Full-Duplex Self-Backhaul Small Cell: Capacity Gain and Traffic Adaptation

Wireless backhaul, a cost-effective alternative to fiber, is becoming an attractive candidate for high-speed 5G deployment. Unlike half-duplex (HD) small cells that require either extra spectrum or well-designed time-frequency sharing to provide wireless backhaul, full-duplex (FD) self-backhaul small cells can reuse the same time-frequency resource to flexibly deliver low latency connections for both backhaul and small cell access. Additionally, FD capability simplifies the signaling design to coordinate backhaul and access transmission, thus reducing the overall network maintenance complexity. This paper investigates the performance advantage of FD self-backhaul over its HD counterpart. Our analysis shows that FD can achieve the most gain in scenarios where spectrum resource is under-utilized with HD small cells. Simulation results demonstrate that FD self-backhaul small cells can potentially achieve >1.8× spectral efficiency gain in overlay small cell deployments and around 5× latency reduction under imbalanced network loading conditions.