Simple MMSE Interference Suppression for Real and Rate-1/2 Complex Orthogonal Space-time Block Codes

Orthogonal space-time block codes (OSTBCs) are known to provide transmit diversity gain with negligible decoding complexity. In this paper, we present a single-stage MMSE multi-user interference suppression technique that exploits the temporal and spatial structure of OSTBCs, leading to simple linear processing. In particular, we show that MMSE-based detection can be implemented for real OSTBCs as well as the derived rate-1/2 complex OSTBCs, using simple linear processing that avoids computationally intensive matrix inversions.