MIMO-OFDM Transmission Using Complexity Reduced Near ML Detection
QR decomposition and M-algorithm based near Maximum Likelihood Detection (QRM-MLD) is a promising detection scheme for Multiple-Input Multiple-Output (MIMO) - Orthogonal Frequency Division Multiplexing (OFDM). However, QRM-MLD requires still high computational complexity. Recently, the authors proposed a complexity reduced 2-step QRM-MLD for Single-Carrier (SC) block transmissions. The complexity reduction is achieved by identifying unreliable symbol candidates and pruning them from the tree using the output of Minimum Mean Square Error based Frequency-Domain Equalization (MMSE-FDE). The detection order is known to affect the achievable transmission performance.