Implementation of error detection & correction methods in C

TITLE: Lab #7- Implementation of error detection & correction methods in C

Objective: 

To implement CRC encoding at the Sender, and CRC decoding at the Receiver

In C, write a function MakeCRC, which takes in 2 parameters Divisor and Dividend, and returns a Remainder.
At the Sender, provide the Divisor and Dividend according to Figure 10.15.
Check that MakeCRC returns the correct remainder, to be appended to the Dataword.
At the Receiver, enter the Dataword, as the Dividend to the MakeCRC function.
If no error is detected, the Remainder (also known as the Syndrome) is 000.  Else, an error has been detected.
Inject error(s) into the Dataword received by the Receiver:-
single-bit (isolated) errors

• burst (consecutive) errors

Is the Receiver able to detect the errors? 

Send the data - 1001000 - using the divisor - 1000.

Inject single-bit error(s) into the Dataword received by the Receiver.

Is the Receiver able to detect the errors?  Why?

Answer:- 
 

#include<stdio.h>

#include<string.h>

int dividend[7]={1,0,0,1,0,0,0};

int divisor[4]={1,0,1,1};

int dividend1[7];

void makecrc(){

int len1=(sizeof(dividend)/sizeof(int));

int len2=(sizeof(divisor)/sizeof(int));

//printf("%d",len2);

int i;

for(i=0;i<len2;i++){

if(dividend[i]==1) {

int j;

 

for(j=0;j<len2;j++){

dividend[i+j]=dividend[i+j]^divisor[j];

//printf("%d\n",dividend[i+j]);

}

}

else{ int j;

for(j=0;j<len2;j++){

dividend[i+j]=dividend[i+j]^0;

//printf("%d\n",dividend[i+j]);

}

}

}

//return dividend;

}

void sender(){

int len1=(sizeof(dividend)/sizeof(int));

int len2=(sizeof(divisor)/sizeof(int));

int i;

for(i=0;i<len1;i++)

dividend1[i]=dividend[i];

makecrc();

for(i=0;i<len2;i++)

dividend[i]=dividend1[i];

//dividend[0]=0;(For inserting single bit error )

/*for(i=3;i<=5;i++)(For inserting burst Error )

dividend[i]=0;*/

printf("The new dividend!");

for(i=0;i<len1;i++)

printf("%d",dividend[i]);

printf("\n");

}

void receiver(){

int len1=(sizeof(dividend)/sizeof(int));

int len2=(sizeof(divisor)/sizeof(int));

int i,c=0;

makecrc();

for(i=len2;i<len1;i++){

if(dividend[i]!=0)

break;

else

c=1;

}

if(c==1)

printf("No Error DEtected!\n");

else

printf("Error Detected! \n");

}

int main(){

printf("Calling the sender Function.....\n");

sender();

printf("Calling the receiver Function\n");

receiver();

/*int i;

makecrc();

for(i=4;i<7;i++)

printf("%d ",dividend[i]);

printf("\n");*/

return 0;

}

 

Checking without error:-

 

Yes,it can identify both single bit error as well as burst error.

Checking with Singlebit error:-

Checking with Burst error:-