An Approach to Introducing Interference Aggregation Effect Into the Emission-Limit-Setting Model for Radio Protection

In this article, the effect of interference aggregation by unintentional emissions on the limit-setting model is investigated. It is assumed that emitters are uniformly distributed but excluded from a circular area with the radius of a reference distance. The mean, standard deviation, and probability density of the decibel-scaled aggregate interference power are estimated by deriving some approximate expressions and compared with those without aggregation. The results are validated with Monte Carlo simulations. It is shown that a critical emitter density given by a simple expression is an important index for evaluating the aggregation effect. For a very low emitter density, the probability density of the aggregate interference power exhibits a broadly distributed asymmetric shape, which results in a significant difference of the mean decibel-scaled interference power from the decibel conversion of the linear average. As the emitter density increases, the probability density becomes sharper and relatively symmetric owing to the interference aggregation. As a result, the standard deviation of the interference power decreases, and the mean decibel-scaled interference power approaches the decibel conversion of the linear average. On the basis of the obtained results, we discuss how the interference aggregation can be introduced into the probability factors in the conventional limit-setting model.