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: "fast accurate beam and channel tracking for two dimensional phased antenna array"
  Abstract: The sparsity and the severe attenuation of millimeter-wave (mmWave) channel imply that highly directional communication is needed. The narrow beam caused by large array requires accurate alignment, which can be achieved by beam training with large exploration overhead in static scenarios. However, this training expense is prohibitive when serving fast-moving users. In this paper, we focus on accurate two-dimensional (2D) beam and channel tracking problem in mmWave mobile communication. The minimum exploration overhead of 2D beam and channel tracking is given in theory first. Then the channel is divided into three cases: Quasi-static Case, Dynamic Case I and Dynamic Case II according to different time-varying models. We further develop three tracking algorithms corresponding to these three cases. The proposed algorithms have several salient features: (1) fading channel supportive: they can simultaneously track the channel gain and 2D beam direction in fading channel environments; (2) low exploration overhead: they achieve the minimum exploration requirement for joint beam and channel tracking; (3) fast tracking speed and high tracking accuracy: in Quasi-static Case and Dynamic Case I, the tracking error is proved to converge to the minimum Cramer-Rao lower bound (CRLB). In Dynamic Case II, our tracking algorithm outperforms existing tracking algorithms with lower tracking error and faster tracking speed in simulation.

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)