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: "on the spatial separation of multi user channels using 73 ghz statistical channel models"
  Abstract: This paper focuses at the investigation of the degree of orthogonality of channels of multiple users in densely populated indoor and outdoor scenarios. For this purpose, a statistical millimeter wave (mmwave) MIMO channel simulator is carefully designed using state of the art channel models. At the mmwave frequencies, human/vehicular mobility around the mobile users may partially or completely block the communication link. This give rise to the consideration of new channel modeling parameter i.e. probability of a user to be in LOS dynamics. Higher line of sight (LOS) probabilities may increase the spatial correlation among the multiuser channels. Therefore, quantification of the spatial separation of users in different scenarios with distinct LOS probabilities is crucial and it is the subject of investigation of this paper. Additionally, the mutual orthogonality of channels by changing the number of base station (BS) antennas and inter antenna element distance (IED) have also been investigated. Analysis shows that LOS blockage of certain scenario has more impact at the degree of orthogonality among users as compared to the number of BS antennas and the spacing between the antenna elements.

Connected through hyperedge HE-1 (induced by source paper "multiuser separation and performance analysis of millimeter wave channels with linear precoding"):
  with members:
    - "5g 3gpp like channel models for outdoor urban microcellular and macrocellular environments"
    - "on clustered statistical mimo millimeter wave channel simulation"
    - "statistical channel model with multi frequency and arbitrary antenna beamwidth for millimeter wave outdoor communications"
    - "channel hardening exploiting message passing chemp receiver in large scale mimo systems"
    - "millimeter wave channel modeling and cellular capacity evaluation"

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)