New double layer space-time block code for distributed 4 × 2 MIMO systems

A new space-time block code (STBC) is presented for distributed 4 × 2 multiple-input multiple-output (MIMO) systems. A 2 × 2 full-rate full-diversity (FR-FD) low complexity space-time code, presented by Sezginer and Sari, is employed for two distributed links. Alamouti STBC is applied over the two links to obtain a double layer space-time block code (DLSTBC) providing full diversity in a distributed 4 × 2 MIMO system. The proposed technique is simulated in Rayleigh channel and compared to several known STBC techniques. The performance results show that proposed STBC offers almost the same performance as a three-dimensional space-time-space (3D-STS) code presented by Nasser et al., while the receiver decoding complexity with constellation size M is decreased from M⁸ to M⁶.