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: "optimal bandwidth and power allocation for sum ergodic capacity under fading channels in cognitive radio networks"
  Abstract: This paper studies optimal bandwidth and power allocation in a cognitive radio network where multiple secondary users (SUs) share the licensed spectrum of a primary user (PU) under fading channels using the frequency division multiple access scheme. The sum ergodic capacity of all the SUs is taken as the performance metric of the network. Besides the peak/average transmit power constraints at the SUs and the peak/average interference power constraint imposed by the PU, total bandwidth constraint of the licensed spectrum is also taken into account. Optimal bandwidth allocation is derived in closed-form for any given power allocation. The structures of optimal power allocations are also derived under all possible combinations of the aforementioned power constraints. These structures indicate the possible numbers of users that transmit at nonzero power but below their corresponding peak powers, and show that other users do not transmit or transmit at their corresponding peak powers. Based on these structures, efficient algorithms are developed for finding the optimal power allocations.

Connected through hyperedge HE-1 (induced by source paper "spectral efficiency of ofdma cognitive radios under imperfect cross link knowledge"):
  with members:
    - "on ergodic sum capacity of fading cognitive multiple access and broadcast channels"

Connected through hyperedge HE-2 (induced by source paper "spectral efficiency of multi user adaptive cognitive radio networks"):
  with members:
    - "on ergodic sum capacity of fading cognitive multiple access and broadcast channels"

Connected through hyperedge HE-3 (induced by source paper "joint spectrum and power allocation for multi node cooperative wireless systems"):
  with members:
    - "on green energy powered cognitive radio networks"
    - "energy efficient resource allocation in ofdma systems with hybrid energy harvesting base station"

Connected through hyperedge HE-4 (induced by source paper "underlay cognitive radios with capacity guarantees for primary users"):
  with members:
    - "cross layer designs in coded wireless fading networks with multicast"
    - "power control with imperfect exchanges and applications to spectrum sharing"
    - "dynamic resource allocation in cognitive radio networks"
    - "optimizing orthogonal multiple access based on quantized channel state information"
    - "optimal power allocation for fading channels in cognitive radio networks ergodic capacity and outage capacity"
    - "on peak versus average interference power constraints for protecting primary users in cognitive radio networks"
    - "joint design and separation principle for opportunistic spectrum access in the presence of sensing errors"

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)