Difficulty: Easy
Correct Answer: zero
Explanation:
Introduction / Context:
CRC (Cyclic Redundancy Check) is a widely used error-detecting code in data communications and storage. A frame or block is divided by a generator polynomial, and the remainder is appended at the sender. At the receiver, the same division is performed. Understanding what the receiver expects as the result of this division is fundamental to interpreting CRC checks correctly.
Given Data / Assumptions:
Concept / Approach:
The CRC property guarantees that if no bit errors have occurred and both ends use the same generator, the received codeword (data with CRC) is exactly divisible by the generator polynomial. In arithmetic terms, a correct frame yields a zero remainder at the receiver. A nonzero remainder indicates corruption or mismatch.
Step-by-Step Solution:
Verification / Alternative check:
Test with a simple generator (for example, G = 1101) on a small data sequence. Verify that the appended CRC makes the full sequence divisible by G with zero remainder; flipping any bit typically yields a nonzero remainder.
Why Other Options Are Wrong:
Common Pitfalls:
Confusing parity-like comparison with CRC's divisibility test, or assuming the receiver recomputes a remainder on raw data and compares it bitwise rather than checking for a zero remainder on the full codeword.
Final Answer:
zero
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