Wireless Communications Principles and Practice, Second Edition

Appendix F. Q, erf & erfc Functions

The Q-Function

Computation of probabilities that involve a Gaussian process require finding the area under the tail of the Gaussian (normal) probability density function as shown in Figure F.1.

Figure F.1. Gaussian probability density function. Shaded area is Pr(x ≥ x₀) for a Gaussian random variable.

Figure F.1 illustrates the probability that a Gaussian random variable x exceeds x₀, Pr(x ≥ x₀), which is evaluated as

Equation F.1. 

The Gaussian probability density function in Equation (F.1) cannot be integrated in closed ...