Abstract
The commonly used feed-forward equalizer (FFE) in an intensity modulation and direct-detection (IMDD) system is seriously restrained by the enhanced in-band noise in the high-frequency region. In this Letter, a low-complexity equalization scheme including FFE, post-filter (PF), and a newly designed interference cancellation (IC) algorithm is proposed to cope with the FFE-enhanced noise and serious inter-symbol interference (ISI) simultaneously. In our experiment, the achieved bit error rate value of 100 Gb/s optical double-sideband (ODSB) four-level pulse amplitude modulation (PAM4) signal transmission over 10 km standard single-mode fiber (SSMF) can go below the 20% overhead soft-decision forward error correction threshold of ${2.7} \times {{10}^{ - 2}}$2.7×10-2 when the FFE is replaced by the proposed equalizer. Even a 100 Gb/s optical single-sideband (OSSB) PAM4 signal can be successfully transmitted over 80 km SSMF. The results show that the proposed ${\rm FFE}+{\rm PF}+{\rm IC}$FFE+PF+IC algorithm can effectively suppress the FFE-enhanced noise and ISI with a quite low increase in complexity. Moreover, compared to the joint FFE, PF, and maximum likelihood sequence detection (MLSD) algorithm, the proposed ${\rm FFE}+{\rm PF}+{\rm IC}$FFE+PF+IC algorithm has 1.2 dB and 0.4 dB power penalties after 10 km SSMF in ODSB and 80 km SSMF in OSSB cases, respectively. However, the complexity of this IC algorithm is approximately 3% that of the MLSD.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.