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: "distributed linear precoder optimization and base station selection for an uplink heterogeneous network"
  Abstract: In a heterogeneous wireless cellular network, each user may be covered by multiple access points such as macro/pico/relay/femto base stations (BS). An effective approach to maximize the sum utility (e.g., system throughput) in such a network is to jointly optimize users' linear procoders as well as their BS associations. In this paper, we first show that this joint optimization problem is NP-hard and thus is difficult to solve to global optimality. To find a locally optimal solution, we formulate the problem as a noncooperative game in which the users and the BSs both act as players. We introduce a set of new utility functions for the players and show that every Nash equilibrium (NE) of the resulting game is a stationary solution of the original sum utility maximization problem. Moreover, we develop a best-response type algorithm that allows the players to distributedly reach a NE of the game. Simulation results show that the proposed distributed algorithm can effectively relieve local BS congestion and simultaneously achieve high throughput and load balancing in a heterogeneous network.

Connected through hyperedge HE-1 (induced by source paper "load balancing user association in millimeter wave mimo networks"):
  with members:
    - "time fractional user association in millimeter wave mimo networks"
    - "downlink cell association and load balancing for joint millimeter wave microwave cellular networks"
    - "large scale convex optimization for ultra dense cloud ran"
    - "a survey of millimeter wave mmwave communications for 5g opportunities and challenges"
    - "probabilistic omnidirectional path loss models for millimeter wave outdoor communications"
    - "heterogeneous cloud radio access networks a new perspective for enhancing spectral and energy efficiencies"
    - "optimal user cell association for massive mimo wireless networks"
    - "millimeter wave channel modeling and cellular capacity evaluation"

Connected through hyperedge HE-2 (induced by source paper "large scale spectrum allocation for cellular networks via sparse optimization"):
  with members:
    - "scalable spectrum allocation and user association in networks with many small cells"
    - "energy management in heterogeneous networks with cell activation user association and interference coordination"
    - "energy efficient cell activation user association and spectrum allocation in heterogeneous networks"
    - "licensed and unlicensed spectrum allocation in heterogeneous networks"
    - "distributed pricing based user association for downlink heterogeneous cellular networks"
    - "base station activation and linear transceiver design for optimal resource management in heterogeneous networks"
    - "user association for load balancing in heterogeneous cellular networks"

Connected through hyperedge HE-3 (induced by source paper "time fractional user association in millimeter wave mimo networks"):
  with members:
    - "a survey of millimeter wave mmwave communications for 5g opportunities and challenges"
    - "probabilistic omnidirectional path loss models for millimeter wave outdoor communications"
    - "optimal user cell association for massive mimo wireless networks"
    - "spatially sparse precoding in millimeter wave mimo systems"

Connected through hyperedge HE-4 (induced by source paper "scalable spectrum allocation and user association in networks with many small cells"):
  with members:
    - "energy management in heterogeneous networks with cell activation user association and interference coordination"
    - "energy efficient cell activation user association and spectrum allocation in heterogeneous networks"
    - "traffic driven spectrum allocation in heterogeneous networks"
    - "distributed pricing based user association for downlink heterogeneous cellular networks"
    - "base station activation and linear transceiver design for optimal resource management in heterogeneous networks"
    - "on association cells in random heterogeneous networks"
    - "user association for load balancing in heterogeneous cellular networks"

Connected through hyperedge HE-5 (induced by source paper "scalable spectrum allocation for large networks based on sparse optimization"):
  with members:
    - "scalable spectrum allocation and user association in networks with many small cells"
    - "energy management in heterogeneous networks with cell activation user association and interference coordination"
    - "energy efficient cell activation user association and spectrum allocation in heterogeneous networks"
    - "traffic driven spectrum allocation in heterogeneous networks"
    - "joint user association and reuse pattern selection in heterogeneous networks"

Connected through hyperedge HE-6 (induced by source paper "optimal user cell association for massive mimo wireless networks"):
  with members:
    - "an overview of load balancing in hetnets old myths and open problems"
    - "optimizing client association in 60 ghz wireless access networks"
    - "scalable synchronization and reciprocity calibration for distributed multiuser mimo"
    - "joint spatial division and multiplexing for mm wave channels"
    - "downlink multi antenna heterogeneous cellular network with load balancing"
    - "network mimo with linear zero forcing beamforming large system analysis impact of channel estimation and reduced complexity scheduling"
    - "user association for load balancing in heterogeneous cellular networks"
    - "achieving massive mimo spectral efficiency with a not so large number of antennas"

Connected through hyperedge HE-7 (induced by source paper "downlink and uplink energy minimization through user association and beamforming in cloud ran"):
  with members:
    - "base station activation and linear transceiver design for optimal resource management in heterogeneous networks"
    - "joint precoding and multivariate backhaul compression for the downlink of cloud radio access networks"
    - "user association for load balancing in heterogeneous cellular networks"
    - "achieving global optimality for weighted sum rate maximization in the k user gaussian interference channel with multiple antennas"
    - "optimal power and range adaptation for green broadcasting"
    - "optimization with sparsity inducing penalties"
    - "cooperative interference management with miso beamforming"

Connected through hyperedge HE-8 (induced by source paper "backhaul constrained multi cell cooperation leveraging sparsity and spectral clustering"):
  with members:
    - "backhaul limited asymmetric cooperation for mimo cellular networks via semidefinite relaxation"
    - "base station activation and linear transceiver design for optimal resource management in heterogeneous networks"
    - "uplink multicell processing with limited backhaul via per base station successive interference cancellation"
    - "optimal channel training in uplink network mimo systems"
    - "linear precoding in cooperative mimo cellular networks with limited coordination clusters"
    - "a tutorial on spectral clustering"

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)