R18 B.TECH ECE

EC403PC: ANALOG AND DIGITAL COMMUNICATIONS

B.Tech. II Year II Semester L T P C

3 1 0 4

Prerequisite: Probability theory and Stochastic Processes

Course Objectives:

• To develop ability to analyze system requirements of analog and digital communication systems.
• To understand the generation, detection of various analog and digital modulation techniques.
• To acquire theoretical knowledge of each block in AM, FM transmitters and receivers.
• To understand the concepts of baseband transmissions.

Course Outcomes: Upon completing this course, the student will be able to

• Analyze and design of various continuous wave and angle modulation and demodulation techniques
• Understand the effect of noise present in continuous wave and angle modulation techniques.
• Attain the knowledge about AM , FM Transmitters and Receivers
• Analyze and design the various Pulse Modulation Techniques.
• Understand the concepts of Digital Modulation Techniques and Baseband transmission.

UNIT - I

Amplitude Modulation: Need for modulation, Amplitude Modulation - Time and frequency domain description, single tone modulation, power relations in AM waves, Generation of AM waves - Switching modulator, Detection of AM Waves - Envelope detector, DSBSC modulation - time and frequency domain description, Generation of DSBSC Waves - Balanced Modulators, Coherent detection of DSB-SC Modulated waves, COSTAS Loop, SSB modulation - time and frequency domain description, frequency discrimination and Phase discrimination methods for generating SSB, Demodulation of SSB Waves, principle of Vestigial side band modulation.

UNIT - II

Angle Modulation: Basic concepts of Phase Modulation, Frequency Modulation: Single tone frequency modulation, Spectrum Analysis of Sinusoidal FM Wave using Bessel functions, Narrow band FM, Wide band FM, Constant Average Power, Transmission bandwidth of FM Wave - Generation of FM Signal- Armstrong Method, Detection of FM Signal: Balanced slope detector, Phase locked loop, Comparison of FM and AM., Concept of Pre-emphasis and de-emphasis.

UNIT - III

Transmitters: Classification of Transmitters, AM Transmitters, FM Transmitters 

Receivers: Radio Receiver - Receiver Types - Tuned radio frequency receiver, Superhetrodyne receiver, RF section and Characteristics - Frequency changing and tracking, Intermediate frequency, Image frequency, AGC, Amplitude limiting, FM Receiver, Comparison of AM and FM Receivers.

UNIT - IV

Pulse Modulation: Types of Pulse modulation- PAM, PWM and PPM. Comparison of FDM and TDM.

Pulse Code Modulation: PCM Generation and Reconstruction, Quantization Noise, Non-Uniform Quantization and Companding, DPCM, Adaptive DPCM, DM and Adaptive DM, Noise in PCM and DM.

UNIT - V

Digital Modulation Techniques: ASK- Modulator, Coherent ASK Detector, FSK- Modulator, Non- Coherent FSK Detector, BPSK- Modulator, Coherent BPSK Detection. Principles of QPSK, Differential PSK and QAM.

Baseband Transmission and Optimal Reception of Digital Signal: A Baseband Signal Receiver, Probability of Error, Optimum Receiver, Coherent Reception, ISI, Eye Diagrams.

TEXTBOOKS:

1. Analog and Digital Communications – Simon Haykin, John Wiley, 2005.

2. Electronics Communication Systems-Fundamentals through Advanced-Wayne Tomasi, 5th

Edition, 2009, PHI.

REFERENCE BOOKS:

1. Principles of Communication Systems - Herbert Taub, Donald L Schilling, Goutam Saha, 3rd

Edition, McGraw-Hill, 2008.

2. Electronic Communications – Dennis Roddy and John Coolean , 4th Edition , PEA, 2004

3. Electronics & Communication System – George Kennedy and Bernard Davis, TMH 2004

4. Analog and Digital Communication – K. Sam Shanmugam, Willey ,2005