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/*!
* \file
* \brief Vector ("MIMO") modulator classes test program
* \author Erik G. Larsson, Adam Piatyszek, and Mirsad Cirkic
*
* -------------------------------------------------------------------------
*
* Copyright (C) 1995-2012 (see AUTHORS file for a list of contributors)
*
* This file is part of IT++ - a C++ library of mathematical, signal
* processing, speech processing, and communications classes and functions.
*
* IT++ 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.
*
* IT++ 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 IT++. If not, see <http://www.gnu.org/licenses/>.
*
* -------------------------------------------------------------------------
*/
#include <itpp/itcomm.h>
#include <itpp/itstat.h>
#include <iomanip>
using namespace std;
using namespace itpp;
int main()
{
cout << "========================================================" << endl;
cout << " Test of ND (MIMO) Modulators " << endl;
cout << "========================================================" << endl;
cout.setf(ios::fixed);
cout.precision(2);
RNG_reset(12345);
double sigma2 = 0.05;
{ // --- Test for M-PAM, M^2-QAM, and M^2-PSK constellations
ND_UPAM pammod;
ND_UQAM qammod;
ND_UPSK pskmod;
int nt = 2;
for (int nb = 1; nb <= 2; nb++) {
cout << "================== " << (1 << nb) << "-PAM, " << (1<<2*nb) << "-QAM, and " << (1<<2*nb) << "-PSK ==================\n";
pammod.set_M(2*nt, 1<<nb);
qammod.set_M(nt, 1<<2*nb);
pskmod.set_M(nt, 1<<2*nb);
cout << pammod << endl;
cout << qammod << endl;
cout << pskmod << endl;
bvec b=randb(2*nt*nb);
cvec xqam = qammod.modulate_bits(b);
cvec xpsk = pskmod.modulate_bits(b);
cmat Hc = randn_c(nt, nt);
cvec ec=sqrt(2*sigma2) * randn_c(nt);
cvec yqam = Hc * xqam + ec;
cvec ypsk = Hc * xpsk + ec;
vec x=pammod.modulate_bits(b);
mat H(2*nt,2*nt);
H.set_submatrix(0, 0, real(Hc)/sqrt(2.0));
H.set_submatrix(nt, 0, imag(Hc)/sqrt(2.0));
H.set_submatrix(nt, nt, real(Hc)/sqrt(2.0));
H.set_submatrix(0, nt, -imag(Hc)/sqrt(2.0));
vec y=H*x+sqrt(sigma2) * randn(2*nt);
QLLRvec LLR_ap = randi(2*nt*nb,-5000,5000);
QLLRvec LLR;
pammod.init_soft_demodulator(H, sigma2);
qammod.init_soft_demodulator(Hc, 2*sigma2);
pskmod.init_soft_demodulator(Hc, 2*sigma2);
pammod.demodulate_soft_bits(y, LLR_ap, LLR);
cout << "PAM: full LLR: " << pammod.get_llrcalc().to_double(LLR) << endl;
pammod.demodulate_soft_bits(y, H, sigma2, LLR_ap, LLR);
cout << " : " << pammod.get_llrcalc().to_double(LLR) << endl;
qammod.demodulate_soft_bits(yqam, LLR_ap, LLR);
cout << "QAM: full LLR: " << qammod.get_llrcalc().to_double(LLR) << endl;
qammod.demodulate_soft_bits(yqam, Hc, 2*sigma2, LLR_ap, LLR);
cout << " : " << qammod.get_llrcalc().to_double(LLR) << endl;
pskmod.demodulate_soft_bits(ypsk, LLR_ap, LLR);
cout << "PSK: full LLR: " << pskmod.get_llrcalc().to_double(LLR) << endl;
pskmod.demodulate_soft_bits(ypsk, Hc, 2*sigma2, LLR_ap, LLR);
cout << " : " << pskmod.get_llrcalc().to_double(LLR) << endl;
