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: "sub modularity and antenna selection in mimo systems"
  Abstract: In this paper, we show that the optimal receive antenna subset selection problem for maximizing the mutual information in a point-to-point MIMO system is sub-modular. Consequently, a greedy step-wise optimization approach, where at each step an antenna that maximizes the incremental gain is added to the existing antenna subset, is guaranteed to be within a (1 - 1/e) fraction of the global optimal value. For a single antenna equipped source and destination with multiple relays, we show that the relay antenna selection problem to maximize the mutual information is modular, when complete channel state information is available at the relays. As a result a greedy step-wise optimization approach leads to an optimal solution for the relay antenna selection problem with linear complexity in comparison to the brute force search that incurs exponential complexity.

Connected through hyperedge HE-1 (induced by source paper "reversible computation in wireless communications"):
  with members:
    - "reversible hardware for acoustic communications"
    - "controlling reversibility in reversing petri nets with application to wireless communications"
    - "distributing complexity a new approach to antenna selection for distributed massive mimo"
    - "reversible computation in petri nets"
    - "massive mimo in real propagation environments do all antennas contribute equally"

Connected through hyperedge HE-2 (induced by source paper "distributing complexity a new approach to antenna selection for distributed massive mimo"):
  with members:
    - "operating massive mimo in unlicensed bands for enhanced coexistence and spatial reuse"
    - "massive mimo in real propagation environments do all antennas contribute equally"

Connected through hyperedge HE-3 (induced by source paper "receiver antenna partitioning for simultaneous wireless information and power transfer"):
  with members:
    - "sub modularity of waterfilling with applications to online basestation allocation"
    - "throughput maximization in wireless powered communication networks"
    - "simultaneous information and power transfer for broadband wireless systems"
    - "wireless information and power transfer a dynamic power splitting approach"
    - "wireless information and power transfer architecture design and rate energy tradeoff"
    - "mimo broadcasting for simultaneous wireless information and power transfer"

Connected through hyperedge HE-4 (induced by source paper "multi user mimo scheduling in the fourth generation cellular uplink"):
  with members:
    - "multi user scheduling in the 3gpp lte cellular uplink"
    - "efficient submodular function maximization under linear packing constraints"
    - "on k column sparse packing programs"
    - "limited feedback based block diagonalization for the mimo broadcast channel"
    - "message passing resource allocation for the uplink of multicarrier systems"
    - "joint beamforming for multiaccess mimo systems with finite rate feedback"
    - "a tight lower bound to the outage probability of discrete input block fading channels"
    - "multiuser mimo achievable rates with downlink training and channel state feedback"

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)