NATIONAL OPEN UNIVERSITY OF NIGERIA

UNIVERSITY VILLAGE, PLOT 91, CASDASTRAL ZONE, NNAMDI AZIKIWE EXPRESS WAY, JABI, ABUJA.
FACULTY OF SCIENCES
APRIL 2019 EXAMINATION

Course Code:              CIT758                                                           

Course Title:              WIRELESS COMMUNICATION II

Credit Unit:                3 units

Time Allowed:            2½ Hours

Instruction:                Answer Question 1 and any other FOUR (4) questions

1a) Briefly describe the four distinct components/subsystems of a cellular system  (10 marks)

1b) With the aid of a mathematical model, explain the concept of Free Space Propagation. (5 marks)

1c) Discuss Link budget (4 marks)

1d) State three importance of link budget (3 marks)

2(a) Explain two types of channel assignment (4 marks)

2b)  What is Equivalent Isotropically Radiated Power (EIRP)? (4 marks)

2c)  State four characteristics of Medium Earth Orbit (4 marks)

3a)  List two types of Error control methods (2 marks)

3b)  Write short notes on Error Detection Code scheme (5 marks)

3c)  Explain the term ‘fading’ and its effect in radio channel and digital transmissions (5 marks)

4a)  Give four types of error detection  (4 marks)

4b)  List eight examples of Wireless Communication devices (4 marks)

4c) State four benefits of Diversity scheme in telecommunications (4 marks)

5a)  Mention four types of diversity scheme in telecommunications (4 marks)

5b) Distinguish between 'flat' fading and 'frequency-selective' fading with respect to ‘coherence bandwidth’ of a channel. (4 marks)

5c)  State four features of Low Earth Orbits(4 marks)

6a) List the advantages and disadvantage of Medium Earth Orbit satellites  (3 marks)

6b)  Enumerate four types of modulation techniques (4 marks)

6c)  Compare Microwaves and radio waves for satellite communications  (5 marks)