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: "time frequency foundations of communications"
  Abstract: In the tradition of Gabor's 1946 landmark paper [1], we advocate a time-frequency (TF) approach to communications. TF methods for communications have been proposed very early (see the box History). While several tutorial papers and book chapters on the topic are available (see, e.g., [2]-[4] and references therein), the goal of this paper is to present the fundamental aspects in a coherent and easily accessible manner. Specifically, we establish the role of TF methods in communications across a range of subject areas including TF dispersive channels, orthogonal frequency division multiplexing (OFDM), information-theoretic limits, and system identification and channel estimation. Furthermore, we present fundamental results that are stated in the literature for the continuous-time case in simple linear algebra terms.

Connected through hyperedge HE-1 (induced by source paper "preamble based channel estimation in ofdm oqam systems a time domain approach"):
  with members:
    - "preamble based channel estimation for cp ofdm and ofdm oqam systems a comparative study"

Connected through hyperedge HE-2 (induced by source paper "a survey on multicarrier communications prototype filters lattice structures and implementation aspects"):
  with members:
    - "a new model for interference analysis in asynchronous multi carrier transmission"
    - "soft output demodulation on frequency selective rayleigh fading channels using ar channel models"

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)