1 files changed, 101 insertions, 0 deletions
diff --git a/gr-fec/lib/polar_decoder_sc_systematic.cc b/gr-fec/lib/polar_decoder_sc_systematic.cc
new file mode 100644
index 0000000000..c65c80f7aa
--- /dev/null
+++ b/gr-fec/lib/polar_decoder_sc_systematic.cc
@@ -0,0 +1,101 @@
+/* -*- c++ -*- */
+/* 
+ * Copyright 2015 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gnuradio/io_signature.h>
+#include <gnuradio/fec/polar_decoder_sc_systematic.h>
+#include <volk/volk.h>
+
+namespace gr {
+  namespace fec {
+    namespace code {
+
+      generic_decoder::sptr
+      polar_decoder_sc_systematic::make(int block_size, int num_info_bits,
+                                        std::vector<int> frozen_bit_positions)
+      {
+        return generic_decoder::sptr(
+            new polar_decoder_sc_systematic(block_size, num_info_bits, frozen_bit_positions));
+      }
+
+      polar_decoder_sc_systematic::polar_decoder_sc_systematic(
+          int block_size, int num_info_bits, std::vector<int> frozen_bit_positions) :
+              polar_decoder_common(block_size, num_info_bits, frozen_bit_positions, std::vector<char>())
+      {
+        d_llr_vec = (float*) volk_malloc(sizeof(float) * block_size * (block_power() + 1), volk_get_alignment());
+        memset(d_llr_vec, 0, sizeof(float) * block_size * (block_power() + 1));
+        d_u_hat_vec = (unsigned char*) volk_malloc(block_size * (block_power() + 1), volk_get_alignment());
+        memset(d_u_hat_vec, 0, sizeof(unsigned char) * block_size * (block_power() + 1));
+        d_frame_vec = (unsigned char*) volk_malloc(block_size, volk_get_alignment());
+        memset(d_frame_vec, 0, sizeof(unsigned char) * block_size);
+      }
+
+      polar_decoder_sc_systematic::~polar_decoder_sc_systematic()
+      {
+      }
+
+      void
+      polar_decoder_sc_systematic::generic_work(void* in_buffer, void* out_buffer)
+      {
+        const float *in = (const float*) in_buffer;
+        unsigned char *out = (unsigned char*) out_buffer;
+
+        initialize_decoder(d_u_hat_vec, d_llr_vec, in);
+        sc_decode(d_llr_vec, d_u_hat_vec);
+        volk_encode_block(d_frame_vec, d_u_hat_vec);
+        extract_info_bits_reversed(out, d_frame_vec);
+      }
+
+      void
+      polar_decoder_sc_systematic::sc_decode(float* llrs, unsigned char* u)
+      {
+        for(int i = 0; i < block_size(); i++){
+          butterfly(llrs, u, 0, i, i);
+          u[i] = retrieve_bit_from_llr(llrs[i], i);
+        }
+      }
+
+      unsigned char
+      polar_decoder_sc_systematic::retrieve_bit_from_llr(float llr, const int pos)
+      {
+        if(is_frozen_bit(pos)){
+          return next_frozen_bit();
+        }
+        return llr_bit_decision(llr);
+      }
+
+      void
+      polar_decoder_sc_systematic::extract_info_bits_reversed(unsigned char* outbuf,
+                                                              const unsigned char* inbuf)
+      {
+        for(int i = 0; i < num_info_bits(); i++){
+          *outbuf++ = inbuf[d_info_bit_positions_reversed[i]];
+        }
+      }
+
+    } // namespace code
+  } /* namespace fec */
+} /* namespace gr */
+