Syllabus Communication Systems (EC3491) 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. (Chapters - 1, 2) 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. (Chapters - 3, 4) 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. (Chapters - 5, 6) 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. (Chapter - 7) 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. (Chapter - 8)
