digital: pimplified old blocks

author: Martin Braun <martin.braun@kit.edu> 2013-03-17 02:26:39 +0100
committer: Martin Braun <martin.braun@kit.edu> 2013-03-17 15:54:24 +0100
commit: 046f442fe430a7f8d9b7c1d48422e72aeeeeab13 (patch)
tree: 111ee1c6bf463a333d63d10ac8954eb34651e528 /gr-digital/include/digital
parent: f15400470ce5cb68f5339ead7af726b8bbafd364 (diff)
14 files changed, 714 insertions, 30 deletions
diff --git a/gr-digital/include/digital/CMakeLists.txt b/gr-digital/include/digital/CMakeLists.txt
index 06438c092b..84f0ef50d0 100644
--- a/gr-digital/include/digital/CMakeLists.txt
+++ b/gr-digital/include/digital/CMakeLists.txt
@@ -89,6 +89,7 @@ install(FILES
     costas_loop_cc.h
     cpmmod_bc.h
     crc32.h
+    crc32_bb.h
     descrambler_bb.h
     diff_decoder_bb.h
     diff_encoder_bb.h
@@ -107,7 +108,12 @@ install(FILES
     mpsk_receiver_cc.h
     mpsk_snr_est.h
     mpsk_snr_est_cc.h
+    ofdm_carrier_allocator_cvc.h
+    ofdm_chanest_vcvc.h
     ofdm_cyclic_prefixer.h
+    ofdm_equalizer_base.h
+    ofdm_equalizer_simpledfe.h
+    ofdm_equalizer_static.h
     ofdm_frame_acquisition.h
     ofdm_frame_equalizer_vcvc.h
     ofdm_frame_sink.h
@@ -115,6 +121,7 @@ install(FILES
     ofdm_mapper_bcv.h
     ofdm_sampler.h
     ofdm_serializer_vcc.h
+    ofdm_sync_sc_cfb.h
     packet_header_default.h
     packet_header_ofdm.h
     packet_headergenerator_bb.h
@@ -135,3 +142,4 @@ install(FILES
     DESTINATION ${GR_INCLUDE_DIR}/gnuradio/digital
     COMPONENT "digital_devel"
 )
+
diff --git a/gr-digital/include/digital/crc32_bb.h b/gr-digital/include/digital/crc32_bb.h
new file mode 100644
index 0000000000..4bfac76070
--- /dev/null
+++ b/gr-digital/include/digital/crc32_bb.h
@@ -0,0 +1,60 @@
+/* -*- c++ -*- */
+/* 
+ * Copyright 2013 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.
+ */
+
+
+#ifndef INCLUDED_DIGITAL_CRC32_BB_H
+#define INCLUDED_DIGITAL_CRC32_BB_H
+
+#include <digital/api.h>
+#include <gr_tagged_stream_block.h>
+
+namespace gr {
+  namespace digital {
+
+    /*!
+     * \brief Byte-stream CRC block
+     * \ingroup digital
+     *
+     * Input: stream of bytes, which form a packet. The first byte of the packet
+     * has a tag with key "length" and the value being the number of bytes in the
+     * packet.
+     *
+     * Output: The same bytes as incoming, but trailing a CRC32 of the packet.
+     * The tag is re-set to the new length.
+     */
+    class DIGITAL_API crc32_bb : virtual public gr_tagged_stream_block
+    {
+     public:
+      typedef boost::shared_ptr<crc32_bb> sptr;
+
+      /*!
+       * \param check Set to true if you want to check CRC, false to create CRC.
+       * \param lengthtagname Length tag key
+       */
+      static sptr make(bool check=false, const std::string& lengthtagname="packet_len");
+    };
+
+  } // namespace digital
+} // namespace gr
+
+#endif /* INCLUDED_DIGITAL_CRC32_BB_H */
+
diff --git a/gr-digital/include/digital/ofdm_carrier_allocator_cvc.h b/gr-digital/include/digital/ofdm_carrier_allocator_cvc.h
new file mode 100644
index 0000000000..8915c23c45
--- /dev/null
+++ b/gr-digital/include/digital/ofdm_carrier_allocator_cvc.h
@@ -0,0 +1,95 @@
+/* -*- c++ -*- */
+/* 
+ * Copyright 2013 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.
+ */
+
+
+#ifndef INCLUDED_DIGITAL_OFDM_CARRIER_ALLOCATOR_CVC_H
+#define INCLUDED_DIGITAL_OFDM_CARRIER_ALLOCATOR_CVC_H
+
+#include <digital/api.h>
+#include <gr_tagged_stream_block.h>
+
+namespace gr {
+  namespace digital {
+
+    /*!
+     * \brief Create frequency domain OFDM symbols from complex values, add pilots.
+     * \ingroup ofdm_blk
+     *
+     * This block turns a stream of complex, scalar modulation symbols into vectors
+     * which are the input for an IFFT in an OFDM transmitter. It also supports the
+     * possibility of placing pilot symbols onto the carriers.
+     *
+     * The carriers can be allocated freely, if a carrier is not allocated, it is set
+     * to zero. This allows doing OFDMA-style carrier allocations.
+     *
+     * Input: A tagged stream of complex scalars. The first item must have a tag
+     *        containing the number of complex symbols in this frame.
+     * Output: A tagged stream of complex vectors of length fft_len. This can directly
+     *         be connected to an FFT block. Make sure to set this block to 'reverse'
+     *         for the IFFT and to deactivate FFT shifting.
+     *
+     * Carrier indexes are always such that index 0 is the DC carrier (note: you should
+     * not allocate this carrier). The carriers below the DC carrier are either indexed
+     * with negative numbers, or with indexes larger than fft_len/2. Index -1 and index
+     * fft_len-1 both identify the carrier below the DC carrier.
+     *
+     */
+    class DIGITAL_API ofdm_carrier_allocator_cvc : virtual public gr_tagged_stream_block
+    {
+     public:
+      typedef boost::shared_ptr<ofdm_carrier_allocator_cvc> sptr;
+
+      virtual std::string len_tag_key() = 0;
+      virtual const int fft_len() = 0;
+      virtual std::vector<std::vector<int> > occupied_carriers() = 0;
+
+      /*
+       * \param occupied_carriers A vector of vectors of indexes. Example: if
+       *                          occupied_carriers = ((1, 2, 3), (1, 2, 4)), the first
+       *                          three input symbols will be mapped to carriers 1, 2
+       *                          and 3. After that, a new OFDM symbol is started. The next
+       *                          three input symbols will be placed onto carriers 1, 2
+       *                          and 4 of the second OFDM symbol. The allocation then
+       *                          starts from the beginning.
+       *                          Order matters! The first input symbol is always mapped
