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/*! \file PHY/LTE_REFSIG/lte_dl_uespec.c
* \brief Top-level routines for generating UE-specific Reference signals from 36-211, V11.3.0 2013-06
* \author R. Knopp
* \date 2014
* \version 0.1
* \company Eurecom
* \email: knopp@eurecom.fr
* \note
* \warning
*/

#ifdef USER_MODE
#include <stdio.h>
#include <stdlib.h>
#endif

#include "defs.h"
#include "PHY/defs.h"
#include "log.h"

//extern unsigned int lte_gold_table[3][20][2][14];
//#define DEBUG_DL_CELL_SPEC

int Wbar_NCP[8][4] = {{1,1,1,1},{1,-1,1,-1},{1,1,1,1},{1,-1,1,-1},{1,1,-1,-1},{-1,-1,1,1},{1,-1,-1,1},{-1,1,1,-1}};

int lte_dl_ue_spec(PHY_VARS_eNB *phy_vars_eNB,
		   uint8_t UE_id,
		   mod_sym_t *output,
		   short amp,
		   uint8_t Ns,
		   uint8_t p,
		   int SS_flag ) {

  mod_sym_t qpsk[4],nqpsk[4],*qpsk_p,*output_p;
  int16_t a;
  int w,lprime,ind,l,ind_dword,ind_qpsk_symb,nPRB;
  //  LTE_eNB_DLSCH_t *dlsch = phy_vars_eNB->dlsch_eNB[UE_id][0];

  a = (amp*ONE_OVER_SQRT2_Q15)>>15;
  ((short *)&qpsk[0])[0] = a;
  ((short *)&qpsk[0])[1] = a;
  ((short *)&qpsk[1])[0] = -a;
  ((short *)&qpsk[1])[1] = a;
  ((short *)&qpsk[2])[0] = a;
  ((short *)&qpsk[2])[1] = -a;
  ((short *)&qpsk[3])[0] = -a;
  ((short *)&qpsk[3])[1] = -a;

  ((short *)&nqpsk[0])[0] = -a;
  ((short *)&nqpsk[0])[1] = -a;
  ((short *)&nqpsk[1])[0] = a;
  ((short *)&nqpsk[1])[1] = -a;
  ((short *)&nqpsk[2])[0] = -a;
  ((short *)&nqpsk[2])[1] = a;
  ((short *)&nqpsk[3])[0] = a;
  ((short *)&nqpsk[3])[1] = a;

  if (p>=7) {
    if (SS_flag==0) {
      if (phy_vars_eNB->lte_frame_parms.Ncp == NORMAL) {
	// this is 3GPP 36-211 6.10.3.2, NORMAL CP, p>=7



	// position output pointer to 5th symbol in slot
	output_p = output+(60*phy_vars_eNB->lte_frame_parms.N_RB_DL);
	// shift to 2nd RE in PRB for p=7,8,11,13
	if ((p==7) || (p==8) || (p==11) || (p==13)) output_p++;
	

	for (lprime=0;lprime<2;lprime++) {
	  
	  ind = 3*lprime*phy_vars_eNB->lte_frame_parms.N_RB_DL;
	  l = lprime + ((Ns&1)<<1);

	  // loop over pairs of PRBs, this is the periodicity of the W_bar_NCP sequence
	  // unroll the computations for the 6 pilots, select qpsk or nqpsk as function of W_bar_NCP
	  for (nPRB=0;nPRB<phy_vars_eNB->lte_frame_parms.N_RB_DL;nPRB+=2) {
 
	    // First pilot 	    
	    w = Wbar_NCP[p-7][l];
	    qpsk_p = (w==1) ? qpsk : nqpsk;


	    ind_dword     = ind>>4;
	    ind_qpsk_symb = ind&0xf;
	    
	    *output_p = qpsk_p[(phy_vars_eNB->lte_gold_uespec_table[0][Ns][lprime][ind_dword]>>(2*ind_qpsk_symb))&3];


#ifdef DEBUG_DL_UESPEC
	    LOG_D(PHY,"Ns %d, l %d, m %d,ind_dword %d, ind_qpsk_symbol %d\n",
		  Ns,l,m,mprime_dword,mprime_qpsk_symb);
	    LOG_D(PHY,"index = %d\n",(phy_vars_eNB->lte_gold_uespec_table[0][Ns][lprime][ind_dword]>>(2*ind_qpsk_symb))&3);
#endif 

	    output_p+=5;	    
	    ind++;

	    w =  Wbar_NCP[p-7][3-l];
	    qpsk_p = (w==1) ? qpsk : nqpsk;

