GNU Radio Manual and C++ API Reference 3.7.14.0
The Free & Open Software Radio Ecosystem
mmse_fir_interpolator_ff.h
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1/* -*- c++ -*- */
2/*
3 * Copyright 2002,2012 Free Software Foundation, Inc.
4 *
5 * This file is part of GNU Radio
6 *
7 * GNU Radio is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
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10 * any later version.
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12 * GNU Radio is distributed in the hope that it will be useful,
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14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
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21 */
22
23#ifndef _MMSE_FIR_INTERPOLATOR_FF_H_
24#define _MMSE_FIR_INTERPOLATOR_FF_H_
25
26#include <gnuradio/filter/api.h>
28#include <vector>
29
30namespace gr {
31namespace filter {
32
33/*!
34 * \brief Compute intermediate samples between signal samples x(k*Ts)
35 * \ingroup filter_primitive
36 *
37 * \details
38 * This implements a Minimum Mean Squared Error interpolator with
39 * 8 taps. It is suitable for signals where the bandwidth of
40 * interest B = 1/(4*Ts) Where Ts is the time between samples.
41 *
42 * Although mu, the fractional delay, is specified as a float, it
43 * is actually quantized. 0.0 <= mu <= 1.0. That is, mu is
44 * quantized in the interpolate method to 32nd's of a sample.
45 *
46 * For more information, in the GNU Radio source code, see:
47 * \li gr-filter/lib/gen_interpolator_taps/README
48 * \li gr-filter/lib/gen_interpolator_taps/praxis.txt
49 */
51{
52public:
55
56 unsigned ntaps() const;
57 unsigned nsteps() const;
58
59 /*!
60 * \brief compute a single interpolated output value.
61 * \p input must have ntaps() valid entries.
62 * input[0] .. input[ntaps() - 1] are referenced to compute the output value.
63 *
64 * \p mu must be in the range [0, 1] and specifies the fractional delay.
65 *
66 * \returns the interpolated input value.
67 */
68 float interpolate(const float input[], float mu) const;
69
70protected:
71 std::vector<kernel::fir_filter_fff*> filters;
72};
73
74} /* namespace filter */
75} /* namespace gr */
76
77#endif /* _MMSE_FIR_INTERPOLATOR_FF_H_ */
Compute intermediate samples between signal samples x(k*Ts)
Definition: mmse_fir_interpolator_ff.h:51
std::vector< kernel::fir_filter_fff * > filters
Definition: mmse_fir_interpolator_ff.h:71
float interpolate(const float input[], float mu) const
compute a single interpolated output value. input must have ntaps() valid entries....
#define FILTER_API
Definition: gr-filter/include/gnuradio/filter/api.h:30
Include this header to use the message passing features.
Definition: basic_block.h:45