/*******************************************************************************
    OpenAirInterface 
    Copyright(c) 1999 - 2014 Eurecom

    OpenAirInterface is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.


    OpenAirInterface is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with OpenAirInterface.The full GNU General Public License is 
   included in this distribution in the file called "COPYING". If not, 
   see <http://www.gnu.org/licenses/>.

  Contact Information
  OpenAirInterface Admin: openair_admin@eurecom.fr
  OpenAirInterface Tech : openair_tech@eurecom.fr
  OpenAirInterface Dev  : openair4g-devel@eurecom.fr
  
  Address      : Eurecom, Campus SophiaTech, 450 Route des Chappes, CS 50193 - 06904 Biot Sophia Antipolis cedex, FRANCE

 *******************************************************************************/
//#include "defs.h"
#include <stdio.h>
#include <stdlib.h>
#include <math.h>

//#include "PHY/defs.h"
#include "SIMULATION/TOOLS/defs.h"
 
/*
extern void randominit(void);
extern double gaussdouble(double,double);
  //free(input_data);

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

//double pn[1024];

//#define DEBUG_RF 1

  //free(input_data);
void rf_rx(double **r_re,
	   double **r_im,
	   double **r_re_i1,
	   double **r_im_i1,
	   double I0_dB,
	   unsigned int nb_rx_antennas,
	   unsigned int length,
	   double s_time,
	   double f_off,
	   double drift,
	   double noise_figure,
	   double rx_gain_dB,
	   int IP3_dBm,
	   double *initial_phase,
	   double pn_cutoff,
	   double pn_amp_dBc,
	   double IQ_imb_dB,
	   double IQ_phase) {
 
  double phase       = *initial_phase;
  double phase2      = *initial_phase;
  double phase_inc   = 2*M_PI*f_off*s_time*1e-9;
  double IQ_imb_lin  = pow(10.0,-.05*IQ_imb_dB);
  double rx_gain_lin = pow(10.0,.05*rx_gain_dB);
  double IP3_lin     = pow(10.0,-.1*IP3_dBm);
  double p_noise     = 0.0;
  double tmp_re,tmp_im;
  double N0W         = pow(10.0,.1*(-174.0 - 10*log10(s_time*1e-9)));
  //  printf("s_time=%f, N0W=%g\n",s_time,10*log10(N0W));

  // phase-noise filter coefficients (2nd order digital Butterworth)
  double pn_cutoff_d = tan(M_PI*s_time*1e-9*pn_cutoff);
  double pn_c        = 1+2*cos(M_PI/4)*pn_cutoff_d + (pn_cutoff_d*pn_cutoff_d);
  double pn_a0       = pn_cutoff_d*pn_cutoff_d/pn_c;
  double pn_b1       = 2*((pn_cutoff_d*pn_cutoff_d) - 1)/pn_c;
  double pn_b2       = (4*pn_a0) - pn_b1 - 1;
  double x_n=0.0,x_n1=0.0,x_n2=0.0,y_n1=0.0,y_n2=0.0;

  double pn_amp      = pow(10.0,.1*pn_amp_dBc);
  double I0 = pow(10.0,.05*I0_dB);
  //  double dummy;

  int i,a,have_interference=0;


  if (pn_amp_dBc > -20.0){
    printf("rf.c: Illegal pn_amp_dBc %f\n",pn_amp_dBc);
    exit(-1);
  }

  if ((pn_cutoff > 1e6) || (pn_cutoff<1e3)){
    printf("rf.c: Illegal pn_cutoff %f\n",pn_cutoff);
    exit(-1);
  }

  if (fabs(IQ_imb_dB) > 1.0) {
    printf("rf.c: Illegal IQ_imb %f\n",IQ_imb_dB);
    exit(-1);
  }

  if (fabs(IQ_phase) > 0.1) {
    printf("rf.c: Illegal IQ_phase %f\n",IQ_phase);
    exit(-1);
  }

  if (fabs(f_off) > 10000.0) {
    printf("rf.c: Illegal f_off %f\n",f_off);
    exit(-1);
  }

  if (fabs(drift) > 1000.0) {
    printf("rf.c: Illegal drift %f\n",drift);
    exit(-1);
  }

#ifdef DEBUG_RF
  printf("pn_a0 = %f, pn_b1=%f,pn_b2=%f\n",pn_a0,pn_b1,pn_b2);
#endif

