filter: adding PFB decimator with GRC and QA.

3 files changed, 134 insertions, 2 deletions

diff --git a/gr-filter/include/filter/CMakeLists.txt b/gr-filter/include/filter/CMakeLists.txt
index e9ba8c246..77ae78e35 100644
--- a/gr-filter/include/filter/CMakeLists.txt
+++ b/gr-filter/include/filter/CMakeLists.txt
@@ -101,6 +101,7 @@ install(FILES
     hilbert_fc.h
     iir_filter_ffd.h
     pfb_channelizer_ccf.h
+    pfb_decimator_ccf.h
     single_pole_iir_filter_cc.h
     single_pole_iir_filter_ff.h
     DESTINATION ${GR_INCLUDE_DIR}/gnuradio/filter
diff --git a/gr-filter/include/filter/pfb_channelizer_ccf.h b/gr-filter/include/filter/pfb_channelizer_ccf.h
index ab79f7036..ba55782b4 100644
--- a/gr-filter/include/filter/pfb_channelizer_ccf.h
+++ b/gr-filter/include/filter/pfb_channelizer_ccf.h
@@ -26,13 +26,12 @@
 
 #include <filter/api.h>
 #include <gr_block.h>
-#include <gruel/thread.h>
 
 namespace gr {
   namespace filter {
 
     /*!
-     * \class gr_pfb_channelizer_ccf
+     * \class pfb_channelizer_ccf
      *
      * \brief Polyphase filterbank channelizer with
      *        gr_complex input, gr_complex output and float taps
diff --git a/gr-filter/include/filter/pfb_decimator_ccf.h b/gr-filter/include/filter/pfb_decimator_ccf.h
new file mode 100644
index 000000000..a933fbb5b
--- /dev/null
+++ b/gr-filter/include/filter/pfb_decimator_ccf.h
@@ -0,0 +1,132 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2009,2012 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_PFB_DECIMATOR_CCF_H
+#define	INCLUDED_PFB_DECIMATOR_CCF_H
+
+#include <filter/api.h>
+#include <gr_sync_block.h>
+#include <gruel/thread.h>
+
+namespace gr {
+  namespace filter {
+
+    /*!
+     * \class pfb_decimator_ccf
+     * \brief Polyphase filterbank bandpass decimator with gr_complex
+     *        input, gr_complex output and float taps
+     *
+     * \ingroup filter_blk
+     * \ingroup pfb_blk
+     *
+     * This block takes in a signal stream and performs interger down-
+     * sampling (decimation) with a polyphase filterbank. The first
+     * input is the integer specifying how much to decimate by. The
+     * second input is a vector (Python list) of floating-point taps
+     * of the prototype filter. The third input specifies the channel
+     * to extract.  By default, the zeroth channel is used, which is
+     * the baseband channel (first Nyquist zone).
+     *
+     * The <EM>channel</EM> parameter specifies which channel to use
+     * since this class is capable of bandpass decimation. Given a
+     * complex input stream at a sampling rate of <EM>fs</EM> and a
+     * decimation rate of <EM>decim</EM>, the input frequency domain
+     * is split into <EM>decim</EM> channels that represent the
+     * Nyquist zones. Using the polyphase filterbank, we can select
+     * any one of these channels to decimate.
+     *
+     * The output signal will be the basebanded and decimated signal
+     * from that channel. This concept is very similar to the PFB
+     * channelizer (see #gr_pfb_channelizer_ccf) where only a single
+     * channel is extracted at a time.
+     *
+     * The filter's taps should be based on the sampling rate before
+     * decimation.
+     *
+     * For example, using the GNU Radio's firdes utility to building
+     * filters, we build a low-pass filter with a sampling rate of
+     * <EM>fs</EM>, a 3-dB bandwidth of <EM>BW</EM> and a transition
+     * bandwidth of <EM>TB</EM>. We can also specify the out-of-band
+     * attenuation to use, <EM>ATT</EM>, and the filter window
+     * function (a Blackman-harris window in this case). The first
+     * input is the gain of the filter, which we specify here as
+     * unity.
+     *
+     *   <B><EM>self._taps = gr.firdes.low_pass_2(1, fs, BW, TB,
+     *      attenuation_dB=ATT, window=gr.firdes.WIN_BLACKMAN_hARRIS)</EM></B>
+     *
+     * The PFB decimator code takes the taps generated above and
+     * builds a set of filters. The set contains <EM>decim</EM> number
+     * of filters and each filter contains ceil(taps.size()/decim)
+     * number of taps.  Each tap from the filter prototype is
+     * sequentially inserted into the next filter. When all of the
+     * input taps are used, the remaining filters in the filterbank
+     * are filled out with 0's to make sure each filter has the same
+     * number of taps.
+     *
+     * The theory behind this block can be found in Chapter 6 of
+     * the following book.
+     *
+     *   <B><EM>f. harris, "Multirate Signal Processing for Communication
+     *      Systems," Upper Saddle River, NJ: Prentice Hall, Inc. 2004.</EM></B>
+     */
+
+    class FILTER_API pfb_decimator_ccf : virtual public gr_sync_block
+    {
+    public:
+      // gr::filter::pfb_decimator_ccf::sptr
+      typedef boost::shared_ptr<pfb_decimator_ccf> sptr;
+
+      /*!
+       * Build the polyphase filterbank decimator.
+       * \param decim   (unsigned integer) Specifies the decimation rate to use
+       * \param taps    (vector/list of floats) The prototype filter to populate the filterbank.
+       * \param channel (unsigned integer) Selects the channel to return [default=0].
+       */
+      static FILTER_API sptr make(unsigned int decim,
+				  const std::vector<float> &taps,
+				  unsigned int channel);
+
+      /*!
+       * Resets the filterbank's filter taps with the new prototype filter
+       * \param taps    (vector/list of floats) The prototype filter to populate the filterbank.
+       */
+      virtual void set_taps(const std::vector<float> &taps) = 0;
+
+      /*!
+       * Return a vector<vector<>> of the filterbank taps
+       */
+      virtual std::vector<std::vector<float> > taps() const = 0;
+
+      /*!
+       * Print all of the filterbank taps to screen.
+       */
+      virtual void print_taps() = 0;
+
+      //virtual void set_channel(unsigned int channel) = 0;
+    };
+
+  } /* namespace filter */
+} /* namespace gr */
+
+#endif /* INCLUDED_FILTER_PFB_DECIMATOR_CCF_H */