+       *                          onto occupied_carriers[0][0].
+       * \param pilot_carriers The position of the pilot symbols. Same as occupied_carriers,
+       *                       but the actual symbols are taken from pilot_symbols instead
+       *                       of the input stream.
+       * \param pilot_symbols The pilot symbols which are placed onto the pilot carriers.
+       *                      pilot_symbols[0][0] is placed onto the first OFDM symbol, on
+       *                      carrier index pilot_carriers[0][0] etc.
+       * \param len_tag_key The key of the tag identifying the length of the input packet.
+       */
+      static sptr make(
+	  int fft_len,
+	  const std::vector<std::vector<int> > &occupied_carriers,
+	  const std::vector<std::vector<int> > &pilot_carriers,
+	  const std::vector<std::vector<gr_complex> > &pilot_symbols,
+	  const std::string &len_tag_key = "packet_len");
+    };
+
+  } // namespace digital
+} // namespace gr
+
+#endif /* INCLUDED_DIGITAL_OFDM_CARRIER_ALLOCATOR_CVC_H */
+
diff --git a/gr-digital/include/digital/ofdm_chanest_vcvc.h b/gr-digital/include/digital/ofdm_chanest_vcvc.h
new file mode 100644
index 0000000000..0c29d630da
--- /dev/null
+++ b/gr-digital/include/digital/ofdm_chanest_vcvc.h
@@ -0,0 +1,95 @@
+/* -*- c++ -*- */
+/* 
+ * Copyright 2013 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.
+ */
+
+#ifndef INCLUDED_DIGITAL_OFDM_CHANEST_VCVC_H
+#define INCLUDED_DIGITAL_OFDM_CHANEST_VCVC_H
+
+#include <digital/api.h>
+#include <gr_block.h>
+
+namespace gr {
+  namespace digital {
+
+    /*!
+     * \brief Estimate channel and coarse frequency offset for OFDM from preambles
+     * \ingroup ofdm_blk
+     * \ingroup sync_blk
+     *
+     * Input: OFDM symbols (in frequency domain). The first one (or two) symbols are expected
+     *        to be synchronisation symbols, which are used to estimate the coarse freq offset
+     *        and the initial equalizer taps (these symbols are removed from the stream).
+     *        The following \p n_data_symbols are passed through unmodified (the actual equalisation
+     *        must be done elsewhere).
+     * Output: The data symbols, without the synchronisation symbols.
+     *         The first data symbol passed through has two tags:
+     *         'ofdm_sync_carr_offset' (integer), the coarse frequency offset as number of carriers,
+     *         and 'ofdm_sync_eq_taps' (complex vector).
+     *         Any tags attached to the synchronisation symbols are attached to the first data
+     *         symbol. All other tags are propagated normally.
+     *
+     * This block assumes the frequency offset is even (i.e. an integer multiple of 2).
+     *
+     * [1] Schmidl, T.M. and Cox, D.C., "Robust frequency and timing synchronization for OFDM",
+     *     Communications, IEEE Transactions on, 1997.
+     * [2] K.D. Kammeyer, "Nachrichtenuebertragung," Chapter. 16.3.2.
+     */
+    class DIGITAL_API ofdm_chanest_vcvc : virtual public gr_block
+    {
+     public:
+      typedef boost::shared_ptr<ofdm_chanest_vcvc> sptr;
+
+      /*
+       * \param sync_symbol1 First synchronisation symbol in the frequency domain. Its length must be
+       *                     the FFT length. For Schmidl & Cox synchronisation, every second sub-carrier
+       *                     has to be zero.
+       * \param sync_symbol2 Second synchronisation symbol in the frequency domain. Must be equal to
+       *                     the FFT length, or zero length if only one synchronisation symbol is used.
+       *                     Using this symbol is how synchronisation is described in [1]. Leaving this
+       *                     empty forces us to interpolate the equalizer taps.
+       *                     If you are using an unusual sub-carrier configuration (e.g. because of OFDMA),
+       *                     this sync symbol is used to identify the active sub-carriers. If you only
+       *                     have one synchronisation symbol, set the active sub-carriers to a non-zero
+       *                     value in here, and also set \p force_one_sync_symbol parameter to true.
+       * \param n_data_symbols The number of data symbols following each set of synchronisation symbols.
+       *                       Must be at least 1.
+       * \param eq_noise_red_len If non-zero, noise reduction for the equalizer taps is done according
+       *                         to [2]. In this case, it is the channel influence time in number of
+       *                         samples. A good value is usually the length of the cyclic prefix.
+       * \param max_carr_offset Limit the number of sub-carriers the frequency offset can maximally be.
+       *                        Leave this zero to try all possibilities.
+       * \param force_one_sync_symbol See \p sync_symbol2.
+       */
+      static sptr make(
+	  const std::vector<gr_complex> &sync_symbol1,
+	  const std::vector<gr_complex> &sync_symbol2,
+	  int n_data_symbols,
+	  int eq_noise_red_len=0,
+	  int max_carr_offset=-1,
+	  bool force_one_sync_symbol=false
+      );
+    };
+
+  } // namespace digital
+} // namespace gr
+
+#endif /* INCLUDED_DIGITAL_OFDM_CHANEST_VCVC_H */
+
diff --git a/gr-digital/include/digital/ofdm_cyclic_prefixer.h b/gr-digital/include/digital/ofdm_cyclic_prefixer.h
index 551d1ee834..6292d62697 100644
--- a/gr-digital/include/digital/ofdm_cyclic_prefixer.h
+++ b/gr-digital/include/digital/ofdm_cyclic_prefixer.h
@@ -1,6 +1,6 @@
 /* -*- c++ -*- */
-/*
- * Copyright 2004-2006,2011,2012 Free Software Foundation, Inc.
+/* 
+ * Copyright 2013 Free Software Foundation, Inc.
  * 
  * This file is part of GNU Radio
  * 
@@ -24,34 +24,48 @@
 #define INCLUDED_DIGITAL_OFDM_CYCLIC_PREFIXER_H
 
