International Journal of Networks and Communications 2020, 10(2): 33-40 DOI: 10.5923/j.ijnc.20201002.01 Towards Optical Frequency Comb-Based High-Capacity Superchannel Transmission-Part II: Transmission Performance Adnan A. Abdullah 1 , Raad S. Fyath 2,* 1 Department of Electronic and Communications Engineering, Al-Nahrain University, Baghdad, Iraq 2 Department of Computer Engineering, Al-Nahrain University, Baghdad, Iraq Abstract The proposed comb reported in the accompanying paper (Part I) is used in wavelength-division multiplexing (WDM) superchannels operating with 160 and 320 Gbps polarization multiplexing (PM)-16QAM signal per comb line. The transmission performance of these superchannel communication systems is investigated using Optisystem ver. 15.0 software. The investigation is extended further to design a pilot-assisted receiver local comb operates synchronously with the transmitter comb. The results reveal that the best figure-of-merit (FoM) for superchannal designed with 25 GHz channel spacing and 160 Gbps PM-16QAM signaling is 5120 Tbps.km when 64 comb lines are used. Keywords Comb-based superchannel transmission, Polarization multiplexing, 16 Quadrature amplitude modulation 1. Introduction Recently, there is increasing interest in high-capacity WDM communication systems using optical comb-based superchannel transmission [1-5]. This paper investigates the transmission performance of Tbps superchannel communication systems incorporating the optical frequency comb generator (OFCG) proposed in the accompanying paper [1] and used here as a C-band WDM source [6-16]. The investigations are based on a series of transmission simulations using two different comb frequency spacings, ∆ = 25 and 50 GHz, and polarization multiplexing-16 quadrature amplitude modulation (PM-16QAM). The maximum achieved transmission distances are recorded when the received BER approaches the BER threshold level BER= BER th = 4.5×10 −3 . This threshold corresponds to 7% overhead hard decision (HD) FEC code frequently and it is usually assumed in the simulation of optical networks and optical communication systems. This code uses 7%-bit redundancy and yields a 10 −15 BER when the precoded BER th = 4.5×10 −3 . The PM-16QAM signaling is used for of each single comb line (channel). Two bit rates B r per channel, 160 and 320 Gbps, are used in this simulations when ∆ = 25 and 50 GHz, respectively. Simulation results are obtained using Optisystem ver.15.0 software. Unless otherwise stated, the parameter values of the superchannel * Corresponding author: rsfyath@yahoo.com (Raad S. Fyath) Received: July 20, 2020; Accepted: August 4, 2020; Published: August 15, 2020 Published online at http://journal.sapub.org/ijnc system are given in Table 1. The rest of the paper is organized as follows. Section 2 introduces the configuration of the comb-based superchannel transmission system. Design issues and performance evaluation of WDM superchannels operating with 160 and 320 Gbps line data rates are given in Sections 3 and 4, respectively. Section 5 gives feasibility study for regeneration of Com Lines at the Receiver Side Using a Single-Pilot Tone. The concluding remarks are given in Section 6. Table 1. Simulation parameter values, respectively