Capacity Scaling of Indoor Pico-cellular Networks via Reuse
01 February 2012
Cell splitting/frequency reuse is a fundamental characteristic of cellular networks. In macrocellular networks, where pathloss is governed by the distance-to-a-power law, the SINR distribution is invariant to scale, i.e. the spectral efficiency per base (bps/Hz/base) remains constant, and hence the capacity increases linearly with the density of cells. We show for indoor networks, where signals suffer exponential loss in addition to the inverse square distance law, the median SINR decreases with the density of cells. This results in the capacity being proportional to the square-root of the improvement in the density of cells. As a consequence of this scaling, when thermal noise is not a concern, multiple antenna techniques, can be more effective per antenna rather than increasing cell density.