Downlink coverage performance of a relay cellular network considering non-uniform user distribution

Despite the complex cellular network models, when it comes to analytical techniques for modeling intercell interference, researchers often resort to simpler network models. The conventional network models such as the simple Wyner model including its modifications have been widely used for this purpose. However, all these network models including the popular grid based one-dimensional model have always considered users to be uniformly distributed within cells for simplicity. However, in a real cellular network users are not always uniformly distributed specially due to hot-spot regions and capacity centric deployment of base stations. Unfortunately, these popular network models are not capable of considering such non-uniform user distribution scenarios. As the performance evaluation of a cellular network will greatly depend on the cell´s user distribution, we propose a relay network model for downlink transmission which considers both uniform and non-uniform distribution of users. We compare the coverage performance of our proposed model with the complex grid model for a non-uniform user distribution scenario. We also show that using relays opportunistically near the cell boundary can improve coverage performance of a cell edge user to a great extent.