Analog and Digital Communication — Summer 2025

Explain the importance of modulation in communication system.

Acarrier wave of 500 watts is subjected to 100% amplitude modulation. Determine:

power in sidebands. (ii) power of the modulated wave.

Explain various types of noises in the communication system and derive the relation between noise temperature and noise figure.

Define modulation index in AM modulation. What will be the effect on AM transmitted signal if the modulation index in 1 or 100%.

Explain Pre-emphasis and de-emphasys in FM System.

Define Amplitude Modulation. And Derive the expression of Amplitude modulation.

What is DSB-SC? Explain it with the help of a block diagram of the modulator and demodulator

Differentiate between FM and PM with mathematical expression.

Determine the bandwidth required for an FM signal having frequency 2KHz and a maximum Deviation 10KHz

Describe the methods used to generate SSB modulation signal. Explain any one method in detail.

Explain PPM with diagram.

Differentiate between PAM and PWM.

Explain FM Receiver with neat and clean diagram.

Explain with block diagram the Basic Radio communication channel with transmitter and receiver.

Explain Differential PCM.

Explain super-hetrodyne receiver with neat and clean diagram.

Differentiate between Analog and Digital Modulation.

Draw the frequency sectrum of sinusoidal FM.

Define the role of Quantization in commuication system. Explain PCM.

Write short note on latest trends in Digital Communication.

What is the effect of transmitted power in case of DSB and SSB-SC, explain with numerical calculation.

Compare different digital modulation techniques with example.1

Define Noise Figure(F). Explain its effect taking various cases (F=1,F>1 &F<1) in communication system.

Explain CDMA.

What is the difference between Coherent and Non-Coherent Detection techniques? Discuss Coherent detection techniques of FSK signal.