,dl_ch0,12*sizeof(int));
          dl_ch0+=12;
          dl_ch0_ext+=12;
        } else {
          j=0;

          for (i=0; i<12; i++) {
            if ((i!=nushiftmod3) &&
                (i!=(nushiftmod3+3)) &&
                (i!=(nushiftmod3+6)) &&
                (i!=(nushiftmod3+9))) {
              //        printf("PBCH extract i %d j %d => (%d,%d)\n",i,j,*(short *)&dl_ch0[i],*(1+(short*)&dl_ch0[i]));
              dl_ch0_ext[j++]=dl_ch0[i];
            }
          }

          dl_ch0+=12;
          dl_ch0_ext+=8;
        }
      }
    }  //tx antenna loop
  }

  return(0);
}

//__m128i avg128;

//compute average channel_level on each (TX,RX) antenna pair
int pbch_channel_level(int **dl_ch_estimates_ext,
                       LTE_DL_FRAME_PARMS *frame_parms,
                       uint32_t symbol) {
  int16_t rb, nb_rb=6;
  uint8_t aatx, aarx;
  simde__m128i avg128;
  simde__m128i *dl_ch128;
  int avg1=0,avg2=0;
  uint32_t nsymb = (frame_parms->Ncp==0) ? 7:6;
  uint32_t symbol_mod = symbol % nsymb;

  for (aatx=0; aatx<4; aatx++) //frame_parms->nb_antenna_ports_eNB;aatx++)
    for (aarx=0; aarx<frame_parms->nb_antennas_rx; aarx++) {
      // clear average level
      avg128 = simde_mm_setzero_si128();
      dl_ch128 = (simde__m128i *)&dl_ch_estimates_ext[(aatx << 1) + aarx][symbol_mod * 6 * 12];

      for (rb = 0; rb < nb_rb; rb++) {
        avg128 = simde_mm_add_epi32(avg128, simde_mm_madd_epi16(dl_ch128[0], dl_ch128[0]));
        avg128 = simde_mm_add_epi32(avg128, simde_mm_madd_epi16(dl_ch128[1], dl_ch128[1]));
        avg128 = simde_mm_add_epi32(avg128, simde_mm_madd_epi16(dl_ch128[2], dl_ch128[2]));
        dl_ch128+=3;
        /*
          if (rb==0) {
          print_shorts("dl_ch128",&dl_ch128[0]);
          print_shorts("dl_ch128",&dl_ch128[1]);
          print_shorts("dl_ch128",&dl_ch128[2]);
          }
        */
      }

      avg1 = (((int *)&avg128)[0] +
              ((int *)&avg128)[1] +
              ((int *)&avg128)[2] +
              ((int *)&avg128)[3])/(nb_rb*12);

      if (avg1>avg2)
        avg2 = avg1;

      //msg("Channel level : %d, %d\n",avg1, avg2);
    }

  simde_mm_empty();
  simde_m_empty();
  return(avg2);
}

simde__m128i mmtmpP0, mmtmpP1, mmtmpP2, mmtmpP3;
void pbch_channel_compensation(int **rxdataF_ext,
                               int **dl_ch_estimates_ext,
                               int **rxdataF_comp,
                               LTE_DL_FRAME_PARMS *frame_parms,
                               uint8_t symbol,
                               uint8_t output_shift) {
  uint16_t rb,nb_rb=6;
  uint8_t aatx, aarx, symbol_mod;
  simde__m128i *dl_ch128, *rxdataF128, *rxdataF_comp128;
  symbol_mod = (symbol>=(7-frame_parms->Ncp)) ? symbol-(7-frame_parms->Ncp) : symbol;

  for (aatx=0; aatx<4; aatx++) //frame_parms->nb_antenna_ports_eNB;aatx++)
    for (aarx = 0; aarx < frame_parms->nb_antennas_rx; aarx++) {
      dl_ch128 = (simde__m128i *)&dl_ch_estimates_ext[(aatx << 1) + aarx][symbol_mod * 6 * 12];
      rxdataF128 = (simde__m128i *)&rxdataF_ext[aarx][symbol_mod * 6 * 12];
      rxdataF_comp128 = (simde__m128i *)&rxdataF_comp[(aatx << 1) + aarx][symbol_mod * 6 * 12];

