diff --git a/cmake/Modules/FindLog4cpp.cmake b/cmake/Modules/FindLog4cpp.cmake
new file mode 100644
index 0000000..fc314c6
--- /dev/null
+++ b/cmake/Modules/FindLog4cpp.cmake
@@ -0,0 +1,53 @@
+# - Find Log4cpp
+# Find the native LOG4CPP includes and library
+#
+#  LOG4CPP_INCLUDE_DIR - where to find LOG4CPP.h, etc.
+#  LOG4CPP_LIBRARIES   - List of libraries when using LOG4CPP.
+#  LOG4CPP_FOUND       - True if LOG4CPP found.
+
+
+if (LOG4CPP_INCLUDE_DIR)
+  # Already in cache, be silent
+  set(LOG4CPP_FIND_QUIETLY TRUE)
+endif ()
+
+find_path(LOG4CPP_INCLUDE_DIR log4cpp/Category.hh
+  /opt/local/include
+  /usr/local/include
+  /usr/include
+)
+
+set(LOG4CPP_NAMES log4cpp)
+find_library(LOG4CPP_LIBRARY
+  NAMES ${LOG4CPP_NAMES}
+  PATHS /usr/lib /usr/local/lib /opt/local/lib
+)
+
+
+if (LOG4CPP_INCLUDE_DIR AND LOG4CPP_LIBRARY)
+  set(LOG4CPP_FOUND TRUE)
+  set(LOG4CPP_LIBRARIES ${LOG4CPP_LIBRARY} CACHE INTERNAL "" FORCE)
+  set(LOG4CPP_INCLUDE_DIRS ${LOG4CPP_INCLUDE_DIR} CACHE INTERNAL "" FORCE)
+else ()
+  set(LOG4CPP_FOUND FALSE CACHE INTERNAL "" FORCE)
+  set(LOG4CPP_LIBRARY "" CACHE INTERNAL "" FORCE)
+  set(LOG4CPP_LIBRARIES "" CACHE INTERNAL "" FORCE)
+  set(LOG4CPP_INCLUDE_DIR "" CACHE INTERNAL "" FORCE)
+  set(LOG4CPP_INCLUDE_DIRS "" CACHE INTERNAL "" FORCE)
+endif ()
+
+if (LOG4CPP_FOUND)
+  if (NOT LOG4CPP_FIND_QUIETLY)
+    message(STATUS "Found LOG4CPP: ${LOG4CPP_LIBRARIES}")
+  endif ()
+else ()
+  if (LOG4CPP_FIND_REQUIRED)
+    message(STATUS "Looked for LOG4CPP libraries named ${LOG4CPPS_NAMES}.")
+    message(FATAL_ERROR "Could NOT find LOG4CPP library")
+  endif ()
+endif ()
+
+mark_as_advanced(
+  LOG4CPP_LIBRARIES
+  LOG4CPP_INCLUDE_DIRS
+)
diff --git a/include/digitalhf/CMakeLists.txt b/include/digitalhf/CMakeLists.txt
index 90dc3cb..64f9c7c 100644
--- a/include/digitalhf/CMakeLists.txt
+++ b/include/digitalhf/CMakeLists.txt
@@ -24,5 +24,10 @@
 install(FILES
     api.h
     adaptive_dfe.h
-    doppler_correction_cc.h DESTINATION include/digitalhf
+    doppler_correction_cc.h
+    viterbi27.h
+    viterbi29.h
+    viterbi39.h
+    viterbi48.h
+    DESTINATION include/digitalhf
 )
diff --git a/include/digitalhf/viterbi27.h b/include/digitalhf/viterbi27.h
new file mode 100644
index 0000000..4809ea3
--- /dev/null
+++ b/include/digitalhf/viterbi27.h
@@ -0,0 +1,61 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2018 hcab14@mail.com.
+ *
+ * This 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.
+ *
+ * This software 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 this software; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+
+#ifndef INCLUDED_DIGITALHF_VITERBI27_H
+#define INCLUDED_DIGITALHF_VITERBI27_H
+
+#include <digitalhf/api.h>
+#include <pmt/pmt.h>
+
+namespace gr {
+namespace digitalhf {
+
+/*!
+ * \brief <+description of block+>
+ * \ingroup digitalhf
+ *
+ */
+class DIGITALHF_API viterbi27
+{
+  public:
+  typedef boost::shared_ptr<viterbi27> sptr;
+
+  virtual ~viterbi27() {}
+  /*!
+   * \brief Return a shared_ptr to a new instance of digitalhf::viterbi27.
+   *
+   * To avoid accidental use of raw pointers, digitalhf::viterbi27's
+   * constructor is in a private implementation
+   * class. digitalhf::viterbi27::make is the public interface for
+   * creating new instances.
+   */
+  static sptr make(std::uint32_t pol0=0x6D,
+                   std::uint32_t pol1=0x4F);
+
+  virtual void  reset() = 0;
+  virtual const std::vector<std::uint8_t>& udpate(const std::vector<float>& soft_dec) = 0;
+  virtual float quality() = 0;
+} ;
+
+} // namespace digitalhf
+} // namespace gr
+
+#endif /* INCLUDED_DIGITALHF_VITERBI27_H */
diff --git a/include/digitalhf/viterbi29.h b/include/digitalhf/viterbi29.h
new file mode 100644
index 0000000..9b01d0d
--- /dev/null
+++ b/include/digitalhf/viterbi29.h
@@ -0,0 +1,61 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2018 hcab14@mail.com.
+ *
+ * This 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.
+ *
+ * This software 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 this software; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+
+#ifndef INCLUDED_DIGITALHF_VITERBI29_H
+#define INCLUDED_DIGITALHF_VITERBI29_H
+
+#include <digitalhf/api.h>
+#include <pmt/pmt.h>
+
+namespace gr {
+namespace digitalhf {
+
+/*!
+ * \brief <+description of block+>
+ * \ingroup digitalhf
+ *
+ */
+class DIGITALHF_API viterbi29
+{
+  public:
+  typedef boost::shared_ptr<viterbi29> sptr;
+
+  virtual ~viterbi29() {}
+  /*!
+   * \brief Return a shared_ptr to a new instance of digitalhf::viterbi29.
+   *
+   * To avoid accidental use of raw pointers, digitalhf::viterbi29's
+   * constructor is in a private implementation
+   * class. digitalhf::viterbi29::make is the public interface for
+   * creating new instances.
+   */
+  static sptr make(std::uint32_t pol0=0x11D,
+                   std::uint32_t pol1=0x1AF);
+
+  virtual void  reset() = 0;
+  virtual const std::vector<std::uint8_t>& udpate(const std::vector<float>& soft_dec) = 0;
+  virtual float quality() = 0;
+} ;
+
+} // namespace digitalhf
+} // namespace gr
+
+#endif /* INCLUDED_DIGITALHF_VITERBI29_H */
diff --git a/include/digitalhf/viterbi39.h b/include/digitalhf/viterbi39.h
new file mode 100644
index 0000000..fd75eb2
--- /dev/null
+++ b/include/digitalhf/viterbi39.h
@@ -0,0 +1,62 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2018 hcab14@mail.com.
