Outage probabilities in CDMA networks with Poisson traffic

摘要

In the present paper, we consider a very general model of mobility, and investigate the spatial distribution of active mobile calls in the system at an arbitrary time t. We show that the set of active mobile locations forms a Poisson process in space. We consider a CDMA model with shadowing and distance-dependent path loss, and with soft handoff. We show that the set of active users in each cell (at time t) forms an independent Poisson process in space. We use Campbell's Theorem to characterize the first two moments of the interference of other-cell users at each cell-site, and in this way obtain a Gaussian approximation for the other-cell interference at time t. We consider an example and use this approximation to calculate outage probabilities and compare with simulation. Our work combines the theory of Poisson processes reviewed in [3], with that of CDMA traffic modeling. Due to the length limitation of the present paper, we do not have the opportunity here to develop the notation and theorems of Poisson processes, and refer the reader to [3] whenever we need to draw on this theory.