I. Introduction
Multiple-Input MULTIPLE-OUTPUT (MIMO) antenna systems have become mainstream technology for achieving high spectral efficiency in modern wireless communications standards. Detection of spatially multiplexed MIMO streams plays a key role in receiver design in terms of performance and complexity [1], and has remained an active area of research. MIMO detection schemes are either based on joint-stream detection to separate the streams, such as ML detection [2]–[4], or subset-stream detection such as those employed in successive interference cancellation (SIC), interference coordination, transmit beamforming, network MIMO, and coordinated multi-point transmission and reception [5]–[9].