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 communications in cdma networks a game theoretic analysis considering operating costs"
  Abstract: A game-theoretic analysis is used to study the effects of receiver choice and transmit power on the energy efficiency of communications in cellular, multi-hop, and peer-to-peer networks in which the nodes communicate using direct-sequence code-division multiple access (DS-CDMA). The unique Nash equilibrium of the game in which the network nodes can choose their receivers as well as their transmit powers to maximize the total number of bits they transmit per unit of energy spent (including both transmit and operating energy) is derived. The energy efficiencies resulting from the use of different linear multiuser receivers in this context are compared for the noncooperative game. Significant gains in energy efficiency are observed when the linear minimum mean-square error (MMSE) receiver is used instead of conventional matched filter receivers.

Connected through hyperedge HE-1 (induced by source paper "distributed power control with partial channel state information performance characterization and design"):
  with members:
    - "interference coordination via power domain channel estimation"
    - "ultra dense small cell networks turning density into energy efficiency"
    - "a survey of energy efficient techniques for 5g networks and challenges ahead"
    - "coordination in distributed networks via coded actions with application to power control"
    - "coded power control performance analysis"
    - "robust precoding for network mimo with hierarchical csit"
    - "a game theoretic analysis for energy efficient heterogeneous networks"
    - "mac with action dependent state information at one encoder"

Connected through hyperedge HE-2 (induced by source paper "decision oriented communications application to energy efficient resource allocation"):
  with members:
    - "energy efficient precoding for multiple antenna terminals"

Connected through hyperedge HE-3 (induced by source paper "totally distributed energy efficient transmission in mimo interference channels"):
  with members:
    - "energy efficiency optimization in relay assisted mimo systems with perfect and statistical csi"
    - "what will 5g be"
    - "distributed optimal beamformers for cognitive radios robust to channel uncertainties"
    - "the mimo iterative waterfilling algorithm"
    - "competitive design of multiuser mimo systems based on game theory a unified view"
    - "cognitive beamforming made practical effective interference channel and learning throughput tradeoff"
    - "energy efficient resource allocation in multiuser mimo systems a game theoretic framework"
    - "energy efficient resource allocation in wireless networks"

Connected through hyperedge HE-4 (induced by source paper "a cross layer approach for distributed energy efficient power control in interference networks"):
  with members:
    - "green power control in cognitive wireless networks"
    - "implicit cooperation in distributed energy efficient networks"
    - "cross layer design for green power control"
    - "energy efficient precoding for multiple antenna terminals"
    - "asynchronous capacity per unit cost"
    - "on the base station selection and base station sharing in self configuring networks"
    - "introducing hierarchy in energy games"
    - "competitive design of multiuser mimo systems based on game theory a unified view"

Connected through hyperedge HE-5 (induced by source paper "cross layer distributed power control a repeated game formulation to improve the sum energy efficiency"):
  with members:
    - "a cross layer approach for distributed energy efficient power control in interference networks"
    - "cross layer design for green power control"
    - "framework for link level energy efficiency optimization with informed transmitter"
    - "energy efficient precoding for multiple antenna terminals"
    - "methodologies for analyzing equilibria in wireless games"
    - "introducing hierarchy in energy games"

Connected through hyperedge HE-6 (induced by source paper "distributed energy efficient channel allocation"):
  with members:
    - "asymptotically optimal resource block allocation with limited feedback"
    - "distributed learning for channel allocation over a shared spectrum"
    - "game theoretic dynamic channel allocation for frequency selective interference channels"
    - "a survey of energy efficient techniques for 5g networks and challenges ahead"
    - "distributed channel assignment in cognitive radio networks stable matching and walrasian equilibrium"
    - "matching theory for future wireless networks fundamentals and applications"
    - "fully distributed optimal channel assignment for open spectrum access"
    - "on optimizing energy efficiency in multi radio multi channel wireless networks"

Connected through hyperedge HE-7 (induced by source paper "energy efficiency optimization in relay assisted mimo systems with perfect and statistical csi"):
  with members:
    - "cooperative algorithms for mimo amplify and forward relay networks"
    - "energy efficiency optimization for mimo broadcast channels"
    - "joint source and relay precoding designs for mimo two way relaying based on mse criterion"
    - "power allocation in two hop amplify and forward mimo relay systems with qos requirements"
    - "framework for link level energy efficiency optimization with informed transmitter"
    - "energy efficient precoding for multiple antenna terminals"
    - "energy efficient resource allocation in multiuser mimo systems a game theoretic framework"
    - "on the capacity and diversity multiplexing tradeoff of the two way relay channel"

Connected through hyperedge HE-8 (induced by source paper "energy efficient scheduling and power allocation in downlink ofdma networks with base station coordination"):
  with members:
    - "what will 5g be"
    - "fundamental limits of cooperation"
    - "framework for link level energy efficiency optimization with informed transmitter"
    - "energy efficient precoding for multiple antenna terminals"
    - "slow adaptive ofdma systems through chance constrained programming"
    - "introducing hierarchy in energy games"

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)