K-Best Sphere Detection for the Sphere Packing Modulation Aided SDMA/OFDM Uplink

Recently, the turbo-detected Sphere Packing (SP) aided Space-Time Block-Coding (STBC) STBC-SP scheme was demonstrated to provide useful performance improvements over conventionally-modulated orthogonal design based STBC schemes in the context of Single-User Multiple-Input Multiple-Output (SU-MIMO) systems. Hence, in this treatise the authors extend its employment to the multi-user MIMO (MU-MIMO) scenario. For the sake of achieving a near Maximum A Posteriori (MAP) performance while imposing a moderate complexity, they specifically design the K-best Sphere Detection (SD) scheme for supporting the operation of the SP-modulated system, since the conventional SD cannot be directly applied to such a system.