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 mitigation for cognitive radio mimo systems based on practical precoding"
  Abstract: Abstract   In this paper, we propose two subspace-projection-based precoding schemes, namely, full-projection (FP)- and partial-projection (PP)-based precoding, for a cognitive radio multiple-input multiple-output (CR-MIMO) network to mitigate its interference to a primary time-division-duplexing (TDD) system. The proposed precoding schemes are capable of estimating interference channels between CR and primary networks, and incorporating the interference from the primary to the CR system into CR precoding via a novel sensing approach. Then, the CR performance and resulting interference of the proposed precoding schemes are analyzed and evaluated. By fully projecting the CR transmission onto a null space of the interference channels, the FP-based precoding scheme can effectively avoid interfering the primary system with boosted CR throughput. While, the PP-based scheme is able to further improve the CR throughput by partially projecting its transmission onto the null space.

Connected through hyperedge HE-1 (induced by source paper "a practical spectrum sharing scheme for cognitive radio networks design and experiments"):
  with members:
    - "an efficient precoder design for multiuser mimo cognitive radio networks with interference constraints"
    - "nonorthogonal multiple access in large scale underlay cognitive radio networks"
    - "coordinated shared spectrum precoding with distributed csit"
    - "cognitive beamforming made practical effective interference channel and learning throughput tradeoff"

Connected through hyperedge HE-2 (induced by source paper "the one bit null space learning algorithm and its convergence"):
  with members:
    - "optimal spectrum sharing in mimo cognitive radio networks via semidefinite programming"
    - "on active learning and supervised transmission of spectrum sharing based cognitive radios by exploiting hidden primary radio feedback"
    - "design of learning based mimo cognitive radio systems"
    - "exploiting multi antennas for opportunistic spectrum sharing in cognitive radio networks"
    - "cognitive mimo radio"
    - "cognitive beamforming made practical effective interference channel and learning throughput tradeoff"

Connected through hyperedge HE-3 (induced by source paper "blind null space learning for mimo underlay cognitive radio networks"):
  with members:
    - "spatial mac in mimo communications and its application to underlay cognitive radio"
    - "optimal spectrum sharing in mimo cognitive radio networks via semidefinite programming"
    - "exploiting multi antennas for opportunistic spectrum sharing in cognitive radio networks"
    - "cognitive mimo radio"

Connected through hyperedge HE-4 (induced by source paper "spatial mac in mimo communications and its application to underlay cognitive radio"):
  with members:
    - "optimal spectrum sharing in mimo cognitive radio networks via semidefinite programming"
    - "exploiting multi antennas for opportunistic spectrum sharing in cognitive radio networks"
    - "cognitive mimo radio"

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)