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A PAPR reduction scheme combining superimposed O-OFDM and M-law mapping for VLC-OFDM systems
یک طرح کاهش PAPR ترکیبی از نقشه برداری O-OFDM و لایه برداری قانون برای سیستم های VLC-OFDM-2020 Due to the high peak-to-average power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM)
signals, the inherent nonlinearity of light emitting diodes (LEDs) is a challenge for optical OFDM (O-OFDM)
schemes in visible light communication (VLC) systems. In order to reduce PAPR to mitigate the effects of
the nonlinearity of LEDs, and avoid the asymmetric clipping interference in the conventional hybrid OOFDM
schemes, a novel superimposed O-OFDM scheme is proposed in this paper, which reduce the PAPR
by combining the ????-law mapping and the superposition modulation. Moreover, at the transmitter, the hybrid
O-OFDM components are superimposed in an interference-free way, the receiver does not require the operation
of interference cancellation, and the symbols of each branch can be demodulated independently. Simulation
results verify that the proposed scheme can significantly reduce the PAPR. At the same time, the comprehensive
performance of the proposed scheme outperforms other competing schemes under the constraints of the
nonlinearity and limited dynamic range of LEDs. Keywords: Visible light communications | Optical orthogonal frequency division | multiplexing | Peak-to-average power ratio | M-law mapping | LED nonlinearity |
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