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: "resource allocation for downlink cellular ofdma systems part i optimal allocation"
  Abstract: In this pair of papers (Part I and Part II in this issue), we investigate the issue of power control and subcarrier assignment in a sectorized two-cell downlink OFDMA system impaired by multicell interference. As recommended for WiMAX, we assume that the first part of the available bandwidth is likely to be reused by different base stations (and is thus subject to multicell interference) and that the second part of the bandwidth is shared in an orthogonal way between the different base stations (and is thus protected from multicell interference). #R##N#Although the problem of multicell resource allocation is nonconvex in this scenario, we provide in Part I the general form of the global solution. In particular, the optimal resource allocation turns out to be "binary" in the sense that, except for at most one pivot-user in each cell, any user receives data either in the reused bandwidth or in the protected bandwidth, but not in both. The determination of the optimal resource allocation essentially reduces to the determination of the latter pivot-position.

Connected through hyperedge HE-1 (induced by source paper "resource allocation and power control in cooperative small cell networks in frequency selective channels with backhaul constraint"):
  with members:
    - "backhaul aware user association and resource allocation for energy constrained hetnets"
    - "tier aware resource allocation in ofdma macrocell small cell networks"
    - "sinr and throughput scaling in ultradense urban cellular networks"
    - "distributed pricing based user association for downlink heterogeneous cellular networks"
    - "optimal user cell association for massive mimo wireless networks"
    - "user association for load balancing in heterogeneous cellular networks"
    - "resource allocation for downlink cellular ofdma systems part ii practical algorithms and optimal reuse factor"

Connected through hyperedge HE-2 (induced by source paper "spectral and energy efficiency of parallel gaussian broadcast channels"):
  with members:
    - "spectral and energy efficiency trade offs in cellular networks"

Connected through hyperedge HE-3 (induced by source paper "joint user association and resource allocation in virtualized wireless networks"):
  with members:
    - "virtualization of multi cell 802 11 networks association and airtime control"

Connected through hyperedge HE-4 (induced by source paper "an analytical framework for heterogeneous partial feedback design in heterogeneous multicell ofdma networks"):
  with members:
    - "sum rate analysis of a reduced feedback ofdma downlink system employing joint scheduling and diversity"
    - "a tutorial on the optimization of amplify and forward mimo relay systems"
    - "modeling and analysis of k tier downlink heterogeneous cellular networks"
    - "refim a practical interference management in heterogeneous wireless access networks"
    - "information exchange limits in cooperative mimo networks"
    - "downlink interference alignment"
    - "adaptive limited feedback for sum rate maximizing beamforming in cooperative multicell systems"

Connected through hyperedge HE-5 (induced by source paper "low complexity resource allocation for load minimization in ofdma wireless networks"):
  with members:
    - "joint bandwidth and power allocation with admission control in wireless multi user networks with and without relaying"

Connected through hyperedge HE-6 (induced by source paper "nearly optimal resource allocation for downlink ofdma in 2 d cellular networks"):
  with members:
    - "resource allocation for downlink cellular ofdma systems part ii practical algorithms and optimal reuse factor"
    - "joint power control and user scheduling in multicell wireless networks capacity scaling laws"

Connected through hyperedge HE-7 (induced by source paper "resource allocation for downlink cellular ofdma systems part ii practical algorithms and optimal reuse factor"):
  with members:
    - "joint power control and user scheduling in multicell wireless networks capacity scaling laws"

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)