An optimal scaling scheme for DCO-OFDM based visible light communications

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• 作者：Rui Jiang ; ^{jr14@mails.tsinghua.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; Qi Wang ^{qiwang11@mails.tsinghua.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; Fang Wang ^{fang-wang10@mails.tsinghua.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; Linglong Dai ^{daill@tsinghua.edu.cn" class="auth_mail" title="E-mail the corresponding author} ; Zhaocheng Wang ^{zcwang@tsinghua.edu.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Visible light communication ; DCO-OFDM ; Scaling factor ; Clipping distortion ; Dimming control
• 刊名：Optics Communications
• 出版年：2015
• 出版时间：1 December 2015
• 年：2015
• 卷：356
• 期：Complete
• 页码：136-140
• 全文大小：670 K

文摘

DC-biased optical orthogonal frequency-division multiplexing (DCO-OFDM) is widely used in visible light communication (VLC) systems to provide high data rate transmission. As intensity modulation with direct detection (IM/DD) is employed to modulate the OFDM signal, scale up the amplitude of the signal can increase the effective transmitted electrical power whereas more signals are likely to be clipped due to the limited dynamic range of LEDs, resulting in severe clipping distortion. Thus, it is crucial to scale the signal to find a tradeoff between the effective electrical power and the clipping distortion. In this paper, an optimal scaling scheme is proposed to maximize the received signal-to-noise-plus-distortion ratio (SNDR) with the constraint of the radiated optical power in a practical scenario where DC bias is fixed for a desired dimming level. Simulation results show that the system with the optimal scaling factor outperforms that with fixed scaling factor under different equivalent noise power in terms of the bit error ratio (BER) performance.