Following 7 bit single error correcting hamming coded message is received.
Determine if the message is correct (assuming that at most 1 bit could be corrupted). If the message contains an error find the bit which is erroneous and gives correct message.
Here Answer is yes. There is error in This message. Error is in bit 6.
How to calculate it ? First of all reverse given input to get it in correct position from 1 to 7.
Bit 1, Bit 2 & Bit 4 are partity bits.
Calculating position of error =>
c3 c2 c1
1 1 0
Here c1 = bit4⊕bit5⊕bit6⊕bit7=0⊕0⊕0⊕1=1 (Taking Even parity )
c2 = bit2⊕bit3⊕bit6⊕bit7=1⊕1⊕0⊕1=1
c3 = bit1⊕bit3⊕bit5⊕bit7=0⊕1⊕0⊕1=0
Ref -> https://en.wikipedia.org/wiki/Hamming%287,4%29
When you correct bit 6 .
You get message as 0110011.
IF you calculate C1,c2,c3 all will be 0 now !
See example here..
good read if u want to grasp it completely.
Error bit is 6 ... Msg is 1100110
the answer is wrong.it should be bit 6.if you consider forouzan's book of data networking, the answer should be bit 6.then the correct message will be 1100110.
her the parity bits are bit 1,bit 2, bit 4.
now to calculate bit 1=bit1⊕bit3⊕bit5⊕bit7=0⊕1⊕0⊕1=0
again,to calculate bit 2=bit2⊕bit3⊕bit6⊕bit7=1⊕1⊕0⊕1=1
again,to calculate bit 3=bit4⊕bit5⊕bit6⊕bit7=0⊕0⊕0⊕1=1
therefore ,the error is at the position 110 = 6
please ,think of it mr @jon_snow.
Your answer is correct !
Yes there is an error in this message at 6-bit position so the correct message is 1100110