Space-time block code design for LTE-advanced systems

The number of time slot (or symbols per slot in 3rd Generation Partnership Project language) in the long-term evolution frame structure for data transmission is not guaranteed to be an even number, so the Alamouti orthogonal space-time block code (STBC) can not be applied. Recently, Lei et al. (Institute of Electrical and Electronics Engineers Transactions on Wireless Communications, 2011) introduced a quasi-orthogonal space time block code (QOSTBC) for two transmit antennas and three time slots (which is named as L-QOSTBC in this paper). This code achieves two desirable properties as full rate and full diversity. However, the main disadvantage of the L-QOSTBC is high decoding complexity due to pair-symbol maximum likelihood decoding. In this paper, we propose a novel three-time-slot STBC (TTS-STBC) for two transmit antennas. The proposed TTS-STBC can achieve full-rate full-diversity transmission with single-symbol maximum likelihood decoding. In comparison to L-QOSTBC, the proposed TTS-STBC has lower decoding complexity and higher coding gain. In addition, a new decoding strategy for the proposed TTS-STBC that named as single-symbol quasi-maximum likelihood is also developed to overcome the performance degradation caused by time-varying fading channels. Simulation results show that the proposed TTS-STBC outperforms the L-QOSTBC in both quasi-static and time-varying fading channels. © 2014 John Wiley & Sons, Ltd.