Proposal and Performance Evaluation of an Efficient RZ-DQPSK Modulation Scheme in All-Optical OFDM Transmission Systems

Abstract

Abstract-A return-to-zero differential quadrature phase-shift keying (DQPSK) modulation scheme is proposed for all-optical orthogonal frequency-division multiplexing transmission systems. The system uses coupler-based inverse fast Fourier transform/fast Fourier transform to support a 700 km single-mode fiber link and a transmission rate of 40 Gb∕s without any nonlinear compensation. The performance of the proposed system is evaluated using simulation and four performance measures are obtained, namely, the eye diagram, the eyeopening penalty (EOP), the power spectral broadening, and the bit error rate (BER). The effect of self-phase modulation is taken into account in the performance evaluation. In addition, the performance of the proposed system is compared to that of a traditional one adopting a non-return-to-zero DQPSK scheme. Our results reveal that the proposed system outperforms the traditional one in all four aforementioned performance measures, yet the spectral efficiency is almost preserved. Specifically, for an input average power of 12 dBm, a reduction in both the required optical-signal-to-noise ratio of about 4 dB (to achieve a BER of 10 −6 ) and the EOP of about 5 dB are reported when adopting the proposed system, as compared to the traditional one.Index Terms-All-optical OFDM; Eye diagram; Fiber optic nonlinearity; Non-return-to-zero differential quadrature phase-shift keying (NRZ-DQPSK); Return-to-zero differential quadrature phase-shift keying (RZ-DQPSK); Selfphase modulation (SPM).

Performance evaluation of an efficient RZ-MQAM modulation scheme in all-optical OFDM transmission systems

“…AO-OFDM technique also can avoid some of the transmission impairments such as polarization modal dispersion (PMD), chromatic dispersion (CD) and inter-symbol interference (ISI) but AO-OFDM transmission systems still suffer from nonlinearity [2][3].…”

“…Phase-Shift Keying (QPSK) [3][4]. It is important to note that, the AO-OFDM systems with N optical tones require N independent modulators.…”

1.12Tbps-16QAM Uncompensated Long-Haul Transmission Employing a New Self-Oscillating Optical Frequency Comb Generator Both at Transmitter and Receiver

“…Coupled with rapid progress in electronics, the silicon photonics are driving performance gains in terms of speed and bandwidth [5]. Recent advancements in the field of optical communications have enabled the way to deal with high data rate transmission, particularly when one or more multiplexing techniques are considered [6], [7], [8]. The solution to achieve the bit rate enhancement is wavelength division multiplexing (WDM) which also shows resilience towards fiber impairments such as chromatic dispersion [9].…”

Optical frequency comb generation based on chirping of Mach–Zehnder Modulators

“…Nowadays, optical frequency comb generator (OFCG) is widely used as multi-wavelength source for optical communication systems such as dense wavelength-division multiplexing (DWDM), optical time-division multiplexing, and optical orthogonal frequency-division multiplexing systems [1][2][3][4][5][6]. The generated comb is required to provide a stable frequency with a fixed phase and spacing for these applications.…”