Near-Capacity MIMO Subspace Detection

In this paper, we present a low complexity detection algorithm for Multiple-Input Multiple-Output (MIMO) systems. The novel subspace approach involves QR or Cholesky decomposition to triangularize the effective channel matrix so that several (possibly overlapping) groups of data streams can be detected separately. Link layer simulations show that the ergodic MIMO capacity can be closely approached by exploiting an Overlapped Subspace Detection (OSD) strategy. The OSD algorithm offers a scalable performance/complexity trade-off between ZF and APP detection. The proposed algorithm can be straightforwardly applied to large MIMO systems, as prevalent with recent advances in the field such as network MIMO and Coordinated Multi-Point schemes (CoMP).