DSP-Assisted Nonlinear Impairments Tolerant 100 Gbps Optical Backhaul Network for Long-Haul Transmission  
[PERSON]  
1 Electrical Engineering Department, College of Engineering, Najiran University Saudia Arabia, Najran 61441, Saudia Arabia; [EMAIL_ADDRESS]  
2 Department of Electrical Engineering, Qurutba University of Science and IT, D. I. Khan 29050, Pakistan; [EMAIL_ADDRESS]  
3 Department of Electrical Engineering, City University of Science and Information Technology, Peshawar 25000, Pakistan; [EMAIL_ADDRESS]  
4 School of Electrical Engineering, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea; [EMAIL_ADDRESS]  
5 Department of Automatic, Control and Robotics, AGH University of Science and Technology, 30-059 Krakow, Poland; [EMAIL_ADDRESS]  
6 Faculty of Electrical Engineering, GIK Institute of Engineering Sciences and Technology, Topi 23640, Pakistan; [EMAIL_ADDRESS]  
7 Department of Biocyhematics and Biomedical Engineering, Faculty of Electrical Engineering, Automatics, Computer Science and Biomedical Engineering, AGH University of Science and Technology, Al. A. Mickiewicza 30, 30-059 Krakow, Poland; [EMAIL_ADDRESS]  
8 July 20202066 September 2020202068 July 2020206 September 20202068 July 2020206 September 20202068 July 2020206 September 2020206 September  
to the erbium doped fiber amplifier (EDFA) [1]. The associated amplified spontaneous emission (ASE) noise from the EDFA and transmission fiber nonlinearities are the major limitations for such systems to achieve high data rates in optical communication system over long distances [2]. Another major source for nonlinearities is the use of high input optical power level which is required to minimize the number of repeaters in a long haul link [3]. Because of the components that have nonlinear transfer function, the aggregated distortion to the signal becomes manifold and, hence, causes severe performance degradation [4; 5]. Cross phase modulation (XPM) [6], four wave mixing (FWM) [7], and self phase modulation (SPM) [8] are the key nonlinear impairments in optical fiber communication system, which needs to be mitigated for reliable and error-free transmission. As fiber transmission impairments are generally associated with the analog transmission over the fiber [9], the digital modulation also undergoes performance degradation due to the accumulated non-linear effects. Recent research work in this domain include the use of digital Nonlinearity Compensation (NLC) in a fully loaded WDM multiplexed transmission system [10], the shaping algorithm for mitigating the effect of nonlinear phase noise in fiber optic transmission [11], the single step nonlinear impairment based on the Gaussian mixture model [12], and a complex equalizer for a 40 Gbps system to achieve transmission over 240 km optical fiber using a single channel [13]. However, these mentioned models have complex build up and cost restrictions. To overcome these limitations, we propose a cost effective and simple network structure for long haul high data rate system. The proposed architecture is tested for higher data rates, i.e., beyond 100 Gbps. Satisfactory results are achieved for high data rates, e.g., 1.56 \(\times\) 10\({}^{-6}\) bit error rate (BER) while using effective fiber area of 90 \(\upmu\)m\({}^{2}\) by keeping 25 GHz frequency spacing among WDM channels, which is an acceptable range for the design of future backhaul networks. The aggregated effect of ASE due to the multiple use of EDFA in each transmission span [14] and filtration effects due to the use of Fiber Brag Grating (FBG) at the WDM demultiplexer end is also considered to realize a practical long haul transmission system [15].