      for (rb=0; rb<nb_rb; rb++) {
        // printf("rb %d\n",rb);
        //  multiply by conjugated channel
        mmtmpP0 = simde_mm_madd_epi16(dl_ch128[0], rxdataF128[0]);
        //  print_ints("re",&mmtmpP0);
        // mmtmpP0 contains real part of 4 consecutive outputs (32-bit)
        mmtmpP1 = simde_mm_shufflelo_epi16(dl_ch128[0], SIMDE_MM_SHUFFLE(2, 3, 0, 1));
        mmtmpP1 = simde_mm_shufflehi_epi16(mmtmpP1, SIMDE_MM_SHUFFLE(2, 3, 0, 1));
        mmtmpP1 = simde_mm_sign_epi16(mmtmpP1, *(simde__m128i *)&conjugate[0]);
        //  print_ints("im",&mmtmpP1);
        mmtmpP1 = simde_mm_madd_epi16(mmtmpP1, rxdataF128[0]);
        // mmtmpP1 contains imag part of 4 consecutive outputs (32-bit)
        mmtmpP0 = simde_mm_srai_epi32(mmtmpP0, output_shift);
        //  print_ints("re(shift)",&mmtmpP0);
        mmtmpP1 = simde_mm_srai_epi32(mmtmpP1, output_shift);
        //  print_ints("im(shift)",&mmtmpP1);
        mmtmpP2 = simde_mm_unpacklo_epi32(mmtmpP0, mmtmpP1);
        mmtmpP3 = simde_mm_unpackhi_epi32(mmtmpP0, mmtmpP1);
        //      print_ints("c0",&mmtmpP2);
        //  print_ints("c1",&mmtmpP3);
        rxdataF_comp128[0] = simde_mm_packs_epi32(mmtmpP2, mmtmpP3);
        //  print_shorts("rx:",rxdataF128);
        //  print_shorts("ch:",dl_ch128);
        //  print_shorts("pack:",rxdataF_comp128);
        // multiply by conjugated channel
        mmtmpP0 = simde_mm_madd_epi16(dl_ch128[1], rxdataF128[1]);
        // mmtmpP0 contains real part of 4 consecutive outputs (32-bit)
        mmtmpP1 = simde_mm_shufflelo_epi16(dl_ch128[1], SIMDE_MM_SHUFFLE(2, 3, 0, 1));
        mmtmpP1 = simde_mm_shufflehi_epi16(mmtmpP1, SIMDE_MM_SHUFFLE(2, 3, 0, 1));
        mmtmpP1 = simde_mm_sign_epi16(mmtmpP1, *(simde__m128i *)&conjugate[0]);
        mmtmpP1 = simde_mm_madd_epi16(mmtmpP1, rxdataF128[1]);
        // mmtmpP1 contains imag part of 4 consecutive outputs (32-bit)
        mmtmpP0 = simde_mm_srai_epi32(mmtmpP0, output_shift);
        mmtmpP1 = simde_mm_srai_epi32(mmtmpP1, output_shift);
        mmtmpP2 = simde_mm_unpacklo_epi32(mmtmpP0, mmtmpP1);
        mmtmpP3 = simde_mm_unpackhi_epi32(mmtmpP0, mmtmpP1);
        rxdataF_comp128[1] = simde_mm_packs_epi32(mmtmpP2, mmtmpP3);
        //  print_shorts("rx:",rxdataF128+1);
        //  print_shorts("ch:",dl_ch128+1);
        //  print_shorts("pack:",rxdataF_comp128+1);