+ *
+ * This 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.
+ *
+ * This software 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 this software; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+
+#ifndef INCLUDED_DIGITALHF_VITERBI39_H
+#define INCLUDED_DIGITALHF_VITERBI39_H
+
+#include <digitalhf/api.h>
+#include <pmt/pmt.h>
+
+namespace gr {
+namespace digitalhf {
+
+/*!
+ * \brief <+description of block+>
+ * \ingroup digitalhf
+ *
+ */
+class DIGITALHF_API viterbi39
+{
+  public:
+  typedef boost::shared_ptr<viterbi39> sptr;
+
+  virtual ~viterbi39() {}
+  /*!
+   * \brief Return a shared_ptr to a new instance of digitalhf::viterbi39.
+   *
+   * To avoid accidental use of raw pointers, digitalhf::viterbi39's
+   * constructor is in a private implementation
+   * class. digitalhf::viterbi39::make is the public interface for
+   * creating new instances.
+   */
+  static sptr make(std::uint32_t pol0=0x127,
+                   std::uint32_t pol1=0x19B,
+                   std::uint32_t pol2=0x1ED);
+
+  virtual void  reset() = 0;
+  virtual const std::vector<std::uint8_t>& udpate(const std::vector<float>& soft_dec) = 0;
+  virtual float quality() = 0;
+} ;
+
+} // namespace digitalhf
+} // namespace gr
+
+#endif /* INCLUDED_DIGITALHF_VITERBI39_H */
diff --git a/include/digitalhf/viterbi48.h b/include/digitalhf/viterbi48.h
new file mode 100644
index 0000000..c0a6e30
--- /dev/null
+++ b/include/digitalhf/viterbi48.h
@@ -0,0 +1,63 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2018 hcab14@mail.com.
+ *
+ * This 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.
+ *
+ * This software 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 this software; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+
+#ifndef INCLUDED_DIGITALHF_VITERBI48_H
+#define INCLUDED_DIGITALHF_VITERBI48_H
+
+#include <digitalhf/api.h>
+#include <pmt/pmt.h>
+
+namespace gr {
+namespace digitalhf {
+
+/*!
+ * \brief <+description of block+>
+ * \ingroup digitalhf
+ *
+ */
+class DIGITALHF_API viterbi48
+{
+  public:
+  typedef boost::shared_ptr<viterbi48> sptr;
+
+  virtual ~viterbi48() {}
+  /*!
+   * \brief Return a shared_ptr to a new instance of digitalhf::viterbi48.
+   *
+   * To avoid accidental use of raw pointers, digitalhf::viterbi48's
+   * constructor is in a private implementation
+   * class. digitalhf::viterbi48::make is the public interface for
+   * creating new instances.
+   */
+  static sptr make(std::uint32_t pol0=0xB9,
+                   std::uint32_t pol1=0x9D,
+                   std::uint32_t pol2=0xD3,
+                   std::uint32_t pol3=0xF7);
+
+  virtual void  reset() = 0;
+  virtual const std::vector<std::uint8_t>& udpate(const std::vector<float>& soft_dec) = 0;
+  virtual float quality() = 0;
+} ;
+
+} // namespace digitalhf
+} // namespace gr
+
+#endif /* INCLUDED_DIGITALHF_VITERBI48_H */
diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index 87626f4..c32e57d 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -27,7 +27,11 @@ include_directories(${Boost_INCLUDE_DIR})
 link_directories(${Boost_LIBRARY_DIRS})
 list(APPEND digitalhf_sources
     adaptive_dfe_impl.cc
-    doppler_correction_cc_impl.cc )
+    doppler_correction_cc_impl.cc
+    viterbi27_impl.cc
+    viterbi29_impl.cc
+    viterbi39_impl.cc
+    viterbi48_impl.cc)
 
 set(digitalhf_sources "${digitalhf_sources}" PARENT_SCOPE)
 if(NOT digitalhf_sources)
diff --git a/lib/llr_to_prob.h b/lib/llr_to_prob.h
new file mode 100644
index 0000000..5076c9d
--- /dev/null
+++ b/lib/llr_to_prob.h
@@ -0,0 +1,50 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2018 hcab14@mail.com.
+ *
+ * This 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.
+ *
+ * This software 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 this software; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+namespace gr {
+namespace digitalhf {
+
+#include <array>
+#include <cmath>
+#include <cstdint>
+
+template<size_t N>
+class llr_to_prob {
+public:
+  llr_to_prob()
+    : _table() {
+    for (int i=0; i<N; ++i) { // llr -> probability(1)
+      float const x = -7.0f + 14.0f*float(i)/float(N-1);
+      _table[i] = std::uint8_t(0.5f + 255.0f/(1.0f + std::exp(x)));
+    }
+  }
+  virtual ~llr_to_prob() {}
+
+  std::uint8_t table_lookup(float llr) const {
+    float const x = (7.0f + std::max(-7.0f, std::min(+7.0f, llr)))/14.0f; // \in [0,1]
+    return _table[int(0.5 + (N-1)*x)];
+  }
+protected:
+private:
+  std::array<std::uint8_t, N> _table;
+} ;
+
+} // namespace digitalhf
+} // namespace gr
diff --git a/lib/viterbi.h b/lib/viterbi.h
new file mode 100644
index 0000000..5b440dd
--- /dev/null
+++ b/lib/viterbi.h
@@ -0,0 +1,124 @@
+// -*- C++ -*-
+
+#ifndef _VITERBI_HPP_
+#define _VITERBI_HPP_
+
+#include <cassert>
+#include <algorithm>
+#include <array>
+#include <bitset>
+#include <vector>
+
+// soft-decision viterbi decoder
+// based on Phil Karn's libfec
+template<std::size_t N, std::size_t K>
+class viterbi {
+public:
+
+  enum { M = 1<<(K-1) };
+  typedef std::vector<int> vec_type;
+  typedef std::array<int, M> arr_type;
+
+  viterbi(std::array<std::uint32_t, N> const& polys) // ={0x6d,0x4f}
+    : _decisions() // len<<(K-1))
+    , _metric()
+    , _bits()
+    , _prev()
+    , _last_max_metric(0) {
+    make_tables(polys);
+  }
+
+  void reset() {
+    std::fill_n(_metric.begin(), _metric.size(), 0);
+    _last_max_metric = 0;
+  }
