[1] [1] ARMSTRONG J. OFDM for Optical Communications [J]. Journal of Lightwave Technology, 2009, 27(3): 189-204.

[2] [2] MAIVAN Lap, HE Jing, CHEN Ming, et al. A PAPR reduction scheme based on a new spreading code in optical direct detection OFDM system[J]. Photonic Network

          Communications, 2016, 31(1): 155-161.

[3] [3] SHIEH W, BAO H, TANG Y. Coherent optical OFDM: Theory and design[J]. Optics Express, 2008, 16(2): 841-859.

[4] [4] 2017, 18(2): 123-131.

          VITTAL M V R, NAIDU K R. A novel reduced complexity optimized PTS technique for PAPR reduction in wireless OFDM systems[J]. Egyptian Informatics Journal,

[5] [5] 1313-1329.

          ZHUANG L, LIU L, LI J, et al. Discrete Sine and Cosine Transforms in Single Carrier Modulation Systems[J]. Wireless Personal Communications, 2014, 78(2):

[6] [6] WOO J Y, JOO H S, KIM K H, et al. PAPR Analysis of Class-III SLM Scheme Based on Variance of Correlation of Alternative OFDM Signal Sequences[J]. IEEE

          Communications Letters, 2015, 19(6): 989-992.

[7] [7] Information Sciences, 2014, 57(6): 1-11.

          CHEN Z, ZHANG S, YANG L, et al. Optimal phase searching of PTS using modified genetic algorithm for PAPR reduction in OFDM systems[J]. Science China

[8] [8] Communications, 2013, 61(5): 1891-1901.

          ZHU X, PAN W, LI H, et al. Simplified Approach to Optimized Iterative Clipping and Filtering for PAPR Reduction of OFDM Signals[J]. IEEE Transactions on

[9] [9] Communications Letters, 2016, 27(12): 2378-2381.

          WANG S H, LIN W L, HUANG B R, et al. PAPR Reduction in OFDM Systems Using Active Constellation Extension and Subcarrier Grouping Techniques[J]. IEEE

[10] [10] OUQOUR A, JABRANE Y, SAID B A E, et al. PAPR Reduction in OFDM via Active Constellation Extension-Projection Onto Convex Sets Combined with Particle Swarm

          Optimization [J]. The Computer Journal, 2014, 57(8): 1230-1237.

[12] [12] PACHORI K, MISHRA A. PAPR Reduction in MIMO-OFDM by Using Active Partial Sequence[J]. Circuits, Systems, and Signal Processing, 2015, 34(12): 3999-4010.

[14] [14] HAN S H, LEE J H. PAPR reduction of OFDM signals using a reduced complexity PTS technique [J]. IEEE Signal Processing Letters, 2004(11): 887-890.