int main( int argc, char* argv[])
{
//Arg initial here
int Number_of_bits = 2048;
//Declarations basic
int i;
double Ps, N0, dist_1, dist_2, h1, h2, Eb;
double EbN0;
double rcvd_power_1, rcvd_power_2;
int nFFT, nCylicPrefix;
//Read arg Simple
if( argc == 4) {
Number_of_bits = atoi( argv[1]);
dist_1 = strtod(argv[2], NULL);
dist_2 = strtod(argv[3], NULL);
}
//Declare vectors and others
vec alpha; //vec is a vector containing double
vec bit_error_rate_1, bit_error_rate_2;
vec ber_theo_1, ber_theo_2; // Theoretical results for multiple access
bvec transmitted_bits_1, transmitted_bits_2; //bvec is a vector containing bits
bvec received_bits_1, received_bits_2;
cvec transmitted_symbols_1, transmitted_symbols_2, transmitted_symbols; //cvec is a vector containing double_complex
cvec received_symbols_1, received_symbols_2, feedback_symbols_1, feedback_symbols_2;
cvec ofdm_symbols_1, ofdm_symbols_2;
// Declarations of classes:
QPSK mod; //The QPSK modulator class
QAM qammod(16); //QAM-16
//QAM mod(64); // -64
AWGN_Channel awgn_channel; //The AWGN channel class
it_file ff; //For saving the results to file
BERC berc; //Used to count the bit errors
Real_Timer tt; //The timer used to measure the execution time
OFDM ofdm; //OFDM modulator class
MA_Filter<std::complex<double>, std::complex<double>, std::complex<double> > multipath_channel; //Simulate multi-path enviornment
int ch_nb_taps = 3;
cvec ini_state = to_cvec( zeros(ch_nb_taps));
vec ch_imp_response_real = "1.000000000000000 0.436232649307735 0.198694326007661";//randray( ch_nb_taps);
ch_imp_response_real /= sqrt(sum_sqr( ch_imp_response_real));//normalized power profile
cvec ch_imp_response = to_cvec( ch_imp_response_real);
multipath_channel.set_coeffs( ch_imp_response);
multipath_channel.set_state(ini_state);//inital state is zero
//Reset and start the timer:
tt.tic();
//Init:
//Ps = 5 * pow(10, -3); //The transmitted energy per mod symbol is 1, 5e-3 W/MHz 802.11
Ps = 4 * pow(10, 0.0); //ETSI TS 136 104 V9.4.0 (2010-07) p17 LTE JAPAN 4 W/MHz
//Ps = 4 * pow(10, 1.0); //max 46 dbm
N0 = 4 * pow(10, -15); //Thermal noise -144dBm/MHz
//dist_1 = 800; //Distance form transmitter to receiver 1 (meter)
//dist_2 = 1000; // * 2
double f = 2600; // Mhz 150-1500
double hM = 2; // meter 1-10
double hb = 120; // meter 30-200
double C_H = 0.8 + (1.1 * log10(f) - 0.7) * hM - 1.56 * log10(f); // Hata medium size city
double h1dB = 69.55 + 26.16 * log10(f) - 13.82*log10(hb) - C_H + (44.9 - 6.55*log10(hb)) * log10(dist_1/1000);
double h2dB = 69.55 + 26.16 * log10(f) - 13.82*log10(hb) - C_H + (44.9 - 6.55*log10(hb)) * log10(dist_2/1000);
//cout << "HatadB:" << h1dB << endl;
//cout << "HatadB:" << h2dB << endl;
//h1 = pow(10, -h1dB/10);
//h2 = pow(10, -h2dB/10);
h1 = pow(dist_1, -4.5); //Channel gain for receiver 1
h2 = pow(dist_2, -4.5); //
cout << "h1 = " << h1 << " h2 = " << h2 << endl;
alpha = linspace(0.3, 0.0, 13);//Simulate for different weight on power
nFFT = 2048; //FFT size, default is 2048 LTE-a
nCylicPrefix = 144; //Length of Prefix, standard 144 (first prefix is different in real case)
// test upconv
cvec ocsi;
cvec t_spanned;
double unit_time = 3.25520833 * pow(10,-8); // 1/(2048*15k)
const double pi = 3.1415926535897;
const std::complex<double> unit_img (0.0,1.0);
double fc = 2.6 * pow(10,9); // 2.6GHz
t_spanned.set_size(2048, false);
for (int i = 0; i < 2048; i++) {
t_spanned[i] = exp(2*pi*fc*unit_time*i*unit_img);
}
// Declarations for equalizer & NSC coding
ivec gen = "07 05"; //octal notation
int constraint_length = 3; //constraint length
int blockSize = 13;//permutation length //encoder output block size
// other parameters
int nb_bits_tail = blockSize / gen.length(); //encoder input size + tail size
int nb_bits = nb_bits_tail - (constraint_length - 1); //encoder block size
int nb_blocks; //number of blocks
// Convolutional code
Convolutional_Code nsc;
nsc.set_generator_polynomials(gen, constraint_length);
//Allocate storage space for the result vector.
