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diff --git a/gr-atsc/include/atsc/sssr_impl.h b/gr-atsc/include/atsc/sssr_impl.h
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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.
+ */
+
+/*
+ *   --- ATSC Segment and Symbol Sync Recovery ---
+ */
+
+#ifndef _ATSC_SSSR_H_
+#define _ATSC_SSSR_H_
+
+#include <atsc/api.h>
+#include <atsc/consts.h>
+#include <filter/mmse_fir_interpolator_ff.h>
+#include <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_ */