Moments of the sum of correlated log-normal random variables

The paper presents a comparison of Fenton´s (1960) and Schwartz and Yeh´s (1982) methods concerning their capability of predicting the mean and the variance of the sum of a finite number of correlated log-normal random variables. The predictions by the two methods differ more with decreased correlation between the log-normal components, with increasing number of components and increasing component variance. Schwartz and Yeh´s method seems to provide more realistic predictions for the mean and the standard deviation of the power sum by showing a closer agreement with the results of an exact formulation for the outage probability in mobile radio systems.