//The "false" argument means "Do not copy the old content of the vector to the new storage area."
bit_error_rate_1.set_size(alpha.length(), false);
bit_error_rate_2.set_size(alpha.length(), false);
//Storage for theoretical ber
ber_theo_1.set_size(alpha.length(), false);
ber_theo_2.set_size(alpha.length(), false);
//Randomize the random number generators in it++:
RNG_randomize();
//Set OFDM parameters
ofdm.set_parameters(nFFT, nCylicPrefix);
//Iterate over all EbN0dB values:
for (i = 0; i < alpha.length(); i++) {
//Show how the simulation progresses:
//cout << "Now simulating alpha value = " << alpha(i);
//cout << " # " << i + 1 << "/" << alpha.length() << endl;
//Generate a vector of random bits to transmit:
transmitted_bits_1 = randb(Number_of_bits*2);
transmitted_bits_2 = randb(Number_of_bits);
//convolutional code encode
//bvec out_binary_1 = encode(nsc, constraint_length, transmitted_bits_1, blockSize, false);
//bvec out_binary_2 = encode(nsc, constraint_length, transmitted_bits_2, blockSize, false);
bvec out_binary_1 = transmitted_bits_1;
bvec out_binary_2 = transmitted_bits_2;
//Modulate the bits to mod symbols:
transmitted_symbols_1 = qammod.modulate_bits(out_binary_1);
transmitted_symbols_2 = mod.modulate_bits(out_binary_2);
//Multiplex two signals
transmitted_symbols = transmitted_symbols_1 * pow(alpha(i), 0.5) + transmitted_symbols_2 * pow(1 - alpha(i), 0.5);
transmitted_symbols = transmitted_symbols * pow(Ps, 0.5);
//eval_avg_power(transmitted_symbols);
//Fading
transmitted_symbols_1 = transmitted_symbols * pow(h1, 0.5);
transmitted_symbols_2 = transmitted_symbols * pow(h2, 0.5);
//OFDM modulate
zero_pad_back(transmitted_symbols_1, 2048);
zero_pad_back(transmitted_symbols_2, 2048);
ofdm.modulate(transmitted_symbols_1, ofdm_symbols_1);
ofdm.modulate(transmitted_symbols_2, ofdm_symbols_2);
//Set the noise variance of the AWGN channel:
//ofdm_symbols_1 = concat(ofdm_symbols_1, zeros_c(2)); //B
//ofdm_symbols_2 = concat(ofdm_symbols_2, zeros_c(2)); //B
//ofdm_symbols_1 = concat(ofdm_symbols_1, zeros_c(4)); //A
//ofdm_symbols_2 = concat(ofdm_symbols_2, zeros_c(4)); //A
//cout << "N0: " << N0 << endl;
awgn_channel.set_noise(N0);
//Up-conversion
//Run the transmited symbols through the channel using the () operator:
//ofdm_symbols_1 = awgn_channel( multipath_channel( ofdm_symbols_1));
//ofdm_symbols_2 = awgn_channel( multipath_channel( ofdm_symbols_2));
ofdm_symbols_1 = awgn_channel( ofdm_symbols_1);
ofdm_symbols_2 = awgn_channel( ofdm_symbols_2);
//ofdm_symbols_1 = ofdm_symbols_1.get(0, ofdm_symbols_1.length()-3); //B
//ofdm_symbols_2 = ofdm_symbols_2.get(0, ofdm_symbols_2.length()-3); //B
// test zone!! KEEP OUT!! //A