 #include <digital/api.h>
-#include <gr_sync_interpolator.h>
+#include <gr_tagged_stream_block.h>
 
 namespace gr {
   namespace digital {
-    
+
     /*!
-     * \brief adds a cyclic prefix vector to an input size long ofdm
-     * symbol(vector) and converts vector to a stream output_size
-     * long. 
+     * \brief Adds a cyclic prefix and performs pulse shaping on OFDM symbols.
      * \ingroup ofdm_blk
+     *
+     * Input: OFDM symbols (in the time domain, i.e. after the IFFT). Optionally,
+     *        entire frames can be processed. In this case, \p len_tag_key must be
+     *        specified which holds the key of the tag that denotes how
+     *        many OFDM symbols are in a frame.
+     * Output: A stream of (scalar) complex symbols, which include the cyclic prefix
+     *         and the pulse shaping.
+     *         Note: If complete frames are processed, and \p rolloff_len is greater
+     *         than zero, the final OFDM symbol is followed by the delay line of
+     *         the pulse shaping.
+     *
+     * The pulse shape is a raised cosine in the time domain.
      */
-    class DIGITAL_API ofdm_cyclic_prefixer : virtual public gr_sync_interpolator
+    class DIGITAL_API ofdm_cyclic_prefixer : virtual public gr_tagged_stream_block
     {
-    public:
-      // gr::digital::ofdm_cyclic_prefixer::sptr
+     public:
       typedef boost::shared_ptr<ofdm_cyclic_prefixer> sptr;
 
