  A neighborhood restricted Mixed Gibbs Sampling (MGS) based approach is
proposed for low-complexity high-order modulation large-scale Multiple-Input
Multiple-Output (LS-MIMO) detection. The proposed LS-MIMO detector applies a
neighborhood limitation (NL) on the noisy solution from the MGS at a distance d
- thus, named d-simplified MGS (d-sMGS) - in order to mitigate its impact,
which can be harmful when a high order modulation is considered. Numerical
simulation results considering 64-QAM demonstrated that the proposed detection
method can substantially improve the MGS algorithm convergence, whereas no
extra computational complexity per iteration is required. The proposed
d-sMGS-based detector suitable for high-order modulation LS-MIMO further
exhibits improved performance vs. complexity tradeoff when the system loading
is high, i.e., when K >= 0.75. N. Also, with increasing the number of
dimensions, i.e., increasing the number of antennas and/or modulation order, a
smaller restriction of 2-sMGS was shown to be a more interesting choice than
1-sMGS.