	    // Second pilot 
	    ind_dword     = ind>>4;
	    ind_qpsk_symb = ind&0xf;
	    
	    *output_p = qpsk_p[(phy_vars_eNB->lte_gold_uespec_table[0][Ns][lprime][ind_dword]>>(2*ind_qpsk_symb))&3];
	    
#ifdef DEBUG_DL_UESPEC
	    LOG_D(PHY,"Ns %d, l %d, m %d,ind_dword %d, ind_qpsk_symbol %d\n",
		  Ns,l,m,mprime_dword,mprime_qpsk_symb);
	    LOG_D(PHY,"index = %d\n",(phy_vars_eNB->lte_gold_uespec_table[0][Ns][lprime][ind_dword]>>(2*ind_qpsk_symb))&3);
#endif 

	    output_p+=5;	    
	    ind++;

	    w = Wbar_NCP[p-7][l];
	    qpsk_p = (w==1) ? qpsk : nqpsk;
	    // Third pilot 
	    ind_dword     = ind>>4;
	    ind_qpsk_symb = ind&0xf;
	    
	    *output_p = qpsk_p[(phy_vars_eNB->lte_gold_uespec_table[0][Ns][lprime][ind_dword]>>(2*ind_qpsk_symb))&3];
	    
#ifdef DEBUG_DL_UESPEC
	    LOG_D(PHY,"Ns %d, l %d, m %d,ind_dword %d, ind_qpsk_symbol %d\n",
		  Ns,l,m,mprime_dword,mprime_qpsk_symb);
	    LOG_D(PHY,"index = %d\n",(phy_vars_eNB->lte_gold_uespec_table[0][Ns][lprime][ind_dword]>>(2*ind_qpsk_symb))&3);
#endif 

	    output_p+=2;	    
	    ind++;

	    // Fourth pilot 	    
	    w = Wbar_NCP[p-7][3-l];
	    qpsk_p = (w==1) ? qpsk : nqpsk;


	    ind_dword     = ind>>4;
	    ind_qpsk_symb = ind&0xf;
	    
	    *output_p = qpsk_p[(phy_vars_eNB->lte_gold_uespec_table[0][Ns][lprime][ind_dword]>>(2*ind_qpsk_symb))&3];


#ifdef DEBUG_DL_UESPEC
	    LOG_D(PHY,"Ns %d, l %d, m %d,ind_dword %d, ind_qpsk_symbol %d\n",
		  Ns,l,m,mprime_dword,mprime_qpsk_symb);
	    LOG_D(PHY,"index = %d\n",(phy_vars_eNB->lte_gold_uespec_table[0][Ns][lprime][ind_dword]>>(2*ind_qpsk_symb))&3);
#endif 

	    output_p+=5;	    
	    ind++;

	    w =  Wbar_NCP[p-7][l];
	    qpsk_p = (w==1) ? qpsk : nqpsk;

	    // Fifth pilot 
	    ind_dword     = ind>>4;
	    ind_qpsk_symb = ind&0xf;
	    
	    *output_p = qpsk_p[(phy_vars_eNB->lte_gold_uespec_table[0][Ns][lprime][ind_dword]>>(2*ind_qpsk_symb))&3];
	    
#ifdef DEBUG_DL_UESPEC
	    LOG_D(PHY,"Ns %d, l %d, m %d,ind_dword %d, ind_qpsk_symbol %d\n",
		  Ns,l,m,mprime_dword,mprime_qpsk_symb);
	    LOG_D(PHY,"index = %d\n",(phy_vars_eNB->lte_gold_uespec_table[0][Ns][lprime][ind_dword]>>(2*ind_qpsk_symb))&3);
#endif 

	    output_p+=5;	    
	    ind++;

	    w = Wbar_NCP[p-7][3-l];
	    qpsk_p = (w==1) ? qpsk : nqpsk;
	    // Sixth pilot 
	    ind_dword     = ind>>4;
	    ind_qpsk_symb = ind&0xf;
	    
	    *output_p = qpsk_p[(phy_vars_eNB->lte_gold_uespec_table[0][Ns][lprime][ind_dword]>>(2*ind_qpsk_symb))&3];
	    
#ifdef DEBUG_DL_UESPEC
	    LOG_D(PHY,"Ns %d, l %d, m %d,ind_dword %d, ind_qpsk_symbol %d\n",
		  Ns,l,m,mprime_dword,mprime_qpsk_symb);
	    LOG_D(PHY,"index = %d\n",(phy_vars_eNB->lte_gold_uespec_table[0][Ns][lprime][ind_dword]>>(2*ind_qpsk_symb))&3);
#endif 

	    output_p+=2;	    
	    ind++;
	  }
	}
      }
      else {
	LOG_E(PHY,"Special subframe not supported for UE specific pilots yet\n");
      }
    }
  }
  else if (p==5) {
    LOG_E(PHY,"p=5 not supported for UE specific pilots yet\n");
  }
  else {
    LOG_E(PHY,"Illegal p %d UE specific pilots\n",p);
  }
  return(0);
}

