human: Given a node-centered hypergraph: <hypergraph>, where nodes represent papers and hyperedges represent sets of papers co-cited by a source paper.

Details of the hypergraph:
Center node: "decision feedback detection strategy for nonlinear frequency division multiplexing"
  Abstract: By exploiting a causality property of the nonlinear Fourier transform, a novel decision-feedback detection strategy for nonlinear frequency-division multiplexing (NFDM) systems is introduced. The performance of the proposed strategy is investigated both by simulations and by theoretical bounds and approximations, showing that it achieves a considerable performance improvement compared to previously adopted techniques in terms of Q-factor. The obtained improvement demonstrates that, by tailoring the detection strategy to the peculiar properties of the nonlinear Fourier transform, it is possible to boost the performance of NFDM systems and overcome current limitations imposed by the use of more conventional detection techniques suitable for the linear regime.

Connected through hyperedge HE-1 (induced by source paper "improved detection strategies for nonlinear frequency division multiplexing"):
  with members:
    - "why noise and dispersion may seriously hamper nonlinear frequency division multiplexing"
    - "linear and nonlinear frequency division multiplexing"

Connected through hyperedge HE-2 (induced by source paper "linear and nonlinear frequency division multiplexing"):
  with members:
    - "a novel detection strategy for nonlinear frequency division multiplexing"
    - "communication using eigenvalues of higher multiplicity of the nonlinear fourier transform"
    - "the kolmogorov zakharov model for optical fiber communication"
    - "correlated eigenvalues optical communications"
    - "why noise and dispersion may seriously hamper nonlinear frequency division multiplexing"
    - "polarization division multiplexing based on the nonlinear fourier transform"
    - "nonlinear frequency division multiplexing in the focusing regime"
    - "demonstration of fully nonlinear spectrum modulated system in the highly nonlinear optical transmission regime"

Question: Please tell me which class the center node belongs to. The 40 classes are: cs.NA(Numerical Analysis), cs.MM(Multimedia), cs.LO(Logic in Computer Science), cs.CY(Computers and Society), cs.CR(Cryptography and Security), cs.DC(Distributed, Parallel, and Cluster Computing), cs.HC(Human-Computer Interaction), cs.CE(Computational Engineering, Finance, and Science), cs.NI(Networking and Internet Architecture), cs.CC(Computational Complexity), cs.AI(Artificial Intelligence), cs.MA(Multiagent Systems), cs.GL(General Literature), cs.NE(Neural and Evolutionary Computing), cs.SC(Symbolic Computation), cs.AR(Hardware Architecture), cs.CV(Computer Vision and Pattern Recognition), cs.GR(Graphics), cs.ET(Emerging Technologies), cs.SY(Systems and Control), cs.CG(Computational Geometry), cs.OH(Other Computer Science), cs.PL(Programming Languages), cs.SE(Software Engineering), cs.LG(Machine Learning), cs.SD(Sound), cs.SI(Social and Information Networks), cs.RO(Robotics), cs.IT(Information Theory), cs.PF(Performance), cs.CL(Computation and Language), cs.IR(Information Retrieval), cs.MS(Mathematical Software), cs.FL(Formal Languages and Automata Theory), cs.DS(Data Structures and Algorithms), cs.OS(Operating Systems), cs.GT(Computer Science and Game Theory), cs.DB(Databases), cs.DL(Digital Libraries), cs.DM(Discrete Mathematics). Directly output the class name.

gpt: cs.IT(Information Theory)