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Orthogonal frequency division multiplexing (OFDM) is an attractive technique to realize high data rate in light emitting diodes (LEDs)-based visible light communication (VLC). However, high peak-to-average power ratio (PAPR) of OFDM makes VLC-OFDM very sensitive to the nonlinearity of LEDs. In this paper, the discrete Fourier transform-spread (DFT-spread) combined with clipping method is proposed to reduce the PAPR of OFDM signal in VLC system. Combining simulation with experiment, a performance comparison is made among conventional OFDM, DFT-spread-OFDM, and clipped DFT-spread-OFDM with different clipping ratios (CRs) in a single LED-based VLC system. The experimental results show that the proposed clipped DFT-spread-OFDM method can effectively improve the system performance compared with the other two methods. At the optimum signal peak-to-peak (PTP) value, by using the clipped DFT-spread-OFDM scheme with CR at 8 dB, the bit error rate (BER) of the system can be reduced from 0.003 7 to 0.000 287. E-mail:dengrui189@126.com 相似文献
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针对毫米波步进频率高距离分辨制导雷达体制以及反地面静止及慢速目标应用背景,提出了一种二维带状成像并以此为基础进行运动目标鉴别、波束内多目标分辨的新方法;首先分析了步进频率雷达带状成像原理;然后给出了一种带状像末制导雷达的参数设计;理论分析以及对单目标及多目标带状像的仿真实验结果证明了该方法的正确性。 相似文献
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为给激光雷达三维点云目标检测提供一种更智能、更稳健的信息处理算法,提出一种基于激光雷达获取的点云数据的车辆目标检测算法。采用局部高程对地面进行拟合,对目标场景进行预分类;根据目标的几何尺寸建立ROI (感兴趣区域),对该区域内的点云数据进行聚类分析,大致检测出目标物体。由于现实场景中往往存在与目标高程相近的物体,采用基于Harr-like特征的AdaBoost分类器对ROI进行复核,划定检测目标。实验结果表明,在目标遮挡率为50%的情况下,算法的检测准确率也能将近90%。 相似文献
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