An improved analysis of outage probability with correlated co-channel interferers

The problem of computing the outage probability in mobile radio systems is investigated in the presence of log-normal shadowing. A relevant feature is that the proposed analysis assumes a general correlation for and pair of links. Various approaches are considered to compute the joint statistic of the user signal strength and the sum of interferers, namely: the Schwartz and Yeh's (1982) method, the Wilkinson's method, and the Fenton's (1960) method. All these methods, which are based on the log-normal approximation of the power sum of log-normal random variables, are extended in order to estimate the correlation coefficient between the user signal and the total interference. The accuracy of the methods is checked in a number of situations of interest, by comparing numerical results obtained from the analysis and results obtained from simulations. Moreover, in the particular case where the same correlation is assigned to any pair of links, we can observe that our analysis is more accurate than previously proposed approaches.