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: "towards compact and frequency tunable antenna solutions for mimo transmission with a single rf chain"
  Abstract: Recently, a technique called beam-space MIMO has been demonstrated as an effective approach for transmitting multiple signals while using a single RF-chain. In this work, we present novel design considerations and a compact antenna solution to stimulate the deployment of beam-space MIMO in future wireless applications. Targeting integration in small wireless devices, the novel antenna is made of a single integrated radiator rather than an array of physically-separated dipoles. It also drastically simplifies the implementation of variable loads and DC bias circuits for BPSK modulated signals, and does not require any external reconfigurable matching circuit. Finally, we show that this antenna system could be reconfigured by dynamic adjustment of terminating loads to preserve its beam-space multiplexing capabilities over a 1:2 tuning range, thereby promoting the convergence of MIMO and dynamic spectrum allocation via reduced-complexity hardware. A prototype achieving single-RF-chain multiplexing at a fixed frequency is designed and measured, showing excellent agreement between simulations and measurements.

Connected through hyperedge HE-1 (induced by source paper "millimeter wave multi beam switching antenna"):
  with members:
    - "millimeter wave cellular wireless networks potentials and challenges"

Connected through hyperedge HE-2 (induced by source paper "spatial multiplexing of qpsk signals with a single radio antenna design and over the air experiments"):
  with members:
    - "efficient mimo transmission of psk signals with a single radio reconfigurable antenna"

Connected through hyperedge HE-3 (induced by source paper "near field perturbation effect on constellation error in beam space mimo"):
  with members:
    - "user effects in beam space mimo"

Connected through hyperedge HE-4 (induced by source paper "user effects in beam space mimo"):
  with members:
    - "efficient mimo transmission of psk signals with a single radio reconfigurable antenna"

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)