Communication Systems

EC3491

COMMUNICATION SYSTEMS

COURSE OBJECTIVES:

i. To introduce Analog Modulation Schemes

ii. To impart knowledge in random process

iii. To study various Digital techniques

iv. To introduce the importance of sampling & quantization

v. To impart knowledge in demodulation techniques

vi. To enhance the class room teaching using smart connectivity instruments

UNIT I

AMPLITUDE MODULATION

Review of signals and systems, Time and Frequency domain representation of signals, Principles of Amplitude Modulation Systems- DSB, SSB and VSB modulations. Angle Modulation, Representation of FM and PM signals, Spectral characteristics of angle modulated signals. SSB Generation – Filter and Phase Shift Methods, VSB Generation – Filter Method, Hilbert Transform, Pre-envelope & complex envelope AM techniques, Superheterodyne Receiver.

UNIT II

RANDOM PROCESS & SAMPLING

Review of probability and random process. Gaussian and white noise characteristics, Noise in amplitude modulation systems, Noise in Frequency modulation systems. Pre-emphasis and De- emphasis, Threshold effect in angle modulation. Low pass sampling – Aliasing- Signal Reconstruction-Quantization - Uniform & non-uniform quantization - quantization noise - Nyquist criterion- Logarithmic Companding –PAM, PPM, PWM, PCM – TDM, FDM

UNIT III

DIGITAL TECHNIQUES

Pulse modulation Differential pulse code modulation. Delta modulation, Noise considerations in PCM,, Digital Multiplexers, Channel coding theorem - Linear Block codes - Hamming codes - Cyclic codes - Convolutional codes - Viterbi Decoder

UNIT IV

DIGITAL MODULATION SCHEME

Geometric Representation of signals - Generation, detection, IQ representation, PSD & BER of Coherent BPSK, BFSK, & QPSK - QAM - Carrier Synchronization - Structure of Non-coherent Receivers Synchronization and Carrier Recovery for Digital modulation, Spectrum Analysis – Occupied bandwidth – Adjacent channel power, EVM, Principle of DPSK

UNIT V

DEMODULATION TECHNIQUES

Elements of Detection Theory, Optimum detection of signals in noise, Coherent communication with waveforms- Probability of Error evaluations. Baseband Pulse Transmission- Inter symbol Interference, Optimum demodulation of digital signals over band-limited channels.

TOTAL: 45 PERIODS

COURSE OUTCOMES:

At the end of the course students will be able to

CO1: Gain knowledge in amplitude modulation techniques

CO2: Understand the concepts of Random Process to the design of communication systems

CO3: Gain knowledge in digital techniques

CO4: Gain knowledge in sampling and quantization

CO5: Understand the importance of demodulation techniques

TEXTBOOKS :

i. Simon Haykins,” Communication Systems”, Wiley, 5th Edition, 2009.(Unit I - V)

ii. B.P.Lathi, “Modern Digital and Analog Communication Systems”, 4th Edition, Oxford University Press, 2011.

REFERENCES :

i. Wayner Tomasi, Electronic Communication System, 5th Edition, Pearson Education,2008.

ii. D.Roody, J.Coolen, Electronic Communications, 4th edition PHI 2006

iii. A.Papoulis, “Probability, Random variables and Stochastic Processes”, McGraw Hill, 3rd edition, 1991.

iv. B.Sklar, “Digital Communications Fundamentals and Applications”, 2nd Edition Pearson Education 2007

v. H P Hsu, Schaum Outline Series - “Analog and Digital Communications” TMH 2006

vi. Couch.L., "Modern Communication Systems", Pearson, 2001