Analog communications

UNIT-1. INTRODUCTION TO COMMUNICATION SYSTEM

Introduction,Orientation Introduction to communication system, Need for modulation, Amplitude modulation, Time domain and Frequency domain description, Power relations in AM wave,, Square law modulator, Switching modulator, Detection of AM waves, Square law detector, Envelope detector.

UNIT-2. DSB MODULATION DSB-SC

modulation, time domain and frequency domain description, Generation of DSB-SC waves, Balanced Modulator, Ring Modulator, Coherent detection of DSB-SC Modulated waves, COSTAS Loop, Radio transmitter, Classification, AM Transmitter block diagram

UNIT- 3. SSB MODULATION

Frequency domain description, Frequency discrimination method for generation of AM- SSB Modulated wave, Time domain description, Phase discrimination method for generating of AM SSB Modulated waves, Demodulation of SSB Waves, Vestigial side band modulation, Generation of VSB modulated wave, Time domain description, Envelop detection of VSB wave pulse carrier, Comparison of AM techniques, Applications of different AM waves.

UNIT-4. ANGLE MODULATION CONCEPTS

Frequency Modulation, Single tone frequency modulation, Spectrum Analysis of Sinusoidal FM Wave, Narrow band FM, Wide band FM, Constant Average Power, Transmission band width of FM wave, Generation of FM Waves, Comparison of AM & FM

UNIT-5 . ANGLE MODULATION METHODS

 Generation of FM wave: Direct method, Parametric variation method, varactor diode, Reactance modulator, Armstrong method, Detection of FM waves, Balanced frequency discriminator, Zero crossing detector, Phase locked loop, Foster seely discriminator, ratio detector, FM transmitter block diagram.

UNIT-6. NOISE

 Nose in DSB and SSB system, Nose in A M system, Nose in angle modulated system, Threshold effect in Angle modulation system, Pre-emphasis and De-emphasis.

UNIT-7. RECEIVERS

 Receiver types, Tuned Radio Frequency receivers, Super heterodyne receiver, RF section and characteristics, Frequency changing and Tracking, Intermediate frequency, AGC, FM receiver, Comparison with AM receiver, amplitude limiting.

UNIT-8. PULSE MODULATION

Types of pulse modulation PAM, PWM, Generation and Demodulation of PWM, PPM, Generation and demodulation of PPM