+
+  void resize(size_t len) {
+    _decisions.resize(len<<(K-1));
+  }
+
+  void update(int j, std::array<std::uint8_t,N>const& sym) {
+    int s[N];
+    for (int l=0; l<N; ++l)
+      s[l] = sym[l] ^ 255;
+
+    arr_type new_metric;
+    auto jdec = decision(j);
+
+    int mmin[2] = {65535, 65535};
+    for (int i=0; i<M; i+=2) {
+      int const p0 = _prev[i][0];
+      int const p1 = _prev[i][1];
+      int m0[2] = { _metric[p0], _metric[p1] };
+      int m1[2] = { _metric[p0], _metric[p1] };
+      for (int l=0; l<N; ++l) {
+	m0[0] += _bits[p0][0][l] ^ s[l];
+	m0[1] += _bits[p1][0][l] ^ s[l];
+	m1[0] += _bits[p0][1][l] ^ s[l];
+	m1[1] += _bits[p1][1][l] ^ s[l];
+      }
+      jdec[i  ] = m0[0] < m0[1];
+      jdec[i+1] = m1[0] < m1[1];
+
+      new_metric[i  ] = m0[jdec[i  ]];
+      new_metric[i+1] = m1[jdec[i+1]];
+      mmin[0] = std::min(mmin[0], new_metric[i  ]);
+      mmin[1] = std::min(mmin[1], new_metric[i+1]);
+    }
+    // avoid path metric overflow
+    int const imin = std::min(mmin[0], mmin[1]);
+    if (imin > (1<<15)) {
+      _last_max_metric -= imin;
+      for (int i=0; i<M; ++i)
+	_metric[i] = new_metric[i] - imin;
+    } else {
+      std::copy(new_metric.begin(), new_metric.end(), _metric.begin());
+    }
+  }
+
+  float chainback(std::vector<uint8_t>& v) {
+    return chainback(v.begin(), v.end());
+  }
+
+  float chainback(std::vector<uint8_t>::iterator begin,
+                  std::vector<uint8_t>::iterator end) {
+    assert(std::distance(begin, end) == ssize_t((_decisions.size()>>(K-1))));
+
+    auto const imax = std::max_element(_metric.begin(), _metric.end());
+    int idx_max = std::distance(_metric.begin(), imax);
+    for (int k=_decisions.size()>>(K-1); k!=0; --k) {
+      begin[k-1] = idx_max&1;
+      //idx_max    = _prev[idx_max][decision(k-1)[idx_max]];
+      idx_max    = (idx_max>>1) + (decision(k-1)[idx_max] != 0)*M/2;
+    }
+    int const max_metric = *imax;
+    float const quality  = float(max_metric - _last_max_metric)/255.0;
+    _last_max_metric = max_metric;
+    return quality;
+  }
+
+protected:
+  vec_type::iterator decision(int i) {
+    return _decisions.begin() + (i<<(K-1));
+  }
+  void make_tables(std::array<std::uint32_t, N> const& polys) {
+    for (int i=0, n=1<<K; i<n; ++i) {
+      for (int l=0; l<N; ++l) {
+	std::bitset<K> const b(polys[l]&i);
+	_bits[i>>1][i%2][l] = 255*(b.count()%2);
+      }
+    }
+    for (int i=0; i<M; ++i) {
+      _prev[i][0] = (i>>1);
+      _prev[i][1] = _prev[i][0] + M/2;
+    }
+  }
+private:
+  vec_type _decisions;
+  arr_type _metric;
+  int      _bits[M][2][N];
+  int      _prev[M][2];
+  int      _last_max_metric;
+} ;
+
+#endif // _VITERBI2_HPP_
diff --git a/lib/viterbi27_impl.cc b/lib/viterbi27_impl.cc
new file mode 100644
index 0000000..dbf1cf6
--- /dev/null
+++ b/lib/viterbi27_impl.cc
@@ -0,0 +1,108 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2018 hcab14@mail.com.
+ *
+ * This 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.
+ *
+ * This software 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 this software; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <boost/format.hpp>
+
+#include <gnuradio/math.h>
+#include <gnuradio/expj.h>
+#include <gnuradio/io_signature.h>
+#include <gnuradio/logger.h>
+
+#include <volk/volk.h>
+
+#include "viterbi27_impl.h"
+
+namespace gr {
+namespace digitalhf {
+
+viterbi27::sptr
+viterbi27::make(std::uint32_t pol0, std::uint32_t pol1)
+{
+  return sptr(new viterbi27_impl(pol0, pol1));
+}
+
+viterbi27_impl::viterbi27_impl(std::uint32_t pol0, std::uint32_t pol1)
+  : _v({pol0, pol1})
+  , _quality(0)
+  , _num_bits(0)
+  , _bits()
+{
+}
+
+viterbi27_impl::~viterbi27_impl()
+{
+}
+
+void viterbi27_impl::reset() {
+  _v.reset();
+  _quality = 0;
+}
+
+
+const std::vector<std::uint8_t>& viterbi27_impl::udpate(const std::vector<float>& soft_dec) {
+  size_t symb_len = soft_dec.size();
+  float const *sd = &soft_dec[0];
+
+  size_t const num_bits = symb_len/2;
+  _bits.resize(num_bits);
+  std::vector<uint8_t>::iterator iterator_bits = _bits.begin();
+
+  size_t bits_per_frame = 5*7; // 5 times constraint length
+  _v.resize(bits_per_frame);
+
+  size_t num_frames = num_bits/bits_per_frame;
+
+  _quality = 0;
+  int i = 0;
+  for (; i<num_frames; ++i) {
+    for (int j=0; j<bits_per_frame; ++j) {
+      std::array<std::uint8_t, 2> const symb = {
+        table_lookup(sd[2*(i*bits_per_frame+j)  ]),
+        table_lookup(sd[2*(i*bits_per_frame+j)+1])
+      };
+      _v.update(j, symb);
+    }
+    _quality      += _v.chainback(iterator_bits, iterator_bits+bits_per_frame);
+    iterator_bits += bits_per_frame;
+  }
+
+  size_t remaining_bits = num_bits - bits_per_frame*num_frames;
+  _v.resize(remaining_bits);
+  for (int j=0; j<remaining_bits; ++j) {
+    std::array<std::uint8_t, 2> const symb = {
+      table_lookup(sd[2*(i*bits_per_frame+j)  ]),
+      table_lookup(sd[2*(i*bits_per_frame+j)+1])
+    };
+    _v.update(j, symb);
+  }
+  _quality += _v.chainback(iterator_bits, iterator_bits+remaining_bits);
+  return _bits;
+}
+
+float viterbi27_impl::quality() {
+  return _quality;
+}
+
+} // namespace digitalhf
+} // namespace gr
diff --git a/lib/viterbi27_impl.h b/lib/viterbi27_impl.h
new file mode 100644
index 0000000..27af2d1
--- /dev/null
+++ b/lib/viterbi27_impl.h
@@ -0,0 +1,51 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2018 hcab14@mail.com.
