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: "experimental demonstration of nonlinear frequency division multiplexed transmission"
  Abstract: We experimentally demonstrate an NFDM optical system with modulation over nonlinear discrete spectrum. Particularly, each symbol carries 4-bits from multiplexing two eigenvalues modulated by QPSK constellation. We show a low error performance using NFT detection with 4Gbps rate over 640km.

Connected through hyperedge HE-1 (induced by source paper "efficient precoding scheme for dual polarization multi soliton spectral amplitude modulation"):
  with members:
    - "experimental demonstration of dual polarization nonlinear frequency division multiplexed optical transmission system"
    - "polarization division multiplexing based on the nonlinear fourier transform"

Connected through hyperedge HE-2 (induced by source paper "communication using eigenvalues of higher multiplicity of the nonlinear fourier transform"):
  with members:
    - "information transmission using the nonlinear fourier transform part i mathematical tools"
    - "information transmission using the nonlinear fourier transform part iii spectrum modulation"

Connected through hyperedge HE-3 (induced by source paper "correlated eigenvalues optical communications"):
  with members:
    - "information transmission using the nonlinear fourier transform part ii numerical methods"
    - "information transmission using the nonlinear fourier transform part i mathematical tools"
    - "information transmission using the nonlinear fourier transform part iii spectrum modulation"

Connected through hyperedge HE-4 (induced by source paper "probabilistic eigenvalue shaping for nonlinear fourier transform transmission"):
  with members:
    - "capacity lower bounds of the noncentral chi channel with applications to soliton amplitude modulation"
    - "demonstration of fully nonlinear spectrum modulated system in the highly nonlinear optical transmission regime"

Connected through hyperedge HE-5 (induced by source paper "on time bandwidth product of multi soliton pulses"):
  with members:
    - "fast numerical nonlinear fourier transforms"

Connected through hyperedge HE-6 (induced by source paper "nonlinear frequency division multiplexing"):
  with members:
    - "the kolmogorov zakharov model for optical fiber communication"
    - "digital backpropagation in the nonlinear fourier domain"
    - "information transmission using the nonlinear fourier transform part ii numerical methods"
    - "information transmission using the nonlinear fourier transform part i mathematical tools"
    - "information transmission using the nonlinear fourier transform part iii spectrum modulation"
    - "on the achievable communication rates of generalized soliton transmission systems"

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)