PAPR and security in OFDM-PON via optimum block dividing with dynamic key and 2D-LASM

) and the optimization ratio (η) are gradually equal to 146, 269 and 1.82, respectively, with the number of quadrature amplitude modulation (QAM) symbols in each subcarrier increasing. Simulating 1000 sets of 120×200 QAM symbols, the distribution of η approximately meets the Rayleigh distribution and its central distribution is around 1.7. The processing time decreases with the number of QAM symbols increasing in each block. The performance of PAPR reduction is more than 3 dB between the secure optimum signal and the original signal. In addition, the hyper-threading technique with two algorithms is applied to improve the performance of the encryption method. They promote the processing time by 38.6% and 50%, respectively. Finally, a 22.06 Gb/s optimum encryption OFDM signal transmits through a back-to-back (BTB) system and a 25-km standard single mode fiber (SSMF). These experimental results verify that the proposed approach is a promising candidate for solving both of PAPR reduction and security improvement in access network systems.