中文摘要：

针对时分双工（TDD,Time Division Duplex）多天线系统的下行传输,研究了以能量效率（EE,Energy Efficiency）最大为准则的上行训练设计问题.证明了存在信道估计误差时系统EE和频谱效率（SE,Spectrum Efficiency）上界是上行训练长度的凹函数,分析了信噪比和电路功耗等因素对两种准则下最优训练长度的影响.分析和仿真结果表明,当信噪比很高时,基于EE最优的设计将退化成基于SE最优的设计;而一般情况下,与最大化SE的训练设计相比,最大化EE要求系统配置更长的训练.

英文摘要：

The design of uplink training aimed at maximizing the energy efficiency（EE） for time division duplex（TDD） multi-antenna systems was investigated.It was proved that when the channel estimation errors are taken into account,both the upper bounds of EE and spectrum efficiency（SE） are concave functions of the uplink training length,based on which the impacts of signal-to-noise ratio（SNR） and circuit power consumption on the optimal training length were analyzed.Analytical and simulation results show that the EE-oriented optimization reduces to the SE-oriented optimization at high SNR regime.Yet in general scenarios,a longer training signal is necessary to maximize EE compared to that maximizing SE.