Abstract
In the information-theoretic literature, Wyner's model has been the starting point for studying the capacity limits of cellular systems. This simple cellular model was adopted and extended by researchers in order to incorporate flat fading and path loss. However, the majority of these extensions preserved a fundamental assumption of Wyner's model, namely the collocation of User Terminals (UTs). In this paper, we alleviate this assumption and we evaluate the effect of user distribution on the sum-rate capacity. In this context, we show that the effect of user distribution is only considerable in low cell-density systems and we argue that "collocated" models can be utilized to approximate the "distributed" ones in the high cell-density regime. Subsequently, we provide closed forms for the calculation of the interference factors of "collocated" models given the system parameters. In addition, the asymptotics of the per-cell sum-rate capacity are investigated. Finally, the presented results are interpreted in the context of practical cellular systems using appropriate figures of merit.