Title :
Highly accurate simple closed-form approximations to lognormal sum distributions and densities
Author :
Beaulieu, Norman C. ; Rajwani, Faruq
Author_Institution :
iCORE Wireless Commun. Lab., Univ. of Alberta, Edmonton, Canada
Abstract :
Sums of lognormal random variables occur extensively in wireless communications, in part, because a shadowing environment is well modeled by a lognormal distribution. A closed-form expression does not exist for the sum distribution and, furthermore, it is difficult to numerically calculate the distribution. Numerous approximations exist that are based on approximating a sum of lognormal random variables as another lognormal random variable. A new paradigm to calculate an approximation to the lognormal sum distribution, based on curve fitting on lognormal probability paper, is introduced in this letter. Highly accurate, simple closed-form approximations to lognormal sum distributions are presented.
Keywords :
curve fitting; log normal distribution; probability; radiocommunication; closed-form approximations; curve fitting; lognormal sum distributions; probability distributions; random variables; wireless communications; Closed-form solution; Curve fitting; Distributed computing; Helium; Probability density function; Probability distribution; Random variables; Shadow mapping; Tail; Wireless communication;
Journal_Title :
Communications Letters, IEEE
DOI :
10.1109/LCOMM.2004.837657