#include "itcomm.h"


int main()
{

  Real_Timer time;
  int N=10000, M=8, k=needed_bits(M);
  
  vec EbN0 = "0:2:20";
  vec EN0ggr = inv_dB(EbN0)*k;
  vec pb(EbN0.size());

  PAM pam(M);
  Array<BERC> berc(EbN0.size());
  
  bvec transmitted_bits, received_bits;
  vec transmitted_symbols, received_symbols, noise;

  transmitted_bits = randb(N*k);

  pam.modulate_bits(transmitted_bits, transmitted_symbols);

  cout << "Energy=" << sum(sqr(transmitted_symbols))/double(transmitted_symbols.size()) << endl;
  randn(transmitted_symbols.size(), noise);

  for (int i=0; i<EbN0.size(); i++) {
    received_symbols = transmitted_symbols + sqrt(1.0/EN0ggr(i)/2.0)*noise;    
    pam.demodulate_bits(received_symbols, received_bits);
    berc(i).count(transmitted_bits, received_bits);
    pb(i) = berc(i).get_errorrate();
  }
  cout << "SNR=" << EbN0 << endl;
  cout << "pb=" << pb << endl;

}