Space–time block code design for LTE‐advanced systems

Abstract 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. Copyright © 2013 John Wiley & Sons, Ltd.