ABSTRACT
This chapter reviews some signal characteristics and system properties. The review helps to visualize the implementation of the basic ideas and the corresponding relationships among the building blocks. It aims to interpret a given signal and/or system scenario. Most problems addressed will be of the additive noise type that is the signal, if it is present, has an additive noise component. Some probability density functions occur frequently in communication/detection related work. The chapter examines some of the standard probability density functions. Gaussian random variables are closed under scalar multiplication and typical linear transformations. These properties are easily verified using the transformation of random variables or by using the characteristic function. The Rician density is a modified Rayleigh density which is obtained as the envelope of two independent Gaussian random variables that have one or two signal related components in one or both variables, respectively.