        if (symbol_mod>1) {
          // multiply by conjugated channel
          mmtmpP0 = simde_mm_madd_epi16(dl_ch128[2], rxdataF128[2]);
          // mmtmpP0 contains real part of 4 consecutive outputs (32-bit)
          mmtmpP1 = simde_mm_shufflelo_epi16(dl_ch128[2], SIMDE_MM_SHUFFLE(2, 3, 0, 1));
          mmtmpP1 = simde_mm_shufflehi_epi16(mmtmpP1, SIMDE_MM_SHUFFLE(2, 3, 0, 1));
          mmtmpP1 = simde_mm_sign_epi16(mmtmpP1, *(simde__m128i *)&conjugate[0]);
          mmtmpP1 = simde_mm_madd_epi16(mmtmpP1, rxdataF128[2]);
          // mmtmpP1 contains imag part of 4 consecutive outputs (32-bit)
          mmtmpP0 = simde_mm_srai_epi32(mmtmpP0, output_shift);
          mmtmpP1 = simde_mm_srai_epi32(mmtmpP1, output_shift);
          mmtmpP2 = simde_mm_unpacklo_epi32(mmtmpP0, mmtmpP1);
          mmtmpP3 = simde_mm_unpackhi_epi32(mmtmpP0, mmtmpP1);
          rxdataF_comp128[2] = simde_mm_packs_epi32(mmtmpP2, mmtmpP3);
          //  print_shorts("rx:",rxdataF128+2);
          //  print_shorts("ch:",dl_ch128+2);
          //      print_shorts("pack:",rxdataF_comp128+2);
          dl_ch128+=3;
          rxdataF128+=3;
          rxdataF_comp128+=3;
        } else {
          dl_ch128+=2;
          rxdataF128+=2;
          rxdataF_comp128+=2;
        }
      }
    }

  simde_mm_empty();
  simde_m_empty();
}

void pbch_detection_mrc(LTE_DL_FRAME_PARMS *frame_parms,
                        int **rxdataF_comp,
                        uint8_t symbol) {
  uint8_t aatx, symbol_mod;
  int i, nb_rb = 6;
  simde__m128i *rxdataF_comp128_0, *rxdataF_comp128_1;
  symbol_mod = (symbol>=(7-frame_parms->Ncp)) ? symbol-(7-frame_parms->Ncp) : symbol;

  if (frame_parms->nb_antennas_rx>1) {
    for (aatx = 0; aatx < 4; aatx++) { // frame_parms->nb_antenna_ports_eNB;aatx++) {
      rxdataF_comp128_0 = (simde__m128i *)&rxdataF_comp[(aatx << 1)][symbol_mod * 6 * 12];
      rxdataF_comp128_1 = (simde__m128i *)&rxdataF_comp[(aatx << 1) + 1][symbol_mod * 6 * 12];

      // MRC on each re of rb, both on MF output and magnitude (for 16QAM/64QAM llr computation)
      for (i = 0; i < nb_rb * 3; i++) {
        rxdataF_comp128_0[i] =
            simde_mm_adds_epi16(simde_mm_srai_epi16(rxdataF_comp128_0[i], 1), simde_mm_srai_epi16(rxdataF_comp128_1[i], 1));
      }
    }
  }

  simde_mm_empty();
  simde_m_empty();
}

void pbch_unscrambling(LTE_DL_FRAME_PARMS *frame_parms,
                       int8_t *llr,
                       uint32_t length,
                       uint8_t frame_mod4) {
  int i;
  uint8_t reset;
  uint32_t x1 = 0, x2 = 0, s = 0;
  reset = 1;
  // x1 is set in first call to lte_gold_generic
  x2 = frame_parms->Nid_cell; //this is c_init in 36.211 Sec 6.6.1
  //  msg("pbch_unscrambling: Nid_cell = %d\n",x2);

  for (i=0; i<length; i++) {
    if (i%32==0) {
      s = lte_gold_generic(&x1, &x2, reset);
      //      printf("lte_gold[%d]=%x\n",i,s);
      reset = 0;
    }

