  This paper considers an uplink multiuser massive
multiple-input-multiple-output (MIMO) system with low-resolution
analog-to-digital converters (ADCs), in which K users with a single-antenna
communicate with one base station (BS) with Nr antennas. In this system, we
present a novel multiuser MIMO detection framework that is inspired by coding
theory. The key idea of the proposed framework is to create a code C of length
2Nr over a spatial domain. This code is constructed by a so-called
auto-encoding function that is not designable but is completely described by a
channel transformation followed by a quantization function of the ADCs. From
this point of view, we convert a multiuser MIMO detection problem into an
equivalent channel coding problem, in which a codeword of C corresponding to
users' messages is sent over 2Nr parallel channels, each with different channel
reliability. To the resulting problem, we propose a novel weighted minimum
distance decoding (wMDD) that appropriately exploits the unequal channel
reliabilities. It is shown that the proposed wMDD yields a non-trivial gain
over the conventional minimum distance decoding (MDD). From coding-theoretic
viewpoint, we identify that bit-error-rate (BER) exponentially decreases with
the minimum distance of the code C, which plays a similar role with a condition
number in conventional MIMO systems. Furthermore, we develop the communication
method that uses the wMDD for practical scenarios where the BS has no knowledge
of channel state information. Finally, numerical results are provided to verify
the superiority of the proposed method.
