# Mumbai University Question Papers Analog and Digital Communication

# Mumbai University question papers

# IV Sem CSE

# Examination June 2010

# Analog and Digital Communication

N.S. (1) Question NO.1 is compulsory.

(2) Attempt any four questions from the remaining six questions.

(3) Answer to questions should be grouped and written together.

1. (a) An AM signal appears across a 50 n load has the following equation :-

V(t) = 12 (1 + sin 12.566 x 103t) sin 18.85 x 106 t Volts.

(i) Sketch the envelope of this signal in time domain.

(ii) Calculate the modulation index, side band frequencies, total power and bandwidth.

(b) Explain Ratio detector with circuit diagram and explain why Ratio detector preferred over Foster-Seeley detector for FM demodulation.

2. (a) Explain the transmitter and receiver for the Adaptive delta modulation system.

(b) Explain: (i) Shannon Hartley capacity theorem.

(ii) Shannon limit.

3. (a) Explain: (i) Intersymbol Interference and equalization.

(ii) White Gaussian noise.

(b) What is line coding? Draw the waveforms if the sequence is transmitted using

(i) Unipolar Rz (iv) Split Phase Manchester

(ii) Polar Rz (v) Mary where M = 4

(iii) AMI

Assume the binary sequence 1 1 0 1 0 0 1 1

4. (a) Write a short note on :-

(i) Viterbi Algorithm

(ii) Cyclic Code.

(b) The generator matrix of (6, 3) systematic block code is given by –

generator matrix of (6, 3) systematic block code is given by –

5

5

10

5. (a) Explain the QAM Transmitter and Receiver. 10

(b) Explain Differentialy Encoded PSK and also show that in DEPSK error occur in pair. 10

6. (a) State and prove the sampling theorem for Low pass filters.

(b) Explain TDM and FDM.

10

10

7. Write short notes on any

three

of the following :-

(a) Pre-emphasis and De-emphasis (c) Thermal Noise

(b) Ring Modulator (d) Companding.

(i) Find the code Vectors.

(ii) Find the parity check matrix.

(iii) Find the error syndrome.

5. (a) Explain the QAM Transmitter and Receiver.

(b) Explain Differentialy Encoded PSK and also show that in DEPSK error occur in pair.

6. (a) State and prove the sampling theorem for Low pass filters.

(b) Explain TDM and FDM.

7. Write short notes on any three of the following :-

(a) Pre-emphasis and De-emphasis (c) Thermal Noise

(b) Ring Modulator (d) Companding.