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pfb_interpolator_ccf.h
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/* -*- c++ -*- */
/*
* Copyright 2009,2012 Free Software Foundation, Inc.
*
* This file is part of GNU Radio
*
* SPDX-License-Identifier: GPL-3.0-or-later
*
*/
#ifndef INCLUDED_PFB_INTERPOLATOR_CCF_H
#define INCLUDED_PFB_INTERPOLATOR_CCF_H
#include <gnuradio/filter/api.h>
#include <gnuradio/sync_interpolator.h>
namespace gr {
namespace filter {
/*!
* \brief Polyphase filterbank interpolator with gr_complex input,
* gr_complex output and float taps
* \ingroup channelizers_blk
*
* \details
* This block takes in a signal stream and performs integer up-
* sampling (interpolation) with a polyphase filterbank. The first
* input is the integer specifying how much to interpolate by. The
* second input is a vector (Python list) of floating-point taps
* of the prototype filter.
*
* The filter's taps should be based on the interpolation rate
* specified. That is, the bandwidth specified is relative to the
* bandwidth after interpolation.
*
* For example, using the GNU Radio's firdes utility to building
* filters, we build a low-pass filter with a sampling rate of
* <EM>fs</EM>, a 3-dB bandwidth of <EM>BW</EM> and a transition
* bandwidth of <EM>TB</EM>. We can also specify the out-of-band
* attenuation to use, ATT, and the filter window function (a
* Blackman-harris window in this case). The first input is the
* gain, which is also specified as the interpolation rate so that
* the output levels are the same as the input (this creates an
* overall increase in power).
*
* <B><EM>self._taps = filter.firdes.low_pass_2(interp, interp*fs, BW, TB,
* attenuation_dB=ATT, window=fft.window.WIN_BLACKMAN_hARRIS)</EM></B>
*
* The PFB interpolator code takes the taps generated above and
* builds a set of filters. The set contains <EM>interp</EM>
* filters and each filter contains
* ceil(taps.size()/interp) taps. Each tap from the
* filter prototype is sequentially inserted into the next
* filter. When all of the input taps are used, the remaining
* filters in the filterbank are filled out with 0's to make sure
* each filter has the same number of taps.
*
* The theory behind this block can be found in Chapter 7.1 of the
* following book:
*
* <B><EM>f. harris, "Multirate Signal Processing for Communication
* Systems</EM>," Upper Saddle River, NJ: Prentice Hall,
* Inc. 2004.</EM></B>
*/
class FILTER_API pfb_interpolator_ccf : virtual public sync_interpolator
{
public:
// gr::filter::pfb_interpolator_ccf::sptr
typedef std::shared_ptr<pfb_interpolator_ccf> sptr;
/*!
* Build the polyphase filterbank interpolator.
* \param interp (unsigned integer) Specifies the interpolation rate to use
* \param taps (vector/list of floats) The prototype filter to populate the
* filterbank. The taps should be generated at the interpolated sampling rate.
*/
static sptr make(unsigned int interp, const std::vector<float>& taps);
/*!
* Resets the filterbank's filter taps with the new prototype filter
* \param taps (vector/list of floats) The prototype filter to populate the
* filterbank. The taps should be generated at the interpolated sampling rate.
*/
virtual void set_taps(const std::vector<float>& taps) = 0;
/*!
* Return a vector<vector<>> of the filterbank taps
*/
virtual std::vector<std::vector<float>> taps() const = 0;
/*!
* Print all of the filterbank taps to screen.
*/
virtual void print_taps() = 0;
};
} /* namespace filter */
} /* namespace gr */
#endif /* INCLUDED_FILTER_PFB_INTERPOLATOR_CCF_H */
gr::filter::pfb_interpolator_ccf
Polyphase filterbank interpolator with gr_complex input, gr_complex output and float taps.
Definition pfb_interpolator_ccf.h:68
gr::filter::pfb_interpolator_ccf::make
static sptr make(unsigned int interp, const std::vector< float > &taps)
gr::filter::pfb_interpolator_ccf::taps
virtual std::vector< std::vector< float > > taps() const =0
gr::filter::pfb_interpolator_ccf::print_taps
virtual void print_taps()=0
gr::filter::pfb_interpolator_ccf::set_taps
virtual void set_taps(const std::vector< float > &taps)=0
gr::filter::pfb_interpolator_ccf::sptr
std::shared_ptr< pfb_interpolator_ccf > sptr
Definition pfb_interpolator_ccf.h:71
gr::sync_interpolator::sync_interpolator
sync_interpolator(void)
Definition sync_interpolator.h:31
api.h
FILTER_API
#define FILTER_API
Definition gr-filter/include/gnuradio/filter/api.h:18
gr::filter
Definition dc_blocker_cc.h:18
gr
GNU Radio logging wrapper.
Definition basic_block.h:29
sync_interpolator.h