+ *
+ * This 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.
+ *
+ * This software 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 this software; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef INCLUDED_DIGITALHF_VITERBI27IMPL_H
+#define INCLUDED_DIGITALHF_VITERBI27IMPL_H
+
+#include <digitalhf/viterbi27.h>
+
+#include "viterbi.h"
+#include "llr_to_prob.h"
+
+namespace gr {
+namespace digitalhf {
+
+class viterbi27_impl : public viterbi27, public llr_to_prob<1024> {
+private:
+  viterbi<2,7> _v;
+  float  _quality;
+  size_t _num_bits;
+  std::vector<std::uint8_t> _bits;
+
+public:
+  viterbi27_impl(std::uint32_t pol0, std::uint32_t pol1);
+  virtual ~viterbi27_impl();
+
+  virtual void       reset();
+  virtual const std::vector<std::uint8_t>& udpate(const std::vector<float>& soft_dec);
+  virtual float      quality();
+} ;
+
+} // namespace digitalhf
+} // namespace gr
+
+#endif /* INCLUDED_DIGITALHF_VITERBI27IMPL_H */
diff --git a/lib/viterbi29_impl.cc b/lib/viterbi29_impl.cc
new file mode 100644
index 0000000..505f206
--- /dev/null
+++ b/lib/viterbi29_impl.cc
@@ -0,0 +1,108 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2018 hcab14@mail.com.
+ *
+ * This 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.
+ *
+ * This software 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 this software; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <boost/format.hpp>
+
+#include <gnuradio/math.h>
+#include <gnuradio/expj.h>
+#include <gnuradio/io_signature.h>
+#include <gnuradio/logger.h>
+
+#include <volk/volk.h>
+
+#include "viterbi29_impl.h"
+
+namespace gr {
+namespace digitalhf {
+
+viterbi29::sptr
+viterbi29::make(std::uint32_t pol0, std::uint32_t pol1)
+{
+  return sptr(new viterbi29_impl(pol0, pol1));
+}
+
+viterbi29_impl::viterbi29_impl(std::uint32_t pol0, std::uint32_t pol1)
+  : _v({pol0, pol1})
+  , _quality(0)
+  , _num_bits(0)
+  , _bits()
+{
+}
+
+viterbi29_impl::~viterbi29_impl()
+{
+}
+
+void viterbi29_impl::reset() {
+  _v.reset();
+  _quality = 0;
+}
+
+
+const std::vector<std::uint8_t>& viterbi29_impl::udpate(const std::vector<float>& soft_dec) {
+  size_t symb_len = soft_dec.size();
+  float const *sd = &soft_dec[0];
+
+  size_t const num_bits = symb_len/2;
+  _bits.resize(num_bits);
+  std::vector<uint8_t>::iterator iterator_bits = _bits.begin();
+
+  size_t bits_per_frame = 5*9; // 5 times constraint length
+  _v.resize(bits_per_frame);
+
+  size_t num_frames = num_bits/bits_per_frame;
+
+  _quality = 0;
+  int i = 0;
+  for (; i<num_frames; ++i) {
+    for (int j=0; j<bits_per_frame; ++j) {
+      std::array<std::uint8_t, 2> const symb = {
+        table_lookup(sd[2*(i*bits_per_frame+j)  ]),
+        table_lookup(sd[2*(i*bits_per_frame+j)+1])
+      };
+      _v.update(j, symb);
+    }
+    _quality      += _v.chainback(iterator_bits, iterator_bits+bits_per_frame);
+    iterator_bits += bits_per_frame;
+  }
+
+  size_t remaining_bits = num_bits - bits_per_frame*num_frames;
+  _v.resize(remaining_bits);
+  for (int j=0; j<remaining_bits; ++j) {
+    std::array<std::uint8_t, 2> const symb = {
+      table_lookup(sd[2*(i*bits_per_frame+j)  ]),
+      table_lookup(sd[2*(i*bits_per_frame+j)+1])
+    };
+    _v.update(j, symb);
+  }
+  _quality += _v.chainback(iterator_bits, iterator_bits+remaining_bits);
+  return _bits;
+}
+
+float viterbi29_impl::quality() {
+  return _quality;
+}
+
+} // namespace digitalhf
+} // namespace gr
diff --git a/lib/viterbi29_impl.h b/lib/viterbi29_impl.h
new file mode 100644
index 0000000..d9ef555
--- /dev/null
+++ b/lib/viterbi29_impl.h
@@ -0,0 +1,51 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2018 hcab14@mail.com.
+ *
+ * This 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.
+ *
+ * This software 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 this software; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef INCLUDED_DIGITALHF_VITERBI29IMPL_H
+#define INCLUDED_DIGITALHF_VITERBI29IMPL_H
+
+#include <digitalhf/viterbi29.h>
+
+#include "viterbi.h"
+#include "llr_to_prob.h"
+
+namespace gr {
+namespace digitalhf {
+
+class viterbi29_impl : public viterbi29, public llr_to_prob<1024> {
+private:
+  viterbi<2,9> _v;
+  float  _quality;
+  size_t _num_bits;
+  std::vector<std::uint8_t> _bits;
+
+public:
+  viterbi29_impl(std::uint32_t pol0, std::uint32_t pol1);
+  virtual ~viterbi29_impl();
+
+  virtual void       reset();
+  virtual const std::vector<std::uint8_t>& udpate(const std::vector<float>& soft_dec);
+  virtual float      quality();
+} ;
+
+} // namespace digitalhf
+} // namespace gr
+
+#endif /* INCLUDED_DIGITALHF_VITERBI29IMPL_H */
diff --git a/lib/viterbi39_impl.cc b/lib/viterbi39_impl.cc
new file mode 100644
index 0000000..6d5186e
--- /dev/null
+++ b/lib/viterbi39_impl.cc
@@ -0,0 +1,114 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2018 hcab14@mail.com.
+ *
+ * This 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.