/*cvec ofdm_symbols_eqed_tmp;
mmse_equalizer_simple(ofdm_symbols_1, ofdm_symbols_eqed_tmp, ch_imp_response_real, N0, false);
ofdm_symbols_1 = ofdm_symbols_eqed_tmp;
mmse_equalizer_simple(ofdm_symbols_2, ofdm_symbols_eqed_tmp, ch_imp_response_real, N0, false);
ofdm_symbols_2 = ofdm_symbols_eqed_tmp;*/
//alpha no greater than 0.5
//OFDM demodulate
ofdm.demodulate(ofdm_symbols_1, received_symbols_1);
ofdm.demodulate(ofdm_symbols_2, received_symbols_2);
//cvec FDMtmp; //B
//FDE(received_symbols_1, FDMtmp, ch_imp_response_real, 2048, false); //B
//ofdm_symbols_1 = FDMtmp; //B
//FDE(received_symbols_2, FDMtmp, ch_imp_response_real, 2048, false); //B
//ofdm_symbols_2 = FDMtmp; //B
//Demodulate the received mod symbols into received bits: Layer 1
received_bits_2 = mod.demodulate_bits(received_symbols_2 / pow(1-alpha(i), 0.5) / pow(Ps, 0.5) / pow(h2, 0.5));
//bvec out_binary_recover_2 = decode(nsc, constraint_length, received_bits_2, blockSize, false);
bvec out_binary_recover_2 = received_bits_2;
//Demodulate the received mod symbols into received bits: Layer 2
received_bits_1 = mod.demodulate_bits(received_symbols_1 / pow(1-alpha(i), 0.5) / pow(Ps, 0.5) / pow(h1, 0.5));
feedback_symbols_2 = pow(Ps * (1-alpha(i)) * h1, 0.5) * mod.modulate_bits(received_bits_1);
received_bits_1 = qammod.demodulate_bits((received_symbols_1-feedback_symbols_2) / pow(alpha(i), 0.5) / pow(Ps, 0.5) / pow(h1, 0.5));
//bvec out_binary_recover_1 = decode(nsc, constraint_length, received_bits_1, blockSize, false);
bvec out_binary_recover_1 = received_bits_1;
//Calculate the bit error rate:
berc.clear(); //Clear the bit error rate counter
berc.count(transmitted_bits_2, out_binary_recover_2.get(0, Number_of_bits)); //Count the bit errors
bit_error_rate_2(i) = berc.get_errorrate(); //Save the estimated BER in the result vector
berc.clear();
berc.count(transmitted_bits_1, out_binary_recover_1.get(0, Number_of_bits));
bit_error_rate_1(i) = berc.get_errorrate();
}
tt.toc();
// Theoretical results for multiple access
for (size_t i = 0; i < alpha.length(); ++i) { //BER for theo 1
EbN0 = (Ps * 0.5 * h1 * alpha(i)) / (N0 + Ps * 0.5 * h1 * (1 - alpha(i)));
ber_theo_1(i) = 0.5*erfc(pow(EbN0, 0.5));
}
for (size_t i = 0; i < alpha.length(); ++i) { //BER for theo 2
EbN0 = (Ps * 0.5 * h2 * (1-alpha(i))) / N0;
ber_theo_2(i) = 0.5*erfc(pow(EbN0, 0.5));
}
//Print the results:
cout << endl;
time_t rawtime;
time (&rawtime);
std::string nowTime( ctime( &rawtime));
/*cout << nowTime << endl;
cout << "alpha = " << alpha << " " << endl;
cout << "BER 1 = " << bit_error_rate_1 << endl;
cout << "BER 2 = " << bit_error_rate_2 << endl;
cout << "Theoretical BER 1 = " << ber_theo_1 << endl;
