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: "robust precoding for network mimo with hierarchical csit"
  Abstract: In this work, we consider a wireless network with K cooperating transmitters (TXs) serving jointly K receivers (RXs). Due to the practical limitations of the backhaul network, it is relevant to consider a setting where each TX receives its own imperfect estimate of the multi-user channel state, denoted as the distributed channel state information (CSI) setting. We focus in this work on a particular distributed CSI configuration called hierarchical CSI configuration in which the TXs can be ordered by increasing level of CSI. This scenario is particularly relevant for future networks with heterogeneous backhaul where the TXs connected with a weak backhaul link will receive only a coarse estimate while the TXs with a stronger backhaul will have a more accurate CSI. In that scenario, we formulate the optimal precoding as a team decision problem. Solving optimally this problem is extremely challenging such that we propose a heuristic approach allowing to obtain a simple, yet efficient and practical, precoding algorithm. The proposed precoding algorithm exploits the hierarchical structure of the CSI to make the transmission more robust to the imperfect CSI knowledge at the TXs.

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"
    - "a game theoretic analysis for energy efficient heterogeneous networks"
    - "mac with action dependent state information at one encoder"
    - "framework for link level energy efficiency optimization with informed transmitter"

Connected through hyperedge HE-2 (induced by source paper "cooperative mimo precoding with distributed csi a hierarchical approach"):
  with members:
    - "drone small cells in the clouds design deployment and performance analysis"
    - "a coordinated approach to channel estimation in large scale multiple antenna systems"

Connected through hyperedge HE-3 (induced by source paper "network mimo transmitters with no csi can still be very useful"):
  with members:
    - "distributed space time interference alignment with moderately delayed csit"
    - "degrees of freedom of the k user miso interference channel with delayed local csit"
    - "aligned image sets under channel uncertainty settling a conjecture by lapidoth shamai and wigger on the collapse of degrees of freedom under finite precision csit"
    - "degrees of freedom of time correlated miso broadcast channel with delayed csit"
    - "csi feedback reduction for mimo interference alignment"
    - "fundamental limits of caching"
    - "optimal use of current and outdated channel state information degrees of freedom of the miso bc with mixed csit"
    - "interference alignment with incomplete csit sharing"

Connected through hyperedge HE-4 (induced by source paper "dof robust strategies for the k user distributed broadcast channel with weak csi"):
  with members:
    - "distributed space time interference alignment with moderately delayed csit"
    - "degrees of freedom of the k user miso interference channel with delayed local csit"
    - "degrees of freedom of time correlated miso broadcast channel with delayed csit"
    - "csi feedback reduction for mimo interference alignment"
    - "fundamental limits of caching"
    - "optimal use of current and outdated channel state information degrees of freedom of the miso bc with mixed csit"
    - "interference alignment with incomplete csit sharing"
    - "completely stale transmitter channel state information is still very useful"

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)