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: "on the relationship between the multi antenna secrecy communications and cognitive radio communications"
  Abstract: This paper studies the capacity of the multi-antenna or multiple-input multiple-output (MIMO) secrecy channels with multiple eavesdroppers having single/multiple antennas. It is known that the MIMO secrecy capacity is achievable with the optimal transmit covariance matrix that maximizes the minimum difference between the channel mutual information of the secrecy user and those of the eavesdroppers. The MIMO secrecy capacity computation can thus be formulated as a non-convex max-min problem, which cannot be solved efficiently by standard convex optimization techniques. To handle this difficulty, we explore a relationship between the MIMO secrecy channel and the recently developed MIMO cognitive radio (CR) channel, in which the multi-antenna secondary user transmits over the same spectrum simultaneously with multiple primary users, subject to the received interference power constraints at the primary users, or the so-called ``interference temperature (IT)'' constraints. By constructing an auxiliary CR MIMO channel that has the same channel responses as the MIMO secrecy channel, we prove that the optimal transmit covariance matrix to achieve the secrecy capacity is the same as that to achieve the CR spectrum sharing capacity with properly selected IT constraints. Based on this relationship, several algorithms are proposed to solve the non-convex secrecy capacity computation problem by transforming it into a sequence of CR spectrum sharing capacity computation problems that are convex. For the case with single-antenna eavesdroppers, the proposed algorithms obtain the exact capacity of the MIMO secrecy channel, while for the case with multi-antenna eavesdroppers, the proposed algorithms obtain both upper and lower bounds on the MIMO secrecy capacity.

Connected through hyperedge HE-1 (induced by source paper "robust an aided beamforming and power splitting design for secure miso cognitive radio with swipt"):
  with members:
    - "robust beamforming for secure communication in systems with wireless information and power transfer"
    - "secrecy outage and diversity analysis of cognitive radio systems"
    - "secure and green swipt in distributed antenna networks with limited backhaul capacity"
    - "simultaneous wireless information and power transfer in modern communication systems"
    - "wireless networks with rf energy harvesting a contemporary survey"
    - "on green energy powered cognitive radio networks"
    - "spatially selective artificial noise aided transmit optimization for miso multi eves secrecy rate maximization"
    - "outage constrained robust secure transmission for miso wiretap channels"

Connected through hyperedge HE-2 (induced by source paper "joint power control in wiretap interference channels"):
  with members:
    - "secure degrees of freedom of one hop wireless networks"
    - "secrecy in the 2 user symmetric deterministic interference channel with transmitter cooperation"
    - "outage constrained robust secure transmission for miso wiretap channels"
    - "spectrum leasing via cooperation for enhanced physical layer secrecy"
    - "interference assisted secret communication"
    - "the gaussian many to one interference channel with confidential messages"
    - "cooperative secret communication with artificial noise in symmetric interference channel"
    - "on the secrecy rate of interference networks using structured codes"

Connected through hyperedge HE-3 (induced by source paper "byzantine attack and defense in cognitive radio networks a survey"):
  with members:
    - "data falsification attacks on consensus based detection systems"
    - "distributed bayesian detection in the presence of byzantine data"
    - "physical layer security with multiuser scheduling in cognitive radio networks"
    - "attack prevention for collaborative spectrum sensing in cognitive radio networks"
    - "robust beamforming for security in mimo wiretap channels with imperfect csi"
    - "the secrecy capacity of the mimo wiretap channel"

Connected through hyperedge HE-4 (induced by source paper "secrecy wireless information and power transfer with miso beamforming"):
  with members:
    - "multiuser miso beamforming for simultaneous wireless information and power transfer"
    - "spatially selective artificial noise aided transmit optimization for miso multi eves secrecy rate maximization"
    - "joint wireless information and energy transfer in a k user mimo interference channel"
    - "a novel mode switching scheme utilizing random beamforming for opportunistic energy harvesting"
    - "wireless information and power transfer a dynamic power splitting approach"
    - "simultaneous information and energy transfer a two user miso interference channel case"
    - "wireless information transfer with opportunistic energy harvesting"
    - "wireless information and power transfer architecture design and rate energy tradeoff"

Connected through hyperedge HE-5 (induced by source paper "security in cognitive radio networks"):
  with members:
    - "effective capacity analysis of cognitive radio channels for quality of service provisioning"
    - "secrecy in cooperative relay broadcast channels"
    - "secure communication over fading channels"
    - "on the secrecy capacity of fading channels"

Connected through hyperedge HE-6 (induced by source paper "secrecy outage and diversity analysis of cognitive radio systems"):
  with members:
    - "optimal relay selection for physical layer security in cooperative wireless networks"
    - "physical layer security with multiuser scheduling in cognitive radio networks"
    - "robust beamforming for security in mimo wiretap channels with imperfect csi"
    - "the secrecy capacity of the mimo wiretap channel"

Connected through hyperedge HE-7 (induced by source paper "waveform design for secure siso transmissions and multicasting"):
  with members:
    - "robust beamforming for security in mimo wiretap channels with imperfect csi"
    - "secure transmission with multiple antennas ii the mimome wiretap channel"
    - "towards the secrecy capacity of the gaussian mimo wire tap channel the 2 2 1 channel"
    - "the secrecy capacity of the mimo wiretap channel"
    - "achievable rates for the general gaussian multiple access wire tap channel with collective secrecy"
    - "applications of ldpc codes to the wiretap channel"

Connected through hyperedge HE-8 (induced by source paper "full rank solutions for the mimo gaussian wiretap channel with an average power constraint"):
  with members:
    - "towards the secrecy capacity of the gaussian mimo wire tap channel the 2 2 1 channel"
    - "transmitter optimization for achieving secrecy capacity in gaussian mimo wiretap channels"
    - "discrete memoryless interference and broadcast channels with confidential messages secrecy rate regions"
    - "the secrecy capacity of the mimo wiretap 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)