Throughput Performance of Denser Mobile Networks Incorporating Fiber-Optic Relay Nodes

Denser mobile networks can reduce user equipment (UE)-to base station (BS) distance and thus improve the link budget. Heterogeneous networks and relay technology can reduce the distance between UE and BS. Conventional relay node (RN) suffers from a self-interference problem, if the carrier frequencies used for the backhaul (BS–RN) and access (RN–UE) links are the same and when the two links simultaneously operate. To mitigate the self-interference, we have proposed a new type of RNs in which the antenna facing the BS is geographically separated from the antenna facing the UE, and the two antennas are connected by an optical fiber. So far, we have investigated the theoretical desired signal to self-interference ratio as parameters of the optical fiber length, and validated the design method for the proposed fiber-optic RNs. In this paper, we investigate the user throughput performance of denser mobile networks incorporating the fiber-optic RNs. Using system-level computer simulations, we clarify the user throughput of the networks incorporating the fiber-optic RNs versus distance between BS and the RN facing UE.