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: "the feasibility of interference alignment for reverse tdd systems in mimo cellular networks"
  Abstract: The feasibility conditions of interference alignment (IA) are analyzed for reverse TDD systems, i.e., one cell operates as downlink (DL) but the other cell operates as uplink (UL). Under general multiple-input and multiple-output (MIMO) antenna configurations, a necessary condition and a sufficient condition for one-shot linear IA are established, i.e., linear IA without symbol or time extension. In several example networks, optimal sum degrees of freedom (DoF) is characterized by the derived necessary condition and sufficient condition. For symmetric DoF within each cell, a sufficient condition is established in a more compact expression, which yields the necessary and sufficient condition for a class of symmetric DoF. An iterative construction of transmit and received beamforming vectors is further proposed, which provides a specific beamforming design satisfying one-shot IA. Simulation results demonstrate that the proposed IA not only achieve lager DoF but also significantly improve the sum rate in the practical signal-to-noise ratio (SNR) regime.

Connected through hyperedge HE-1 (induced by source paper "degrees of freedom of full duplex cellular networks with reconfigurable antennas at base station"):
  with members:
    - "linear degrees of freedom of mimo broadcast channels with reconfigurable antennas in the absence of csit"
    - "prototyping real time full duplex radios"
    - "degrees of freedom of full duplex multiantenna cellular networks"
    - "degrees of freedom of uplink downlink multiantenna cellular networks"
    - "in band full duplex wireless challenges and opportunities"
    - "diophantine approach to blind interference alignment of homogeneous k user 2x1 miso broadcast channels"
    - "experiment driven characterization of full duplex wireless systems"
    - "downlink interference alignment"

Connected through hyperedge HE-2 (induced by source paper "degrees of freedom of full duplex multiantenna cellular networks"):
  with members:
    - "degrees of freedom of uplink downlink multiantenna cellular networks"
    - "degrees of freedom of interference channels with comp transmission and reception"
    - "on the spatial degrees of freedom of multicell and multiuser mimo channels"
    - "degrees of freedom region for an interference network with general message demands"
    - "downlink interference alignment"
    - "real interference alignment with real numbers"
    - "ergodic interference alignment"
    - "degrees of freedom of the k user m times n mimo interference channel"

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)