WorksheetsWCT UNT 3
Total questions: 12
Worksheet time: 6mins
1. Which of the following is NOT one of the three basic propagation mechanisms in mobile radio communication?
a) Reflection
b) Diffraction
c) Refraction
d) Scattering
2. The phenomenon that allows radio signals to travel around obstacles like hills, even without a direct line-of-sight path, is known as:
a) Reflection
b) Diffraction
c) Scattering
d) Fading
3. What occurs when a propagating electromagnetic wave impinges on an object with large dimensions compared to its wavelength, such as a building wall?
a) Diffraction
b) Scattering
c) Reflection
d) Transmission
4. Path loss is defined as:
a) The increase in signal power density with distance.
b) The reduction in signal power density as a wave propagates through space.
c) The random variation in signal strength due to multipath.
d) The bending of radio waves around obstacles.
5. In a free space propagation model, the received power is ideally proportional to:
a) The distance (𝑑)
b) The square of the distance (𝑑2)
c) The inverse of the distance (1/𝑑)
d) The inverse of the square of the distance (1/𝑑2)
6. The propagation phenomenon where radio signals reach the receiving antenna via two or more paths is called:
a) Path loss
b) Fading
c) Multipath propagation
d) Scattering
7. Which of the following is a result of multipath propagation?
a) A constant signal amplitude and phase.
b) Constructive and destructive interference at the receiver.
c) Elimination of the need for a line-of-sight path.
d) An increase in signal power with distance.
8. When the mobile station is moving, the random frequency modulation of the signal due to different Doppler shifts on each multipath component causes:
a) Reflection
b) Diffraction
c) Fading
d) Path loss
9. Which modulation technique is a modified version of QPSK that minimizes phase transitions to reduce spectral regrowth?
a) MSK
b) GMSK
c) Offset-QPSK (OQPSK)
d) FDMA
10. MSK is a form of:
a) Phase modulation
b) Amplitude modulation
c) Continuous-phase frequency shift keying (CPFSK)
d) Quadrature amplitude modulation (QAM)
11. In DSSS (Direct Sequence Spread Spectrum), the user data is multiplied by a high-rate pseudo-noise (PN) code, which has the effect of:
a) Compressing the signal's bandwidth.
b) Spreading the signal's energy over a wider bandwidth.
c) Preventing all users from transmitting at the same time.
d) Assigning different frequency bands to each user.
12. In CDMA, multiple users can transmit simultaneously over the same wide frequency band because:
a) They use different time slots.
b) Their signals are separated by unique spreading codes.
c) Each user is assigned a separate frequency.
d) They only transmit one at a time.
