maxentropychannel.h

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/*-*-c++-*-*****************************************************************
                          maxentropychannel.h  -  MIMO channel class
                             -------------------
    begin                : Oct 2003
    copyright            : (C) 2003 by Cornelius Heckrott
    email                : cornelius.heckrott@tu-harburg.de
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   This library is free software; you can redistribute it and/or         *
 *   modify it under the terms of the GNU Lesser General Public            *
 *   License as published by the Free Software Foundation; either          *
 *   version 2.1 of the License, or (at your option) any later version.    *
 *                                                                         *
 *   This library 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     *
 *   Lesser General Public License for more details.                       *
 *                                                                         *
 *   You should have received a copy of the GNU Lesser General Public      *
 *   License along with this library; if not, write to the Free Software   *
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston,                 *
 *   MA  02111-1307  USA                                                   *
 *                                                                         *
 ***************************************************************************/

#ifndef MAXENTROPYCHANNEL_H
#define MAXENTROPYCHANNEL_H

#include <iostream>
#include <fstream>
#include <complex>

#include <simthetic/phbib.h>
#include <simthetic/phrand.h>
#include <simthetic/signals.h>
#include <simthetic/basicdevice.h>
#include <simthetic/interfaces.h>

#include "matrixseq.h"
#include "mimo-channel.h"

namespace simthlib {
    class DelayProfile;
}

namespace mimo {
class MaxEntropyChannel : public MIMOChannel
{

  private:
    // global_time is set to zero at the beginning of each simulation run
    unsigned absolut_time;
    // delta_t is the sampling time of the transmitted sequences
    double delta_t;
    // delta_f is a frequency step in the frequency domain
    mutable double delta_f;
    // delay_steps stores the values which roundTimeToSamples() is returning
    mutable size_t delay_steps;
    // scatterers_s holds information about the number of the directions of
    // arrival DoA (see Merouane Debbah Page 59/60), to be set in the .par file,
    // if it is not declared, default is  " DoA: 5 "
    unsigned scatterers_s;
    // scatterers_s1 holds information about the number of the directions of
    // departure DoD (see Merouane Debbah Page 59/60), to be set in the .par file,
    // if it is not declared, default is  " DoD: 5 "
    unsigned scatterers_s1;
    // The vector AoD stores the informarion under which angle the different directions
    // of departure leave the transmitter. In the same way stores AoA the angles of arrival
    mimo::Vector AoD, AoA;
    // samples_cache stores the samples that can't be placed in the actual sequence (because
    // their delay is to long), they will be written into the next sequence
    VectorTimeSignal::storage_type samples_cache;
    // PSI_Matrix is a pseudo complex matrix which stores the phase shifts psi
    mimo::CMatrix PSI_Matrix;
    // the phaseshifts phi at the receiving antennas (a result of the
    // different directions of arrival) are stored in the real matrix PHI
    mimo::Matrix PHI;
    // the doppler frequencies are written into the real matrix PHI_Doppler
    mimo::Matrix PHI_Doppler;
    // PHI_Matrix with time variant entries, see Merouane Debbah Page 59/60 for details
    mutable mimo::CMatrix PHI_Matrix;
    // time delay matrix holds information about the delays of the paths
    mimo::Matrix DELAY;
    // the pseudo complex GAUSS_Matrix contains i.i.d. gaussian variables
    mimo::CMatrix GAUSS_Matrix;
    // the pseudo complex GAUSS_DELAY_Matrix links a DoD with a DoA
    // taking into account a certain delay
    mutable mimo::CMatrix GAUSS_DELAY_Matrix;
    // an object of the class DelayProfile, to get random delays
    simthlib::DelayProfile *PathDelay;
    // an object of the class GaussRng, to get random Gauss variables
    simth::GaussRng *GaussVar;
    // an object of the class UniformRng, to get random angles
    UniformRng random_uniform;
    // the normfactor depends on the number of scatterers s and s1,
    // see Merouane Debbah Page 59/60 for details
    double normfactor;
    // no_refresh makes sure that no channel refresh is done during transmission/estimation
    mutable bool no_refresh;
    // is false after first call of refresh()
    bool SimulationStart;
    // Geometry of the antenna arrays
    AntennaArray *thisArray;
    // angle of receivers steering vector relative to the antenna array,
    // the vectors length is stored in receiver_speed
    double ReceiverSteering;
    // Whether we actually have the doppler effect
    bool have_doppler;

  public:
    MaxEntropyChannel(int deviceID, DeviceSystemIntf* system,
                        const simth::PropertyList& pl);

    ~MaxEntropyChannel();

    void getTransfer(int relative_time, MatrixFreqSignal &transfer) const;
    void transmit(const VectorTimeSignal &insym, VectorTimeSignal &outsym);
    int roundTimeToSamples(double value) const;
    virtual void refresh();
    void set_normfactor();
    void getImpulseResponse(int relative_time, MatrixTimeSignal &impulse) const;
    double get_angle() const;
    double get_delay() const;
    double get_gauss() const;
    virtual void print(std::ostream &os) const;

  protected:
    void updateInputLengths();
    void updateOutputLengths();
};

} // namespace

#endif // MAXENTROPYCHANNEL_H

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