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: "channel estimation for wireless communication systems assisted by large intelligent surfaces"
  Abstract: In this letter, the channel estimation problem is studied for wireless communication systems assisted by large intelligent surface. Due to features of assistant channel, channel estimation (CE) problem for the investigated system is shown as a constrained estimation error minimization problem, which differs from traditional CE problems. A Lagrange multiplier and dual ascent-based estimation scheme is then designed to obtain a closed-form solution for the estimator iteratively. Moreover, the Cramer-Rao lower bounds are deduced for performance evaluation. Simulation results show that the designed scheme could improve estimation accuracy up to 18%, compared with least square method in low signal-to-noise ratio regime.

Connected through hyperedge HE-1 (induced by source paper "beyond max snr joint encoding for reconfigurable intelligent surfaces"):
  with members:
    - "intelligent reflecting surface versus decode and forward how large surfaces are needed to beat relaying"
    - "intelligent reflecting surface with discrete phase shifts channel estimation and passive beamforming"
    - "reflection probability in wireless networks with metasurface coated environmental objects an approach based on random spatial processes"
    - "capacity characterization for intelligent reflecting surface aided mimo communication"
    - "channel capacity optimization using reconfigurable intelligent surfaces in indoor mmwave environments"
    - "intelligent reflecting surface irs enabled covert communications in wireless networks"
    - "secure transmission strategy for intelligent reflecting surface enhanced wireless system"
    - "channel estimation for intelligent reflecting surface assisted multiuser communications"

Connected through hyperedge HE-2 (induced by source paper "channel estimation for intelligent reflecting surface assisted multiuser communications framework algorithms and analysis"):
  with members:
    - "miso wireless communication systems via intelligent reflecting surfaces"
    - "cascaded channel estimation for large intelligent metasurface assisted massive mimo"
    - "capacity characterization for intelligent reflecting surface aided mimo communication"
    - "intelligent reflecting surface meets ofdm protocol design and rate maximization"
    - "enabling secure wireless communications via intelligent reflecting surfaces"
    - "channel estimation for intelligent reflecting surface assisted multiuser communications"
    - "mimo assisted networks relying on large intelligent surfaces a stochastic geometry model"
    - "intelligent reflecting surface enhanced ofdm channel estimation and reflection optimization"

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)