cout << "Theoretical BER 2 = " << ber_theo_2 << endl;
cout << endl;*/
//Chech feasibility
bool feasibility = false;
double threshold = 0.01;
for (size_t i = 1; i < alpha.length(); i++) {
if (bit_error_rate_1(i) < threshold && bit_error_rate_2(i) < threshold) {
feasibility = true;
}
}
if (feasibility) {
cout << " PASS " << endl;
}
//Save the results to file:
const char xFilename[] = "result";
char oFilename[100];
int fileIndex = 0;
strcpy( oFilename, xFilename);
while(std::ifstream( oFilename)){
++fileIndex;
sprintf( oFilename, "%s%d", xFilename, fileIndex);
}
cout << "Saving results to " << oFilename << endl;
std::ofstream oo;
oo.open(oFilename);
oo << alpha << endl;
oo << bit_error_rate_1 << endl;
oo << bit_error_rate_2 << endl;
oo.close();
//Exit program:
return 0;
}
int main()
{
//Declarations of scalars and vectors:
int i, Number_of_bits;
double Ps, N0, dist_1, dist_2, h1, h2, Eb;
double EbN0;
double rcvd_power_1, rcvd_power_2;
vec alpha; //vec is a vector containing double
vec bit_error_rate_1, bit_error_rate_2;
vec ber_theo_1, ber_theo_2; // Theoretical results for multiple access
bvec transmitted_bits_1, transmitted_bits_2; //bvec is a vector containing bits
bvec received_bits_1, received_bits_2;
cvec transmitted_symbols_1, transmitted_symbols_2, transmitted_symbols; //cvec is a vector containing double_complex
cvec received_symbols_1, received_symbols_2, feedback_symbols_1;
//Declarations of classes:
QPSK qpsk; //The QPSK modulator class
QAM qam16(16);
QAM qam64(64);
AWGN_Channel awgn_channel; //The AWGN channel class
it_file ff; //For saving the results to file
BERC berc; //Used to count the bit errors
Real_Timer tt; //The timer used to measure the execution time
//Reset and start the timer:
tt.tic();
//Init:
Ps = 5 * pow(10, -3); //The transmitted energy per QPSK symbol is 1, 5e-3 W/MHz
N0 = 4 * pow(10, -15); //Thermal noise -144dBm/MHz
dist_1 = 150; //Distance form transmitter to receiver 1 (meter)
dist_2 = 220; // * 2
h1 = pow(dist_1, -4.5); //Channel gain for receiver 1
h2 = pow(dist_2, -4.5); //
cout << "h1 = " << h1 << " h2 = " << h2 << endl;
alpha = linspace(1.0, 0.0, 21);//Simulate for different weight on power
// Eb = Ec / 2.0; //The transmitted energy per bit is 0.5.
// EbN0dB = linspace(0.0, 9.0, 10); //Simulate for 10 Eb/N0 values from 0 to 9 dB.
// EbN0 = inv_dB(EbN0dB); //Calculate Eb/N0 in a linear scale instead of dB.
// N0 = Eb * pow(EbN0, -1.0); //N0 is the variance of the (complex valued) noise.
Number_of_bits = 1000000; //One hundred thousand bits is transmitted for each Eb/N0 value
// alpha = 0.8; //Ratio of allocated power
//Allocate storage space for the result vector.
