Imported Upstream version 3.2.2

[debian/gnuradio] / gnuradio-core / src / lib / general / gr_decode_ccsds_27_fb.h

diff --git a/gnuradio-core/src/lib/general/gr_decode_ccsds_27_fb.h b/gnuradio-core/src/lib/general/gr_decode_ccsds_27_fb.h
new file mode 100644 (file)
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+++ b/gnuradio-core/src/lib/general/gr_decode_ccsds_27_fb.h
@@ -0,0 +1,77 @@
+/* -*- c++ -*- */
+/*
+ * Copyright 2008 Free Software Foundation, Inc.
+ * 
+ * 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_GR_DECODE_CCSDS_27_FB_H
+#define INCLUDED_GR_DECODE_CCSDS_27_FB_H
+
+#include <gr_sync_decimator.h>
+
+extern "C" {
+#include "../viterbi/viterbi.h"
+}
+
+class gr_decode_ccsds_27_fb;
+
+typedef boost::shared_ptr<gr_decode_ccsds_27_fb> gr_decode_ccsds_27_fb_sptr;
+
+gr_decode_ccsds_27_fb_sptr gr_make_decode_ccsds_27_fb();
+
+/*! \brief A rate 1/2, k=7 convolutional decoder for the CCSDS standard
+ * \ingroup ecc
+ *  
+ * This block performs soft-decision convolutional decoding using the Viterbi
+ * algorithm.
+ *  
+ * The input is a stream of (possibly noise corrupted) floating point values 
+ * nominally spanning [-1.0, 1.0], representing the encoded channel symbols 
+ * 0 (-1.0) and 1 (1.0), with erased symbols at 0.0.
+ *
+ * The output is MSB first packed bytes of decoded values.
+ *
+ * As a rate 1/2 code, there will be one output byte for every 16 input symbols.
+ *
+ * This block is designed for continuous data streaming, not packetized data.
+ * The first 32 bits out will be zeroes, with the output delayed four bytes
+ * from the corresponding inputs.
+ */
+
+class gr_decode_ccsds_27_fb : public gr_sync_decimator
+{
+private:
+  friend gr_decode_ccsds_27_fb_sptr gr_make_decode_ccsds_27_fb();
+
+  gr_decode_ccsds_27_fb();
+
+  // Viterbi state
+  int d_mettab[2][256];
+  struct viterbi_state d_state0[64];
+  struct viterbi_state d_state1[64];
+  unsigned char d_viterbi_in[16];
+
+  int d_count;
+      
+public:
+  ~gr_decode_ccsds_27_fb();
+
+  int work (int noutput_items,
+           gr_vector_const_void_star &input_items,
+           gr_vector_void_star &output_items);
+};
+
+#endif /* INCLUDED_GR_DECODE_CCSDS_27_FB_H */