OFDM Wireless LANs: A Theoretical and Practical Guide

Review of Stochastic Processes and Random Variables

The necessity for reviewing the subject of random processes in this text is that many digital communication signals [20, 21, 22, 25] can be characterized by a random or stochastic process. In general, a signal can be broadly classified as either deterministic or random. Deterministic signals or waveforms can be known precisely at instant of time, usually expressed as a mathematical function of time. In constrast, random signals or waveforms always possess a measure of uncertainty in their values at any instant in time since random variables are rules for assigning a real number for every outcome ξ of a probabilistic event. In other words, deterministic signals can be reproduced exactly with ...