00001 /* 00002 * SPUC - Signal processing using C++ - A DSP library 00003 * 00004 * This program is free software; you can redistribute it and/or modify 00005 * it under the terms of the GNU General Public License as published by 00006 * the Free Software Foundation; either version 2, or (at your option) 00007 * any later version. 00008 * 00009 * This program is distributed in the hope that it will be useful, 00010 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00011 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00012 * GNU General Public License for more details. 00013 * 00014 * You should have received a copy of the GNU General Public License 00015 * along with this program; if not, write to the Free Software 00016 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 00017 */ 00018 #ifndef QAMCONVD 00019 #define QAMCONVD 00020 #include <math.h> 00021 #include <complex.h> 00022 #include <viterbi.h> 00023 #include <delay.h> 00024 #include <fir.h> 00025 namespace SPUC { 00028 // uses qam_data_deamp for soft decisions then inputs these into 00029 // viterbi decoding using puncturing if necessary 00030 // if output of data_decode is true, use get_bit for data bit output 00033 class qam_conv_decoder { 00034 public: 00035 viterbi viterbi_decoder; 00036 long* viterbi_input; 00037 00038 const long soft_decision_level; 00039 const long Max_bits_per_symbol; 00040 long enc_rate; 00041 long rate_index; 00042 long soft_bit_counter; 00043 long rx_bits_per_symbol; 00044 long raw_bits_this_frame; 00045 long coded_bits_per_frame; 00046 long raw_bits_out; 00047 long sample; 00048 long serial; 00049 00050 bool frame_ready; 00051 bool viterbi_ready; 00052 bool viterbi_data; 00053 bool output_buffer_empty; 00054 bool no_conv; // Bypass Viterbi when true 00055 00056 public: 00057 qam_conv_decoder(int index) : soft_decision_level(64), 00058 Max_bits_per_symbol(8) { 00059 no_conv=0; 00060 rate_index = index; 00061 reset(); 00062 set_rate(0,1); 00063 viterbi_input = new long[Max_bits_per_symbol]; 00064 } 00065 ~qam_conv_decoder() { 00066 delete [] viterbi_input; 00067 } 00068 void reset() { 00069 sample = 0; //16; 00070 raw_bits_this_frame=0; 00071 coded_bits_per_frame=0; 00072 soft_bit_counter=0; 00073 raw_bits_out = 0; 00074 output_buffer_empty = 1; 00075 viterbi_ready = 0; 00076 viterbi_data = 0; 00077 viterbi_decoder.reset(); 00078 frame_ready = 0; 00079 } 00081 void set_rate(int mod, int conv_rate) { 00082 if (conv_rate == 0) no_conv = 1; 00083 else no_conv = 0; 00084 enc_rate = conv_rate; 00085 if (mod>0) rx_bits_per_symbol = 2*mod; 00086 else rx_bits_per_symbol = 1; 00087 rate_index = mod; 00088 } 00090 bool data_decode(complex<long> data_in); 00092 bool get_bit(void) { return(viterbi_data); }; 00094 long* clear_soft_decision(long rate); 00095 }; 00096 } // namespace SPUC 00097 #endif