Three-Layer PAPR Reduction Technique for FBMC Based VLC Systems

Abstract

In this paper, a new non-redundant three-layer peak-to-average power ratio (PAPR) reduction technique is proposed for filter bank multicarrier communication based visible light communication (FBMC based VLC) systems. In the proposed technique, the FBMC based VLC data signal is overlapped with two new non-redundant signals. The initial-layer signals are the FBMC modulated signals. For PAPR reduction, the second-layer signals are constructed to decrease initial-layer large-amplitude signals, while the last-layer signals are used to improve the initial-layer small-amplitude signals. The two non-redundant signals do not overlap with the data signals in the frequency domain, because data signals are distributed on odd subcarriers, while even subcarriers are occupied by the constructed signals. To mitigate the effect of large-amplitude signal reduction in the proposed technique, the negative signals are converted into positive, rather than being clipped off as in conventional FBMC based VLC systems. In order to realize a trade-off between PAPR reduction and bit error rate (BER), we introduce a scaling factor in the converted signals. The performance of the proposed technique is calculated in terms of complementary cumulative distribution function (CCDF) and BER. The obtained results indicate that FBMC based VLC systems with the proposed technique can achieve a good trade-off between PAPR reduction and BER and outperforms the corresponding orthogonal frequency division multiplexing (OFDM) based VLC systems.

PAPR Reduction for Different O-OFDM in VLC Using -Law Companding and Convolutional Encoder

“…8. The BER of QAM at SNR= 28 dB is improved from 0.4 to 0.004 with Cconv(2, 3, 7) and gets even better up to 10 -4 with Cconv (2,3,9). However, for 256QAM, the proposed model becomes better than in the original case it raised from 10 -3 to 1.5×10-5 at SNR=38 dB.…”

“…The general structure of the encoder can be customized to have many memory levels to enforce the performance, but the complexity rises as well. Several simulations have been performed using Cconv(2, 3, 7), Cconv (2,3,9) convolutional encoders, and also Hamming coder/decoder (7,4). The BER graphs have shown that the proposed model-based Cconv (2,3,9) satisfies the best BER improvement in VLC systems.…”

PAPR reduction technique for FBMC based visible light communication systems

“…The reduction of PAPR in the OFDM based VLC system is therefore also an indispensable module. Proposed OFDM Communications PAPR Elimination Schemes [10], The methods for distortion based [13][14][15][16][17][18] so changes to the recipients are avoided [20].…”

“…Although some pilots or side information are required, the spectrum-consuming methods are not spectrum efficient. In general, it is difficult for the methods [13][14][15][16][17][18] to achieve the best trade-off between PAPR reduction, BER performance, and spectral efficiency. So far, there has been no work to utilize the inherent null subcarrier in ACO-FBMC signals to reduce high PAPR for VLC systems.…”

“…By integrating optical and RF communications, it is expected that OFDM will be replaced with FBMC in future IM/DD‐based WOC, including VLC. In the literature, while the FBMC implemented coherent optical communications, only limited work affects IM/DD configuration to the best of the knowledge [15]. OFDM based on offset quadrature amplitude modulation (OFDM/OQAM) is widely discussed in wireless communications science based on OQAM to eliminate restrictive super‐channel implementation efficiently.…”