Time Domain Equalization and Digital Back-Propagation Method-Based Receiver for Fiber Optic Communication Systems

Fazal Muhammad,Imran Khan,Sunghwan Kim,Usman Habib,Muhammad Usman,Farman Ali

doi:10.1155/2020/3146374

Abstract

Fiber optic communication systems (FOCSs) have attained a lot of attention by revolutionizing the telecommunication industry and offering new possibilities with the technical advancements in state-of-the-art high speed digital electronics. Advanced modulation formats make use of the phase, amplitude, and polarization of the optical signals at the same time to provide high spectral efficiency as compared with 1 bit/s/Hz for the intensity modulation direct detection system (IMDD), but are highly prone to transmission impairments. Thus, the effects that add up to the optical fiber impairments such as optical fiber chromatic dispersion (OFCD), polarization model dispersion (PMD), and phase offset and noise (POaN) need to be addressed at the receiver side. The development of components and algorithms to minimize these effects in next generation FOCSs with 100 Gbps data rate and beyond with long-haul transmission is still a challenging issue. In this paper, digital signal processing- (DSP-) assisted dispersion and nonlinear compensation techniques are presented to compensate for physical layer impairments including OFCD, PMD, and POaN. The simulations are performed considering Dual Polarization- (DP-) QPSK modulation format to achieve two-fold data rate to achieve spectral efficiency of 3.28 bits/s/Hz by making use of the polarization diversity and system performance is investigated in terms of bit error rate (BER), constellation diagrams, and quality factor (Q-factor) for different values of optical signal-to-noise ratio (OSNR), launch power (PL), and fiber length.

Highlights

Fiber optic communication systems (FOCSs) have attained a lot of attention by revolutionizing the telecommunication industry and offering new possibilities with the technical advancements in state-of-the-art high speed digital electronics
Digital signal processing- (DSP-) assisted dispersion and nonlinear compensation techniques are presented to compensate for physical layer impairments including optical fiber chromatic dispersion (OFCD), polarization model dispersion (PMD), and phase offset and noise (POaN). e simulations are performed considering Dual Polarization- (DP-) QPSK modulation format to achieve twofold data rate to achieve spectral efficiency of 3.28 bits/s/Hz by making use of the polarization diversity and system performance is investigated in terms of bit error rate (BER), constellation diagrams, and quality factor (Q-factor) for different values of optical signal-to-noise ratio (OSNR), launch power (PL), and fiber length
We focus on OFCD, PMD, and POaN impairments for long-haul transmission distances using time domain equalization, as compared with frequency domain, to support commercially used standards using TDM. e use of DP-QPSK modulation format for high data rate and digital signal processing- (DSP-)assisted receiver with the digital back-propagation method to compensate nonlinear fiber effects has been shown in this work

Summary

Research Article

Fazal Muhammad ,1 Farman Ali ,2 Usman Habib ,3 Muhammad Usman, Imran Khan ,4 and Sunghwan Kim 5. To cope with the demand of multiGb/s of data rates, the channel impairments such as optical fiber chromatic dispersion (OFCD), polarization mode dispersion (PMD), and phase offset and noise (POaN) in the FOCS need to be treated. E use of DP-QPSK modulation format for high data rate and DSP-assisted receiver with the digital back-propagation method to compensate nonlinear fiber effects has been shown in this work. The process of adaptive equalization through advanced DSP and use of Gaussian filters with the digital back-propagation technique to minimize PMD, OFCD, and POaN have only been used at the receiver end to provide a cost-effective solution. (4) e simulation results of the designed FOCS are compared with the use of conventional signal detection schemes at the receiver as compared with the time domain equalization, DSP assistance, and digital back-propagation technique. OFCD, PMD, and POaN impairments are analyzed and mitigated for the proposed FOCS model. e effect of these impairments in a long-haul FOCS are explained as follows

Constellation viewer

Digital back propagating method

POL b

Not available Yes