Multilevel Manchester (2 bits/symbol) coding with optical equaliser for increasing the transmission distance of high-speed fibre optic links

• Published in: IET optoelectronics 2020-08, Vol.14 (4), p.182-188
• Main Authors: Oluwajobi, Festus Idowu, Nguyen, Dong-Nhat, Khan, Nafizah, Malekmohammadi, Amin
• Format: Article
• Language: English
• Subjects: BER performance; bit error rate; bit rate 20 Gbit/s; bit rate 40 Gbit/s; dispersion tolerance; distance 25 km; distance 27.0 km; distance 6.5 km; distance 7.5 km; equalisers; error statistics; eye diagrams; fibre dispersion; four-level Manchester coding; four-level modified Manchester technique; high-speed fibre optic links; high-speed optical transmission links; multilevel Manchester coding; optical fibre dispersion; optical fibre networks; optical links; power penalty; Research Article; second-order optical equaliser; standard single-mode fibre; transmission distance
• ISSN: 1751-8768; 1751-8776; 1751-8776
• DOI: 10.1049/iet-opt.2019.0130

This study accessed the performance of the four-level Manchester coding (4-MC) and four-level modified Manchester (4-MM) technique at the bit rates of 20 and 40 Gb/s for the first-order and second-order optical equalisers. The performances were evaluated with respect to bit error rate (BER), power penalty, eye diagrams, and dispersion tolerance. Based on the results by utilising the second-order optical equaliser, at 20 Gb/s, the transmission distance of 4-MC and 4-MM was extended by 25 and 27 km of standard single-mode fibre (SSMF), respectively, while at the bit rate of 40 Gb/s, the 4-MC and 4-MM transmission distance was extended by 6.5 and 7.5 km of SSMF, respectively. Hence, the second-order optical equaliser can adequately compensate for the fibre dispersion and consequently the overall BER performance. Therefore, the proposed system could serve as an alternative to the next-generation high-speed optical transmission links.