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: "cooperative cognitive networks optimal distributed and low complexity algorithms"
  Abstract: This paper considers the cooperation between a cognitive system and a primary system where multiple cognitive base stations (CBSs) relay the primary user's (PU) signals in exchange for more opportunity to transmit their own signals. The CBSs use amplify-and-forward (AF) relaying and coordinated beamforming to relay the primary signals and transmit their own signals. The objective is to minimize the overall transmit power of the CBSs given the rate requirements of the PU and the cognitive users (CUs). We show that the relaying matrices have unity rank and perform two functions: Matched filter receive beamforming and transmit beamforming. We then develop two efficient algorithms to find the optimal solution. The first one has a linear convergence rate and is suitable for distributed implementation, while the second one enjoys superlinear convergence but requires centralized processing. Further, we derive the beamforming vectors for the linear conventional zero-forcing (CZF) and prior zero-forcing (PZF) schemes, which provide much simpler solutions. Simulation results demonstrate the improvement in terms of outage performance due to the cooperation between the primary and cognitive systems.

Connected through hyperedge HE-1 (induced by source paper "all cognitive mimo a new multiuser detection approach with different priorities"):
  with members:
    - "distributed spatial multiplexing systems with hardware impairments and imperfect channel estimation under rank 1 rician fading channels"
    - "simultaneous spectrum sensing and data reception for cognitive spatial multiplexing distributed systems"
    - "massive mimo ten myths and one critical question"
    - "massive mimo for next generation wireless systems"
    - "full duplex cooperative cognitive radio with transmit imperfections"
    - "effects of channel aging in massive mimo systems"
    - "energy and spectral efficiency of very large multiuser mimo systems"
    - "mimo diversity in the presence of double scattering"

Connected through hyperedge HE-2 (induced by source paper "destination aided wireless power transfer in energy limited cognitive relay systems"):
  with members:
    - "transceiver design to maximize the weighted sum secrecy rate in full duplex swipt systems"
    - "joint wireless information and power transfer for an autonomous multiple antenna relay system"
    - "multi objective optimization for robust power efficient and secure full duplex wireless communication systems"
    - "joint power splitting and secure beamforming design in the wireless powered untrusted relay networks"
    - "joint beamforming optimization and power control for full duplex mimo two way relay channel"
    - "information and energy cooperation in cognitive radio networks"
    - "secrecy wireless information and power transfer with miso beamforming"
    - "throughput maximization in wireless powered communication networks"

Connected through hyperedge HE-3 (induced by source paper "spectrum sharing in rf powered cognitive radio networks using game theory"):
  with members:
    - "distributed power splitting for swipt in relay interference channels using game theory"
    - "rf powered cognitive radio networks technical challenges and limitations"
    - "information and energy cooperation in cognitive radio networks"
    - "price based resource allocation for spectrum sharing femtocell networks a stackelberg game approach"

Connected through hyperedge HE-4 (induced by source paper "information and energy cooperation in cognitive radio networks"):
  with members:
    - "full duplex cooperative cognitive radio with transmit imperfections"
    - "energy cooperation in energy harvesting communications"
    - "energy cooperation in cellular networks with renewable powered base stations"
    - "relaying protocols for wireless energy harvesting and information processing"
    - "wireless information transfer with opportunistic energy harvesting"
    - "wireless information and power transfer architecture design and rate energy tradeoff"
    - "mimo broadcasting for simultaneous wireless information and power transfer"
    - "cognitive radio an information theoretic perspective"

Connected through hyperedge HE-5 (induced by source paper "simultaneous wireless information and power transfer in modern communication systems"):
  with members:
    - "robust beamforming for secure communication in systems with wireless information and power transfer"
    - "information and energy cooperation in cognitive radio networks"
    - "wireless information and power transfer energy efficiency optimization in ofdma systems"
    - "mimo broadcasting for simultaneous wireless information and power transfer"

Connected through hyperedge HE-6 (induced by source paper "practical design for multiple antenna cognitive radio networks with coexistence constraint"):
  with members:
    - "improved transmission strategies for cognitive radio under the coexistence constraint"
    - "inner and outer bounds for the gaussian cognitive interference channel and new capacity results"
    - "optimal and robust transmit designs for miso channel secrecy by semidefinite programming"
    - "cognitive radio with partial channel state information at the transmitter"
    - "exploiting multi antennas for opportunistic spectrum sharing in cognitive radio networks"
    - "a framework for designing mimo systems with decision feedback equalization or tomlinson harashima precoding"
    - "cognitive radio an information theoretic perspective"

Connected through hyperedge HE-7 (induced by source paper "full duplex cooperative cognitive radio with transmit imperfections"):
  with members:
    - "design and characterization of a full duplex multiantenna system for wifi networks"
    - "full duplex bidirectional mimo achievable rates under limited dynamic range"
    - "pushing the limits of full duplex design and real time implementation"
    - "a simple cooperative diversity method based on network path selection"
    - "cognitive radio an information theoretic perspective"

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)