Error Detection and Correction |
1 INCORRECT Which error detection method uses one's complement arithmetic? |
A) Simple parity check |
B) Two-dimensional parity check |
C) CRC |
correct D) Checksum |
2 CORRECT Which error detection method consists of just one redundant bit per data unit? |
correct A) Simple parity check |
B) Two-dimensional parity check |
C) CRC |
D) Checksum |
3 INCORRECT In cyclic redundancy checking, what is the CRC? |
A) The divisor |
B) The quotient |
C) The dividend |
correct D) The remainder |
4 INCORRECT In cyclic redundancy checking, the divisor is _______ the CRC. |
A) The same size as |
B) one bit less than |
correct C) one bit more than |
D) none of the above |
5 INCORRECT A burst error means that two or more bits in the data unit have changed. |
A) double-bit |
correct B) burst |
C) single-bit |
D) none of the above |
6 INCORRECT In ________ error correction, the receiver corrects errors without requesting retransmission. |
A) backward |
B) onward |
correct C) forward |
D) none of the above |
7 INCORRECT In ________ error correction, the receiver asks the sender to send the data again. |
A) backward |
correct B) retransmission |
C) forward |
D) none of the above |
8 INCORRECT We can divide coding schemes into two broad categories: ________ and ______coding. |
A) 'block; linear' |
B) 'linear; nonlinear' |
correct C) 'block; convolution' |
D) none of the above |
9 INCORRECT In modulo-2 arithmetic, __________ give the same results. |
A) addition and multiplication |
B) addition and division |
correct C) addition and subtraction |
D) none of the above |
10 CORRECT In modulo-2 arithmetic, we use the ______ operation for both addition and subtraction. |
correct A) XOR |
B) OR |
C) AND |
D) none of the above |
11 INCORRECT In _____ coding, we divide our message into blocks, each ofÿkÿbits, called ___. |
A) 'block; blockwords' |
B) 'linear; datawords' |
correct C) 'block; datawords' |
D) none of the above |
12 INCORRECT We addÿrÿredundant bits to each block to make the lengthÿnÿ=ÿkÿ+ÿr. The resultingÿn-bit blocks are called _________. |
A) datawords |
B) blockwords |
correct C) codewords |
D) none of the above |
13 INCORRECT The ________ between two words is the number of differences between corresponding bits. |
A) Hamming code |
correct B) Hamming distance |
C) Hamming rule |
D) none of the above |
14 INCORRECT To guarantee the detection of up to 5 errors in all cases, the minimum Hamming distance in a block code must be _______. |
A) 5 |
correct B) 6 |
C) 11 |
D) none of the above |
15 INCORRECT To guarantee correction of up to 5 errors in all cases, the minimum Hamming distance in a block code must be ________. |
A) 5 |
B) 6 |
correct C) 11 |
D) none of the above |
16 CORRECT In a linear block code, the _______ of any two valid codewords creates another valid codeword. |
correct A) XORing |
B) ORing |
C) ANDing |
D) none of the above |
17 INCORRECT A simple parity-check code can detect __________ errors. |
A) an even-number of |
B) two |
C) no errors |
correct D) an odd-number of |
18 INCORRECT _______codes are special linear block codes with one extra property. If a codeword is rotated, the result is another codeword. |
A) Non-linear |
B) Convolution |
correct C) Cyclic |
D) none of the above |
19 CORRECT The _____of errors is more difficult than the ______. |
correct A) 'correction; detection' |
B) 'detection; correction' |
C) 'creation; correction' |
D) 'creation; detection' |
20 INCORRECT In modulo-11 arithmetic, we use only the integers in the range ______, inclusive. |
A) 1 to 10 |
B) 1 to 11 |
correct C) 0 to 10 |
D) none of the above |
21 INCORRECT In modulo-2 arithmetic, we use only ______. |
A) 1 and 2 |
B) 0 and 2 |
correct C) 0 and 1 |
D) none of the above |
22 INCORRECT Adding 1 and 1 in modulo-2 arithmetic results in _________. |
A) 1 |
B) 2 |
correct C) 0 |
D) none of the above |
23 INCORRECT In block coding, if k =2 and n =3, we have _______ invalid codewords. |
A) 8 |
correct B) 4 |
C) 2 |
D) none of the above |
24 INCORRECT The Hamming distance between equal codewords is _________. |
A) 1 |
B) n |
correct C) 0 |
D) none of the above |
25 CORRECT The Hamming distance between 100 and 001 is ________. |
correct A) 2 |
B) 0 |
C) 1 |
D) none of the above |
26 INCORRECT In block coding, if n = 5, the maximum Hamming distance between two codewords is ________. |
A) 2 |
B) 3 |
correct C) 5 |
D) none of the above |
27 CORRECT If the Hamming distance between a dataword and the corresponding codeword is three, there are _____ bits in error. |
correct A) 3 |
B) 4 |
C) 5 |
D) none of the above |
28 INCORRECT The _______ of a polynomial is the highest power in the polynomial. |
A) range |
correct B) degree |
C) power |
D) none of the above |
29 INCORRECT The divisor in a cyclic code is normally called the _________. |
A) degree |
correct B) generator |
C) redundancy |
D) none of the above |
30 INCORRECT A generator that contains a factor of ____ can detect all odd-numbered errors. |
A) x |
correct B) x + 1 |
C) 1 |
D) none of the above |
31 INCORRECT Checksums use _________ arithmetic. |
A) two's complement arithmetic |
correct B) one's complement arithmetic |
C) either (a) or (b) |
D) none of the above |
32 INCORRECT In one's complement arithmetic, if positive 7 is 0111, then negative 7 is ________. |
A) 1111 |
B) 1101 |
correct C) 1000 |
D) none of the above |
33 INCORRECT The checksum of 1111 and 1111 is _________. |
A) 1111 |
correct B) 0 |
C) 1110 |
D) 111 |
34 CORRECT The checksum of 0000 and 0000 is __________. |
correct A) 1111 |
B) 0 |
C) 1110 |
D) 111 |