    // take the quarter of the PBCH that corresponds to this frame
    if ((i>=(frame_mod4*(length>>2))) && (i<((1+frame_mod4)*(length>>2)))) {
      if (((s>>(i%32))&1)==0)
        llr[i] = -llr[i];
    }
  }
}

void pbch_alamouti(LTE_DL_FRAME_PARMS *frame_parms,
                   int **rxdataF_comp,
                   uint8_t symbol) {
  int16_t *rxF0,*rxF1;
  //  simde__m128i *ch_mag0,*ch_mag1,*ch_mag0b,*ch_mag1b;
  uint8_t rb,re,symbol_mod;
  int jj;
  //  printf("Doing alamouti\n");
  symbol_mod = (symbol>=(7-frame_parms->Ncp)) ? symbol-(7-frame_parms->Ncp) : symbol;
  jj         = (symbol_mod*6*12);
  rxF0     = (int16_t *)&rxdataF_comp[0][jj]; //tx antenna 0  h0*y
  rxF1     = (int16_t *)&rxdataF_comp[2][jj]; //tx antenna 1  h1*y

  for (rb=0; rb<6; rb++) {
    for (re=0; re<12; re+=2) {
      // Alamouti RX combining
      rxF0[0] = rxF0[0] + rxF1[2];
      rxF0[1] = rxF0[1] - rxF1[3];
      rxF0[2] = rxF0[2] - rxF1[0];
      rxF0[3] = rxF0[3] + rxF1[1];
      rxF0+=4;
      rxF1+=4;
    }
  }
}

void pbch_quantize(int8_t *pbch_llr8,
                   int16_t *pbch_llr,
                   uint16_t len) {
  uint16_t i;

  for (i=0; i<len; i++) {
    if (pbch_llr[i]>7)
      pbch_llr8[i]=7;
    else if (pbch_llr[i]<-8)
      pbch_llr8[i]=-8;
    else
      pbch_llr8[i] = (char)(pbch_llr[i]);
  }
}

static unsigned char dummy_w_rx[3*3*(16+PBCH_A)];
static int8_t pbch_w_rx[3*3*(16+PBCH_A)],pbch_d_rx[96+(3*(16+PBCH_A))];


uint16_t rx_pbch(LTE_UE_COMMON *lte_ue_common_vars,
                 LTE_UE_PBCH *lte_ue_pbch_vars,
                 LTE_DL_FRAME_PARMS *frame_parms,
                 uint8_t eNB_id,
                 MIMO_mode_t mimo_mode,
                 uint32_t high_speed_flag,
                 uint8_t frame_mod4) {
  uint8_t log2_maxh;//,aatx,aarx;
  int max_h=0;
  int symbol,i;
  uint32_t nsymb = (frame_parms->Ncp==0) ? 14:12;
  uint16_t  pbch_E;
  uint8_t pbch_a[8];
  uint8_t RCC;
  int8_t *pbch_e_rx;
  uint8_t *decoded_output = lte_ue_pbch_vars->decoded_output;
  uint16_t crc;
  //  pbch_D    = 16+PBCH_A;
  pbch_E  = (frame_parms->Ncp==0) ? 1920 : 1728; //RE/RB * #RB * bits/RB (QPSK)
  pbch_e_rx = &lte_ue_pbch_vars->llr[frame_mod4*(pbch_E>>2)];
#ifdef DEBUG_PBCH
  LOG_D(PHY,"[PBCH] starting symbol loop (Ncp %d, frame_mod4 %d,mimo_mode %d\n",frame_parms->Ncp,frame_mod4,mimo_mode);
#endif
  // clear LLR buffer
  memset(lte_ue_pbch_vars->llr,0,pbch_E);

