1 files changed, 136 insertions, 0 deletions
diff --git a/gr-fec/lib/polar_common.cc b/gr-fec/lib/polar_common.cc
new file mode 100644
index 0000000000..ff78d3428e
--- /dev/null
+++ b/gr-fec/lib/polar_common.cc
@@ -0,0 +1,136 @@
+/* -*- 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_common.h>
+
+#include <gnuradio/blocks/pack_k_bits.h>
+#include <gnuradio/blocks/unpack_k_bits.h>
+
+#include <cmath>
+#include <stdexcept>
+#include <iostream>
+#include <vector>
+
+namespace gr {
+  namespace fec {
+    namespace code {
+
+      polar_common::polar_common(int block_size, int num_info_bits,
+                                 std::vector<int> frozen_bit_positions,
+                                 std::vector<char> frozen_bit_values) :
+        d_frozen_bit_positions(frozen_bit_positions), d_frozen_bit_values(frozen_bit_values),
+        d_block_size(block_size), d_block_power((int) log2(float(block_size))),
+        d_num_info_bits(num_info_bits)
+      {
+        if(pow(2, d_block_power) != d_block_size){
+          throw std::runtime_error("block_size MUST be a power of 2!");
+        }
+
+        unsigned int num_frozen_bits = d_block_size - d_num_info_bits;
+        if(num_frozen_bits != d_frozen_bit_positions.size()){
+          throw std::runtime_error(
+                                   "number of frozen bit positions must equal block_size - num_info_bits");
+        }
+
+        // According to papers frozen bits default to '0'.
+        while(d_frozen_bit_values.size() < num_frozen_bits){
+          d_frozen_bit_values.push_back(0);
+        }
+        initialize_info_bit_position_vector();
+
+        d_unpacker = new gr::blocks::kernel::unpack_k_bits(8);
+      }
+
+      void
+      polar_common::initialize_info_bit_position_vector()
+      {
+        int num_frozen_bit = 0;
+        int frozen_pos = d_frozen_bit_positions.at(num_frozen_bit);
+        for(int i = 0; i < d_block_size; i++) {
+          if(i != frozen_pos) {
+            d_info_bit_positions.push_back((int) i);
+          }
+          else {
+            num_frozen_bit++;
+            num_frozen_bit = std::min(num_frozen_bit, (int) (d_frozen_bit_positions.size() - 1));
+            frozen_pos = d_frozen_bit_positions.at(num_frozen_bit);
+          }
+        }
+
+        if((int) d_info_bit_positions.size() != num_info_bits()) {
+          throw std::runtime_error("polar_common: number of info bit positions MUST equal num_info_bits (K)!");
+        }
+      }
+
+      polar_common::~polar_common()
+      {
+        delete d_unpacker;
+      }
+
+      long
+      polar_common::bit_reverse(long value, int active_bits) const
+      {
+        long r = 0;
+        for(int i = 0; i < active_bits; i++) {
+          r <<= 1;
+          r |= value & 1;
+          value >>= 1;
+        }
+        return r;
+      }
+
+      void
+      polar_common::print_packed_bit_array(const unsigned char* printed_array,
+                                           const int num_bytes) const
+      {
+        int num_bits = num_bytes << 3;
+        unsigned char* temp = new unsigned char[num_bits];
+        d_unpacker->unpack(temp, printed_array, num_bytes);
+
+        std::cout << "[";
+        for(int i = 0; i < num_bits; i++) {
+          std::cout << (int) *(temp + i) << " ";
+        }
+        std::cout << "]" << std::endl;
+
+        delete [] temp;
+      }
+
+      void
+      polar_common::print_unpacked_bit_array(const unsigned char* bits,
+                                             const unsigned int num_bytes) const
+      {
+        std::cout << "( ";
+        for(unsigned int i = 0; i < num_bytes; i++){
+          std::cout << (int) *bits++ << ", ";
+        }
+        std::cout << ")" << std::endl;
+      }
+
+    } /* namespace code */
+  } /* namespace fec */
+} /* namespace gr */