Fairness Considerations for Full Duplex Multi-User MIMO Systems

We consider a cellular system with a full-duplex (FD) base station (BS) serving multiple uplink (UL) and downlink (DL) users simultaneously, where all the nodes are equipped with multiple antennas. The self-interference at the BS and the co-channel interference (CCI) caused by the UL users on the DL users are both taken into account. We address the proportional fairness (PF) issue of this system, which is important for networks with asymmetric topology and/or asymmetric traffic demands. The sum of the logarithm of the achievable rate of UL and DL users is maximized subject to power constraints at the BS and UL users. We develop a gradient projection (GP) method to solve this non-convex optimization problem, and demonstrate that the proposed algorithm provides a good balance between maximizing the sum-rate and maintaining fairness among users.