       /*!
-       * Make an OFDM cyclic prefix adder block.
-       *
-       * \param input_size size of the input symbol
-       * \param output_size output of the symbol
-       *        (CP len = output_size - input_size)
+       * \param input_size FFT length (i.e. length of the OFDM symbols)
+       * \param output_size FFT length + cyclic prefix length (in samples)
+       * \param rolloff_len Length of the rolloff flank in samples
+       * \param len_tag_key For framed processing the key of the length tag
        */
-      static sptr make(size_t input_size, size_t output_size);
+      static sptr make(
+	  size_t input_size,
+	  size_t output_size,
+	  int rolloff_len=0,
+	  const std::string &len_tag_key=""
+      );
     };
 
-  } /* namespace digital */
-} /* namespace gr */
+  } // namespace digital
+} // namespace gr
 
 #endif /* INCLUDED_DIGITAL_OFDM_CYCLIC_PREFIXER_H */
+
diff --git a/gr-digital/include/digital/ofdm_equalizer_base.h b/gr-digital/include/digital/ofdm_equalizer_base.h
new file mode 100644
index 0000000000..0e23eb381f
--- /dev/null
+++ b/gr-digital/include/digital/ofdm_equalizer_base.h
@@ -0,0 +1,109 @@
+/* -*- c++ -*- */
+/* Copyright 2012 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.
+ */
+
+#ifndef INCLUDED_DIGITAL_OFDM_EQUALIZER_BASE_H
+#define INCLUDED_DIGITAL_OFDM_EQUALIZER_BASE_H
+
+#include <digital/api.h>
+#include <gr_tags.h>
+#include <gr_complex.h>
+#include <boost/enable_shared_from_this.hpp>
+
+namespace gr {
+  namespace digital {
+
+    /* \brief Base class for implementation details of frequency-domain OFDM equalizers.
+     * \ingroup ofdm_blk
+     * \ingroup eq_blk
+     */
+    class DIGITAL_API ofdm_equalizer_base
+      : public boost::enable_shared_from_this<ofdm_equalizer_base>
+    {
+     protected:
+      int d_fft_len;
+      int d_carr_offset;
+
+     public:
+      typedef boost::shared_ptr<ofdm_equalizer_base> sptr;
+
+      ofdm_equalizer_base(int fft_len);
+      ~ofdm_equalizer_base();
+
+      //! Reset the channel information state knowledge
+      virtual void reset() = 0;
+      //! Set the carrier offset in integer multiples
+      void set_carrier_offset(int offset) { d_carr_offset = offset; };
+      virtual void equalize(
+		      gr_complex *frame,
+		      int n_sym,
+		      const std::vector<gr_complex> &initial_taps = std::vector<gr_complex>(),
+		      const std::vector<gr_tag_t> &tags = std::vector<gr_tag_t>()) = 0;
+      //! Return the current channel state
+      virtual void get_channel_state(std::vector<gr_complex> &taps) = 0;
+      int fft_len() { return d_fft_len; };
+      sptr base() { return shared_from_this(); };
+    };
+
+
+    /* \brief Base class for implementation details of 1-dimensional OFDM FDEs which use pilot tones.
+     * \ingroup digital
+     *
+     */
+    class DIGITAL_API ofdm_equalizer_1d_pilots : public ofdm_equalizer_base
+    {
+     protected:
+      //! If \p d_occupied_carriers[k][l] is true, symbol k, carrier l is carrying data.
+      //  (this is a different format than occupied_carriers!)
+      std::vector<bool> d_occupied_carriers;
+      //! If \p d_pilot_carriers[k][l] is true, symbol k, carrier l is carrying data.
+      //  (this is a different format than pilot_carriers!)
+      std::vector<std::vector<bool> > d_pilot_carriers;
+      //! If \p d_pilot_carriers[k][l] is true, d_pilot_symbols[k][l] is its tx'd value.
+      //  (this is a different format than pilot_symbols!)
+      std::vector<std::vector<gr_complex> > d_pilot_symbols;
+      //! In case the frame doesn't begin with OFDM symbol 0, this is the index of the first symbol
+      int d_symbols_skipped;
+      //! The current position in the set of pilot symbols
+      int d_pilot_carr_set;
+      //! Vector of length d_fft_len saving the current channel state (on the occupied carriers)
+      std::vector<gr_complex> d_channel_state;
+
+     public:
+      typedef boost::shared_ptr<ofdm_equalizer_1d_pilots> sptr;
+
+      ofdm_equalizer_1d_pilots(
+	  int fft_len,
+	  const std::vector<std::vector<int> > &occupied_carriers,
+	  const std::vector<std::vector<int> > &pilot_carriers,
+	  const std::vector<std::vector<gr_complex> > &pilot_symbols,
+	  int symbols_skipped,
+	  bool input_is_shifted);
+      ~ofdm_equalizer_1d_pilots();
+
+      void reset();
+      void get_channel_state(std::vector<gr_complex> &taps);
+    };
+
+  } /* namespace digital */
+} /* namespace gr */
+
+#endif /* INCLUDED_DIGITAL_OFDM_EQUALIZER_BASE_H */
+
diff --git a/gr-digital/include/digital/ofdm_equalizer_simpledfe.h b/gr-digital/include/digital/ofdm_equalizer_simpledfe.h
new file mode 100644
index 0000000000..9d286576bc
--- /dev/null
+++ b/gr-digital/include/digital/ofdm_equalizer_simpledfe.h
@@ -0,0 +1,130 @@
