GNU Radio 3.6.5 C++ API
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00001 /* -*- c++ -*- */ 00002 /* 00003 * Copyright 2007 Free Software Foundation, Inc. 00004 * 00005 * This file is part of GNU Radio 00006 * 00007 * GNU Radio is free software; you can redistribute it and/or modify 00008 * it under the terms of the GNU General Public License as published by 00009 * the Free Software Foundation; either version 3, or (at your option) 00010 * any later version. 00011 * 00012 * GNU Radio is distributed in the hope that it will be useful, 00013 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00015 * GNU General Public License for more details. 00016 * 00017 * You should have received a copy of the GNU General Public License 00018 * along with GNU Radio; see the file COPYING. If not, write to 00019 * the Free Software Foundation, Inc., 51 Franklin Street, 00020 * Boston, MA 02110-1301, USA. 00021 */ 00022 00023 #ifndef INCLUDED_GRI_GLFSR_H 00024 #define INCLUDED_GRI_GLFSR_H 00025 00026 #include <gr_core_api.h> 00027 00028 /*! 00029 * \brief Galois Linear Feedback Shift Register using specified polynomial mask 00030 * \ingroup misc 00031 * 00032 * Generates a maximal length pseudo-random sequence of length 2^degree-1 00033 */ 00034 00035 class GR_CORE_API gri_glfsr 00036 { 00037 private: 00038 int d_shift_register; 00039 int d_mask; 00040 00041 public: 00042 00043 gri_glfsr(int mask, int seed) { d_shift_register = seed; d_mask = mask; } 00044 static int glfsr_mask(int degree); 00045 00046 unsigned char next_bit() { 00047 unsigned char bit = d_shift_register & 1; 00048 d_shift_register >>= 1; 00049 if (bit) 00050 d_shift_register ^= d_mask; 00051 return bit; 00052 } 00053 00054 int mask() const { return d_mask; } 00055 }; 00056 00057 #endif /* INCLUDED_GRI_GLFSR_H */