# Recent questions tagged error-detection 1 vote
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Following text and screenshot are taken from Forouzan's CN book: "In a linear block code, the exclusive OR (XOR) of any two valid codewords creates another valid codeword." My question is EXoring of which two codewords in Table 10.2 will create first codeword 00000?
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Suppose that a message 1001 1100 1010 0011 is transmitted using Internet Checksum (4-bit word). What is the value of the checksum?
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Data is transmitted continuously at $2.048$ Mbps rate for $10$ hours and received $512$ bits errors. What is the bit error rate? $\text{6.9 e-9}$ $\text{6.9 e-6}$ $\text{69 e-9}$ $\text{4 e-9}$
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A block of bits with $n$ rows and $m$ columns uses horizontal and vertical parity bits for error detection. If exactly 4 bits are in error during transmission, derive an expression for the probability that the error will be detected.
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Consider the use of Cyclic Redundancy Code (CRC) with generator polynomial $G(x)$ for error detection. Recall that error detection with a CRC works by appending the CRC value to the bit sequence to make it a multiple of $G(x)$ ... a burst error of length $5$ in such a way that the error cannot be detected by the CRC with the $G(x)$ given above.
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How many check bits are required for $16$ bit data word to detect $2$ bit errors and single bit correction using hamming code? $5$ $6$ $7$ $8$
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How many parity bits will be required for transmitting a 16-bit data ? a 6 b 3 c 2 d 1
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In a communication network, a packet of length $L$ bits takes link $L_1$ with a probability of $p_1$ or link $L_2$ with a probability of $p_2$. Link $L_1$ and $L_2$ have bit error probability of $b_1$ and $b_2$ ... $[1 - (b_1 + b_2)^L]p_1p_2$ $(1 - b_1)^L (1 - b_2)^Lp_1p_2$ $1 - (b_1^Lp_1 + b_2^Lp_2)$
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A software was tested using the error seeding strategy in which 20 errors were seeded in the code. When the code was tested using the complete test suite, 16 of the seeded errors were detected. The same test suite also detected 200 non-seeded errors. What is the estimated number of undetected errors in the code after this testing? 4 50 200 250
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An error correcting code has the following code words: $00000000, 00001111, 01010101, 10101010, 11110000$. What is the maximum number of bit errors that can be corrected? $0$ $1$ $2$ $3$
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Data transmitted on a link uses the following $2D$ parity scheme for error detection: Each sequence of $28$ bits is arranged in a $4\times 7$ matrix (rows $r_0$ through $r_3$, and columns $d_7$ through $d_1$) and is padded with a column $d_0$ and row $r_4$ of parity bits ... shows data received by a receiver and has $n$ corrupted bits. What is the mini­mum possible value of $n$? $1$ $2$ $3$ $4$
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What is the distance of the following code $000000$, $010101$, $000111$, $011001$, $111111$? $2$ $3$ $4$ $1$
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Following $7$ ... (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.
Let $G(x)$ be the generator polynomial used for CRC checking. What is the condition that should be satisfied by $G(x)$ to detect odd number of bits in error? $G(x)$ contains more than two terms $G(x)$ does not divide $1+x^k$, for any $k$ not exceeding the frame length $1+x$ is a factor of $G(x)$ $G(x)$ has an odd number of terms.
The message $11001001$ is to be transmitted using the CRC polynomial $x^3 +1$ to protect it from errors. The message that should be transmitted is: $11001001000$ $11001001011$ $11001010$ $110010010011$
Consider a $3$-$bit$ error detection and $1$-$bit$ error correction hamming code for $4$-$bit$ data. The extra parity bits required would be ___ and the $3$-$bit$ error detection is possible because the code has a minimum distance of ____.