Massive MIMO-Enabled Wireless Backhauls for Full-Duplex Small Cells

Recent advancements in the self-interference (SI) cancellation capability of low power wireless devices pave the way of implementing full-duplex (FD) self-backhauling in small-cell networks. FD self-backhauling allows the use of conventional radio access network (RAN) spectrum for backhaul as well as access links concurrently. In this paper, we model and analyze massive MIMO- enabled wireless backhaul networks that are composed of a mixture of small cells, configured either in in-band or out-of-band backhaul mode with a certain probability. We consider a hierarchical network structure to model these networks and characterize the downlink coverage probability of a small cell base station (SBS) for both the in-band and out-of-band backhaul modes. The impact of co-tier and cross-tier backhaul interferences on downlink signal-to-interference ratio (SIR) coverage of small cell users is investigated. Numerical results demonstrate that implementing only either the in-band or out-of-band backhauling solutions may not be useful. Instead, a hybrid system with correct proportion of in-band and out-of-band small cells should be implemented.