+/* -*- c++ -*- */
+/* Copyright 2012 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.
+ */
+
+#ifndef INCLUDED_DIGITAL_OFDM_EQUALIZER_SIMPLEDFE_H
+#define INCLUDED_DIGITAL_OFDM_EQUALIZER_SIMPLEDFE_H
+
+#include <digital/api.h>
+#include <digital/constellation.h>
+#include <digital/ofdm_equalizer_base.h>
+
+namespace gr {
+  namespace digital {
+
+    /* \brief Simple decision feedback equalizer for OFDM.
+     * \ingroup ofdm_blk
+     * \ingroup eq_blk
+     *
+     * Equalizes an OFDM signal symbol by symbol using knowledge of the
+     * complex modulations symbols.
+     * For every symbol, the following steps are performed:
+     * - On every sub-carrier, decode the modulation symbol
+     * - Use the difference between the decoded symbol and the received symbol
+     *   to update the channel state on this carrier
+     * - Whenever a pilot symbol is found, it uses the known pilot symbol to
+     *   update the channel state.
+     *
+     * This equalizer makes a lot of assumptions:
+     * - The initial channel state is good enough to decode the first
+     *   symbol without error (unless the first symbol only consists of pilot
+     *   tones)
+     * - The channel changes only very slowly, such that the channel state
+     *   from one symbol is enough to decode the next
+     * - SNR low enough that equalization will always suffice to correctly
+     *   decode a symbol
+     * If these assumptions are not met, the most common error is that the
+     * channel state is estimated incorrectly during equalization; after that,
+     * all subsequent symbols will be completely wrong.
+     *
+     * Note that the equalized symbols are *exact points* on the constellation.
+     * This means soft information of the modulation symbols is lost after the
+     * equalization, which is suboptimal for channel codes that use soft decision.
+     *
+     */
+    class DIGITAL_API ofdm_equalizer_simpledfe : public ofdm_equalizer_1d_pilots
+    {
+     public:
+      typedef boost::shared_ptr<ofdm_equalizer_simpledfe> sptr;
+
+      ofdm_equalizer_simpledfe(
+	  int fft_len,
+	  const gr::digital::constellation_sptr &constellation,
+	  const std::vector<std::vector<int> > &occupied_carriers = std::vector<std::vector<int> >(),
+	  const std::vector<std::vector<int> > &pilot_carriers = std::vector<std::vector<int> >(),
+	  const std::vector<std::vector<gr_complex> > &pilot_symbols = std::vector<std::vector<gr_complex> >(),
+	  int symbols_skipped = 0,
+	  float alpha = 0.1,
+	  bool input_is_shifted = true);
+
+      ~ofdm_equalizer_simpledfe();
+
+      void equalize(gr_complex *frame,
+		      int n_sym,
+		      const std::vector<gr_complex> &initial_taps = std::vector<gr_complex>(),
+		      const std::vector<gr_tag_t> &tags = std::vector<gr_tag_t>());
+
+      /*
+       * \param fft_len FFT length
+       * \param constellation The constellation object describing the modulation used
+       *                      on the subcarriers (e.g. QPSK). This is used to decode
+       *                      the individual symbols.
+       * \param occupied_carriers List of occupied carriers, see ofdm_carrier_allocator
+       *                          for a description.
+       * \param pilot_carriers Position of pilot symbols, see ofdm_carrier_allocator
+       *                          for a description.
+       * \param pilot_symbols Value of pilot symbols, see ofdm_carrier_allocator
+       *                          for a description.
+       * \param alpha Averaging coefficient (in a nutshell, if \f$H_{i,k}\f$ is the channel
+       *              state for carrier i and symbol k,
+       *              \f$H_{i,k+1} =  \alpha H_{i,k} + (1 - \alpha) H_{i,k+1}\f$. Make this
+       *              larger if there's more noise, but keep in mind that larger values
+       *              of alpha mean slower response to channel changes).
+       * \param symbols_skipped Starting position within occupied_carriers and pilot_carriers.
+       *                        If the first symbol of the frame was removed (e.g. to decode the
+       *                        header), set this make sure the pilot symbols are correctly
+       *                        identified.
+       * \param input_is_shifted Set this to false if the input signal is not shifted, i.e.
+       *                         the first input items is on the DC carrier.
+       *                         Note that a lot of the OFDM receiver blocks operate on shifted
+       *                         signals!
+       */
+      static sptr make(
+	  int fft_len,
+	  const gr::digital::constellation_sptr &constellation,
+	  const std::vector<std::vector<int> > &occupied_carriers = std::vector<std::vector<int> >(),
