ACS CA1

 

Part A

1. ASK stands for: 

a) Amplitude Shift Keying b) Amplitude Sharing Keying 

c) Analog Signal Keying d) Amplitude Sampling Key 

2. In FSK, data is represented by changes in: 

 a) Phase b) Frequency c) Amplitude d) Pulse width 

3. Which modulation technique changes the phase of the carrier 

signal? 

 a) ASK b) FSK c) PSK d) QAM 

4. The basic concept of OFDM is: 

a) Single carrier transmission b) Multi-carrier transmission 

c) Pulse width modulation d) Frequency multiplexing 

5. QPSK transmits: 

a) One bit per symbol b) Two bits per symbol c) Three bits 

per symbol d) Four bits per symbol 

6. The orbit in which a satellite remains fixed relative to the earth is 

called: 

a) Polar orbit b) Elliptical orbit c) Geostationary orbit d) 

Low earth orbit 

7. The point nearest to Earth in the satellite orbit is known as: 

 a) Apogee b) Perigee c) Nadir d) Zenith

8. TDMA stands for: 

a) Time Division Multiple Access b) Time Delay Multiple Access 

c) Time Dependent Modulation Access d) Transmission Data 

Modulation Access 

9. The frequency band used for satellite communication is: 

 a) HF b) VHF c) C band d) MF 

10. GPS is primarily used for: 

a) Audio transmission b) Positioning and navigation c) 

Video compression d) Digital signal processing

Mobile Comunication CA 1

 

Part A ( one marks )

1. Large-scale path loss in mobile communication mainly depends on: 

 a) Frequency b) Distance c) Environment d) All of these 

2. Which mechanism causes bending of radio waves around obstacles? 

 a) Reflection b) Diffraction c) Scattering d) Polarization 

3. Small-scale fading occurs due to: 

a) Long-term variation in signal strength b) Multipath propagation c) 

Absorption loss d) Interference only 

4. The free-space propagation model assumes: 

a) No reflection and diffraction b) Multiple reflections c) Obstacles 

present d) Attenuation zero 

5. The two-ray ground reflection model is used to study: 

a) Signal path loss over short distances b) Long-distance propagation 

c) Only direct waves d) Only reflected waves 

6. Frequency reuse in cellular systems helps in: 

a) Increasing capacity b) Reducing coverage c) Improving bandwidth 

d) Decreasing number of cells 

7. Channel assignment strategy is used for: 

a) Allocating frequencies b) Signal amplification c) Multiplexing 

d) Modulation

8. Handoff occurs when: 

a) A mobile moves out of coverage b) A call is dropped c) Signal strength 

increases d) Frequency is reused

9. Handoff prioritization ensures: 

a) Continuous call b) Reduced capacity c) More interference d) Better 

modulation 

10. Practical handoff consideration involves: 

 a) Threshold margin b) Antenna height c) Bandwidth d) Duplexing

Part B 2 Marks

1.Define large-scale path loss. 

2. Write short notes on propagation mechanisms in mobile 

radio. 

3.List any two advantages of frequency reuse.

 4.Mention any two factors affecting handoff. 

Part C ( 3 Marks )

1.What are two-ray propagation models?

2.Write the effect of small scale fading. 

3.List the handoff strategies used in mobile networks. 

4.What are channel assignment strategies?