  for (symbol=(nsymb>>1); symbol<(nsymb>>1)+4; symbol++) {
#ifdef DEBUG_PBCH
    LOG_D(PHY,"[PBCH] starting extract\n");
#endif
    pbch_extract(lte_ue_common_vars->common_vars_rx_data_per_thread[0].rxdataF,
                 lte_ue_common_vars->common_vars_rx_data_per_thread[0].dl_ch_estimates[eNB_id],
                 lte_ue_pbch_vars->rxdataF_ext,
                 lte_ue_pbch_vars->dl_ch_estimates_ext,
                 symbol,
                 high_speed_flag,
                 frame_parms);
#ifdef DEBUG_PBCH
    LOG_D(PHY,"[PHY] PBCH Symbol %d\n",symbol);
    LOG_D(PHY,"[PHY] PBCH starting channel_level\n");
#endif
    max_h = pbch_channel_level(lte_ue_pbch_vars->dl_ch_estimates_ext,
                               frame_parms,
                               symbol);
    log2_maxh = 3+(log2_approx(max_h)/2);
#ifdef DEBUG_PBCH
    LOG_D(PHY,"[PHY] PBCH log2_maxh = %d (%d)\n",log2_maxh,max_h);
#endif
    pbch_channel_compensation(lte_ue_pbch_vars->rxdataF_ext,
                              lte_ue_pbch_vars->dl_ch_estimates_ext,
                              lte_ue_pbch_vars->rxdataF_comp,
                              frame_parms,
                              symbol,
                              log2_maxh); // log2_maxh+I0_shift

    if (frame_parms->nb_antennas_rx > 1)
      pbch_detection_mrc(frame_parms,
                         lte_ue_pbch_vars->rxdataF_comp,
                         symbol);

    if (mimo_mode == ALAMOUTI) {
      pbch_alamouti(frame_parms,lte_ue_pbch_vars->rxdataF_comp,symbol);
    } else if (mimo_mode != SISO) {
      LOG_D(PHY,"[PBCH][RX] Unsupported MIMO mode\n");
      return(-1);
    }

    if (symbol>(nsymb>>1)+1) {
      pbch_quantize(pbch_e_rx,
                    (short *)&(lte_ue_pbch_vars->rxdataF_comp[0][(symbol%(nsymb>>1))*72]),
                    144);
      pbch_e_rx+=144;
    } else {
      pbch_quantize(pbch_e_rx,
                    (short *)&(lte_ue_pbch_vars->rxdataF_comp[0][(symbol%(nsymb>>1))*72]),
                    96);
      pbch_e_rx+=96;
    }
  }

  pbch_e_rx = lte_ue_pbch_vars->llr;
  //un-scrambling
#ifdef DEBUG_PBCH
  LOG_D(PHY,"[PBCH] doing unscrambling\n");
#endif
  pbch_unscrambling(frame_parms,
                    pbch_e_rx,
                    pbch_E,
                    frame_mod4);
  //un-rate matching
#ifdef DEBUG_PBCH
  LOG_D(PHY,"[PBCH] doing un-rate-matching\n");
#endif
  memset(dummy_w_rx,0,3*3*(16+PBCH_A));
  RCC = generate_dummy_w_cc(16+PBCH_A,
                            dummy_w_rx);
  lte_rate_matching_cc_rx(RCC,pbch_E,pbch_w_rx,dummy_w_rx,pbch_e_rx);
  sub_block_deinterleaving_cc((unsigned int)(PBCH_A+16),
                              &pbch_d_rx[96],
                              &pbch_w_rx[0]);
  memset(pbch_a,0,((16+PBCH_A)>>3));
  phy_viterbi_lte_sse2(pbch_d_rx+96,pbch_a,16+PBCH_A);

  // Fix byte endian of PBCH (bit 23 goes in first)
  for (i=0; i<(PBCH_A>>3); i++)
    decoded_output[(PBCH_A>>3)-i-1] = pbch_a[i];

#ifdef DEBUG_PBCH

  for (i=0; i<(PBCH_A>>3); i++)
    LOG_I(PHY,"[PBCH] pbch_a[%d] = %x\n",i,decoded_output[i]);

