Article ID Journal Published Year Pages File Type
463350 Optical Fiber Technology 2015 6 Pages PDF
Abstract

•A new approach for reducing peak-to-average power ratio in all-optical OFDM systems.•This approach is based on modulated half subcarriers with rotated QAM constellation.•The impact of the rotation angle on the PAPR is mathematically modeled.•The all-optical system is numerically demonstrated with 29 subcarriers.•The results reveal that PAPR is reduced with increasing the angle of rotation.

In this paper, a new approach for reducing peak-to-average power ratio (PAPR) based on modulated half subcarriers in all-optical OFDM systems with rotated QAM constellation is presented. To reduce the PAPR, the odd subcarriers are modulated with rotated QAM constellation, while the even subcarriers are modulated with standard QAM constellation. The impact of the rotation angle on the PAPR is mathematically modeled. The effect of PAPR reduction on the system performance is investigated by simulating the all-optical OFDM system, which uses optical coupler-based inverse fast Fourier transform (IFFT)/fast Fourier transform (FFT). The all-optical system is numerically demonstrated with 29 subcarriers. Each subcarrier is modulated by a QAM modulator at a symbol rate of 25 Gsymbol/s. The results reveal that PAPR is reduced with increasing the angle of rotation. The PAPR reduction can reach about 0.8 dB when the complementary cumulative distribution function (CCDF) is 1 × 10−3. Furthermore, both the nonlinear phase noise and the optical signal-to-noise ratio (OSNR) of the system are improved in comparison with the original all-optical OFDM without PAPR reduction.

Related Topics
Physical Sciences and Engineering Computer Science Computer Networks and Communications
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