  /*
  for (i=0;i<nb_rx_antennas;i++) 
    if (noise_figure[i] < 1.0) {
      printf("rf.c: Illegal noise_figure %d %f\n",i,noise_figure[i]);
      exit(-1);
    }
  */

  //Loop over input
#ifdef DEBUG_RF
  printf("N0W = %f dBm\n",10*log10(N0W));
  printf("rx_gain = %f dB(%f)\n",rx_gain_dB,rx_gain_lin);
  printf("IQ_imb = %f dB(%f)\n",IQ_imb_dB,IQ_imb_lin);
#endif
  p_noise=0.0;



  if ((r_re_i1) && (r_im_i1) )
    have_interference=1;

  for (i=0;i<length;i++) {

    
    for (a=0;a<nb_rx_antennas;a++) {

      if (have_interference==1) {
	r_re[a][i] = r_re[a][i] + (I0 * r_re_i1[a][i]);
	r_im[a][i] = r_im[a][i] + (I0 * r_im_i1[a][i]);
      }

      // Amplify by receiver gain and apply 3rd order non-linearity
      r_re[a][i] = rx_gain_lin*(r_re[a][i] + IP3_lin*(pow(r_re[a][i],3.0) + 3.0*r_re[a][i]*r_im[a][i]*r_im[a][i])) + rx_gain_lin*(sqrt(.5*N0W)*gaussdouble(0.0,1.0));
      r_im[a][i] = rx_gain_lin*(r_im[a][i] + IP3_lin*(pow(r_im[a][i],3.0) + 3.0*r_im[a][i]*r_re[a][i]*r_re[a][i])) + rx_gain_lin*(sqrt(.5*N0W)*gaussdouble(0.0,1.0));



      // Apply phase offsets
      tmp_re = r_re[a][i]*cos(phase2) - r_im[a][i]*sin(phase2);
      tmp_im = IQ_imb_lin*(r_re[a][i]*sin(phase2+IQ_phase) + r_im[a][i]*cos(phase2+IQ_phase));

      r_re[a][i] = tmp_re;
      r_im[a][i] = tmp_im;

    }


    //    if (nb_rx_antennas == 1) {
    //      dummy = gaussdouble(0.0,1.0);
    //      dummy = gaussdouble(0.0,1.0);
    //    }
    // First apply frequency/phase offsets + phase noise
    //    U[i%pn_len]=uniformrandom()*pn_amp_lin;
    //    p_noise = 0;
    //    for (j=0;j<pn_len;j++)
    //      p_noise += h_pn[j] * U[(i-j)%pn_len];

    // recompute phase offsets for next sample
    phase += phase_inc;
    phase2 = phase + sqrt(pn_amp)*p_noise;

    //    printf("phase = %f, phase2=%f\n",phase,phase2);

    //*initial_phase = phase2;

    //compute next realization of phase-noise process
    x_n2 = x_n1;
    x_n1 = x_n;
    x_n = gaussdouble(0.0,1.0);
    y_n1 = p_noise;
    y_n2 = y_n1;
    p_noise = pn_a0*x_n + 2*pn_a0*x_n1 + pn_a0*x_n2 - pn_b1*y_n1 - pn_b2*y_n2;
 
    //    pn[i] = p_noise;
  }
}

void rf_rx_simple(double **r_re,
		  double **r_im,
		  unsigned int nb_rx_antennas,
		  unsigned int length,
		  double s_time,
		  double rx_gain_dB) {
  
  int i,a;
  double rx_gain_lin = pow(10.0,.05*rx_gain_dB);
  //double rx_gain_lin = 1.0;
  double N0W         = pow(10.0,.1*(-174.0 - 10*log10(s_time*1e-9)));
  //double N0W = 0.0;

  //  printf("s_time=%f, N0W=%g\n",s_time,10*log10(N0W));

  //Loop over input
#ifdef DEBUG_RF
  printf("N0W = %f dBm\n",10*log10(N0W));
  printf("rx_gain = %f dB(%f)\n",rx_gain_dB,rx_gain_lin);
#endif

  for (i=0;i<length;i++) {
    for (a=0;a<nb_rx_antennas;a++) {
      // Amplify by receiver gain and apply 3rd order non-linearity
      r_re[a][i] = rx_gain_lin*(r_re[a][i] + sqrt(.5*N0W)*gaussdouble(0.0,1.0));
      r_im[a][i] = rx_gain_lin*(r_im[a][i] + sqrt(.5*N0W)*gaussdouble(0.0,1.0));
    }
  }
}

