Abstract:

To simplify the problem of multiple lognormal random interferences, an equivalent method is proposed to approximate the sum of correlated random variables to the sum of uncorrelated ones. With this approximation, the theories based on uncorrelated shadowing model can be used to analyze and simulate the system performance in the presence of multiple correlated lognormal interferers by simply modifying the standard deviation of lognormal shadowing. The formula to modify the standard deviation is derived. The modified standard deviation is generally larger than the original one and increases with the correlation coefficient between lognormal interferers and with the number of interferers. With the Sørensen correlation model, the validity of the approximation method has been verified by simulation of both the cumulative distribution function of the total interference and the outage probability.

Key words: correlation, shadowing fading, interference, outage probability