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: "robust secure transmission in miso channels based on worst case optimization"
  Abstract: This paper studies robust transmission schemes for multiple-input single-output (MISO) wiretap channels. Both the cases of direct transmission and cooperative jamming with a helper are investigated with imperfect channel state information (CSI) for the eavesdropper links. Robust transmit covariance matrices are obtained based on worst-case secrecy rate maximization, under both individual and global power constraints. For the case of an individual power constraint, we show that the nonconvex maximin optimization problem can be transformed into a quasi-convex problem that can be efficiently solved with existing methods. For a global power constraint, the joint optimization of the transmit covariance matrices and power allocation between the source and the helper is studied. We also investigate the robust wiretap transmission problem for the case with a quality-of-service constraint at the legitimate receiver. Numerical results show the advantage of the proposed robust design. In particular, for the global power constraint scenario, although cooperative jamming is not necessary for optimal transmission with perfect eavesdropper's CSI, we show that robust jamming support can increase the worst-case secrecy rate and lower the signal to interference-plus-noise ratio at the eavesdropper in the presence of channel mismatches between the transmitters and the eavesdropper.

Connected through hyperedge HE-1 (induced by source paper "secure millimeter wave cloud radio access networks relying on microwave multicast fronthaul"):
  with members:
    - "hybrid precoding based millimeter wave massive mimo noma with simultaneous wireless information and power transfer"
    - "optimized base station cache allocation for cloud radio access network with multicast backhaul"
    - "safeguarding millimeter wave communications against randomly located eavesdroppers"
    - "energy efficient power allocation in millimeter wave massive mimo with non orthogonal multiple access"
    - "adaptive coding and modulation for large scale antenna array based aeronautical communications in the presence of co channel interference"
    - "robust an aided beamforming and power splitting design for secure miso cognitive radio with swipt"
    - "energy efficient joint congestion control and resource optimization in heterogeneous cloud radio access networks"
    - "content centric sparse multicast beamforming for cache enabled cloud ran"

Connected through hyperedge HE-2 (induced by source paper "robust beamforming and jamming for enhancing the physical layer security of full duplex radios"):
  with members:
    - "a new design paradigm for secure full duplex multiuser systems"
    - "iterative distributed minimum total mse approach for secure communications in mimo interference channels"
    - "detecting byzantine attacks without clean reference"
    - "secrecy transmit beamforming for heterogeneous networks"
    - "robust beamforming for secure communication in systems with wireless information and power transfer"
    - "secure beamforming for mimo broadcasting with wireless information and power transfer"
    - "security versus reliability analysis of opportunistic relaying"
    - "in band full duplex wireless challenges and opportunities"

Connected through hyperedge HE-3 (induced by source paper "physical layer security in uav systems challenges and opportunities"):
  with members:
    - "wireless communications with unmanned aerial vehicles opportunities and challenges"
    - "secure massive mimo transmission with an active eavesdropper"
    - "principles of physical layer security in multiuser wireless networks a survey"

Connected through hyperedge HE-4 (induced by source paper "beam domain secure transmission for massive mimo communications"):
  with members:
    - "free deterministic equivalents for the analysis of mimo multiple access channel"
    - "linear precoding of data and artificial noise in secure massive mimo systems"
    - "massive mimo ten myths and one critical question"
    - "secure communications in millimeter wave ad hoc networks"
    - "pilot reuse for massive mimo transmission over spatially correlated rayleigh fading channels"
    - "massive mimo for next generation wireless systems"
    - "downlink training techniques for fdd massive mimo systems open loop and closed loop training with memory"
    - "principles of physical layer security in multiuser wireless networks a survey"

Connected through hyperedge HE-5 (induced by source paper "secure transmission and self energy recycling with partial eavesdropper csi"):
  with members:
    - "power allocation for secure swipt systems with wireless powered cooperative jamming"
    - "proactive eavesdropping in relaying systems"
    - "robust resource allocation for mimo wireless powered communication networks based on a non linear eh model"
    - "secure communications in the presence of a buffer aided wireless powered relay with self energy recycling"
    - "robust an aided beamforming and power splitting design for secure miso cognitive radio with swipt"
    - "accumulate and jam towards secure communication via a wireless powered full duplex jammer"
    - "secure massive mimo transmission with an active eavesdropper"
    - "secure communication via a wireless energy harvesting untrusted relay"

Connected through hyperedge HE-6 (induced by source paper "robust physical layer security for power domain non orthogonal multiple access based hetnets and hudns sic avoidance at eavesdroppers"):
  with members:
    - "user association and resource allocation in unified non orthogonal multiple access enabled heterogeneous ultra dense networks"
    - "massive connectivity with massive mimo part i device activity detection and channel estimation"
    - "joint power allocation and beamforming for non orthogonal multiple access noma in 5g millimeter wave communications"
    - "secrecy sum rate maximization in non orthogonal multiple access"
    - "on the spectral efficiency and security enhancements of noma assisted multicast unicast streaming"
    - "optimal joint power and subcarrier allocation for full duplex multicarrier non orthogonal multiple access systems"
    - "enhancing the physical layer security of non orthogonal multiple access in large scale networks"
    - "fairness for non orthogonal multiple access in 5g systems"

Connected through hyperedge HE-7 (induced by source paper "pilot spoofing attack by multiple eavesdroppers"):
  with members:
    - "admm based fast algorithm for multi group multicast beamforming in large scale wireless systems"
    - "impact of artificial noise on cellular networks a stochastic geometry approach"
    - "an algorithm for global maximization of secrecy rates in gaussian mimo wiretap channels"
    - "secure massive mimo transmission with an active eavesdropper"
    - "physical layer security in massive mimo"
    - "secret key agreement with large antenna arrays under the pilot contamination attack"
    - "securing massive mimo at the physical layer"
    - "secure communication over parallel relay channel"

Connected through hyperedge HE-8 (induced by source paper "cooperative prediction and sensing based spectrum sharing in cognitive radio networks"):
  with members:
    - "an efficient precoder design for multiuser mimo cognitive radio networks with interference constraints"
    - "joint beamforming and antenna selection for sum rate maximization in cognitive radio networks"
    - "on the limits of predictability in real world radio spectrum state dynamics from entropy theory to 5g spectrum sharing"
    - "robust cooperative spectrum sensing scheduling optimization in multi channel dynamic spectrum access networks"
    - "primary user traffic classification in dynamic spectrum access networks"
    - "joint transmit beamforming and receive power splitting for miso swipt systems"
    - "exploiting multi antennas for opportunistic spectrum sharing in cognitive radio networks"
    - "weighted sum rate optimization for cognitive radio mimo broadcast channels"

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)