  Full-duplex self-backhauling is promising to provide cost-effective and
flexible backhaul connectivity for ultra-dense wireless networks, but also
poses a great challenge to resource management between the access and backhaul
links. In this paper, we propose a user-centric joint access-backhaul
transmission framework for full-duplex self-backhauled wireless networks. In
the access link, user-centric clustering is adopted so that each user is
cooperatively served by multiple small base stations (SBSs). In the backhaul
link, user-centric multicast transmission is proposed so that each user's
message is treated as a common message and multicast to its serving SBS
cluster. We first formulate an optimization problem to maximize the network
weighted sum rate through joint access-backhaul beamforming and SBS clustering
when global channel state information (CSI) is available. This problem is
efficiently solved via the successive lower-bound maximization approach with a
novel approximate objective function and the iterative link removal technique.
We then extend the study to the stochastic joint access-backhaul beamforming
optimization with partial CSI. Simulation results demonstrate the effectiveness
of the proposed algorithms for both full CSI and partial CSI scenarios. They
also show that the transmission design with partial CSI can greatly reduce the
CSI overhead with little performance degradation.
