  Overcoming the conventional trade-off between throughput and bit error rate
(BER) performance, versus computational complexity is a long-term challenge for
uplink Multiple-Input Multiple-Output (MIMO) detection in base station design
for the cellular 5G New Radio roadmap, as well as in next generation wireless
local area networks. In this work, we present ParaMax, a MIMO detector
architecture that for the first time brings to bear physics-inspired parallel
tempering algorithmic techniques [28, 50, 67] on this class of problems.
ParaMax can achieve near optimal maximum-likelihood (ML) throughput performance
in the Large MIMO regime, Massive MIMO systems where the base station has
additional RF chains, to approach the number of base station antennas, in order
to support even more parallel spatial streams. ParaMax is able to achieve a
near ML-BER performance up to 160x160 and 80x80 Large MIMO for low-order
modulations such as BPSK and QPSK, respectively, only requiring less than tens
of processing elements. With respect to Massive MIMO systems, in 12x24 MIMO
with 16-QAM at SNR 16 dB, ParaMax achieves 330 Mbits/s near-optimal system
throughput with 4--8 processing elements per subcarrier, which is approximately
1.4x throughput than linear detector-based Massive MIMO systems.