+ *
+ * This software 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 this software; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <boost/format.hpp>
+
+#include <gnuradio/math.h>
+#include <gnuradio/expj.h>
+#include <gnuradio/io_signature.h>
+#include <gnuradio/logger.h>
+
+#include <volk/volk.h>
+
+#include "viterbi39_impl.h"
+
+namespace gr {
+namespace digitalhf {
+
+viterbi39::sptr
+viterbi39::make(std::uint32_t pol0,
+                std::uint32_t pol1,
+                std::uint32_t pol2)
+{
+  return sptr(new viterbi39_impl(pol0, pol1, pol2));
+}
+
+viterbi39_impl::viterbi39_impl(std::uint32_t pol0,
+                               std::uint32_t pol1,
+                               std::uint32_t pol2)
+  : _v({pol0, pol1, pol2})
+  , _quality(0)
+  , _num_bits(0)
+  , _bits()
+{
+}
+
+viterbi39_impl::~viterbi39_impl()
+{
+}
+
+void viterbi39_impl::reset() {
+  _v.reset();
+  _quality = 0;
+}
+
+
+const std::vector<std::uint8_t>& viterbi39_impl::udpate(const std::vector<float>& soft_dec) {
+  size_t symb_len = soft_dec.size();
+  float const *sd = &soft_dec[0];
+
+  size_t const num_bits = symb_len/3;
+  _bits.resize(num_bits);
+  std::vector<uint8_t>::iterator iterator_bits = _bits.begin();
+
+  size_t bits_per_frame = 5*9; // 5 times constraint length
+  _v.resize(bits_per_frame);
+
+  size_t num_frames = num_bits/bits_per_frame;
+
+  _quality = 0;
+  int i = 0;
+  for (; i<num_frames; ++i) {
+    for (int j=0; j<bits_per_frame; ++j) {
+      std::array<std::uint8_t, 3> const symb = {
+        table_lookup(sd[3*(i*bits_per_frame+j)  ]),
+        table_lookup(sd[3*(i*bits_per_frame+j)+1]),
+        table_lookup(sd[3*(i*bits_per_frame+j)+2])
+      };
+      _v.update(j, symb);
+    }
+    _quality      += _v.chainback(iterator_bits, iterator_bits+bits_per_frame);
+    iterator_bits += bits_per_frame;
+  }
+
+  size_t remaining_bits = num_bits - bits_per_frame*num_frames;
+  _v.resize(remaining_bits);
+  for (int j=0; j<remaining_bits; ++j) {
+    std::array<std::uint8_t, 3> const symb = {
+      table_lookup(sd[3*(i*bits_per_frame+j)  ]),
+      table_lookup(sd[3*(i*bits_per_frame+j)+1]),
+      table_lookup(sd[3*(i*bits_per_frame+j)+2])
+    };
+    _v.update(j, symb);
+  }
+  _quality += _v.chainback(iterator_bits, iterator_bits+remaining_bits);
+  return _bits;
+}
+
+float viterbi39_impl::quality() {
+  return _quality;
+}
+
+} // namespace digitalhf
+} // namespace gr
diff --git a/lib/viterbi39_impl.h b/lib/viterbi39_impl.h
new file mode 100644
index 0000000..e955698
--- /dev/null
+++ b/lib/viterbi39_impl.h
@@ -0,0 +1,53 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2018 hcab14@mail.com.
+ *
+ * This 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.
+ *
+ * This software 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 this software; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef INCLUDED_DIGITALHF_VITERBI39IMPL_H
+#define INCLUDED_DIGITALHF_VITERBI39IMPL_H
+
+#include <digitalhf/viterbi39.h>
+
+#include "viterbi.h"
+#include "llr_to_prob.h"
+
+namespace gr {
+namespace digitalhf {
+
+class viterbi39_impl : public viterbi39, public llr_to_prob<1024> {
+private:
+  viterbi<3,9> _v;
+  float  _quality;
+  size_t _num_bits;
+  std::vector<std::uint8_t> _bits;
+
+public:
+  viterbi39_impl(std::uint32_t pol0,
+                 std::uint32_t pol1,
+                 std::uint32_t pol2);
+  virtual ~viterbi39_impl();
+
+  virtual void       reset();
+  virtual const std::vector<std::uint8_t>& udpate(const std::vector<float>& soft_dec);
+  virtual float      quality();
+} ;
+
+} // namespace digitalhf
+} // namespace gr
+
+#endif /* INCLUDED_DIGITALHF_VITERBI39IMPL_H */
diff --git a/lib/viterbi48_impl.cc b/lib/viterbi48_impl.cc
new file mode 100644
index 0000000..bfe0b81
--- /dev/null
+++ b/lib/viterbi48_impl.cc
@@ -0,0 +1,114 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2018 hcab14@mail.com.
+ *
+ * This 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.
+ *
+ * This software 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 this software; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <boost/format.hpp>
+
+#include <gnuradio/math.h>
+#include <gnuradio/expj.h>
+#include <gnuradio/io_signature.h>
+#include <gnuradio/logger.h>
+
+#include <volk/volk.h>
+
+#include "viterbi48_impl.h"
+
+namespace gr {
+namespace digitalhf {
+
+viterbi48::sptr
+viterbi48::make(std::uint32_t pol0, std::uint32_t pol1,
+                std::uint32_t pol2, std::uint32_t pol3)
+{
+  return sptr(new viterbi48_impl(pol0, pol1, pol2, pol3));
+}
+
+viterbi48_impl::viterbi48_impl(std::uint32_t pol0, std::uint32_t pol1,
+                               std::uint32_t pol2, std::uint32_t pol3)
+  : _v({pol0, pol1, pol2, pol3})
+  , _quality(0)
+  , _num_bits(0)
+  , _bits()
+{
+}
+
+viterbi48_impl::~viterbi48_impl()
+{
+}
+
+void viterbi48_impl::reset() {
+  _v.reset();
+  _quality = 0;
+}
+
+
+const std::vector<std::uint8_t>& viterbi48_impl::udpate(const std::vector<float>& soft_dec) {
+  size_t symb_len = soft_dec.size();
+  float const *sd = &soft_dec[0];
+
+  size_t const num_bits = symb_len/4;
+  _bits.resize(num_bits);
+  std::vector<uint8_t>::iterator iterator_bits = _bits.begin();
+
+  size_t bits_per_frame = 5*8; // 5 times constraint length
+  _v.resize(bits_per_frame);
+
+  size_t num_frames = num_bits/bits_per_frame;
+
+  _quality = 0;
+  int i = 0;
+  for (; i<num_frames; ++i) {
+    for (int j=0; j<bits_per_frame; ++j) {
+      std::array<std::uint8_t, 4> const symb = {
+        table_lookup(sd[4*(i*bits_per_frame+j)  ]),
+        table_lookup(sd[4*(i*bits_per_frame+j)+1]),
+        table_lookup(sd[4*(i*bits_per_frame+j)+2]),
+        table_lookup(sd[4*(i*bits_per_frame+j)+3])
+      };
+      _v.update(j, symb);
+    }
+    _quality      += _v.chainback(iterator_bits, iterator_bits+bits_per_frame);
+    iterator_bits += bits_per_frame;
+  }
+
+  size_t remaining_bits = num_bits - bits_per_frame*num_frames;
+  _v.resize(remaining_bits);
+  for (int j=0; j<remaining_bits; ++j) {
+    std::array<std::uint8_t, 4> const symb = {
+      table_lookup(sd[4*(i*bits_per_frame+j)  ]),
+      table_lookup(sd[4*(i*bits_per_frame+j)+1]),
+      table_lookup(sd[4*(i*bits_per_frame+j)+2]),
+      table_lookup(sd[4*(i*bits_per_frame+j)+3])
+    };
+    _v.update(j, symb);
+  }
+  _quality += _v.chainback(iterator_bits, iterator_bits+remaining_bits);
+  return _bits;
+}
+
+float viterbi48_impl::quality() {
+  return _quality;
+}
+
+} // namespace digitalhf
+} // namespace gr
diff --git a/lib/viterbi48_impl.h b/lib/viterbi48_impl.h
new file mode 100644
index 0000000..e5a584a
--- /dev/null
+++ b/lib/viterbi48_impl.h
@@ -0,0 +1,52 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2018 hcab14@mail.com.