pammod.demodulate_soft_bits(y, LLR_ap, LLR, ND_UPAM::FULL_ENUM_MAXLOG);
cout << "PAM: Max-Log : " << pammod.get_llrcalc().to_double(LLR) << endl;
LLR_calc_unit llrcalctmp=pammod.get_llrcalc();
pammod.set_llrcalc(LLR_calc_unit(12, 0, 7));
pammod.demodulate_soft_bits(y, LLR_ap, LLR);
cout << " : " << pammod.get_llrcalc().to_double(LLR) << endl;
qammod.demodulate_soft_bits(yqam, LLR_ap, LLR, ND_UQAM::FULL_ENUM_MAXLOG);
cout << "QAM: Max-Log : " << qammod.get_llrcalc().to_double(LLR) << endl;
pskmod.demodulate_soft_bits(ypsk, LLR_ap, LLR, ND_UPSK::FULL_ENUM_MAXLOG);
cout << "PSK: Max-Log : " << pskmod.get_llrcalc().to_double(LLR) << endl << endl;
pammod.set_llrcalc(llrcalctmp);
pammod.demodulate_soft_bits(y, diag(H), sigma2, LLR_ap, LLR);
cout << "PAM: diag. model : " << pammod.get_llrcalc().to_double(LLR) << endl;
pammod.demodulate_soft_bits(y, H, sigma2, LLR_ap, LLR, ND_UPAM::ZF_LOGMAP);
cout << "PAM: zero-forcing: " << pammod.get_llrcalc().to_double(LLR) << endl;
ivec zhat;
pammod.sphere_decoding(y, H, 0.01, 10000, 2.0, zhat);
cout << "PAM: sphere-dec. : " << zhat << endl << endl;
}
}
{ // --- Test for M-PAM and M^2-QAM with variable constellations
ND_UQAM qammod;
ND_UPAM pammod;
int nt = 3;
qammod.set_M(nt, "4 64 16");
pammod.set_M(2*nt, "2 8 4 2 8 4");
cout << qammod << endl << pammod << endl;
cmat Hc = randn_c(nt, nt);
mat H(2*nt,2*nt);
H.set_submatrix(0, 0, real(Hc)/sqrt(2.0));
H.set_submatrix(nt, 0, imag(Hc)/sqrt(2.0));
H.set_submatrix(nt, nt, real(Hc)/sqrt(2.0));
H.set_submatrix(0, nt, -imag(Hc)/sqrt(2.0));
QLLRvec LLR_ap = zeros_i(sum(qammod.get_k()));
pammod.init_soft_demodulator(H, sigma2);
qammod.init_soft_demodulator(Hc, 2*sigma2);
double pamerrs=0, qamerrs=0;
int TRIALS=1000;
for(int i=0; i<TRIALS; i++){
bvec b=randb(sum(pammod.get_k()));
cvec xqam = qammod.modulate_bits(b);
cvec yqam = Hc * xqam + sqrt(2*sigma2) * randn_c(nt);
vec x=pammod.modulate_bits(b);
vec y=H*x+sqrt(sigma2) * randn(2*nt);
QLLRvec LLR;
pammod.demodulate_soft_bits(y, LLR_ap, LLR);
pamerrs+=hamming_distance(LLR<0,b);
qammod.demodulate_soft_bits(yqam, LLR_ap, LLR);
qamerrs+=hamming_distance(LLR<0,b);
}
pamerrs/=TRIALS*sum(pammod.get_k());
qamerrs/=TRIALS*sum(pammod.get_k());
cout << itpp::round(100*pamerrs)/100 << " " << itpp::round(100*qamerrs)/100 << endl;
if(round_i(100*qamerrs)==round_i(100*pamerrs)) cout << "BER passed" << endl;
else cout << "BER failed" << endl;
bvec b=randb(sum(pammod.get_k()));
cvec xqam = qammod.modulate_bits(b);
cvec yqam = Hc * xqam + sqrt(2*sigma2) * randn_c(nt);
vec x=pammod.modulate_bits(b);
vec y=H*x+sqrt(sigma2) * randn(2*nt);
QLLRvec LLR;
pammod.demodulate_soft_bits(y, LLR_ap, LLR);
cout << "bit sequence : " << b << endl;
cout << "PAM: full LLR: " << pammod.get_llrcalc().to_double(LLR) << endl;
qammod.demodulate_soft_bits(yqam, LLR_ap, LLR);
cout << "QAM: full LLR: " << qammod.get_llrcalc().to_double(LLR) << endl;
}
return 0;
}
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