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/* -*- c++ -*- */
/*
* Copyright 2002 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 _CONVOLUTIONAL_INTERLEAVER_H_
#define _CONVOLUTIONAL_INTERLEAVER_H_
#include <vector>
#include <interleaver_fifo.h>
#include <assert.h>
/*!
* \brief template class for generic convolutional interleaver
*/
template<class symbol_type>
class convolutional_interleaver {
public:
convolutional_interleaver (bool interleave_p, int nbanks, int fifo_size_incr);
virtual ~convolutional_interleaver ();
//! reset interleaver (flushes contents and resets commutator)
void reset ();
//! sync interleaver (resets commutator, but doesn't flush fifos)
void sync () { m_commutator = 0; }
//! return end to end delay in symbols (delay through concatenated interleaver / deinterleaver)
int end_to_end_delay ();
//! transform a single symbol
symbol_type transform (symbol_type input){
symbol_type retval = m_fifo[m_commutator]->stuff (input);
m_commutator++;
if (m_commutator >= m_nbanks)
m_commutator = 0;
return retval;
}
//! transform a bunch of symbols
void transform (symbol_type *out, const symbol_type *in, int nsymbols);
protected:
int m_commutator;
int m_nbanks;
int m_fifo_size_incr;
std::vector<interleaver_fifo<symbol_type> *> m_fifo;
};
template<class symbol_type>
convolutional_interleaver<symbol_type>::convolutional_interleaver (
bool interleave_p,
int nbanks,
int fifo_size_incr)
{
assert (nbanks >= 1);
assert (fifo_size_incr >= 1);
m_nbanks = nbanks;
m_fifo_size_incr = fifo_size_incr;
m_fifo.resize (nbanks);
if (interleave_p){ // configure as interleaver
for (int i = 0; i < nbanks; i++)
m_fifo[i] = new interleaver_fifo<symbol_type>(i * fifo_size_incr);
}
else { // configure as de-interleaver
for (int i = 0; i < nbanks; i++)
m_fifo[nbanks - 1 - i] = new interleaver_fifo<symbol_type>(i * fifo_size_incr);
}
sync ();
}
template<class symbol_type>
convolutional_interleaver<symbol_type>::~convolutional_interleaver ()
{
for (int i = 0; i < m_nbanks; i++)
delete m_fifo[i];
}
template<class symbol_type> void
convolutional_interleaver<symbol_type>::reset ()
{
sync ();
for (int i = 0; i < m_nbanks; i++)
m_fifo[i]->reset ();
}
template<class symbol_type> int
convolutional_interleaver<symbol_type>::end_to_end_delay ()
{
int m = m_nbanks * m_fifo_size_incr;
return m * (m_nbanks - 1);
}
template<class symbol_type> void
convolutional_interleaver<symbol_type>::transform (symbol_type *out,
const symbol_type *in,
int nsymbols)
{
// we may want to unroll this a couple of times...
for (int i = 0; i < nsymbols; i++)
out[i] = transform (in[i]);
}
#endif /* _CONVOLUTIONAL_INTERLEAVER_H_ */
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