+	  const std::vector<std::vector<int> > &pilot_carriers = std::vector<std::vector<int> >(),
+	  const std::vector<std::vector<gr_complex> > &pilot_symbols = std::vector<std::vector<gr_complex> >(),
+	  int symbols_skipped=0,
+	  float alpha=0.1,
+	  bool input_is_shifted=true
+      );
+
+     private:
+      gr::digital::constellation_sptr d_constellation;
+      //! Averaging coefficient
+      float d_alpha;
+    };
+
+  } /* namespace digital */
+} /* namespace gr */
+
+#endif /* INCLUDED_DIGITAL_OFDM_EQUALIZER_SIMPLEDFE_H */
+
diff --git a/gr-digital/include/digital/ofdm_equalizer_static.h b/gr-digital/include/digital/ofdm_equalizer_static.h
new file mode 100644
index 0000000000..67586be6fb
--- /dev/null
+++ b/gr-digital/include/digital/ofdm_equalizer_static.h
@@ -0,0 +1,100 @@
+/* -*- c++ -*- */
+/* Copyright 2012 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.
+ */
+
+#ifndef INCLUDED_DIGITAL_OFDM_EQUALIZER_STATIC_H
+#define INCLUDED_DIGITAL_OFDM_EQUALIZER_STATIC_H
+
+#include <digital/api.h>
+#include <digital/constellation.h>
+#include <digital/ofdm_equalizer_base.h>
+
+namespace gr {
+  namespace digital {
+
+    /* \brief Very simple static equalizer for OFDM.
+     * \ingroup ofdm_blk
+     * \ingroup eq_blk
+     *
+     * This is an extremely simple equalizer. It will only work for high-SNR, very, very
+     * slowly changing channels.
+     * It simply divides the signal with the currently known channel state. Whenever
+     * a pilot symbol comes around, it updates the channel state on that particular
+     * carrier by dividing the received symbol with the known pilot symbol.
+     */
+    class DIGITAL_API ofdm_equalizer_static : public ofdm_equalizer_1d_pilots
+    {
+     public:
+      typedef boost::shared_ptr<ofdm_equalizer_static> sptr;
+
+      ofdm_equalizer_static(
+	  int fft_len,
+	  const std::vector<std::vector<int> > &occupied_carriers = std::vector<std::vector<int> >(),
+	  const std::vector<std::vector<int> > &pilot_carriers = std::vector<std::vector<int> >(),
+	  const std::vector<std::vector<gr_complex> > &pilot_symbols = std::vector<std::vector<gr_complex> >(),
+	  int symbols_skipped = 0,
+	  bool input_is_shifted = true
+      );
+      ~ofdm_equalizer_static();
+
+      /*! \brief Divide the input signal with the current channel state.
+       *
+       * Does the following (and nothing else):
+       * - Divide every OFDM symbol with the current channel state
+       * - If a pilot symbol is found, re-set the channel state by dividing the received
+       *   symbol with the known pilot symbol
+       */
+      void equalize(gr_complex *frame,
+		      int n_sym,
+		      const std::vector<gr_complex> &initial_taps = std::vector<gr_complex>(),
+		      const std::vector<gr_tag_t> &tags = std::vector<gr_tag_t>());
+
+      /*
+       * \param fft_len FFT length
+       * \param occupied_carriers List of occupied carriers, see ofdm_carrier_allocator
+       *                          for a description.
+       * \param pilot_carriers Position of pilot symbols, see ofdm_carrier_allocator
+       *                          for a description.
+       * \param pilot_symbols Value of pilot symbols, see ofdm_carrier_allocator
+       *                          for a description.
+       * \param symbols_skipped Starting position within occupied_carriers and pilot_carriers.
+       *                        If the first symbol of the frame was removed (e.g. to decode the
+       *                        header), set this make sure the pilot symbols are correctly
+       *                        identified.
+       * \param input_is_shifted Set this to false if the input signal is not shifted, i.e.
+       *                         the first input items is on the DC carrier.
+       *                         Note that a lot of the OFDM receiver blocks operate on shifted
+       *                         signals!
+       */
+      static sptr make(
+	int fft_len,
+	const std::vector<std::vector<int> > &occupied_carriers = std::vector<std::vector<int> >(),
+	const std::vector<std::vector<int> > &pilot_carriers = std::vector<std::vector<int> >(),
+	const std::vector<std::vector<gr_complex> > &pilot_symbols = std::vector<std::vector<gr_complex> >(),
+	int symbols_skipped = 0,
+	bool input_is_shifted = true
+      );
+    };
+
+  } /* namespace digital */
+} /* namespace gr */
+
+#endif /* INCLUDED_DIGITAL_OFDM_EQUALIZER_STATIC_H */
+
diff --git a/gr-digital/include/digital/ofdm_frame_equalizer_vcvc.h b/gr-digital/include/digital/ofdm_frame_equalizer_vcvc.h
index d5d526ddc3..68e8b7ad9f 100644
--- a/gr-digital/include/digital/ofdm_frame_equalizer_vcvc.h
+++ b/gr-digital/include/digital/ofdm_frame_equalizer_vcvc.h
@@ -19,12 +19,11 @@
  * Boston, MA 02110-1301, USA.
  */
 
