Résumé : By analogy with an approach widely used in physics, we consider a discrete set of base stations (BS) as a continuum of transmitters. This model allows us to establish a simple closedform formula of the interferences and the SINR received by a mobile, whatever its location. As an application of this model, we propose an analytical study of a virtual MIMO network. Indeed, we consider that the useful power received by each user of a cell is the sum of useful powers coming from all base stations of the network. The physical wireless network model enables to quantify, in a simple way, the impact of virtual MIMO on the instantaneous throughput. We moreover show that the outage probability increases.