/*
int lte_dl_cell_spec_rx(PHY_VARS_UE *phy_vars_ue,
			uint8_t eNB_offset,
			int *output,
			unsigned char Ns,
			unsigned char l,
			unsigned char p) {
  

  unsigned char mprime,mprime_dword,mprime_qpsk_symb,m;
  unsigned short k=0;
  unsigned int qpsk[4];
  short pamp;
  
  // Compute the correct pilot amplitude, sqrt_rho_b = Q3.13
  pamp = ONE_OVER_SQRT2_Q15;

  // This includes complex conjugate for channel estimation

  ((short *)&qpsk[0])[0] = pamp;
  ((short *)&qpsk[0])[1] = -pamp;
  ((short *)&qpsk[1])[0] = -pamp;
  ((short *)&qpsk[1])[1] = -pamp;
  ((short *)&qpsk[2])[0] = pamp;
  ((short *)&qpsk[2])[1] = pamp;
  ((short *)&qpsk[3])[0] = -pamp;
  ((short *)&qpsk[3])[1] = pamp;

  mprime = 110 - phy_vars_ue->lte_frame_parms.N_RB_DL;
  
  for (m=0;m<phy_vars_ue->lte_frame_parms.N_RB_DL<<1;m++) {

    mprime_dword     = mprime>>4;
    mprime_qpsk_symb = mprime&0xf;

    // this is r_mprime from 3GPP 36-211 6.10.1.2 
    output[k] = qpsk[(phy_vars_ue->lte_gold_table[eNB_offset][Ns][l][mprime_dword]>>(2*mprime_qpsk_symb))&3];
#ifdef DEBUG_DL_CELL_SPEC
    printf("Ns %d, l %d, m %d,mprime_dword %d, mprime_qpsk_symbol %d\n",
	   Ns,l,m,mprime_dword,mprime_qpsk_symb);
    printf("index = %d (k %d)\n",(phy_vars_ue->lte_gold_table[eNB_offset][Ns][l][mprime_dword]>>(2*mprime_qpsk_symb))&3,k);
#endif 

    mprime++;
#ifdef DEBUG_DL_CELL_SPEC
    if (m<4)
    printf("Ns %d l %d output[%d] = (%d,%d)\n",Ns,l,k,((short *)&output[k])[0],((short *)&output[k])[1]);
#endif
    k++;
  }
  return(0);
}

*/

#ifdef LTE_DL_CELL_SPEC_MAIN



//extern int write_output(const char *,const char *,void *,int,int,char);
// flag change eren
extern int write_output(const char *,const char *,void *,int,int,char);
main() {

  unsigned short Nid_cell=0;
  unsigned int Ncp = 0;
  int output00[1024];
  int output01[1024];
  int output10[1024];
  int output11[1024];

  memset(output00,0,1024*sizeof(int));
  memset(output01,0,1024*sizeof(int));  
  memset(output10,0,1024*sizeof(int));
  memset(output11,0,1024*sizeof(int));

  lte_gold(Nid_cell,Ncp);

  lte_dl_cell_spec(output00,
		   ONE_OVER_SQRT2_Q15,
		   50,
		   Nid_cell,
		   Ncp,
		   0,
		   0,
		   0,
		   0);
  
  lte_dl_cell_spec(output10,
		   ONE_OVER_SQRT2_Q15,
		   50,
		   Nid_cell,
		   Ncp,
		   0,
		   1,
		   0,
		   0);

  lte_dl_cell_spec(output01,
		   ONE_OVER_SQRT2_Q15,
		   50,
		   Nid_cell,
		   Ncp,
		   0,
		   0,
		   1,
		   0);

  lte_dl_cell_spec(output11,
		   ONE_OVER_SQRT2_Q15,
		   50,
		   Nid_cell,
		   Ncp,
		   0,
		   1,
		   1,
		   0);
  

  write_output("dl_cell_spec00.m","dl_cs00",output00,1024,1,1);
  write_output("dl_cell_spec01.m","dl_cs01",output01,1024,1,1);
  write_output("dl_cell_spec10.m","dl_cs10",output10,1024,1,1);  
  write_output("dl_cell_spec11.m","dl_cs11",output11,1024,1,1);
}		   

  
#endif
