title: Sub-Nyquist field trial using time frequency packed DP-QPSK super-channel within fixed ITU-T grid.
abstract: Sub-Nyquist time frequency packing technique was demonstrated for the first time in a super-channel field trial transmission over long-haul distances. The technique allows a limited spectral occupancy even with low order modulation formats. The transmission was successfully performed on a deployed Australian link between Sydney and Melbourne which included 995 km of uncompensated SMF with coexistent traffic. 40 and 100 Gb/s co-propagating channels were transmitted together with the super-channel in a 50 GHz ITU-T grid without additional penalty. The super-channel consisted of eight sub-channels with low-level modulation format, i.e. DP-QPSK, guaranteeing better OSNR robustness and reduced complexity with respect to higher order formats. At the receiver side, coherent detection was used together with iterative maximum-a-posteriori (MAP) detection and decoding. A 975 Gb/s DP-QPSK super-channel was successfully transmitted between Sydney and Melbourne within four 50GHz WSS channels (200 GHz). A maximum potential SE of 5.58 bit/s/Hz was achieved with an OSNR = 15.8 dB, comparable to the OSNR of the installed 100 Gb/s channels. The system reliability was proven through long term measurements. In addition, by closing the link in a loop back configuration, a potential SE∙d product of 9254 bit/s/Hz·km was achieved.
authors.forename: L
authors.initials: L
authors.lastname: Potì
authors.forename: G
authors.initials: G
authors.lastname: Meloni
authors.forename: G
authors.initials: G
authors.lastname: Berrettini
authors.forename: F
authors.initials: F
authors.lastname: Fresi
authors.forename: T
authors.initials: T
authors.lastname: Foggi
authors.forename: M
authors.initials: M
authors.lastname: Secondini
authors.forename: L
authors.initials: L
authors.lastname: Giorgi
authors.forename: F
authors.initials: F
authors.lastname: Cavaliere
authors.forename: S
authors.initials: S
authors.lastname: Hackett
authors.forename: A
authors.initials: A
authors.lastname: Petronio
authors.forename: P
authors.initials: P
authors.lastname: Nibbs
authors.forename: R
authors.initials: R
authors.lastname: Forgan
authors.forename: A
authors.initials: A
authors.lastname: Leong
authors.forename: R
authors.initials: R
authors.lastname: Masciulli
authors.forename: C
authors.initials: C
authors.lastname: Pfander