Leveraging interference for increasing throughput and reliability of commercial wireless femtocells

Small cells continue to increase in popularity among 3G and 4G LTE service providers as a solution to provide coverage in dead zones and to offload traffic from the macro base to service more customers without adding more frequency bands. Issues with wide spread deployment of small cells include interference-degraded links and higher dropped call rates. This paper considers HetNets with a dense deployment of closed access femtocells that is likely to be typical for future dense HetNets. We investigate whether a new interference leveraging scheme that relies upon multiuser detection (MUD) can successfully mitigate interference problems arising due to closed access femtocells. A combined Monte Carlo simulation and information theoretical approach is used to compute upper bounds on throughput that can be achieved in the system. The paper compares achievable throughput in HetNets with open access femtocells, closed access femtocells with non-MUD receivers, and closed access femtocells with smart-MUD interference mitigation receivers. Preliminary results shown in this paper indicate that smart-MUD enabled femtocells (HeNBs) can successfully operate in closed access mode and can establish links in occupied bands as well as survive severe interference to already-established small cell and macrocell links. Similarly, preliminary results indicate that smart-MUD enabled UEs can mitigate downlink interference coming from closed access femtocells and significantly improve throughput.