  We propose new low-fidelity (LoFi) user equipment (UE) scheduling algorithms
for multiuser multiple-input multiple-output (MIMO) wireless communication
systems. The proposed methods rely on an efficient guess-and-check procedure
that, given an objective function, performs paired comparisons between random
subsets of UEs that should be scheduled in certain time slots. The proposed
LoFi scheduling methods are computationally efficient, highly parallelizable,
and gradient-free, which enables the use of almost arbitrary,
non-differentiable objective functions. System simulations in a millimeter-wave
(mmWave) multiuser MIMO scenario demonstrate that the proposed LoFi schedulers
outperform a range of state-of-the-art user scheduling algorithms in terms of
bit error-rate and/or computational complexity.
