[7] HU W W. PAPR reduction in DCO-OFDM visible light communication systems using optimized odd and even sequences combination[J]. IEEE Photonics Journal, 2019, 11(1): 1-15.

[8] WANG T Q, LI H, HUANG X. Analysis and mitigation of clipping noise in layered ACO-OFDM based visible light communication systems[J]. IEEE Transactions on Communications, 2018, 67(1): 564-577.

[9] DISSANAYAKE S D, ARMSTRONG J. Comparison of ACO-OFDM, DCO-OFDM and ADO-OFDM in IM/DD systems[J]. Journal of Lightwave Technology, 2013, 31(7): 1063-1072.

[10] RANJHA B, KAVEHRAD M. Hybrid asymmetrically clipped OFDM-based IM/DD optical wireless system[J]. Journal of Optical Communica-tions and Networking, 2014, 6(4): 387-396.

[11] WU N, BAR-NESS Y. A novel power-efficient scheme asymmetrically and symmetrically clipping optical(ASCO)-OFDM for IM/DD optical systems[J]. EURASIP Journal on Advances in Signal Processing, 2015, 2015(1): 1-10.

[12] WANG Q, QIAN C, GUO X, et al. Layered ACO-OFDM for intensity- modulated direct-detection optical wireless transmission[J]. Optics Express, 2015, 23(9): 12382-12393.

[13] ZHANG X, WANG Q, ZHANG R, et al. Performance analysis of layered ACO-OFDM[J]. IEEE Access, 2017, 5: 18366-18381.

[14] AZIM A W, LE G Y, MAURY G. Spectrally augmented Hartley transform precoded asymmetrically clipped optical OFDM for VLC[J]. IEEE Photonics Technology Letters, 2018, 30(23): 2029-2032.

[15] AZIM A W, LE G Y, MAURY G. Performance analysis of precoded layered ACO-OFDM for visible light communication systems[J]. Optics Communications, 2019, 440: 49-60.

[16] RANJHA B, KAVEHRAD M. Hybrid asymmetrically clipped OFDM-based IM/DD optical wireless system[J]. Journal of Optical Communications and Networking, 2014, 6(4): 387-396.

[17] DISSANAYAKE S D, ARMSTRONG J. Comparison of ACO-OFDM, DCO-OFDM and ADO-OFDM in IM/DD systems[J]. Journal of Lightwave Technology, 2013, 31(7): 1063-1072.