 
#ifdef RF_MAIN
#define INPUT_dBm -70.0

int QPSK[4]={AMP_OVER_SQRT2|(AMP_OVER_SQRT2<<16),AMP_OVER_SQRT2|((65536-AMP_OVER_SQRT2)<<16),((65536-AMP_OVER_SQRT2)<<16)|AMP_OVER_SQRT2,((65536-AMP_OVER_SQRT2)<<16)|(65536-AMP_OVER_SQRT2)};
int QPSK2[4]={AMP_OVER_2|(AMP_OVER_2<<16),AMP_OVER_2|((65536-AMP_OVER_2)<<16),((65536-AMP_OVER_2)<<16)|AMP_OVER_2,((65536-AMP_OVER_2)<<16)|(65536-AMP_OVER_2)};


int main(int argc, char* argv[]) {

  // Fill input vector with complex sinusoid

  int nb_antennas = 1;
  int length      = 100000;
  int i,j,n;
  double input_amp = pow(10.0,(.05*INPUT_dBm))/sqrt(2);
  double nf[2] = {3.0,3.0};
  double ip =0.0;
  double path_loss_dB = -90, rx_gain_dB = 125;
  double tx_pwr, rx_pwr;

  uint32_t **input = malloc(nb_antennas*sizeof(uint32_t*));
  uint32_t **output = malloc(nb_antennas*sizeof(uint32_t*));
  
  double **s_re = malloc(nb_antennas*sizeof (double *));
  double **s_im = malloc(nb_antennas*sizeof (double *));
  double **r_re = malloc(nb_antennas*sizeof (double *));
  double **r_im = malloc(nb_antennas*sizeof (double *));

  channel_desc_t *channel;

  srand(0);
  randominit(0);
  set_taus_seed(0);

  channel = new_channel_desc_scm(nb_antennas,
				 nb_antennas,
				 AWGN,
				 7.68e6,
				 0,
				 0,
				 path_loss_dB);

  for (i=0;i<nb_antennas;i++) {
    s_re[i] = (double *)malloc(length * sizeof (double ));
    s_im[i] = (double *)malloc(length * sizeof (double ));
    r_re[i] = (double *)malloc(length * sizeof (double ));
    r_im[i] = (double *)malloc(length * sizeof (double ));
    input[i] = (uint32_t*)malloc(length * sizeof(uint32_t));
    output[i] = (uint32_t*)malloc(length * sizeof(uint32_t));
  }    

  for (i=0;i<nb_antennas;i++) {
    // generate a random QPSK signal
    for (j=0;j<length/2;j++) {
      input[i][j] = QPSK[taus()&3];
    }
  }
  
  tx_pwr = dac_fixed_gain(s_re,
			  s_im,
			  input,
			  0,
			  nb_antennas,
			  length,
			  0,
			  512,
			  14,
			  15.0);

  multipath_channel(channel,s_re,s_im,r_re,r_im,
		    length,0);
  
  rf_rx_simple(r_re,
	       r_im,
	       nb_antennas,
	       length,
	       1.0/7.68e6 * 1e9,// sampling time (ns)
	       rx_gain_dB - 66.227);

  /*
  rf_rx(r_re,
	r_im,
	nb_antennas,
	length,
	1.0/6.5e6 * 1e9,// sampling time (ns)
	1000.0  ,          //freq offset (Hz)
	0.0,            //drift (Hz) NOT YET IMPLEMENTED
	nf,             //noise_figure NOT YET IMPLEMENTED
	-INPUT_dBm,           //rx_gain (dB)
	200,            // IP3_dBm (dBm)
	&ip,            // initial phase
	30.0e3,         // pn_cutoff (kHz)
	-500.0,          // pn_amp (dBc)
	-0.0,              // IQ imbalance (dB),
	0.0);           // IQ phase imbalance (rad)
  */

  adc(r_re,
      r_im,
      0,
      0,
      output,
      nb_antennas,
      length,
      12);
  
  write_output("s_im.m","s_im",s_im[0],length,1,7);
  write_output("s_re.m","s_re",s_re[0],length,1,7);
  write_output("r_im.m","r_im",r_im[0],length,1,7);
  write_output("r_re.m","r_re",r_re[0],length,1,7);
  write_output("input.m","rfin",input[0],length,1,1);
  write_output("output.m","rfout",output[0],length,1,1);
}
#endif