FDD方式下的自适应调制的研究
Adaptive Modulation in FDD Communications over a Fading Channel
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摘要: 论文主要针对在频分双工(FDD)方式下的自适应调制方式进行了研究,提出了自适应调制的结构框图,并对反馈的上下行链路的包结构进行了阐述。分析了多普勒频移和包时间长度的乘积对系统参数选择的影响,提出了迭代的自适应调制方式,即在不同的乘积范围内,选择不同的模式控制发送调制方式。仿真结果表明了在不同的乘积范围内,选择不同模式可以获得最大的频谱效率,而且系统的频谱效率是随着该乘积的增加而逐渐降低的。Abstract: In this paper adaptive modulation in Frequency Division Duplexing(FDD)communications over a fading channel is studied and packet structure and structure of adaptive modulation are proposed. Further, influence of multiplication of Doppler frequency and packet length is analyzed. Iterative modulation scheme is proposed which adjusts modulation scheme according to different multiplication. Simulation results show that in different multiplication region, different mode can get maximum spectrum efficiency and spectrum efficiency decreases with the increase of multiplication.
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