Mathematical Representation of Noise

Department of ECE Raghu Institute of Technology 

Course : Digital Communications

Topic : Mathematical Representation of Noise Principles of Communication Systems, Third Edition Herbert Taub, Donald L Schilling, Goutam Saha

Sources of Noise • Thermal Noise • Shot Noise • Additive Noise • Multiplicative Noise (fading) • Gaussian Noise

Noise: Frequency Domain Representation

Noise : Power Spectrum

Noise Represetation

Filtering Gaussian Noise

Noise : Spectral Component

Noise : Narrowband Narrowband Filter Response

Noise PSD : Effect of Filter

Mixing Noise with Sinusoid

Mixing Noise with Noise

Linear Filtering of Noise

Noise and Low Pass Filter RC Low

Pass Filter:

Ideal Low Pass Filter:

Noise and Band Pass Filter

Noise and Differentiator  A differentiator follows

Noise and Integrator-1  An integrator follows

Noise and Integrator-2

Quadrature Components of Noise It is sometimes more advantageous to represent Narrowband noise centred around  f  0 as

Now,

PSD of Quadrature Components

Probability Density of Quadrature Components and Time Derivatives

Noise : Orthonormal Coordinates

Irrelevant Noise Components and Optimum Receiver

 End of Chapter 7