A method and apparatus for reducing the number of erred bits in the decoded signal
by using a channel decoder whose transfer characteristic is matched to the transfer
characteristic of the MIMO detector. This means that the curve of the transfer
characteristic of the MIMO detector is 1) above the curve of the reflected transpose
of the transfer characteristic of the channel decoder for about 95% of the curve,
and 2) close to the reflected transpose of the curve of the transfer characteristic
of the channel decoder. Particularly, an LDPCC decoder can be used as the channel
decoder and can be matched to the MIMO detector by matching 1) the transfer characteristic
of the LDPCC decoder's CND to 2) the transfer characteristic of a combination of
the MIMO detector and the LDPCC VND. Furthermore, the LDPCC can be similarly matched
to any appropriate detector in addition to or instead of the MIMO detector. Additionally,
a receiver can re-match the transfer characteristics of the detector and the channel
decoder when the channel characteristics and/or SNR of the received signals change.