CRC programming code

1. EX.NO:13 DATE:
IMPLEMENTATION OF CRC
AIM:
To studythe CRC algorithmusingajava program.
ALGORITHM:
*Let g[x] be the generatorpolynomial &m[x] be the actual polynomial.
*Let the receivergetthe checksumframe.
*It shouldthatbe dividedbyg[x].
*If remainderisproduced,thenerroroccurs.
*Let 'r' numberof zero bettertothe lowerendof frame.
*Subtract the remainderfromthe message usingmodulo-2- subtraction.
*The resultisthe check sumframe to be transmitted.
*A receiverframe istobe dividedbythe generator.
*At the remainderiszero,thenthe divisioniscorrect,ifn’tanoccur hasoccurred
PROGRAM CODE
importjava.io.*;
importjava.util.*;
classprg13{
publicstaticvoidmain(Stringargs[])throwsIOException
{
DataInputStreamin=newDataInputStream(System.in);
System.out.println("Enterthe databitsto bitsto be transmitted=");
Stringm=in.readLine();
Stringmd=m;
System.out.println("Enterthe generatorcode");

2. Stringg=in.readLine();
for(intx=0;x<g.length()-1;x++){
m=m+"0";
}
char am[]=m.toCharArray();
char ag[]=g.toCharArray();
intlm=am.length;
intlg=ag.length;
inti=0;
for(;i<lm;i++){
while(i<(lm-1)&&am[i]=='0'){
i++;
}
if(i<(lm-lg+1)){
for(intj=0;j<lg;i++,j++)
{
if(am[i]==ag[j]){
am[i]='0';
}
else{
am[i]='1';
}}
i=0;
} else
i=lm;

3. }
inty=0;
while(y<(lm-1)&&am[y]=='0'){
y++;
}
for(;y<lm;y++)
md=md+am[y];
System.out.println("thetransmittedframe is:");
System.out.println(md);
System.out.println("theframe received:"+md);
Stringr=md;
if(r.equals(md))
System.out.println("The transmittedframe iscorrect");
else
System.out.println("The transmittedframe isincorrect");
}}
OUTPUT:
C:j2sdk1.4.0-rcbin>javacprg13.java
Note:prg13.javausesor overridesadeprecatedAPI.
Note:Recompile with -deprecationfordetails.
C:j2sdk1.4.0-rcbin>javaprg13
Enter the data bitsto bitsto be transmitted=
1110001
Enter the generatorcode
1101

4. the transmittedframe is:
111000110
the frame received:111000110
The transmittedframe iscorrect