JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

Course Objectives:

• To understand the functional block diagram of Digital communication system.
• To understand the need for source and channel coding.
• To study various source and channel coding techniques.
• To understand a mathematical model of digital communication system for bit error rate analysis of different digital communication systems.

Course Outcomes

At the end of the course, the student will be able to:

• Understand basic components of Digital Communication Systems.
• Design optimum receiver for Digital Modulation techniques.
• Analyze the error performance of Digital Modulation Techniques.
• Understand the redundancy present in Digital Communication by using various source coding techniques.
• Know about different error detecting and error correction codes like block codes, cyclic codes and convolution codes.

UNIT - I

Elements of Digital Communication Systems: Model of Digital Communication Systems, Digital Representation of Analog Signal, Certain Issues in Digital Transmission, Advantages of Digital Communication Systems, Sampling Theorem, Types of Sampling – Impulse Sampling , Natural Sampling , Flat – Top Sampling. Introduction to Baseband Sampling.

Waveform Coding Techniques: PCM Generation and Reconstruction, Quantization Noise, Non Uniform Quantization and Companding, DPCM, Adaptive DPCM, DM and Adaptive DM, Noise in PCM and DM.

UNIT - II

Information theory: Information and Entropy, Conditional Entropy and Redundancy, Shannon-Fano Coding Mutual information, Information Loss due to Noise, Source coding- Huffman Code, Variable Length Coding, Lempel-ziv coding, Source coding to increase average information per bit, Lossy Source coding, Bandwidth-S/N Trade off, Hartley Shannon Law. Error Control Codes Linear Block Codes: Matrix Description of Linear Block Codes, Error Detection and Error Correction Capabilities of Linear Block Codes. Cyclic Codes: Algebraic Structure, Encoding, Syndrome Calculation, Decoding. Convolution Codes: Encoding, Decoding,

R16 B.TECH ECE.

UNIT - III

Baseband Pulse Transmission: Introduction, Matched Filter, Error Rate Due to Noise, intersymbol interference Nyquist's criterion for Distortionless Baseband Binary Transmission, Correlative -Level Coding Baseband M-Array PAM Transmission PAM Transmission, Digital subscriber Lines, Optimal Liner Receiver, Adaptive Equalization, Eye patterns. Digital pass band transmission: pass band transmission model, Gram-Schmidt orthogonalization procedure, Geometric interpretation of signals Coherent detection of signals in noise, probability of error, Correlation receiver.

UNIT - IV

Digital Modulation Techniques: Introduction, ASK, ASK Modulator, Coherent ASK Detector, Non-Coherent ASK Detector, FSK, Bandwidth and Frequency Spectrum of FSK, Non Coherent FSK Detector, Coherent FSK Detector, FSK Detection using PLL, BPSK, Coherent PSK Detection, QPSK, 8-PSK, 16-PSK Differential PSK, QAM .

UNIT - V

Spread Spectrum Modulation: Use of Spread Spectrum, Direct Sequence Spread (DSSS), and Code Division Multiple Access, Ranging using DSSS, Frequency Hopping Spread Spectrum, PN - Sequence: Generation and characteristics, Synchronization in Spread Spectrum Systems.

TEXT BOOKS:

• 1. Communications system, S. Haykin, Wiley, 4 edition 2009.
• 2. Digital and Analog Communication Systems – Sam Shanmugam, John Wiley, 2005.

REFERENCES:

• 1. Principles of Communication Systems - Herbert Taub, Donald L Schiling, Goutam Saha, 3rd Edition, McGraw-Hill, 2008
• 2. Electronic communication systems, Wayne Tomasi, 5 edition, Pearson
• 3. Communication Systems: Analog and Digital, R. P. Singh , S. Sapre, McGraw-Hill Education, 2012
• 4. Digital Communications – John G. Proakis , Masoud Salehi – 5th Edition, McGraw- Hill, 2008. R16 B.TECH ECE.