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Diffstat (limited to 'gr-atsc/include/gnuradio/atsc/sssr_impl.h')
| -rw-r--r-- | gr-atsc/include/gnuradio/atsc/sssr_impl.h | 241 |
1 files changed, 0 insertions, 241 deletions
diff --git a/gr-atsc/include/gnuradio/atsc/sssr_impl.h b/gr-atsc/include/gnuradio/atsc/sssr_impl.h deleted file mode 100644 index f61d0f340f..0000000000 --- a/gr-atsc/include/gnuradio/atsc/sssr_impl.h +++ /dev/null @@ -1,241 +0,0 @@ -/* -*- 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. - */ - -/* - * --- ATSC Segment and Symbol Sync Recovery --- - */ - -#ifndef _ATSC_SSSR_H_ -#define _ATSC_SSSR_H_ - -#include <gnuradio/atsc/api.h> -#include <gnuradio/atsc/consts.h> -#include <gnuradio/filter/mmse_fir_interpolator_ff.h> -#include <gnuradio/filter/single_pole_iir.h> -#include <cstdio> - -/* - * --- support classes for atsci_sssr --- - */ - -namespace sssr { - - typedef float sample_t; - - // ---------------------------------------------------------------- - //! digital correlator for 1001 and 0110 patterns - - class ATSC_API digital_correlator { - int d_sr; // 4 bit shift register - - public: - - // Constructor - digital_correlator () { reset (); } - - // Manipulators - - //! called on channel change - void reset () { d_sr = 0; } - - //! clock bit in and return true if we've seen 1001 - - bool update (int bit) { - d_sr = ((bit & 1) << 3) | (d_sr >> 1); - - return (d_sr == 0x9); // 1001 - } - - }; - - - // ---------------------------------------------------------------- - //! segment sync integrator - - class ATSC_API seg_sync_integrator { - signed char d_integrator[ATSC_DATA_SEGMENT_LENGTH]; - - public: - - // Constructor - seg_sync_integrator () { reset (); } - - // Manipulators - - //! called on channel change - void reset (); - - //! update current tap with weight and return integrated correlation value - int update (int weight, int index); - - //! return index of maximum correlation value - int find_max (int *value); - - }; - - // ---------------------------------------------------------------- - //! quad filter (used to compute timing error) - - class ATSC_API quad_filter { - sample_t d_delay[4]; - - public: - // Constructor - quad_filter () { reset (); } - - // Manipulators - - //! called on channel change - void reset () { d_delay[0] = d_delay[1] = d_delay[2] = d_delay[3] = 0; } - - double update (sample_t sample){ - d_delay[3] = d_delay[2]; - d_delay[2] = d_delay[1]; - d_delay[1] = d_delay[0]; - d_delay[0] = sample; - - // the coefficients are -1,-1,+1,+1 - return d_delay[3] + d_delay[2] - d_delay[1] - d_delay[0]; - } - }; -} - -// ---------------------------------------------------------------- - -/*! - * \brief ATSC Segment and Symbol Sync Recovery - * - * This class implements data segment sync tracking and symbol timing - * using the method described in "ATSC/VSB Tutorial - Receiver Technology" - * by Wayne E. Bretl of Zenith, pgs 41-45. - */ - -class ATSC_API atsci_sssr { - sssr::digital_correlator d_correlator; - sssr::seg_sync_integrator d_integrator; - sssr::quad_filter d_quad_filter; - double d_quad_output[ATSC_DATA_SEGMENT_LENGTH]; - double d_timing_adjust; - int d_counter; // free running mod 832 counter - int d_symbol_index; - bool d_seg_locked; - FILE *d_debug_fp; - - - bool incr_counter () { - d_counter++; - if (d_counter >= ATSC_DATA_SEGMENT_LENGTH){ - d_counter = 0; - return true; - } - return false; - } - - void incr_symbol_index () { - d_symbol_index++; - if (d_symbol_index >= ATSC_DATA_SEGMENT_LENGTH) - d_symbol_index = 0; - } - -public: - - // Constructor - atsci_sssr (); - ~atsci_sssr (); - - // Manipulators - - //! call on channel change - void reset (); - - - /*! - * \brief process a single sample at the ATSC symbol rate (~10.76 MSPS) - * - * This block computes an indication of our timing error and keeps - * track of where the segment sync's occur. \p timing_adjust is - * returned to indicate how the interpolator timing needs to be - * adjusted to track the transmitter's symbol timing. If \p seg_locked - * is true, then \p symbol_index is the index of this sample in - * the current segment. The symbols are numbered from 0 to 831, where - * symbols 0, 1, 2 and 3 correspond to the data segment sync pattern, - * nominally +5, -5, -5, +5. - */ - - void update (sssr::sample_t sample_in, // input - bool *seg_locked, // are we seeing segment syncs? - int *symbol_index, // 0..831 - double *timing_adjust); // how much to adjust timing - -}; - -// ---------------------------------------------------------------- - -/*! - * \brief interpolator control for segment and symbol sync recovery - */ - -class ATSC_API atsci_interpolator { - gr::filter::mmse_fir_interpolator_ff d_interp; - gr::filter::single_pole_iir<float,float,float> d_loop; // ``VCO'' loop filter - double d_nominal_ratio_of_rx_clock_to_symbol_freq; // FREQ - double d_w; // ratio of PERIOD of Tx to Rx clocks - double d_mu; // fractional delay [0,1] - int d_incr; // diagnostic only - FILE *d_debug_fp; // diagnostic only - -public: - //! \p nominal_ratio_of_rx_clock_to_symbol_freq must be >= 1.8 - atsci_interpolator (double nominal_ratio_of_rx_clock_to_symbol_freq); - ~atsci_interpolator (); - - // Manipulators - - //! call on channel change - void reset (); - - /*! - * \brief produce next sample referenced to Tx clock - * - * If there aren't enough input_samples left to produce - * an output, return false, else true. - */ - - bool update (const sssr::sample_t input_samples[], // I: vector of samples - int nsamples, // I: total number of samples - int *index, // I/O: current input index - double timing_adjustment, // I: how much to bump timing - sssr::sample_t *output_sample); // O: the output sample - - // Accessors - - // how much history we require on our input - unsigned ntaps () const { return d_interp.ntaps (); } - - // diagnostic accessors - double mu () const { return d_mu; } - double w () const { return d_w; } - int incr () const { return d_incr; } - -}; - -#endif /* _ATSC_SSSR_H_ */ |