Received power modelling in ultra-dense networks

In received power modelling for system level simulations, the relative orientation of the transmitter and receiver antennas are not generally considered. By doing that, a constant gain of the receiver antenna, independently of the angle of arrival, is implicitly assumed. This is usually of minor relevance for small or low-dense scenarios. However, in ultra-dense deployments, especially those based on cell-free massive multiple-input-multiple-output architectures where users interact with all access points, the consideration of the antennas relative orientation comes to the forefront. In this paper, the impact of whether to take the receiver antenna gain into account or not for ultra-dense indoor environments with ceiling-mounted antennas are studied. A simple approach to take this gain into account using the antenna effective area is provided. Finally, this approach is compared with that based on antenna radiation patterns.