/* -*- c++ -*- */ /* * Copyright 2002 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. */ #include <cstdio> #include <string> #include <iostream> #include <fstream> #include <stdexcept> #include <cmath> #include "base.h" #include "fsm.h" fsm::fsm() { d_I=0; d_S=0; d_O=0; d_NS.resize(0); d_OS.resize(0); d_PS.resize(0); d_PI.resize(0); d_TMi.resize(0); d_TMl.resize(0); } fsm::fsm(const fsm &FSM) { d_I=FSM.I(); d_S=FSM.S(); d_O=FSM.O(); d_NS=FSM.NS(); d_OS=FSM.OS(); d_PS=FSM.PS(); // is this going to make a deep copy? d_PI=FSM.PI(); d_TMi=FSM.TMi(); d_TMl=FSM.TMl(); } fsm::fsm(int I, int S, int O, const std::vector<int> &NS, const std::vector<int> &OS) { d_I=I; d_S=S; d_O=O; d_NS=NS; d_OS=OS; generate_PS_PI(); generate_TM(); } //###################################################################### //# Read an FSM specification from a file. //# Format (hopefully will become more flexible in the future...): //# I S O (in the first line) //# blank line //# Next state matrix (S lines, each with I integers separated by spaces) //# blank line //# output symbol matrix (S lines, each with I integers separated by spaces) //# optional comments //###################################################################### fsm::fsm(const char *name) { FILE *fsmfile; if((fsmfile=fopen(name,"r"))==NULL) throw std::runtime_error ("fsm::fsm(const char *name): file open error\n"); //printf("file open error in fsm()\n"); fscanf(fsmfile,"%d %d %d\n",&d_I,&d_S,&d_O); d_NS.resize(d_I*d_S); d_OS.resize(d_I*d_S); for(int i=0;i<d_S;i++) { for(int j=0;j<d_I;j++) fscanf(fsmfile,"%d",&(d_NS[i*d_I+j])); } for(int i=0;i<d_S;i++) { for(int j=0;j<d_I;j++) fscanf(fsmfile,"%d",&(d_OS[i*d_I+j])); } generate_PS_PI(); generate_TM(); } //###################################################################### //# Automatically generate the FSM from the generator matrix //# of a (n,k) binary convolutional code //###################################################################### fsm::fsm(int k, int n, const std::vector<int> &G) { // calculate maximum memory requirements for each input stream std::vector<int> max_mem_x(k,-1); int max_mem = -1; for(int i=0;i<k;i++) { for(int j=0;j<n;j++) { int mem = -1; if(G[i*n+j]!=0) mem=(int)(log(G[i*n+j])/log(2.0)); if(mem>max_mem_x[i]) max_mem_x[i]=mem; if(mem>max_mem) max_mem=mem; } } //printf("max_mem_x\n"); //for(int j=0;j<max_mem_x.size();j++) printf("%d ",max_mem_x[j]); printf("\n"); // calculate total memory requirements to set S int sum_max_mem = 0; for(int i=0;i<k;i++) sum_max_mem += max_mem_x[i]; //printf("sum_max_mem = %d\n",sum_max_mem); d_I=1<<k; d_S=1<<sum_max_mem; d_O=1<<n; // binary representation of the G matrix std::vector<std::vector<int> > Gb(k*n); for(int j=0;j<k*n;j++) { Gb[j].resize(max_mem+1); dec2base(G[j],2,Gb[j]); //printf("Gb\n"); //for(int m=0;m<Gb[j].size();m++) printf("%d ",Gb[j][m]); printf("\n"); } // alphabet size of each shift register std::vector<int> bases_x(k); for(int j=0;j<k ;j++) bases_x[j] = 1 << max_mem_x[j]; //printf("bases_x\n"); //for(int j=0;j<max_mem_x.size();j++) printf("%d ",max_mem_x[j]); printf("\n"); d_NS.resize(d_I*d_S); d_OS.resize(d_I*d_S); std::vector<int> sx(k); std::vector<int> nsx(k); std::vector<int> tx(k); std::vector<std::vector<int> > tb(k); for(int j=0;j<k;j++) tb[j].resize(max_mem+1); std::vector<int> inb(k); std::vector<int> outb(n); for(int s=0;s<d_S;s++) { dec2bases(s,bases_x,sx); // split s into k values, each representing on of the k shift registers //printf("state = %d \nstates = ",s); //for(int j=0;j<sx.size();j++) printf("%d ",sx[j]); printf("\n"); for(int i=0;i<d_I;i++) { dec2base(i,2,inb); // input in binary //printf("input = %d \ninputs = ",i); //for(int j=0;j<inb.size();j++) printf("%d ",inb[j]); printf("\n"); // evaluate next state for(int j=0;j<k;j++) nsx[j] = (inb[j]*bases_x[j]+sx[j])/2; // next state (for each shift register) MSB first d_NS[s*d_I+i]=bases2dec(nsx,bases_x); // collect all values into the new state // evaluate transitions for(int j=0;j<k;j++) tx[j] = inb[j]*bases_x[j]+sx[j]; // transition (for each shift register)MSB first for(int j=0;j<k;j++) { dec2base(tx[j],2,tb[j]); // transition in binary //printf("transition = %d \ntransitions = ",tx[j]); //for(int m=0;m<tb[j].size();m++) printf("%d ",tb[j][m]); printf("\n"); } // evaluate outputs for(int nn=0;nn<n;nn++) { outb[nn] = 0; for(int j=0;j<k;j++) { for(int m=0;m<max_mem+1;m++) outb[nn] = (outb[nn] + Gb[j*n+nn][m]*tb[j][m]) % 2; // careful: polynomial 1+D ir represented as 110, not as 011 //printf("output %d equals %d\n",nn,outb[nn]); } } d_OS[s*d_I+i] = base2dec(outb,2); } } generate_PS_PI(); generate_TM(); } //###################################################################### //# Automatically generate an FSM specification describing the //# ISI for a channel //# of length ch_length and a modulation of size mod_size //###################################################################### fsm::fsm(int mod_size, int ch_length) { d_I=mod_size; d_S=(int) (pow(1.0*d_I,1.0*ch_length-1)+0.5); d_O=d_S*d_I; d_NS.resize(d_I*d_S); d_OS.resize(d_I*d_S); for(int s=0;s<d_S;s++) { for(int i=0;i<d_I;i++) { int t=i*d_S+s; d_NS[s*d_I+i] = t/d_I; d_OS[s*d_I+i] = t; } } generate_PS_PI(); generate_TM(); } //###################################################################### //# generate the PS and PI tables for later use //###################################################################### void fsm::generate_PS_PI() { d_PS.resize(d_S); d_PI.resize(d_S); for(int i=0;i<d_S;i++) { d_PS[i].resize(d_I*d_S); // max possible size d_PI[i].resize(d_I*d_S); int j=0; for(int ii=0;ii<d_S;ii++) for(int jj=0;jj<d_I;jj++) { if(d_NS[ii*d_I+jj]!=i) continue; d_PS[i][j]=ii; d_PI[i][j]=jj; j++; } d_PS[i].resize(j); d_PI[i].resize(j); } } //###################################################################### //# generate the termination matrices TMl and TMi for later use //###################################################################### void fsm::generate_TM() { d_TMi.resize(d_S*d_S); d_TMl.resize(d_S*d_S); for(int i=0;i<d_S*d_S;i++) { d_TMi[i] = -1; // no meaning d_TMl[i] = d_S; //infinity: you need at most S-1 steps if (i/d_S == i%d_S) d_TMl[i] = 0; } for(int s=0;s<d_S;s++) { bool done = false; int attempts = 0; while (done == false && attempts < d_S-1) { done = find_es(s); attempts ++; } if (done == false) { //throw std::runtime_error ("fsm::generate_TM(): FSM appears to be disconnected\n"); printf("fsm::generate_TM(): FSM appears to be disconnected\n"); printf("state %d cannot be reached from all other states\n",s); } } } // find a path from any state to the ending state "es" bool fsm::find_es(int es) { bool done = true; for(int s=0;s<d_S;s++) { if(d_TMl[s*d_S+es] < d_S) continue; int minl=d_S; int mini=-1; for(int i=0;i<d_I;i++) { if( 1 + d_TMl[d_NS[s*d_I+i]*d_S+es] < minl) { minl = 1 + d_TMl[d_NS[s*d_I+i]*d_S+es]; mini = i; } } if (mini != -1) { d_TMl[s*d_S+es]=minl; d_TMi[s*d_S+es]=mini; } else done = false; } return done; } //###################################################################### //# generate trellis representation of FSM as an SVG file //###################################################################### void fsm::write_trellis_svg( std::string filename ,int number_stages) { std::ofstream trellis_fname (filename.c_str()); if (!trellis_fname) {std::cout << "file not found " << std::endl ; exit(-1);} const int TRELLIS_Y_OFFSET = 30; const int TRELLIS_X_OFFSET = 20; const int STAGE_LABEL_Y_OFFSET = 25; const int STAGE_LABEL_X_OFFSET = 20; const int STATE_LABEL_Y_OFFSET = 30; const int STATE_LABEL_X_OFFSET = 5; const int STAGE_STATE_OFFSETS = 10; // std::cout << "################## BEGIN SVG TRELLIS PIC #####################" << std::endl; trellis_fname << "<svg viewBox = \"0 0 200 200\" version = \"1.1\">" << std::endl; for( int stage_num = 0;stage_num < number_stages;stage_num ++){ // draw states for ( int state_num = 0;state_num < d_S ; state_num ++ ) { trellis_fname << "<circle cx = \"" << stage_num * STAGE_STATE_OFFSETS + TRELLIS_X_OFFSET << "\" cy = \"" << state_num * STAGE_STATE_OFFSETS + TRELLIS_Y_OFFSET << "\" r = \"1\"/>" << std::endl; //draw branches if(stage_num != number_stages-1){ for( int branch_num = 0;branch_num < d_I; branch_num++){ trellis_fname << "<line x1 =\"" << STAGE_STATE_OFFSETS * stage_num+ TRELLIS_X_OFFSET << "\" "; trellis_fname << "y1 =\"" << state_num * STAGE_STATE_OFFSETS + TRELLIS_Y_OFFSET<< "\" "; trellis_fname << "x2 =\"" << STAGE_STATE_OFFSETS *stage_num + STAGE_STATE_OFFSETS+ TRELLIS_X_OFFSET << "\" "; trellis_fname << "y2 =\"" << d_NS[d_I * state_num + branch_num] * STAGE_STATE_OFFSETS + TRELLIS_Y_OFFSET << "\" "; trellis_fname << " stroke-dasharray = \"3," << branch_num << "\" "; trellis_fname << " stroke = \"black\" stroke-width = \"0.3\"/>" << std::endl; } } } } // label the stages trellis_fname << "<g font-size = \"4\" font= \"times\" fill = \"black\">" << std::endl; for( int stage_num = 0;stage_num < number_stages ;stage_num ++){ trellis_fname << "<text x = \"" << stage_num * STAGE_STATE_OFFSETS + STAGE_LABEL_X_OFFSET << "\" y = \"" << STAGE_LABEL_Y_OFFSET << "\" >" << std::endl; trellis_fname << stage_num << std::endl; trellis_fname << "</text>" << std::endl; } trellis_fname << "</g>" << std::endl; // label the states trellis_fname << "<g font-size = \"4\" font= \"times\" fill = \"black\">" << std::endl; for( int state_num = 0;state_num < d_S ; state_num ++){ trellis_fname << "<text y = \"" << state_num * STAGE_STATE_OFFSETS + STATE_LABEL_Y_OFFSET << "\" x = \"" << STATE_LABEL_X_OFFSET << "\" >" << std::endl; trellis_fname << state_num << std::endl; trellis_fname << "</text>" << std::endl; } trellis_fname << "</g>" << std::endl; trellis_fname << "</svg>" << std::endl; // std::cout << "################## END SVG TRELLIS PIC ##################### " << std::endl; trellis_fname.close(); } //###################################################################### //# Write trellis specification to a text files, //# in the same format used when reading FSM files //###################################################################### void fsm::write_fsm_txt(std::string filename) { std::ofstream trellis_fname (filename.c_str()); if (!trellis_fname) {std::cout << "file not found " << std::endl ; exit(-1);} trellis_fname << d_I << ' ' << d_S << ' ' << d_O << std::endl; trellis_fname << std::endl; for(int i=0;i<d_S;i++) { for(int j=0;j<d_I;j++) trellis_fname << d_NS[i*d_I+j] << ' '; trellis_fname << std::endl; } trellis_fname << std::endl; for(int i=0;i<d_S;i++) { for(int j=0;j<d_I;j++) trellis_fname << d_OS[i*d_I+j] << ' '; trellis_fname << std::endl; } trellis_fname << std::endl; trellis_fname.close(); }