Sampling – Aliasing- Signal Reconstruction-Quantization – Uniform & non-uniform quantization – quantization noise – Logarithmic Companding of speech signal- PCM – Properties of Line codes- Power Spectral Density of Unipolar / Polar RZ & NRZ – Bipolar NRZ – Manchester- ISI – Nyquist criterion for distortionless transmission – Pulse shaping – Correlative coding – Mary schemes – Eye pattern – Equalization.