Analog and Digital Communication — Summer 2023

Describe the need of modulation in communication system.

Acarrier is frequency modulated with a sinusoidal signal of 2 khz 0 resulting in a maximum frequency deviation of 5 khz. Find i) Modulation index ii) bandwidth of modulated signal.

Describe briefly shot noise, Transit-time noise and flicker noise. Why they are generated?

Compare ASK and FSK.

An audio signal given as 15 sin (2π(1500t)) amplitude modulates a carrier given as 60 sin (2π(100,000t)). Determine the following 1.Determine the percentage of index 2.Determine all frequency component

Explain the working of amplitude demodulator circuit with the remedy for avoiding diagonal peak clipping and negative peak clipping?

List the methods used to generate SSB modulation signal .discuss any one method in detail.

ExplainPCM with necessary diagram.

What is noise Temperature and noise factor?

Discuss the basic principal of FM detection and explain Foster-seeley discriminator.

Explain PPM with necessary diagram.

Explain in brief shift keying (FSK) technique and list applications of it.

Discuss the importance of pre-emphasis and de-emphasis circuits in FM.

Explain CDMA in brief.

Write a difference between AM and FM receivers.

Draw the general block diagram of superheterodyne receiver and briefly explain the function of each block.

Write short note on latest trends in digital Communication.

Explain what double spotting is and how it arises.

Draw the block diagram of Tuned radio Frequency (TRF) Receiver and explain its operation. Describe the problems in TRF receiver.1

Compare DM and ADM.

Explain direct sequence spread spectrum system.

Explain non coherent detection of Amplitude shift keying (ASK) signal with necessary equations and diagrams.

Compare DPCM and PCM.

Explain Frequency hopping spread spectrum system.

Explain coherent detection of Frequency shift keying (FSK) signal with necessary equations.