variablenode.c

根据LDPC码中码子的构造方法中的PEG算法

#include <iostream.h>
#include <stdio.h>
#include "VariableNode.h"
#include "Constant.h"
//#include "System.h"

VariableNode::VariableNode(const char *name, int id, int numNeighbours, int size) : Node(name, id, numNeighbours) {
  (*this).size = size;
}

void VariableNode::update(int port) {

  if (numNeighbours > 1) {
    
    // initialization of the output message
    outMessages[port][0] = 0.0;
    
    // update
    for (int n = 0; n < numNeighbours; n++) {
      if (n == port) {
	continue;
      }
      outMessages[port][0] += (*neighbours[n]).getOutMessage(portNumbers[n])[0];
    }
  }
}

void VariableNode::initAsFirstTrellisState(double *outMessageValues){
  if (outMessageValues == NULL) {
    // assume that the zero state is prefered
    for (int i = 1; i < size; i++) {
      outMessages[0][i] = EPS;
    }
    outMessages[0][0] = 1.0 - (size - 1)*EPS;
  } else {
    for (int i = 0; i < size; i++) {
      outMessages[0][i] = outMessageValues[i];
    }
  }
}

void VariableNode::reset(void) {
  for (int n = 0; n < numNeighbours; n++) {
    for (int i = 0; i < size; i++) {
      outMessages[n][i] = 0.0;  //  1.0/size;
    }
  }  
}

int VariableNode::getSize(void) {
  return (size);
}

void VariableNode::draw(void) {
  printf("NODE: %20s, %6d\n", name, id);
  printf("---------------------------------------------\n");
  printf("PORT      NEIGHBOUR                OUTMESSAGE\n");
  for (int n = 0; n < numNeighbours; n++) {
    printf("%3d       %20s%15f\n", n, (*neighbours[n]).getName(), outMessages[n][0]);
    for (int i = 1; i < size; i++) {
      printf("%45f\n", outMessages[n][i]);
    }
  }
  printf("\n");
}

void VariableNode::draw(FILE *file) {
  fprintf(file, "NODE: %20s, %6d\n", name, id);
  fprintf(file, "---------------------------------------------\n");
  fprintf(file, "PORT      NEIGHBOUR                OUTMESSAGE\n");
  for (int n = 0; n < numNeighbours; n++) {
    fprintf(file, "%3d       %20s%15f\n", n, (*neighbours[n]).getName(), outMessages[n][0]);
    for (int i = 1; i < size; i++) {
      fprintf(file, "%45f\n", outMessages[n][i]);
    }
  }
  fprintf(file, "\n");
}

void VariableNode::test(void) {
  VariableNode *node1, *node2, *node3, *node4;
  node1 = new VariableNode("AAA", 1, 2, 2);
  node2 = new VariableNode("BBB", 2, 2, 2);
  node3 = new VariableNode("CCC", 3, 1, 2);
  node4 = new VariableNode("DDD", 4, 3, 2);
  VariableNode::connect(node1, node4, 0, 0, 2);
  VariableNode::connect(node2, node4, 0, 1, 2);
  VariableNode::connect(node3, node4, 0, 2, 2);
  VariableNode::connect(node1, node2, 1, 1, 2);
  (*node1).draw();
  (*node2).draw();
  (*node3).draw();
  (*node4).draw();
  (*node1).reset();
  (*node2).reset();
  (*node3).reset();
  (*node4).reset();
  (*node1).draw();
  (*node2).draw();
  (*node3).draw();
  (*node4).draw();
  delete node1;
  node1 = NULL;
  delete node2;
  node2 = NULL;
  delete node3;
  node3 = NULL;
}