title: Nyquist WDM superchannel using offset-16QAM and receiver-side digital spectral shaping.
abstract: The performance of Nyquist WDM superchannel using advanced modulation formats with coherent detection is degraded due to the existence of both inter-symbol interference (ISI) and inter-channel interference (ICI). Here, we propose and numerically investigate a Nyquist WDM superchannel using offset-16QAM and receiver-side digital spectral shaping (RS-DSS), achieving a spectral efficiency up to 7.44 bit/s/Hz with 7% hard-decision forward error correction (HD-FEC) overhead. Compared with Nyquist WDM superchannel using 16QAM and RS-DSS, the proposed system has 1.4 dB improvement of required OSNR at BER = 10(-3) in the case of back-to-back (B2B) transmission. Furthermore, the range of launched optical power allowed beyond HD-FEC threshold is drastically increased from -6 dBm to 1.2 dBm, after 960 km SSMF transmission with EDFA-only. In particular, no more than 1.8 dB required OSNR penalty at BER = 10(-3) is achieved for the proposed system even with the phase difference between channels varying from 0 to 360 degree.
authors.forename: Meng
authors.initials: M
authors.lastname: Xiang
authors.forename: Songnian
authors.initials: S
authors.lastname: Fu
authors.forename: Ming
authors.initials: M
authors.lastname: Tang
authors.forename: Haoyuan
authors.initials: H
authors.lastname: Tang
authors.forename: Perry
authors.initials: P
authors.lastname: Shum
authors.forename: Deming
authors.initials: D
authors.lastname: Liu