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 and energy efficiency trade off with joint power bandwidth allocation in ofdma networks"
  Abstract: The design of next generation wireless networks is strongly motivated by the need to improve network energy efficiency (EE), while ensuring that the provided performance, often expressed in terms of spectral efficiency (SE), satisfies the vastly increasing user demands. In this context, this paper discusses about the SE-EE trade-off in Orthogonal Frequency-Division Multiple Access (OFDMA) wireless networks, achieved by an optimal joint resource allocation of transmit power and bandwidth on the system downlink direction. A novel theoretical framework is presented initially for the study of a single cell scenario, where a traffic repartition scheme is proposed that simplifies the inherent optimization problem and reveals useful insights. Special attention is also given to the case of the low signal to noise ratio (SNR) and a way to easily evaluate the upper bound of EE in this regime is provided. Finally, by exploiting useful properties of stochastic geometry, this work is extended to a more challenging multi-cell environment, where interference is shown to play an essential role. For this reason, several potential interference reduction techniques are investigated in order to enhance the performance of the SE-EE trade-off curves.

Connected through hyperedge HE-1 (induced by source paper "toward fully coordinated multi level multi carrier energy efficient networks"):
  with members:
    - "spectrum coordination in energy efficient cognitive radio networks"
    - "on the energy spectral efficiency trade off of the mrc receiver in massive mimo systems with transceiver power consumption"
    - "spectral efficiency and energy efficiency of ofdm systems impact of power amplifiers and countermeasures"
    - "a game theoretic analysis for energy efficient heterogeneous networks"
    - "femtocell networks a survey"
    - "energy efficient resource allocation in wireless networks"

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)