Capacity Benefits of Relays with In-Band Backhauling in Cellular Networks

In this paper, the feasibility and capacity benefits of deploying low-cost relay nodes with in-band wireless backhaul capability in cellular networks are studied. Our proposed scheme is similar to a cell-splitting architecture where the base station density is increased, thus reducing the effective cell size. Cell-splitting in an interference-limited deployment provides capacity gains that are proportional to the number of additional base stations deployed, but at significant cost driven primarily by wired backhaul requirements. The use of in-band wireless backhaul may significantly reduce the cost, but sharing bandwidth with the backhaul results in reduced access rates relative to that of cell-splitting with wired backhaul. Further cost savings may be achieved with the use of low power, low complexity relays in lieu of the additional base stations. In this paper, we show that a cellular architecture with base stations supplemented by simple decode-and-forward relays can provide significant capacity improvements despite the overhead associated with in-band backhaul.