//The "false" argument means "Do not copy the old content of the vector to the new storage area."
bit_error_rate_1.set_size(alpha.length(), false);
bit_error_rate_2.set_size(alpha.length(), false);
//Storage for theoretical ber
ber_theo_1.set_size(alpha.length(), false);
ber_theo_2.set_size(alpha.length(), false);
//Randomize the random number generators in it++:
RNG_randomize();
//Iterate over all EbN0dB values:
for (i = 0; i < alpha.length(); i++) {
//Show how the simulation progresses:
cout << "Now simulating alpha value = " << alpha(i);
cout << " # " << i + 1 << "/" << alpha.length() << endl;
//Generate a vector of random bits to transmit:
transmitted_bits_1 = randb(Number_of_bits*2);
transmitted_bits_2 = randb(Number_of_bits);
//Modulate the bits to QPSK symbols:
transmitted_symbols_1 = qam16.modulate_bits(transmitted_bits_1);
transmitted_symbols_2 = qpsk.modulate_bits(transmitted_bits_2);
//Multiplex two signals
transmitted_symbols = transmitted_symbols_1 * pow(alpha(i), 0.5) + transmitted_symbols_2 * pow(1 - alpha(i), 0.5);
transmitted_symbols = transmitted_symbols * pow(Ps, 0.5);
//eval_avg_power(transmitted_symbols);
//Fading
transmitted_symbols_1 = transmitted_symbols * pow(h1, 0.5);
transmitted_symbols_2 = transmitted_symbols * pow(h2, 0.5);
//Set the noise variance of the AWGN channel:
awgn_channel.set_noise(N0);
//Run the transmited symbols through the channel using the () operator:
received_symbols_1 = awgn_channel(transmitted_symbols_1);
received_symbols_2 = awgn_channel(transmitted_symbols_2);
//Demodulate the received QPSK symbols into received bits: Layer 1
received_bits_1 = qam16.demodulate_bits(received_symbols_1 * pow(Ps * alpha(i) * h1, -0.5));
//Demodulate the received QPSK symbols into received bits: Layer 2
received_bits_2 = qam16.demodulate_bits(received_symbols_2 * pow(Ps * alpha(i) * h2, -0.5));
feedback_symbols_1 = pow(Ps * alpha(i) * h2, 0.5) * qam16.modulate_bits(received_bits_2);
received_bits_2 = qpsk.demodulate_bits(received_symbols_2 - feedback_symbols_1);
//Calculate the bit error rate:
berc.clear(); //Clear the bit error rate counter
berc.count(transmitted_bits_1, received_bits_1); //Count the bit errors
bit_error_rate_1(i) = berc.get_errorrate(); //Save the estimated BER in the result vector
berc.clear();
berc.count(transmitted_bits_2, received_bits_2);
bit_error_rate_2(i) = berc.get_errorrate();
}
tt.toc();
// Theoretical results for multiple access
for (size_t i = 0; i < alpha.length(); ++i) { //BER for theo 1
EbN0 = (Ps * 0.5 * h1 * alpha(i)) / (N0 + Ps * 0.5 * h1 * (1 - alpha(i)));
ber_theo_1(i) = 0.5*erfc(pow(EbN0, 0.5));
}
for (size_t i = 0; i < alpha.length(); ++i) { //BER for theo 2
EbN0 = (Ps * 0.5 * h2 * (1-alpha(i))) / N0;
ber_theo_2(i) = 0.5*erfc(pow(EbN0, 0.5));
}
//Print the results:
cout << endl;
cout << "alpha = " << alpha << " " << endl;
cout << "BER 1 = " << bit_error_rate_1 << endl;
cout << "BER 2 = " << bit_error_rate_2 << endl;
cout << "Theoretical BER 1 = " << ber_theo_1 << endl;
cout << "Theoretical BER 2 = " << ber_theo_2 << endl;
cout << "Saving results to ./qam16_result_file.it" << endl;
cout << endl;
//Save the results to file:
std::ofstream oo;
oo.open("qam16_result_file.it");
oo << alpha;
oo << bit_error_rate_1;
oo << bit_error_rate_2;
ff.close();
//Exit program:
return 0;
}
