Consider the following message M = 1010001101. The cyclic redundancy check…
2005
Consider the following message M = 1010001101. The cyclic redundancy check (CRC) for this message using the divisor polynomial x5 + x4 + x2 + 1 is :
- A.
01110
- B.
01011
- C.
10101
- D.
10110
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Correct answer: A
Answer: 01110
Convert the generator polynomial x^5 + x^4 + x^2 + 1 to divisor bits: 110101 (degree 5).
Append five 0 bits to the message: 1010001101 → 101000110100000.
Perform binary long division (bitwise XOR subtraction) of the extended message by the divisor 110101. The remainder after completing the division is 01110.
Append this remainder to the original message to get the transmitted frame: 1010001101 01110 → 101000110101110.
Verification: dividing the transmitted frame 101000110101110 by 110101 yields a zero remainder, confirming the CRC is correct.
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