#endif //DEBUG_PBCH
#ifdef DEBUG_PBCH
  LOG_I(PHY,"PBCH CRC %x : %x\n",
        crc16(pbch_a,PBCH_A),
        ((uint16_t)pbch_a[PBCH_A>>3]<<8)+pbch_a[(PBCH_A>>3)+1]);
#endif
  crc = (crc16(pbch_a,PBCH_A)>>16) ^
        (((uint16_t)pbch_a[PBCH_A>>3]<<8)+pbch_a[(PBCH_A>>3)+1]);

  if (crc == 0x0000)
    return(1);
  else if (crc == 0xffff)
    return(2);
  else if (crc == 0x5555)
    return(4);
  else
    return(-1);
}


void pbch_unscrambling_fembms(LTE_DL_FRAME_PARMS *frame_parms,
                              int8_t *llr,
                              uint32_t length,
                              uint8_t frame_mod4) {
  int i;
  uint8_t reset;
  uint32_t x1 = 0, x2 = 0, s = 0;
  reset = 1;
  // x1 is set in first call to lte_gold_generic
  x2 = frame_parms->Nid_cell+(1<<9); //this is c_init for FeMBMS in 36.211 Sec 6.6.1

  //msg("pbch_unscrambling: Nid_cell = %d, x2 = %d, frame_mod4 %d length %d\n",frame_parms->Nid_cell,x2,frame_mod4,length);
  for (i=0; i<length; i++) {
    if (i%32==0) {
      s = lte_gold_generic(&x1, &x2, reset);
      //      printf("lte_gold[%d]=%x\n",i,s);
      reset = 0;
    }

    // take the quarter of the PBCH that corresponds to this frame
    if ((i>=(frame_mod4*(length>>2))) && (i<((1+frame_mod4)*(length>>2)))) {
      if (((s>>(i%32))&1)==0)
        llr[i] = -llr[i];
    }
  }
}

uint16_t rx_pbch_fembms(LTE_UE_COMMON *lte_ue_common_vars,
                        LTE_UE_PBCH *lte_ue_pbch_vars,
                        LTE_DL_FRAME_PARMS *frame_parms,
                        uint8_t eNB_id,
                        MIMO_mode_t mimo_mode,
                        uint32_t high_speed_flag,
                        uint8_t frame_mod4) {
  uint8_t log2_maxh;//,aatx,aarx;
  int max_h=0;
  int symbol,i;
  uint32_t nsymb = (frame_parms->Ncp==0) ? 14:12;
  uint16_t  pbch_E;
  uint8_t pbch_a[8];
  uint8_t RCC;
  int8_t *pbch_e_rx;
  uint8_t *decoded_output = lte_ue_pbch_vars->decoded_output;
  uint16_t crc;
  //  pbch_D    = 16+PBCH_A;
  pbch_E  = (frame_parms->Ncp==0) ? 1920 : 1728; //RE/RB * #RB * bits/RB (QPSK)
  pbch_e_rx = &lte_ue_pbch_vars->llr[frame_mod4*(pbch_E>>2)];
#ifdef DEBUG_PBCH
  LOG_D(PHY,"[PBCH] starting symbol loop (Ncp %d, frame_mod4 %d,mimo_mode %d\n",frame_parms->Ncp,frame_mod4,mimo_mode);
#endif
  // clear LLR buffer
  memset(lte_ue_pbch_vars->llr,0,pbch_E);

  for (symbol=(nsymb>>1); symbol<(nsymb>>1)+4; symbol++) {
#ifdef DEBUG_PBCH
    LOG_D(PHY,"[PBCH] starting extract\n");
#endif
    pbch_extract(lte_ue_common_vars->common_vars_rx_data_per_thread[0].rxdataF,
                 lte_ue_common_vars->common_vars_rx_data_per_thread[0].dl_ch_estimates[eNB_id],
                 lte_ue_pbch_vars->rxdataF_ext,
                 lte_ue_pbch_vars->dl_ch_estimates_ext,
                 symbol,
                 high_speed_flag,
                 frame_parms);
#ifdef DEBUG_PBCH
    LOG_D(PHY,"[PHY] PBCH Symbol %d\n",symbol);
    LOG_D(PHY,"[PHY] PBCH starting channel_level\n");
#endif
    max_h = pbch_channel_level(lte_ue_pbch_vars->dl_ch_estimates_ext,
                               frame_parms,
                               symbol);
    log2_maxh = 3+(log2_approx(max_h)/2);
#ifdef DEBUG_PBCH
    LOG_D(PHY,"[PHY] PBCH log2_maxh = %d (%d)\n",log2_maxh,max_h);
#endif
    pbch_channel_compensation(lte_ue_pbch_vars->rxdataF_ext,
                              lte_ue_pbch_vars->dl_ch_estimates_ext,
                              lte_ue_pbch_vars->rxdataF_comp,
                              frame_parms,
                              symbol,
                              log2_maxh); // log2_maxh+I0_shift

