This chapter presents a collection of the most important probability density functions (pdfs) that are used to model several aspects of spectrum sensing, including channel impairments, data transmission, signal fading, and noise, in order to access the quality of the system. They can be used to compute the probability of error, or infer the results of hypothesis tests.
5.1 EXPONENTIAL DISTRIBUTION
The exponential pdf models the packet arrival time in a computer network, the duration of a call in a telephone system, and also the interval between the occupancy of spectrum holes in a cognitive network. This distribution is generally written as (Alencar and da Rocha Jr 2005),
in which ...