Digital Communications Past Papers Exam Questions

By Prof. Fazal Rehman Shamil

Guess Paper 1: Digital Communications Fall  2020 Past Papers

Time Allowed: 3 hours

Total Marks:    70, Passing Marks (35)

Q.1. What is Demodulation? Briefly Discuss Base band Demodulation in detail.
(14)
Q.2. What is Digital communication system? Briefly explain the advantages of Digital communication system over analog communications . (4+10)

Q.3. Briefly discuss the Bit Error performance for binary systems (4+10)

Q.4. Briefly Explain Symbol error performance for M-ary systems. (14)

Q.5. Define and explain Noise Figure, Noise Temperature & System Temperature. (14)
Q.6. Draw PCM Transmitter Block Diagram. Explain function of each sub block PCM Transmitter. (14)
Q.7. (a) Define Channel Coding & Waveform Coding?
(b)Discuss in detail Equalization techniques. (14)

Q.8. Write short notes on any TWO of the following.
(a) Difference between Coherent and Non coherent Detection (07)
(b) Communication Link Budget Analysis (07)
(c) Bit Error performance for binary systems (07)

Guess Paper 2: Digital Communications Spring  2020 Past Papers

Time Allowed: 3 hours

Total Marks:    70, Passing Marks (35)

Q.1. Define Signal & Random Signal. Describe the process of Random signal in detail.
(14)
Q.2. What is Digital communication system. Briefly explain the advantages of Digital communication system over analog communications . (4+10)

Q.3. Briefly discuss the Detection of binary signals in Gaussian Noise (4+10)

Q.4. Briefly Explain Symbol error performance for M-ary systems. (14)

Q.5. Discuss in detail Correlation and Auto correlation. (14)

Q.6. Draw PCM Receiver Block Diagram. Explain function of each sub block PCM
Receiver. (14)
Q.7. (a) Define Channel Coding & Waveform Coding?
(b)Discuss in detail Equalization techniques. (14)

Q.8. Write short notes on any TWO of the following.
(a) Difference between Coherent and Non coherent Detection (07)
(b) ISI (Inter symbol Interference) (07)
(c) Bit Error performance for binary systems (07)

Guess Paper 3: Digital Communications Fall  2019 Past Papers

Time Allowed: 3 hours

Total Marks:    70, Passing Marks (35)

Q.1. Define Modulation and Demodulation? Briefly Discuss Base band Demodulation in detail.
(2+2+10)
Q.2. Define Digital communication system. Discuss the merits and demerits of Digital communication system in detail. (4+10)

Q.3. Explain the Equalization Techniques in detail. (4+10)

Q.4. Briefly Explain Symbol error performance for M-ary systems. (14)

Q.5. Define and explain Noise Figure, Noise Temperature & System Temperature. (14)
Q.6. Draw PCM Transmitter Block Diagram. Explain function of each sub block PCM Transmitter. (14)
Q.7. (a) Define Channel Coding & Waveform Coding?
(b)Discuss in detail Equalization techniques. (7+7)

Q.8. Write short notes on any TWO of the following.
(a) Communication Link Budget Analysis (07)
(b) Communication Link Budget Analysis (07)
(c) Bit Error performance for binary systems (07)

Prof.Fazal Rehman Shamil (Available for Professional Discussions)
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