Performance of orthogonal STBC-MIMO with variable-power adaptive modulation and delayed feedback in Nakagami fading channels

Abstract

A variable-power (VP) adaptive modulation (AM) scheme with space-time block code (STBC) is developed in MIMO systems, and the corresponding performance is investigated in Nakagami fading channels. The optimum switching thresholds are derived so that the spectrum efficiency (SE) under an average power and a target bit error rate (BER) constraint is maximized. By the switching thresholds, average BER and SE are further derived. As a result, closed-form expressions are obtained. Besides, the exact and approximate BER expressions of VP AM and constant-power (CP) AM systems with delayed feedback are respectively derived. Simulation results show that the theoretical SE and BER can match the corresponding simulation well. The results indicate that VP-AM with STBC provide higher spectrum efficiency than the CP counterparts, and has slighter bite error rate performance degradation when the normalized delay is less than 0.01.

DOI: 10.1007/s11432-012-4643-2

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Cite this paper

@article{Yu2012PerformanceOO, title={Performance of orthogonal STBC-MIMO with variable-power adaptive modulation and delayed feedback in Nakagami fading channels}, author={Xiangbin Yu and Xiaomin Chen and Guangguo Bi and Yun Rui}, journal={Science China Information Sciences}, year={2012}, volume={56}, pages={1-10} }