modulations.c

5509的代码程序

extern int Cos_map[];
extern int Sin_map[];
extern int Ascend_coe[];
extern int CosW_array[];
extern int SinW_array[];

long sum;
int cos_part[124];   /*golbal vars -- stored in .bss section*/
int sin_part[124];

void modulation(int *point, int Out_p[])/*8psk  waveform  carrymodulation*/
{ 
  int *cos_p=Cos_map;
  int *sin_p=Sin_map;
  int *coe_p=Ascend_coe;
  int *CosW_p=CosW_array;
  int *SinW_p=SinW_array;
  int tribit=0;
  int i,j,k,m,n;
  int *p0,*p1,*p2;
  
  
  
  for (i=0;i<124;i++) {cos_part[i]=0; sin_part[i]=0;}
  
  /*8psk map */  
  for (i=0;i<16;i++)                         
  {
    tribit=*point++;
    cos_part[24+i*5]=cos_p[tribit];
    sin_part[24+i*5]=sin_p[tribit];  
  }
  
  /*I-waveform*/
  p0=p1=cos_part+44;
  p2=coe_p;
  for (i=1;i<=80;i++)
  {
    p1=p0;
    p2=coe_p;
    sum=0;
    for (j=1;j<=45;j++)
    {
      m=*p1--;
      n=*p2++;
      sum=sum+((long)m)*((long)n);
    }
    
    k=sum>>16;
   
    Out_p[i-1]=k;    /*stored in Out_p*/
    p0++;
    
  }
  
  /*Q-waveform*/
  p0=p1=sin_part+44;
  p2=coe_p;
  for (i=1;i<=80;i++)
  {
    p1=p0;
    p2=coe_p;
    sum=0;
    for (j=1;j<=45;j++)
    {
      m=*p1--;
      n=*p2++;
      sum=sum+((long)m)*((long)n);
    }
    
    k=sum>>16;
   
    cos_part[i-1]=k;    /*stored in cos_part*/
    p0++;
    
  }
  
  /*carry modulation*/
  /*I-carry modulation*/
  m=0;
  n=0;
  p1=Out_p;
  p2=CosW_p;
  for (i=1;i<=80;i++)
  {
    sum=0;
    m=*p1;
    n=*p2++;
    sum=(long)m*(long)n;
    *p1++=sum>>17;
    if(i%20==0)  p2=CosW_p;  /*stored in Out_p*/
  } 
  /*Q-carry modulation*/
  p1=cos_part;
  p2=SinW_p;
  for (i=1;i<=80;i++)
  {
    sum=0;
    m=*p1;
    n=*p2++;
    sum=(long)m*(long)n;
    *p1++=sum>>17;
    if(i%20==0)  p2=SinW_p;  /*stored in cos_part*/
  } 
  /*I+Q->Out_p*/
  p1=Out_p;
  p2=cos_part;
  for (i=1;i<=80;i++)
  {
    sum=0;
    m=*p1;
    n=*p2++;
    sum=(long)m+(long)n;
    *p1++=sum;
  }
  
  
  return;   
}