  We propose an effective interference management and beamforming mechanism for
uplink communication systems that yields fair allocation of rates. In
particular, we consider a hotspot area of a millimeter-wave (mmWave) access
network consisting of multiple user equipment (UE) in the uplink and multiple
access points (APs) with directional antennas and adjustable beam widths and
directions (beam configurations). This network suffers tremendously from
multi-beam multi-user interference, and, to improve the uplink transmission
performance, we propose a centralized scheme that optimizes the power, the beam
width, the beam direction of the APs, and the UE - AP assignments. This problem
involves both continuous and discrete variables, and it has the following
structure. If we fix all discrete variables, except for those related to the
UE-AP assignment, the resulting optimization problem can be solved optimally.
This property enables us to propose a heuristic based on simulated annealing
(SA) to address the intractable joint optimization problem with all discrete
variables. In more detail, for a fixed configuration of beams, we formulate a
weighted rate allocation problem where each user gets the same portion of its
maximum achievable rate that it would have under non-interfered conditions. We
solve this problem with an iterative fixed point algorithm that optimizes the
power of UEs and the UE - AP assignment in the uplink. This fixed point
algorithm is combined with SA to improve the beam configurations. Theoretical
and numerical results show that the proposed method improves both the UE rates
in the lower percentiles and the overall fairness in the network.