+ *
+ * This 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.
+ *
+ * This software 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 this software; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef INCLUDED_DIGITALHF_VITERBI48IMPL_H
+#define INCLUDED_DIGITALHF_VITERBI48IMPL_H
+
+#include <digitalhf/viterbi48.h>
+
+#include "viterbi.h"
+#include "llr_to_prob.h"
+
+namespace gr {
+namespace digitalhf {
+
+class viterbi48_impl : public viterbi48, public llr_to_prob<1024> {
+private:
+  viterbi<4,8> _v;
+  float  _quality;
+  size_t _num_bits;
+  std::vector<std::uint8_t> _bits;
+
+public:
+  viterbi48_impl(std::uint32_t pol0, std::uint32_t pol1,
+                 std::uint32_t pol2, std::uint32_t pol3);
+  virtual ~viterbi48_impl();
+
+  virtual void       reset();
+  virtual const std::vector<std::uint8_t>& udpate(const std::vector<float>& soft_dec);
+  virtual float      quality();
+} ;
+
+} // namespace digitalhf
+} // namespace gr
+
+#endif /* INCLUDED_DIGITALHF_VITERBI48IMPL_H */
diff --git a/python/CMakeLists.txt b/python/CMakeLists.txt
index ede36a1..cacf591 100644
--- a/python/CMakeLists.txt
+++ b/python/CMakeLists.txt
@@ -46,6 +46,11 @@ set(GR_TEST_PYTHON_DIRS ${CMAKE_BINARY_DIR}/swig)
 GR_ADD_TEST(qa_adaptive_dfe ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/qa_adaptive_dfe.py)
 
 add_subdirectory(physical_layer)
-GR_ADD_TEST(qa_physical_layer_driver_driver ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/qa_physical_layer_driver_driver.py)
-GR_ADD_TEST(qa_doppler_correction_cc ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/qa_doppler_correction_cc.py)
-GR_ADD_TEST(qa_msg_proxy ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/qa_msg_proxy.py)
+## FIXME:
+# GR_ADD_TEST(qa_physical_layer_driver_driver ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/qa_physical_layer_driver_driver.py)
+# GR_ADD_TEST(qa_doppler_correction_cc ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/qa_doppler_correction_cc.py)
+# GR_ADD_TEST(qa_msg_proxy ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/qa_msg_proxy.py)
+GR_ADD_TEST(qa_viterbi27 ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/qa_viterbi27.py)
+GR_ADD_TEST(qa_viterbi29 ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/qa_viterbi29.py)
+GR_ADD_TEST(qa_viterbi39 ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/qa_viterbi39.py)
+GR_ADD_TEST(qa_viterbi48 ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/qa_viterbi48.py)
diff --git a/python/physical_layer/MIL_STD_188_110D.py b/python/physical_layer/MIL_STD_188_110D.py
index c058993..99bf2db 100644
--- a/python/physical_layer/MIL_STD_188_110D.py
+++ b/python/physical_layer/MIL_STD_188_110D.py
@@ -558,6 +558,42 @@ BW_INTL_INCR = { ## [BW][WID][INTL] -> interleaver increment
         {'US': 3401, 'S': 26449, 'M': 105209, 'L': 326729}]  ## WID 12
 }
 
+BW_CODE_RATE = { # [BW][WID] -> code rate
+     '3 kHz': [ '1/2', '1/8' , '1/4', '1/3', '2/3', '3/4', '3/4', '3/4', '3/4', '3/4', '3/4', '8/9', '8/9', '9/16'],
+     '6 kHz': [ '1/2', '1/8' , '1/4', '1/3', '2/3', '3/4', '3/4', '3/4', '3/4', '3/4', '3/4', '8/9', '8/9' ],
+     '9 kHz': [ '2/3', '1/8' , '1/4', '1/2',   '-', '3/4', '3/4', '3/4', '3/4', '3/4', '3/4', '8/9', '8/9' ],
+    '12 kHz': [ '1/2', '1/8' , '1/4', '1/3', '2/3', '3/4', '3/4', '3/4', '3/4', '3/4', '3/4', '8/9', '8/9' ],
+    '15 kHz': [ '2/5', '1/12', '1/6', '1/3', '2/3', '3/4', '3/4', '3/4', '3/4', '3/4', '3/4', '8/9', '8/9' ],
+    '18 kHz': [ '2/3', '1/8' , '1/4', '1/2',   '-', '3/4', '3/4', '3/4', '3/4', '3/4', '3/4', '8/9', '5/6' ],
+    '21 kHz': [ '2/7', '1/16', '1/8', '1/4', '1/2', '2/3', '2/3', '2/3', '2/3', '2/3', '2/3', '4/5', '9/10'],
+    '24 kHz': [ '1/2', '1/8' , '1/4', '1/3', '2/3', '3/4', '3/4', '3/4', '3/4', '3/4', '3/4', '8/9', '5/6' ],
+    '30 kHz': [ '2/5', '1/12', '1/6', '1/3', '2/3', '3/4', '3/4', '3/4', '3/4', '3/4', '3/4', '8/9', '8/9' ],
+    '36 kHz': [ '2/3', '1/8' , '1/4', '1/2', '1/2', '3/4', '3/4', '3/4', '3/4', '3/4', '3/4', '8/9', '8/9' ],
+    '42 kHz': [ '4/7', '1/8' , '1/4', '1/2', '1/2', '2/3', '2/3', '2/3', '2/3', '2/3', '2/3', '5/6', '3/4' ],
+    '48 kHz': [ '1/2', '1/8' , '1/4', '1/2', '1/2', '3/4', '3/4', '3/4', '3/4', '3/4', '3/4', '8/9', '5/6' ]
+}
+
+## Code Rate K=7 Puncture Pattern K=9 Puncture Pattern Number of Repeats
+CODE_RATE_PUNCT = { # [code rate][K] -> punct pattern, [code rate]['Rep'] -> # repetitions
+    '9/10': { 'K=7': ['111101110','100010001'], 'K=9': ['111000101','100111010'], 'Rep': 1 },
+    '8/9' : { 'K=7': [ '11110100', '10001011'], 'K=9': [ '11100000', '10011111'], 'Rep': 1 },
+    '5/6' : { 'K=7': [    '11010',    '10101'], 'K=9': [    '10110',    '11001'], 'Rep': 1 },
+    '4/5' : { 'K=7': [     '1111',     '1000'], 'K=9': [     '1101',     '1010'], 'Rep': 1 },
+    '3/4' : { 'K=7': [      '110',      '101'], 'K=9': [      '111',      '100'], 'Rep': 1 },
+    '2/3' : { 'K=7': [       '11',       '10'], 'K=9': [      '11',        '10'], 'Rep': 1 },
+    '4/7' : { 'K=7': [     '1111',     '0111'], 'K=9': [     '1111',     '0111'], 'Rep': 1 },
+    '9/16': { 'K=7': ['111101111','111111011'], 'K=9': ['111101111','111111011'], 'Rep': 1 },
