ESAT Forouzan - Chapter 4: Digital Transmission Flashcards
Unipolar, bipolar and polar encoding are types of _______ encoding
a. Line
b. Block
c. NRZ
d. Manchester
a. Line
If a symbol is composed of 3 bits, there are __________ data levels.
a. 2
b. 4
c. 8
d. 16
c. 8
Pulse rate is always ______ the bit rate
a. Greater than
b. Less than
c. Greater than or equal to
d. Less than or equal to
d. Less than or equal to
________ encoding has a transition at the middle of each bit.
a. RZ
b. Manchester
c. Differential Manchester
d. All the above
d. All the above
________ encoding has a transition at the beginning of each 0 bit.
a. RZ
b. Manchester
c. Differential Manchester
d. All the above
c. Differential Manchester
PCM is an example of ______ conversion.
a. Digital-to-digital
b. Digital-to-analog
c. Analog-to-analog
d. Analog-to-Digital
d. Analog-to-Digital
- If the frequency spectrum of a signal has bandwidth of 500 Hz with the highest frequency at 600 Hz, what should be the sampling rate, according to the Nyquist theorem?
a. 200 samples/s
b. 500 samples/s
c. 1000 samples/s
d. 1200 samples/s
d. 1200 samples/s
The Nyquist theorem specifies the minimum sampling rate to be _______.
a. Equal to the lowest frequency of a signal
b. Equal to the highest frequency of a signal
c. Twice the bandwidth of a signal
d. Twice the highest frequency of a signal
d. Twice the highest frequency of a signal
One factor in the accuracy of a reconstructed PCM signal is the __________.
a. Signal bandwidth
b. Carrier frequency
c. Number of bits used for quantization
d. Baud rate
c. Number of bits used for quantization
Which encoding type always has nonzero average amplitude
a. Unipolar
b. Polar
c. Bipolar
d. All the above
a. Unipolar
Which of the following encoding methods does not provide for synchronization?
a. NRZ-L
b. RZ
c. NRZ-I
d. Manchester
a. NRZ-L
Which encoding method uses alternating positive and negative values for 1s?
a. NRZ-I
b. RZ
c. Manchester
d. AMI
d. AMI
In PCM, an analog-to-____________ conversion occurs.
a. Analog
b. Digital
c. QAM
d. Differential
b. Digital
If the maximum value of a PCM signal is 31 and the minimum value is -31, how many bits were used for conding?
a. 4
b. 5
c. 6
d. 7
c. 6
RZ encoding involves _________ signal levels.
a. Two
b. Three
c. Four
d. Five
b. Three
Which quantization level results in a more faithful reproduction of the signal
a. 2
b. 8
c. 16
d. 32
d. 32
Which encoding technique attempts to solve the loss of synchronization due to long strings of 0s.
a. BnZS
b. NRZ
c. AMI
d. (a) and (b)
a. BnZS
Block coding can help in __________ at the receiver.
a. Synchronizations
b. Error detection
c. Attenuation
d. (a) and (b)
d. (a) and (b)
In ____________ transmission, bits are transmitted simultaneously, each across its own wire.
a. Asynchronous serial
b. Synchronous serial
c. Parallel
d. (a) and (b)
c. Parallel
In ________ transmission, bits are transmitted over a single wire, one at a time.
a. Asynchronous serial
b. Synchronous serial
c. Parallel
d. (a) and (b)
d. (a) and (b)
In __________ transmission, a start bit and stop bit frame a character byte.
a. Asynchronous serial
b. Synchronous serial
c. Parallel
d. (a) and (b)
a. Asynchronous serial
In asynchronous transmission, the gap time between bytes is ________.
a. Fixed
b. Variable
c. A function of the data rate
d. Zero
b. Variable
Synchronous transmission does not have __________.
a. A start bit
b. A stop bit
c. Gaps between bytes
d. All the above
d. All the above
