Optimal relay placement for cellular coverage extension

In this paper, we address the problem of optimal relay placement in cellular networks for maximum extension of coverage area. We present a novel definition of the coverage radius after the introduction of relays. Using this, we determine the optimal relay positions to maximize the coverage radius and estimate the number of relays required per cell. We also analyze relay placement in the multi-cell scenario, which takes into account inter-cell interference, a dominant factor in the next generation cellular Orthogonal Frequency Division Multiple Access (OFDMA) systems. Considering inter-cell interference in the multi-cell scenario, leads to an interesting iterative algorithm which is used to determine the optimal relay station (RS) positions.