HetNet capacity with reduced power subframes

The time domain inter-cell interference coordination (eICIC) mechanism specified in LTE Rel. 10 improves the throughput of picocell-edge users by protecting them from macrocell interference. On the other hand, it also degrades the aggregate capacity in macrocell because the macro base station (MBS) does not transmit data during the coordinated subframes (CSFs). The MBS data transmission at a reduced power level during CSFs, which is referred to as FeICIC in LTE Rel. 11, can improve the capacity in macrocell while not causing high interference to the picocell users. Using stochastic geometry, this paper lays a theoretical foundation for analyzing the heterogeneous networks (HetNets) with reduced power subframes and range expansion bias (REB). The analytic expression for average capacity is derived and validated through Monte Carlo simulations. Our analysis shows that with optimum parameter settings FeICIC can provide substantially better performance than eICIC in terms of both aggregate capacity in a cell and fairness among the users.