-
 #ifndef INCLUDED_OFDM_FRAME_EQUALIZER_VCVC_H
 #define INCLUDED_OFDM_FRAME_EQUALIZER_VCVC_H
 
-#include <digital_ofdm_equalizer_base.h>
 #include <digital/api.h>
+#include <digital/ofdm_equalizer_base.h>
 #include <gr_tagged_stream_block.h>
 
 namespace gr {
@@ -50,7 +49,7 @@ namespace gr {
        *                                will be added to the first symbol as a tag
        */
       static sptr make(
-	   digital_ofdm_equalizer_base_sptr equalizer,
+	   ofdm_equalizer_base::sptr equalizer,
 	   const std::string &len_tag_key = "frame_len",
 	   bool propagate_channel_state=false
       );
diff --git a/gr-digital/include/digital/ofdm_serializer_vcc.h b/gr-digital/include/digital/ofdm_serializer_vcc.h
index 3893d6674e..c4dc36ec06 100644
--- a/gr-digital/include/digital/ofdm_serializer_vcc.h
+++ b/gr-digital/include/digital/ofdm_serializer_vcc.h
@@ -24,7 +24,7 @@
 
 #include <digital/api.h>
 #include <gr_tagged_stream_block.h>
-#include <digital_ofdm_carrier_allocator_cvc.h>
+#include <digital/ofdm_carrier_allocator_cvc.h>
 
