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: "interference alignment through user cooperation for two cell mimo interfering broadcast channels"
  Abstract: This paper focuses on two-cell multiple-input multiple-output (MIMO) Gaussian interfering broadcast channels (MIMO-IFBC) with K cooperating users on the cell-boundary of each BS. It corresponds to a downlink scenario for cellular networks with two base stations (BSs), and K users equipped with Wi-Fi interfaces enabling to cooperate among users on a peer-to-peer basis. In this scenario, we propose a novel interference alignment (IA) technique exploiting user cooperation. Our proposed algorithm obtains the achievable degrees of freedom (DoF) of 2K when each BS and user have M = K + 1 transmit antennas and N = K receive antennas, respectively. Furthermore, the algorithm requires only a small amount of channel feedback information with the aid of the user cooperation channels. The simulations demonstrate that not only are the analytical results valid, but the achievable DoF of our proposed algorithm also outperforms those of conventional techniques.

Connected through hyperedge HE-1 (induced by source paper "cooperative limited feedback design for massive machine type communications"):
  with members:
    - "advanced quantizer designs for fdd based fd mimo systems using uniform planar arrays"
    - "exploiting trust degree for multiple antenna user cooperation"
    - "antenna grouping based feedback compression for fdd based massive mimo systems"
    - "five disruptive technology directions for 5g"
    - "multi user diversity vs accurate channel state information in mimo downlink channels"
    - "antenna combining for the mimo downlink channel"

Connected through hyperedge HE-2 (induced by source paper "limited feedback designs for machine type communications exploiting user cooperation"):
  with members:
    - "advanced quantizer designs for fdd based fd mimo systems using uniform planar arrays"
    - "towards massive connectivity support for scalable mmtc communications in 5g networks"
    - "exploiting trust degree for multiple antenna user cooperation"
    - "five disruptive technology directions for 5g"
    - "antenna combining for the mimo downlink channel"
    - "mimo broadcast channels with finite rate feedback"

Connected through hyperedge HE-3 (induced by source paper "feedback topology designs for interference alignment in mimo interference channels"):
  with members:
    - "interference alignment for the k user mimo interference channel"
    - "on feasibility of interference alignment in mimo interference networks"
    - "downlink interference alignment"
    - "interference alignment under limited feedback for mimo interference channels"
    - "interference alignment with limited feedback"
    - "on feasibility of interference alignment in mimo interference networks"
    - "adaptive limited feedback for sum rate maximizing beamforming in cooperative multicell systems"
    - "on the achievability of interference alignment in the k user constant mimo interference channel"

Connected through hyperedge HE-4 (induced by source paper "interference alignment with limited feedback on two cell interfering two user mimo mac"):
  with members:
    - "exploiting channel correlations simple interference alignment schemes with no csit"
    - "on feasibility of interference alignment in mimo interference networks"
    - "interference alignment under limited feedback for mimo interference channels"
    - "interference alignment with limited feedback"
    - "on feasibility of interference alignment in mimo interference networks"
    - "degrees of freedom of the k user m times n mimo interference channel"
    - "antenna combining for the mimo downlink channel"
    - "mimo broadcast channels with finite rate feedback"

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)