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: "spectral efficient optimization in ofdm systems with wireless information and power transfer"
  Abstract: This paper considers an orthogonal frequency division multiplexing (OFDM) point-to-point wireless communication system with simultaneous wireless information and power transfer. We study a receiver which is able to harvest energy from the desired signal, noise, and interference. In particular, we consider a power splitting receiver which dynamically splits the received power into two power streams for information decoding and energy harvesting. We design power allocation algorithms maximizing the spectral efficiency (bit/s/Hz) of data transmission. In particular, the algorithm design is formulated as a nonconvex optimization problem which takes into account the constraint on the minimum power delivered to the receiver. The problem is solved by using convex optimization techniques and a one-dimensional search. The optimal power allocation algorithm serves as a system benchmark scheme due to its high complexity. To strike a balance between system performance and computational complexity, we also propose two suboptimal algorithms which require a low computational complexity. Simulation results demonstrate the excellent performance of the proposed suboptimal algorithms.

Connected through hyperedge HE-1 (induced by source paper "artificial noise aided secrecy information and power transfer in ofdma systems"):
  with members:
    - "secrecy wireless information and power transfer in fading wiretap channel"
    - "energy harvesting for physical layer security in ofdma networks"
    - "secrecy wireless information and power transfer with miso beamforming"
    - "multiuser miso beamforming for simultaneous wireless information and power transfer"
    - "energy efficient resource allocation in multiuser ofdm systems with wireless information and power transfer"
    - "resource allocation for secure communication in systems with wireless information and power transfer"
    - "power allocation and time domain artificial noise design for wiretap ofdm with discrete inputs"
    - "wireless information and power transfer in multiuser ofdm systems"

Connected through hyperedge HE-2 (induced by source paper "simultaneous wireless information and power transfer under different csi acquisition schemes"):
  with members:
    - "robust beamforming for secure communication in systems with wireless information and power transfer"
    - "dynamic resource allocation for multiple antenna wireless power transfer"
    - "energy efficient resource allocation in multiuser ofdm systems with wireless information and power transfer"
    - "opportunistic wireless energy harvesting in cognitive radio networks"
    - "wireless information and power transfer energy efficiency optimization in ofdma systems"
    - "wireless information and power transfer a dynamic power splitting approach"
    - "robust beamforming for wireless information and power transmission"
    - "mimo broadcasting for simultaneous wireless information and power transfer"

Connected through hyperedge HE-3 (induced by source paper "power allocation for conventional and buffer aided link adaptive relaying systems with energy harvesting nodes"):
  with members:
    - "buffer aided relaying with adaptive link selection"
    - "energy cooperation in energy harvesting communications"
    - "throughput maximization for the gaussian relay channel with energy harvesting constraints"
    - "energy efficient resource allocation in ofdma systems with hybrid energy harvesting base station"
    - "broadcasting with an energy harvesting rechargeable transmitter"
    - "optimal energy allocation for wireless communications with energy harvesting constraints"
    - "transmission with energy harvesting nodes in fading wireless channels optimal policies"
    - "optimal packet scheduling in an energy harvesting communication system"

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)