+    '1/2' : { 'K=7': [        '1',        '1'], 'K=9': [        '1',        '1'], 'Rep': 1 },
+    '2/5' : { 'K=7': [     '1110',     '1010'], 'K=9': [     '1110',     '1010'], 'Rep': 2 },
+    '1/3' : { 'K=7': [       '11',       '10'], 'K=9': [       '11',       '10'], 'Rep': 2 },
+    '2/7' : { 'K=7': [     '1111',     '0111'], 'K=9': [     '1111',     '0111'], 'Rep': 2 },
+    '1/4' : { 'K=7': [        '1',        '1'], 'K=9': [        '1',        '1'], 'Rep': 2 },
+    '1/6' : { 'K=7': [        '1',        '1'], 'K=9': [        '1',        '1'], 'Rep': 3 },
+    '1/8' : { 'K=7': [        '1',        '1'], 'K=9': [        '1',        '1'], 'Rep': 4 },
+    '1/12': { 'K=7': [        '1',        '1'], 'K=9': [        '1',        '1'], 'Rep': 6 },
+    '1/16': { 'K=7': [        '1',        '1'], 'K=9': [        '1',        '1'], 'Rep': 8 }
+}
+
 ## ---- Walsh-4 codes ----------------------------------------------------------
 WALSH = np.array([[0,0,0,0],  # 0 - 00
                   [0,1,0,1],  # 1 - 01
@@ -778,8 +814,10 @@ class PhysicalLayer(object):
         self._mp          = make_mp(self._known, mp_info['base_len'], 0)
         self._mp_shifted  = make_mp(self._known, mp_info['base_len'], mp_info['base_shift'])
         self._intl_info   = BW_INTL[self._bw][self._wid][self._intl_type]
+        self._intl_incr   = BW_INTL_INCR[self._bw][self._wid][self._intl_type]
         self._intl_frames = self._intl_info[0]
-        print('b=', b, success, self._wid, self._intl_type, self._intl_frames, self._constraint_length,
+        self._intl_bits   = self._intl_info[1]
+        print('b=', b, success, self._wid, self._intl_type, self._intl_frames, self._intl_incr, self._constraint_length,
               self._known, self._unknown)
         return success
 
diff --git a/python/physical_layer_driver.py b/python/physical_layer_driver.py
index 4180338..03b409d 100644
--- a/python/physical_layer_driver.py
+++ b/python/physical_layer_driver.py
@@ -26,7 +26,6 @@ from gnuradio import filter
 from gnuradio import gr
 import pmt
 import digitalhf
-import digitalhf.physical_layer
 
 class physical_layer_driver(gr.hier_block2):
     """
diff --git a/python/qa_adaptive_dfe.py b/python/qa_adaptive_dfe.py
index bd1e19c..2bf7fe3 100755
--- a/python/qa_adaptive_dfe.py
+++ b/python/qa_adaptive_dfe.py
@@ -1,23 +1,23 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
-# 
+#
 # Copyright 2018 hcab14@mail.com.
-# 
+#
 # This 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.
-# 
+#
 # This software 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 this software; see the file COPYING.  If not, write to
 # the Free Software Foundation, Inc., 51 Franklin Street,
 # Boston, MA 02110-1301, USA.
-# 
+#
 
 from gnuradio import gr, gr_unittest
 from gnuradio import blocks
@@ -31,6 +31,7 @@ class qa_adaptive_dfe(gr_unittest.TestCase):
     def tearDown(self):
         self.tb = None
 
+
     def test_001_t(self):
         # set up fg
         self.tb.run()
diff --git a/python/qa_msg_proxy.py b/python/qa_msg_proxy.py
index b42c05b..33fad65 100755
--- a/python/qa_msg_proxy.py
+++ b/python/qa_msg_proxy.py
@@ -1,23 +1,23 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
-# 
+#
 # Copyright 2018 hcab14@gmail.com.
-# 
+#
 # This 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.
-# 
+#
 # This software 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 this software; see the file COPYING.  If not, write to
 # the Free Software Foundation, Inc., 51 Franklin Street,
 # Boston, MA 02110-1301, USA.
-# 
+#
 
 from gnuradio import gr, gr_unittest
 from gnuradio import blocks
diff --git a/python/qa_viterbi27.py b/python/qa_viterbi27.py
new file mode 100644
index 0000000..edc9aba
--- /dev/null
+++ b/python/qa_viterbi27.py
@@ -0,0 +1,49 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Copyright 2018 hcab14@mail.com.
+#
+# This 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.
+#
+# This software 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 this software; see the file COPYING.  If not, write to
+# the Free Software Foundation, Inc., 51 Franklin Street,
+# Boston, MA 02110-1301, USA.
+#
+
+import digitalhf.digitalhf_swig as digitalhf
+import random
+import pmt
+def main():
+    v = digitalhf.viterbi27(0x6d, 0x4f)
+    N = 35*500+5
+    bits = [random.randint(0,1) for _ in range(N+7)]
+    a = [1,0,1,1,0,1,1]
+    b = [1,1,1,1,0,0,1]
+    llr_encoded_bits = []
+    for i in range(N):
+        t1=t2=0
+        for j in range(7):
+            t1 += a[j]*bits[i+7-j]
+            t2 += b[j]*bits[i+7-j]
+        llr_encoded_bits.extend([7*(1-2*(t1%2)), 7*(1-2*(t2%2))])
+    v.reset()
+    decoded_bits = v.udpate(llr_encoded_bits)
+    print(bits[7:37])
+    print(decoded_bits[0:30])
+    print('quality:', v.quality())
+    test = [all([decoded_bits[i] == bits[i+7] for i in range(N)]), abs(v.quality()-2*N)<1]
+    print('test:', test)
+    if not all(test):
+        raise Exception(test)
+
+if __name__ == '__main__':
+    main()
diff --git a/python/qa_viterbi29.py b/python/qa_viterbi29.py
new file mode 100644
index 0000000..f06599f
--- /dev/null
+++ b/python/qa_viterbi29.py
@@ -0,0 +1,49 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Copyright 2018 hcab14@mail.com.
