A system employs space-time coding characterized at the transmitter by
bit-interleaved coded modulation (BICM) combined with modulating several
streams of the BICM encoded data for transmission over two or more
antennas. Space-time coding techniques improve transmission efficiency in
radio channels by using multiple transmit and/or receive antennas and
coordination of the signaling over these antennas. Bit-interleaved coded
modulation provides good diversity gain with higher-order modulation
schemes that employ binary convolutional codes. A receiver demodulates
the received signals and applies multi-input, multi-output (MIMO)
demapping to estimate the BICM encoded bitstream. After deinterleaving of
the BICM encoded bitstream, maximum a posteriori (MAP) decoding is
applied to the resulting bit stream to generate soft output values. By
applying well-known turbo-decoding principles to iteratively demap and
decode, the overall receiver performance is significantly improved. The
MIMO demapping and MAP decoding processes exchange likelihood information
to improve the bit error rate performance over several iterations of
demapping/decoding. By generating tentative decisions for transmitted
bits, the overall number of evaluations used for demapping may be
reduced.