multiply_matrix.h

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/* -*- c++ -*- */
/*
 * Copyright 2014, 2017, 2018 Free Software Foundation, Inc.
 *
 * This file is part of GNU Radio
 *
 * GNU Radio 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, or (at your option)
 * any later version.
 *
 * GNU Radio 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 GNU Radio; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */


#ifndef MULTIPLY_MATRIX_H
#define MULTIPLY_MATRIX_H

#include <gnuradio/blocks/api.h>
#include <gnuradio/sync_block.h>
#include <cstdint>

namespace gr {
namespace blocks {

/*!
 * \brief Matrix multiplexer/multiplier: y(k) = A x(k)
 * \ingroup blocks
 *
 * This block is similar to gr::blocks::multiply_const_ff, the difference
 * being it can handle several inputs and outputs, and the input-to-output
 * relation can be described by the following mathematical equation:
 * \f[
 *    \mathbf{y}(k) = \mathbf{A} \mathbf{x}(k) \, , \, y \in \mathbb{R}^N, \mathbf{x} \in
 * \mathbb{R}^M, A \in \mathbb{R}^{N \times M} \f] \f$\mathbf{y}(k)\f$ and
 * \f$\mathbf{x}(i)\f$ are column-vectors describing the elements on the input port at
 * time step \f$k\f$ (this is a sync block with no memory).
 *
 * Examples for where to use this block include:
 * - Switch matrices (i.e. switch which ports go where), assuming all ports run on the
 * same rate
 * - Simulation of static MIMO-Channels (in that case, \f$\mathbf{A}\f$ is the channel
 * matrix)
 * - Summing up streams with variable coefficients
 *
 * This block features a special tag propagation mode: When setting the tag propagation
 * policy to gr::block::TPP_CUSTOM, a tag is propagated from input \f$k\f$ to output
 * \f$l\f$, if \f$(A)_{l,k} \neq 0\f$.
 *
 * \section blocks_matrixmult_msgports_multiply_matrix Message Ports
 *
 * This block as one input message port (\p set_A). A message sent to this port will
 * be converted to a std::vector<std::vector<T> >, and then passed on to set_A().
 * If no conversion is possible, a warning is issued via the logging interface, and
 * A remains unchanged.
 *
 * *Note*: It is not possible to change the dimension of the matrix after initialization,
 * as this affects the I/O signature! If a matrix of invalid size is passed to the block,
 * an alert is raised via the logging interface, and A remains unchanged.
 */
template <class T>
class BLOCKS_API multiply_matrix : virtual public gr::sync_block
{
public:
    typedef boost::shared_ptr<multiply_matrix<T>> sptr;

    /*!
     * \param A The matrix
     * \param tag_propagation_policy The tag propagation policy.
     *                               Note this can be any
     *                               gr::block::tag_propagation_policy_t
     *                               value. In case of TPP_CUSTOM, tags are
     *                               only transferred from input \f$k\f$ to
     *                               output \f$l \iff (A)_{l,k} \neq 0\f$.
     */
    static sptr make(std::vector<std::vector<T>> A,
                     gr::block::tag_propagation_policy_t tag_propagation_policy =
                         gr::block::TPP_ALL_TO_ALL);

    //! Returns the current matrix
    virtual const std::vector<std::vector<T>>& get_A() const = 0;
    //! Sets the matrix to a new value \p new_A. Returns true if the new matrix was valid
    //! and could be changed.
    virtual bool set_A(const std::vector<std::vector<T>>& new_A) = 0;

    std::string MSG_PORT_NAME_SET_A;
};

typedef multiply_matrix<float> multiply_matrix_ff;
typedef multiply_matrix<gr_complex> multiply_matrix_cc;
} // namespace blocks
} // namespace gr

#endif /* MULTIPLY_MATRIX_H */