 namespace gr {
   namespace digital {
@@ -77,7 +77,7 @@ namespace gr {
        * \param input_is_shifted If the input has the DC carrier on index 0 (i.e. it is not FFT shifted), set this to false
        */
       static sptr make(
-	  const digital_ofdm_carrier_allocator_cvc_sptr &allocator,
+	  const gr::digital::ofdm_carrier_allocator_cvc::sptr &allocator,
 	  const std::string &packet_len_tag_key="",
 	  int symbols_skipped=0,
 	  bool input_is_shifted=true
diff --git a/gr-digital/include/digital/ofdm_sync_sc_cfb.h b/gr-digital/include/digital/ofdm_sync_sc_cfb.h
new file mode 100644
index 0000000000..0c5c46f38d
--- /dev/null
+++ b/gr-digital/include/digital/ofdm_sync_sc_cfb.h
@@ -0,0 +1,78 @@
+/* -*- c++ -*- */
+/* 
+ * Copyright 2013 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.
+ */
+
+
+#ifndef INCLUDED_DIGITAL_OFDM_SYNC_SC_CFB_H
+#define INCLUDED_DIGITAL_OFDM_SYNC_SC_CFB_H
+
+#include <digital/api.h>
+#include <gr_hier_block2.h>
+
+namespace gr {
+  namespace digital {
+
+    /*!
+     * \brief Schmidl & Cox synchronisation for OFDM
+     * \ingroup ofdm_blk
+     * \ingroup sync_blk
+     *
+     * Input: complex samples.
+     * Output 0: Fine frequency offset, scaled by the OFDM symbol duration.
+     *           This is \f$\hat{\varphi}\f$ in [1]. The normalized frequency
+     *           offset is then 2.0*output0/fft_len.
+     * Output 1: Beginning of the first OFDM symbol after the first (doubled) OFDM
+     *           symbol. The beginning is marked with a 1 (it's 0 everywhere else).
+     *
+     * The evaluation of the coarse frequency offset is *not* done in this block.
+     * Also, the initial equalizer taps are not calculated here.
+     *
+     * Note that we use a different normalization factor in the timing metric than
+     * the authors do in their original work[1]. If the timing metric (8) is
+     * \f[
+     * M(d) = \frac{|P(d)|^2}{(R(d))^2},
+     * \f]
+     * we calculate the normalization as
+     * \f[
+     * R(d) = \frac{1}{2} \sum_{k=0}^{N-1} |r_{k+d}|^2,
+     * \f]
+     * i.e., we estimate the energy from *both* half-symbols. This avoids spurious detects
+     * at the end of a burst, when the energy level suddenly drops.
+     *
+     * [1] Schmidl, T.M. and Cox, D.C., "Robust frequency and timing synchronization for OFDM",
+     *     Communications, IEEE Transactions on, 1997.
+     */
+    class DIGITAL_API ofdm_sync_sc_cfb : virtual public gr_hier_block2
+    {
+     public:
+      typedef boost::shared_ptr<ofdm_sync_sc_cfb> sptr;
+
+      /*! \param fft_len FFT length
+       *  \param cp_len Length of the guard interval (cyclic prefix) in samples
+       */
+      static sptr make(int fft_len, int cp_len);
+    };
+
+  } // namespace digital
+} // namespace gr
+
+#endif /* INCLUDED_DIGITAL_OFDM_SYNC_SC_CFB_H */
+
diff --git a/gr-digital/include/digital/scale_tags.h b/gr-digital/include/digital/scale_tags.h
index 8a9e3efba4..dfe6f4a823 100644
--- a/gr-digital/include/digital/scale_tags.h
+++ b/gr-digital/include/digital/scale_tags.h
@@ -23,7 +23,7 @@
 #ifndef INCLUDED_DIGITAL_SCALE_TAGS_H
 #define INCLUDED_DIGITAL_SCALE_TAGS_H
 
-#include <digital_ofdm_equalizer_base.h> // FIXME: Error without this line. No idea why.
+//#include <digital_ofdm_equalizer_base.h> // FIXME: Error without this line. No idea why.
 #include <digital/api.h>
 #include <gr_sync_block.h>
 
diff --git a/gr-digital/include/digital/tagged_stream_check.h b/gr-digital/include/digital/tagged_stream_check.h
index 73b44a5bb9..68509bcae6 100644
--- a/gr-digital/include/digital/tagged_stream_check.h
+++ b/gr-digital/include/digital/tagged_stream_check.h
@@ -19,15 +19,13 @@
  * Boston, MA 02110-1301, USA.
  */
 
-
 #ifndef INCLUDED_DIGITAL_TAGGED_STREAM_CHECK_H
 #define INCLUDED_DIGITAL_TAGGED_STREAM_CHECK_H
 
-#include <digital_ofdm_equalizer_base.h> // FIXME: Error without this line. No idea why.
+//#include <digital_ofdm_equalizer_base.h> // FIXME: Error without this line. No idea why.
 #include <digital/api.h>
 #include <gr_sync_block.h>
 
-
 namespace gr {
   namespace digital {
 
diff --git a/gr-digital/include/digital/ts_insert_zeros_cc.h b/gr-digital/include/digital/ts_insert_zeros_cc.h
index 299062eb50..588eb300ee 100644
--- a/gr-digital/include/digital/ts_insert_zeros_cc.h
+++ b/gr-digital/include/digital/ts_insert_zeros_cc.h
@@ -19,16 +19,14 @@
  * Boston, MA 02110-1301, USA.
  */
 
-
 #ifndef INCLUDED_DIGITAL_TS_INSERT_ZEROS_CC_H
 #define INCLUDED_DIGITAL_TS_INSERT_ZEROS_CC_H
 
-#include <digital_ofdm_equalizer_base.h> // FIXME: Error without this line. No idea why.
+//#include <digital_ofdm_equalizer_base.h> // FIXME: Error without this line. No idea why.
 #include <digital/api.h>
 #include <gr_block.h>
 #include <string>
 
-
 namespace gr {
   namespace digital {
author	Martin Braun <martin.braun@kit.edu>	2013-03-17 02:26:39 +0100
committer	Martin Braun <martin.braun@kit.edu>	2013-03-17 15:54:24 +0100
commit	046f442fe430a7f8d9b7c1d48422e72aeeeeab13 (patch)
tree	111ee1c6bf463a333d63d10ac8954eb34651e528 /gr-digital/include/digital
parent	f15400470ce5cb68f5339ead7af726b8bbafd364 (diff)