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 efficiency of spectrum pooling systems"
  Abstract: In this contribution, we investigate the idea of using cognitive radio to reuse locally unused spectrum to increase the total system capacity. We consider a multiband/wideband system in which the primary and cognitive users wish to communicate to different receivers, subject to mutual interference and assume that each user knows only his channel and the unused spectrum through adequate sensing. The basic idea under the proposed scheme is based on the notion of spectrum pooling. The idea is quite simple: a cognitive radio will listen to the channel and, if sensed idle, will transmit during the voids. It turns out that, although its simplicity, the proposed scheme showed very interesting features with respect to the spectral efficiency and the maximum number of possible pairwise cognitive communications. We impose the constraint that users successively transmit over available bands through selfish water filling. For the first time, our study has quantified the asymptotic (with respect to the band) achievable gain of using spectrum pooling in terms of spectral efficiency compared to classical radio systems. We then derive the total spectral efficiency as well as the maximum number of possible pairwise communications of such a spectrum pooling system.

Connected through hyperedge HE-1 (induced by source paper "on the two user multi carrier joint channel selection and power control game"):
  with members:
    - "toward fully coordinated multi level multi carrier energy efficient networks"
    - "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"
    - "quantifying potential energy efficiency gain in green cellular wireless networks"
    - "a game theoretic analysis for energy efficient heterogeneous networks"
    - "energy efficient precoding for multiple antenna terminals"
    - "introducing hierarchy in energy games"

Connected through hyperedge HE-2 (induced by source paper "spectrum coordination in energy efficient cognitive radio networks"):
  with members:
    - "a game theoretic analysis for energy efficient heterogeneous networks"
    - "distributed learning policies for power allocation in multiple access channels"
    - "introducing hierarchy in energy games"
    - "femtocell networks a survey"
    - "energy efficient resource allocation in wireless networks"

Connected through hyperedge HE-3 (induced by source paper "on the performance of adaptive modulation in cognitive radio networks"):
  with members:
    - "optimal power allocation for fading channels in cognitive radio networks ergodic capacity and outage capacity"
    - "power control in cognitive radio networks how to cross a multi lane highway"

Connected through hyperedge HE-4 (induced by source paper "from spectrum pooling to space pooling opportunistic interference alignment in mimo cognitive networks"):
  with members:
    - "asymptotic capacity and optimal precoding in mimo multi hop relay networks"
    - "interference alignment with limited feedback"
    - "on the achievability of interference alignment in the k user constant mimo interference channel"
    - "opportunistic interference alignment in mimo interference channels"
    - "approaching the capacity of wireless networks through distributed interference alignment"
    - "asymptotic capacity and optimal precoding strategy of multi level precode forward in correlated channels"
    - "interference alignment on the deterministic channel and application to fully connected awgn interference networks"

Connected through hyperedge HE-5 (induced by source paper "on the benefits of bandwidth limiting in decentralized vector multiple access channels"):
  with members:
    - "bandwidth partitioning in decentralized 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)