Reduced-Complexity Adaptive Receiver Algorithms for 4G SU-MIMO Systems

In this paper we present reduced-complexity high- performance receivers for single-user MIMO systems that employ coded OFDM transmission with bit-interleaved coded modulation (BICM). High data-rate versions of these systems have been proposed for 4G. The near-optimum inner-outer decoder structures for these MIMO/BICM/OFDM/QAM systems have complexity that grows exponentially fast with the number of multiplexed streams (number of transmit antennas) and the number of bits represented by the QAM constellations. We focus on reduced-complexity inner-outer decoder structures that exploit adaptive soft-output M algorithms for soft inner decoding. Our simulations show that these receivers can be systematically optimized to yield substantial complexity reductions without significant loss in performance.