REDUCING THE PEAK-TO-AVERAGE POWER RATIO OF OFDM SYSTEM WITH LOW COMPLEXITY

This paper proposes a companding scheme, where small signals are enlarged and large signals are reduced, to reduce the Peak-to-Average Power Ratio(PAPR). Computer simulation results show that the proposed technique has two advantages at least when compared with the conventional methods such as partial transmit sequence, selective mapping and the previous companding. First, it gets better PAPR performances with a lower complexity. Second, the scheme achieves greater performances gain with hardly any damnification of OFDM signals in some degree.

Optical Feedback Characteristics in He-Ne Dual Frequency Lasers

在 He-Ne 双频率激光的光反馈特征与一个可变衰减器在不同反馈力量比率系统地被学习。反馈力量比率从 0.010 变化直到 0.998。自我干扰效果的五不同政体被发现并且定义为政体我， II， III， IV 和 V。因此，五个光反馈层次在 He-Ne 双频率激光被提出了。强壮的模式比赛在政体 III 和 IV.In 政体 V 被观察，多重反馈效果被调查。基本理论分析也被介绍。我们的结果能预付自我混合的干涉仪和 He-Ne 的排水量传感器的研究直角地极化的双频率激光。