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: "uplink non orthogonal multiple access over mixed rf fso systems"
  Abstract: In this paper, we consider a relay-assisted uplink non-orthogonal multiple access (NOMA) system where two radio frequency (RF) users are grouped for simultaneous transmission, over each resource block, to an intermediate relay which forwards the amplified version of the users' aggregated signals in the presence of multiuser interference to a relatively far destination. In order to cope with the users' ever-increasing desire for higher data rates, a high-throughput free-space optics (FSO) link is employed as the relay-destination backhaul link. Closed-form expressions for the outage probability and ergodic capacity formulas are derived in the case of independent Rayleigh fading for the user-relay access links when the FSO backhaul link is subject to Gamma-Gamma turbulence with pointing error. Moreover, the outage probability and ergodic capacity analysis are extended to the conventional RF-backhauled systems in the presence of multiuser interference to both relay and destination nodes, and Rician fading for the relay-destination RF link. Dynamic-order decoding is employed at the destination to determine the priority of the users based on their instantaneous channel state information (CSI). Extensive numerical results are carried out to illustrate the dependence of the performance of mixed RF-FSO and dual-hop RF/RF NOMA systems to various design parameters. Our results reveal the superiority of FSO backhauling for high-throughput and high-reliability NOMA systems compared to RF backhauling. This work can be regarded as the general analysis of dual-hop uplink NOMA systems as well as first attempt to incorporate power-domain NOMA in mixed RF-FSO systems.

Connected through hyperedge HE-1 (induced by source paper "covert millimeter wave communication via a dual beam transmitter"):
  with members:
    - "first and second order asymptotics in covert communication"
    - "embedding covert information in broadcast communications"
    - "covert communication over a k user multiple access channel"
    - "channel coding at low capacity"
    - "modeling and analyzing millimeter wave cellular systems"
    - "covert communication achieved by a greedy relay in wireless networks"
    - "covert communication in fading channels under channel uncertainty"
    - "covert communications with a full duplex receiver over wireless fading channels"

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)