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: "robust mimo beamforming for cellular and radar coexistence"
  Abstract: In this letter, we consider the coexistence and spectrum sharing between downlink multi-user multiple-input-multiple-output (MU-MIMO) communication and an MIMO radar. For a given performance requirement of the downlink communication system, we design the transmit beamforming such that the detection probability of the radar is maximized. While the original optimization problem is non-convex, we exploit the monotonically increasing relationship of the detection probability with the non-centrality parameter of the resulting probability distribution to obtain a convex lower-bound optimization. The proposed beamformer is designed to be robust to imperfect channel state information (CSI). Simulation results verify that the proposed approach facilitates the coexistence between radar and communication links, and illustrates a scalable tradeoff between the two systems’ performance.

Connected through hyperedge HE-1 (induced by source paper "analysis of worst case interference in underlay radar massive mimo spectrum sharing scenarios"):
  with members:
    - "optimal base station antenna downtilt in downlink cellular networks"
    - "coexistence of outdoor wi fi and radar at 3 5 ghz"
    - "spectrum sharing between a surveillance radar and secondary wi fi networks"
    - "optimum co design for spectrum sharing between matrix completion based mimo radars and a mimo communication system"
    - "modeling and analyzing the coexistence of wi fi and lte in unlicensed spectrum"

Connected through hyperedge HE-2 (induced by source paper "toward dual functional radar communication systems optimal waveform design"):
  with members:
    - "adaptive interference removal for uncoordinated radar communication coexistence"
    - "joint design of overlaid communication systems and pulsed radars"
    - "mu mimo communications with mimo radar from co existence to joint transmission"
    - "interference exploitation for radar and cellular coexistence the power efficient approach"
    - "an efficient global algorithm for single group multicast beamforming"
    - "an efficient manifold algorithm for constructive interference based constant envelope precoding"
    - "optimum co design for spectrum sharing between matrix completion based mimo radars and a mimo communication system"
    - "riemannian dictionary learning and sparse coding for positive definite matrices"

Connected through hyperedge HE-3 (induced by source paper "interference exploitation for radar and cellular coexistence the power efficient approach"):
  with members:
    - "coexistence analysis between radar and cellular system in los channel"
    - "optimum co design for spectrum sharing between matrix completion based mimo radars and a mimo communication system"
    - "constructive interference through symbol level precoding for multi level modulation"
    - "exploiting known interference as green signal power for downlink beamforming optimization"
    - "target detection performance of spectrum sharing mimo radars"
    - "overlapped mimo radar waveform design for coexistence with communication systems"
    - "cooperative radar and communications signaling the estimation and information theory odd couple"
    - "on the impact of time varying interference channel on the spatial approach of spectrum sharing between s band radar and communication system"

Connected through hyperedge HE-4 (induced by source paper "mu mimo communications with mimo radar from co existence to joint transmission"):
  with members:
    - "interference exploitation for radar and cellular coexistence the power efficient approach"
    - "coordinated multicell multicast beamforming based on manifold optimization"
    - "an efficient manifold algorithm for constructive interference based constant envelope precoding"
    - "coexistence analysis between radar and cellular system in los channel"
    - "optimum co design for spectrum sharing between matrix completion based mimo radars and a mimo communication system"
    - "target detection performance of spectrum sharing mimo radars"
    - "manopt a matlab toolbox for optimization on manifolds"

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)