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: "general ber expression for one dimensional constellations"
  Abstract: A novel general ready-to-use bit-error rate (BER) expression for one-dimensional constellations is developed. The BER analysis is performed for bit patterns that form a labeling. The number of patterns for equally spaced M-PAM constellations with different BER is analyzed.

Connected through hyperedge HE-1 (induced by source paper "on the impact of optimal modulation and fec overhead on future optical networks"):
  with members:
    - "on achievable rates for long haul fiber optic communications"
    - "four dimensional coded modulation with bit wise decoders for future optical communications"

Connected through hyperedge HE-2 (induced by source paper "four dimensional coded modulation with bit wise decoders for future optical communications"):
  with members:
    - "high snr asymptotics of mutual information for discrete constellations with applications to bicm"
    - "improving soft fec performance for higher order modulations via optimized bit channel mappings"
    - "probabilistic signal shaping for bit metric decoding"
    - "design of apsk constellations for coherent optical channels with nonlinear phase noise"
    - "signal shaping for bicm at low snr"
    - "a pragmatic coded modulation scheme for high spectral efficiency fiber optic communications"
    - "calculation of mutual information for partially coherent gaussian channels with applications to fiber optics"
    - "optimal alphabets and binary labelings for bicm at low snr"

Connected through hyperedge HE-3 (induced by source paper "high snr asymptotics of mutual information for discrete constellations with applications to bicm"):
  with members:
    - "signal shaping for bicm at low snr"
    - "on the exact ber of bit wise demodulators for one dimensional constellations"
    - "multiple antenna fading coherent channels with arbitrary inputs characterization and optimization of the reliable information transmission rate"
    - "precoding for outage probability minimization on block fading channels"
    - "optimal alphabets and binary labelings for bicm at low snr"
    - "mutual information and minimum mean square error in gaussian channels"

Connected through hyperedge HE-4 (induced by source paper "on the exact ber of bit wise demodulators for one dimensional constellations"):
  with members:
    - "optimal alphabets and binary labelings for bicm at low snr"

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)