A Novel Soft-Output Layered Orthogonal Lattice Detector for Multiple Antenna Communications

This paper presents a soft-output lattice detector algorithm for multiple-input multiple-output (MIMO) communications called layered orthogonal lattice detector (LORD). LORD adopts a new lattice formulation and relies on a channel orthogonalization process. Building on the optimality of LORD for two transmit antennas this paper is a generalization of the algorithm to any number of transmit antennas. The most interesting aspect of LORD is that for two transmit antennas max-log bit soft-output information can be simply generated and for greater than two antennas approximate max-log detection is achieved with reasonable complexity. LORD can be implemented in a parallel fashion, as desirable for VLSI. Extensive simulation results in different scenarios of interest for next generation WLANs (IEEE 802.11n) are reported. The simulations show that LORD is able to achieve very high signal-to-noise ratio (SNR) gains compared to current practical soft-output MIMO detectors.