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: "energy efficient scheduling and power allocation in downlink ofdma networks with base station coordination"
  Abstract: This paper addresses the problem of energy-efficient resource allocation in the downlink of a cellular OFDMA system. Three definitions of the energy efficiency are considered for system design, accounting for both the radiated and the circuit power. User scheduling and power allocation are optimized across a cluster of coordinated base stations with a constraint on the maximum transmit power (either per subcarrier or per base station). The asymptotic noise-limited regime is discussed as a special case. %The performance of both an isolated and a non-isolated cluster of coordinated base stations is examined in the numerical experiments. Results show that the maximization of the energy efficiency is approximately equivalent to the maximization of the spectral efficiency for small values of the maximum transmit power, while there is a wide range of values of the maximum transmit power for which a moderate reduction of the data rate provides a large saving in terms of dissipated energy. Also, the performance gap among the considered resource allocation strategies reduces as the out-of-cluster interference increases.

Connected through hyperedge HE-1 (induced by source paper "multiple antenna technologies for beyond 5g"):
  with members:
    - "intelligent reflecting surface versus decode and forward how large surfaces are needed to beat relaying"
    - "robust trajectory and resource allocation design for secure uav aided communications"
    - "a new look at cell free massive mimo making it practical with dynamic cooperation"
    - "scalability aspects of cell free massive mimo"
    - "cascaded channel estimation for large intelligent metasurface assisted massive mimo"
    - "robust and secure wireless communications via intelligent reflecting surfaces"
    - "channel estimation for intelligent reflecting surface assisted multiuser communications framework algorithms and analysis"
    - "resource allocation for secure irs assisted multiuser miso systems"

Connected through hyperedge HE-2 (induced by source paper "beam squint and channel estimation for wideband mmwave massive mimo ofdm systems"):
  with members:
    - "spatial and frequency wideband effects in millimeter wave massive mimo systems"
    - "beamforming codebook compensation for beam squint with channel capacity constraint"
    - "a new view of multi user hybrid massive mimo non orthogonal angle division multiple access"
    - "multi user precoding and channel estimation for hybrid millimeter wave systems"
    - "millimeter wave channel estimation via exploiting joint sparse and low rank structures"
    - "effect of wideband beam squint on codebook design in phased array wireless systems"
    - "channel estimation for millimeter wave multiuser mimo systems via parafac decomposition"
    - "channel estimation for hybrid architecture based wideband millimeter wave systems"

Connected through hyperedge HE-3 (induced by source paper "energy efficiency maximization via joint sub carrier assignment and power control for ofdma full duplex networks"):
  with members:
    - "energy efficient power control a look at 5g wireless technologies"
    - "optimal joint power and subcarrier allocation for full duplex multicarrier non orthogonal multiple access systems"
    - "energy efficient heterogeneous cellular networks with spectrum underlay and overlay access"
    - "power efficient resource allocation for full duplex radio distributed antenna networks"
    - "throughput analysis for full duplex wireless networks with imperfect self interference cancellation"
    - "power efficient and secure full duplex wireless communication systems"
    - "full duplex mobile device pushing the limits"
    - "wireless information and power transfer energy efficiency optimization in ofdma systems"

Connected through hyperedge HE-4 (induced by source paper "virtual cell clustering with optimal resource allocation to maximize capacity"):
  with members:
    - "virtual cell clustering with optimal resource allocation to maximize cellular system capacity"
    - "optimal resource allocation for cellular networks with virtual cell joint decoding"
    - "cloud radio access network virtualizing wireless access for dense heterogeneous systems"
    - "software defined networking a comprehensive survey"
    - "uplink multicell processing with limited backhaul via per base station successive interference cancellation"
    - "femtocell networks a survey"

Connected through hyperedge HE-5 (induced by source paper "virtual cell clustering with optimal resource allocation to maximize cellular system capacity"):
  with members:
    - "optimal resource allocation for cellular networks with virtual cell joint decoding"
    - "cloud radio access network virtualizing wireless access for dense heterogeneous systems"
    - "uplink multicell processing with limited backhaul via per base station successive interference cancellation"
    - "femtocell networks a survey"

Connected through hyperedge HE-6 (induced by source paper "energy efficiency optimization a new trade off between fairness and total system performance"):
  with members:
    - "a framework for weighted sum energy efficiency maximization in wireless networks"
    - "energy efficient power control a look at 5g wireless technologies"
    - "multiobjective signal processing optimization the way to balance conflicting metrics in 5g systems"

Connected through hyperedge HE-7 (induced by source paper "a new relation between energy efficiency and spectral efficiency in wireless communications systems"):
  with members:
    - "joint energy and spectrum cooperation for cellular communication systems"
    - "cost aware green cellular networks with energy and communication cooperation"
    - "framework for link level energy efficiency optimization with informed transmitter"

Connected through hyperedge HE-8 (induced by source paper "cloud based management of energy efficient dense ieee 802 11ax networks"):
  with members:
    - "joint power control and time division to improve spectral efficiency in dense wi fi networks"
    - "a survey of energy efficient techniques for 5g networks and challenges ahead"

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)