title: Modulation formats for multi-core fiber transmission.
abstract: We investigate high dimensional modulation formats for multi-core fibers (MCFs) and spatial superchannels. We show that the low skew variations between MCF cores maybe exploited to generate 'multi-core' formats that offer significant advantages over independently transmitting conventional 4-dimensional formats in each core. We describe how pulse position modulation formats may be transposed to the spatial domain and then investigate a family of modulation formats referred to as core-coding, one of which has the same power and spectral efficiency as polarization switched quaternary phase shift keying but with half of the optical power, potentially improving non-linear tolerance for long distance transmission, albeit at the cost of implementation challenges. Finally, we investigate the application of set-partitioning to multi-core formats using a single-parity check bit transmitted in one quadrature of one polarization in one of the cores and polarization-division multiplexing quadrature phase shift keying data in all remaining cores. We observe that for high core counts, an advantage of almost 3 dB in asymptotic power efficiency may be obtained with negligible impact on spectral efficiency, which translates into experimentally measured reduction in the required optical signal-to-noise ratio of up to 1.8 dB at a bit-error-rate of 10-5and the same data-rate, and additional transmission reach of up to 20%.
authors.forename: B J
authors.initials: BJ
authors.lastname: Puttnam
authors.forename: T A
authors.initials: TA
authors.lastname: Eriksson
authors.forename: J-M Delgado
authors.initials: JM
authors.lastname: Mendinueta
authors.forename: R S
authors.initials: RS
authors.lastname: Luís
authors.forename: Y
authors.initials: Y
authors.lastname: Awaji
authors.forename: N
authors.initials: N
authors.lastname: Wada
authors.forename: M
authors.initials: M
authors.lastname: Karlsson
authors.forename: E
authors.initials: E
authors.lastname: Agrell
mesh_terms: D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D007368:Interferometry / Q000295:instrumentation*; D055096:Optical Devices; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D013685:Telecommunications / Q000295:instrumentation*