GNU Radio 3.7.3 C++ API
channel_model2.h
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/* -*- c++ -*- */
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/*
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* Copyright 2009,2012,2013 Free Software Foundation, Inc.
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*
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* This file is part of GNU Radio
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*
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* GNU Radio is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 3, or (at your option)
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* any later version.
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*
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* GNU Radio is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with GNU Radio; see the file COPYING. If not, write to
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* the Free Software Foundation, Inc., 51 Franklin Street,
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* Boston, MA 02110-1301, USA.
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*/
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#ifndef INCLUDED_CHANNELS_CHANNEL_MODEL2_H
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#define INCLUDED_CHANNELS_CHANNEL_MODEL2_H
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#include <
gnuradio/channels/api.h
>
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#include <
gnuradio/hier_block2.h
>
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#include <
gnuradio/types.h
>
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namespace
gr {
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namespace
channels {
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/*!
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* \brief Basic channel simulator allowing time-varying frequency
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* and timing inputs.
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* \ingroup channel_models_blk
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*
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* \details
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* This block implements a basic channel model simulator that can
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* be used to help evaluate, design, and test various signals,
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* waveforms, and algorithms.
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*
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* This model allows the user to set the voltage of an AWGN noise
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* source (\p noise_voltage), an initial timing offset (\p
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* epsilon), and a seed (\p noise_seed) to randomize the AWGN
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* noise source.
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*
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* Multipath can be approximated in this model by using a FIR
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* filter representation of a multipath delay profile with the
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* parameter \p taps.
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*
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* Unlike gr::channels::channel_model, this block is designed to
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* enable time-varying frequency and timing offsets.
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* * Port 0: input signal to be run through the channel.
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* * Port 1: frequency function. A constant value between -0.5 and
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* 0.5 here will turn into a constant frequency offset
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* from -fs/2 to fs/2 (where fs is the sample rate).
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* * Port 2: timing offset function. Sets the resampling rate of
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* the channel model. A constant value here produces
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* that value as the timing offset, so a constant 1.0
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* input stream is the same as not having a timing
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* offset.
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*
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* Since the models for frequency and timing offset may vary and
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* what we are trying to model may be different for different
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* simulations, we provide the time-varying nature as an input
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* function that is user-defined. If only constant frequency and
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* timing offsets are required, it is easier and less expensive to
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* use gr::channels::channel_model.
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*/
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class
CHANNELS_API
channel_model2
:
virtual
public
hier_block2
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{
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public
:
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// gr::channels::channel_model2::sptr
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typedef
boost::shared_ptr<channel_model2>
sptr
;
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/*! \brief Build the channel simulator.
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*
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* \param noise_voltage The AWGN noise level as a voltage (to be
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* calculated externally to meet, say, a
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* desired SNR).
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* \param epsilon The initial sample timing offset to emulate the
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* different rates between the sample clocks of
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* the transmitter and receiver. 1.0 is no difference.
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* \param taps Taps of a FIR filter to emulate a multipath delay profile.
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* \param noise_seed A random number generator seed for the noise source.
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* \param block_tags If true, tags will not be able to propagate through this block.
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*/
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static
sptr
make(
double
noise_voltage=0.0,
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double
epsilon=1.0,
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const
std::vector<gr_complex> &
taps
=std::vector<gr_complex>(1,1),
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double
noise_seed=0,
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bool
block_tags=
false
);
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virtual
void
set_noise_voltage(
double
noise_voltage) = 0;
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virtual
void
set_taps(
const
std::vector<gr_complex> &
taps
) = 0;
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virtual
void
set_timing_offset(
double
epsilon) = 0;
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virtual
double
noise_voltage()
const
= 0;
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virtual
std::vector<gr_complex>
taps
()
const
= 0;
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virtual
double
timing_offset()
const
= 0;
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};
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}
/* namespace channels */
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}
/* namespace gr */
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#endif
/* INCLUDED_CHANNELS_CHANNEL_MODEL2_H */
gnuradio
gr-channels
include
gnuradio
channels
channel_model2.h
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