    if (frame_parms->nb_antennas_rx > 1)
      pbch_detection_mrc(frame_parms,
                         lte_ue_pbch_vars->rxdataF_comp,
                         symbol);

    if (mimo_mode == ALAMOUTI) {
      pbch_alamouti(frame_parms,lte_ue_pbch_vars->rxdataF_comp,symbol);
    } else if (mimo_mode != SISO) {
      LOG_D(PHY,"[PBCH][RX] Unsupported MIMO mode\n");
      return(-1);
    }

    if (symbol>(nsymb>>1)+1) {
      pbch_quantize(pbch_e_rx,
                    (short *)&(lte_ue_pbch_vars->rxdataF_comp[0][(symbol%(nsymb>>1))*72]),
                    144);
      pbch_e_rx+=144;
    } else {
      pbch_quantize(pbch_e_rx,
                    (short *)&(lte_ue_pbch_vars->rxdataF_comp[0][(symbol%(nsymb>>1))*72]),
                    96);
      pbch_e_rx+=96;
    }
  }

  pbch_e_rx = lte_ue_pbch_vars->llr;
  //un-scrambling
#ifdef DEBUG_PBCH
  LOG_D(PHY,"[PBCH] doing unscrambling\n");
#endif
  pbch_unscrambling_fembms(frame_parms,
                           pbch_e_rx,
                           pbch_E,
                           frame_mod4);
  //un-rate matching
#ifdef DEBUG_PBCH
  LOG_D(PHY,"[PBCH] doing un-rate-matching\n");
#endif
  memset(dummy_w_rx,0,3*3*(16+PBCH_A));
  RCC = generate_dummy_w_cc(16+PBCH_A,
                            dummy_w_rx);
  lte_rate_matching_cc_rx(RCC,pbch_E,pbch_w_rx,dummy_w_rx,pbch_e_rx);
  sub_block_deinterleaving_cc((unsigned int)(PBCH_A+16),
                              &pbch_d_rx[96],
                              &pbch_w_rx[0]);
  memset(pbch_a,0,((16+PBCH_A)>>3));
  phy_viterbi_lte_sse2(pbch_d_rx+96,pbch_a,16+PBCH_A);

  // Fix byte endian of PBCH (bit 23 goes in first)
  for (i=0; i<(PBCH_A>>3); i++)
    decoded_output[(PBCH_A>>3)-i-1] = pbch_a[i];

#ifdef DEBUG_PBCH

  for (i=0; i<(PBCH_A>>3); i++)
    LOG_I(PHY,"[PBCH] pbch_a[%d] = %x\n",i,decoded_output[i]);

#endif //DEBUG_PBCH
#ifdef DEBUG_PBCH
  LOG_I(PHY,"PBCH CRC %x : %x\n",
        crc16(pbch_a,PBCH_A),
        ((uint16_t)pbch_a[PBCH_A>>3]<<8)+pbch_a[(PBCH_A>>3)+1]);
#endif
  crc = (crc16(pbch_a,PBCH_A)>>16) ^
        (((uint16_t)pbch_a[PBCH_A>>3]<<8)+pbch_a[(PBCH_A>>3)+1]);

  if (crc == 0x0000)
    return(1);
  else if (crc == 0xffff)
    return(2);
  else if (crc == 0x5555)
    return(4);
  else
    return(-1);
}

