  The theoretic results of MIMO capacity tell us that the higher the number of
antennas are employed, the higher the transmission rate is. This makes MIMO
systems with hundreds of antennas very attractive but one of the major problems
that obstructs such large dimensional MIMO systems from the practical
realization is a high complexity of the MIMO detector. We present in this paper
the new soft output MIMO detector based on matched filtering that can be
applied to the large MIMO systems which are coded by the powerful non-binary
LDPC codes. The per-bit complexity of the proposed detector is just 0.28% to
that of low complexity soft output MMSE detector and scales only linearly with
a number of antennas. Furthermore, the coded performances with small
information length 800 bits are within 4.2 dB from the associated MIMO
capacity.