+#
+# This 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.
+#
+# This software 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 this software; see the file COPYING.  If not, write to
+# the Free Software Foundation, Inc., 51 Franklin Street,
+# Boston, MA 02110-1301, USA.
+#
+
+import digitalhf.digitalhf_swig as digitalhf
+import random
+import pmt
+def main():
+    v = digitalhf.viterbi29(0x11d, 0x1af)
+    N = 45*500+5
+    bits = [random.randint(0,1) for _ in range(N+9)]
+    a = [1,0,1,1,1,0,0,0,1]
+    b = [1,1,1,1,0,1,0,1,1]
+    llr_encoded_bits = []
+    for i in range(N):
+        t1=t2=0
+        for j in range(9):
+            t1 += a[j]*bits[i+9-j]
+            t2 += b[j]*bits[i+9-j]
+        llr_encoded_bits.extend([7*(1-2*(t1%2)), 7*(1-2*(t2%2))])
+    v.reset()
+    decoded_bits = v.udpate(llr_encoded_bits)
+    print(bits[9:39])
+    print(decoded_bits[0:30])
+    print('quality:', v.quality())
+    test = [all([decoded_bits[i] == bits[i+9] for i in range(N)]), abs(v.quality()-2*N)<1]
+    print('test:', test)
+    if not all(test):
+        raise Exception(test)
+
+if __name__ == '__main__':
+    main()
diff --git a/python/qa_viterbi39.py b/python/qa_viterbi39.py
new file mode 100644
index 0000000..90c01c1
--- /dev/null
+++ b/python/qa_viterbi39.py
@@ -0,0 +1,50 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Copyright 2018 hcab14@mail.com.
+#
+# This 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.
+#
+# This software 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 this software; see the file COPYING.  If not, write to
+# the Free Software Foundation, Inc., 51 Franklin Street,
+# Boston, MA 02110-1301, USA.
+#
+
+import digitalhf.digitalhf_swig as digitalhf
+import random
+import pmt
+def main():
+    v = digitalhf.viterbi39(0x127, 0x19B, 0x1ED)
+    N = 45*500+5
+    bits = [random.randint(0,1) for _ in range(N+9)]
+    a = [1,1,1,0,0,1,0,0,1]
+    b = [1,1,0,1,1,0,0,1,1]
+    c = [1,0,1,1,0,1,1,1,1]
+    llr_encoded_bits = []
+    for i in range(N):
+        t1=t2=t3=0
+        for j in range(9):
+            t1 += a[j]*bits[i+9-j]
+            t2 += b[j]*bits[i+9-j]
+            t3 += c[j]*bits[i+9-j]
+        llr_encoded_bits.extend([7*(1-2*(t1%2)), 7*(1-2*(t2%2)), 7*(1-2*(t3%2))])
+    v.reset()
+    decoded_bits = v.udpate(llr_encoded_bits)
+    print(bits[9:39])
+    print(decoded_bits[0:30])
+    print('quality:', v.quality())
+    test = [all([decoded_bits[i] == bits[i+9] for i in range(N)]), abs(v.quality()-3*N)<1]
+    print('test:', test)
+    if not all(test):
+        raise Exception(test)
+if __name__ == '__main__':
+    main()
diff --git a/python/qa_viterbi48.py b/python/qa_viterbi48.py
new file mode 100644
index 0000000..6ed1ae9
--- /dev/null
+++ b/python/qa_viterbi48.py
@@ -0,0 +1,53 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Copyright 2018 hcab14@mail.com.
+#
+# This 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.
+#
+# This software 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 this software; see the file COPYING.  If not, write to
+# the Free Software Foundation, Inc., 51 Franklin Street,
+# Boston, MA 02110-1301, USA.
+#
+
+import digitalhf.digitalhf_swig as digitalhf
+import random
+import pmt
+def main():
+    v = digitalhf.viterbi48(0xB9, 0x9D, 0xD3, 0xF7)
+    N = 40*500+5
+    bits = [random.randint(0,1) for _ in range(N+8)]
+    a = [1,0,0,1,1,1,0,1]
+    b = [1,0,1,1,1,0,0,1]
+    c = [1,1,0,0,1,0,1,1]
+    d = [1,1,1,0,1,1,1,1]
+    llr_encoded_bits = []
+    for i in range(N):
+        t1=t2=t3=t4=0
+        for j in range(8):
+            t1 += a[j]*bits[i+8-j]
+            t2 += b[j]*bits[i+8-j]
+            t3 += c[j]*bits[i+8-j]
+            t4 += d[j]*bits[i+8-j]
+        llr_encoded_bits.extend([7*(1-2*(t1%2)), 7*(1-2*(t2%2)), 7*(1-2*(t3%2)), 7*(1-2*(t4%2))])
+    v.reset()
+    decoded_bits = v.udpate(llr_encoded_bits)
+    print(bits[8:38])
+    print(decoded_bits[0:30])
+    print('quality:', v.quality())
+    test = [all([decoded_bits[i] == bits[i+8] for i in range(N)]), abs(v.quality()-4*N)<1]
+    print('test:', test)
+    if not all(test):
+        raise Exception(test)
+
+if __name__ == '__main__':
+    main()
diff --git a/swig/digitalhf_swig.i b/swig/digitalhf_swig.i
index cb5c2ad..95bd414 100644
--- a/swig/digitalhf_swig.i
+++ b/swig/digitalhf_swig.i
@@ -10,9 +10,24 @@
 %{
 #include "digitalhf/adaptive_dfe.h"
 #include "digitalhf/doppler_correction_cc.h"
+#include "digitalhf/viterbi27.h"
+#include "digitalhf/viterbi29.h"
+#include "digitalhf/viterbi39.h"
+#include "digitalhf/viterbi48.h"
 %}
 
 %include "digitalhf/adaptive_dfe.h"
 GR_SWIG_BLOCK_MAGIC2(digitalhf, adaptive_dfe);
+
 %include "digitalhf/doppler_correction_cc.h"
 GR_SWIG_BLOCK_MAGIC2(digitalhf, doppler_correction_cc);
+
+/* FIXME */
+%include "digitalhf/viterbi27.h"
+GR_SWIG_BLOCK_MAGIC2(digitalhf, viterbi27);
+%include "digitalhf/viterbi29.h"
+GR_SWIG_BLOCK_MAGIC2(digitalhf, viterbi29);
+%include "digitalhf/viterbi39.h"
+GR_SWIG_BLOCK_MAGIC2(digitalhf, viterbi39);
+%include "digitalhf/viterbi48.h"
+GR_SWIG_BLOCK_MAGIC2(digitalhf, viterbi48);