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: "secured communication over frequency selective fading channels a practical vandermonde precoding"
  Abstract: In this paper, we study the frequency-selective broadcast channel with confidential messages (BCC) in which the transmitter sends a confidential message to receiver 1 and a common message to receivers 1 and 2. In the case of a block transmission of N symbols followed by a guard interval of L symbols, the frequency-selective channel can be modeled as a N * (N+L) Toeplitz matrix. For this special type of multiple-input multiple-output (MIMO) channels, we propose a practical Vandermonde precoding that consists of projecting the confidential messages in the null space of the channel seen by receiver 2 while superposing the common message. For this scheme, we provide the achievable rate region, i.e. the rate-tuple of the common and confidential messages, and characterize the optimal covariance inputs for some special cases of interest. It is proved that the proposed scheme achieves the optimal degree of freedom (d.o.f) region. More specifically, it enables to send l <= L confidential messages and N-l common messages simultaneously over a block of N+L symbols. Interestingly, the proposed scheme can be applied to secured multiuser scenarios such as the K+1-user frequency-selective BCC with K confidential messages and the two-user frequency-selective BCC with two confidential messages. For each scenario, we provide the achievable secrecy degree of freedom (s.d.o.f.) region of the corresponding frequency-selective BCC and prove the optimality of the Vandermonde precoding. One of the appealing features of the proposed scheme is that it does not require any specific secrecy encoding technique but can be applied on top of any existing powerful encoding schemes.

Connected through hyperedge HE-1 (induced by source paper "securing ofdm based wireless links using temporal artificial noise injection"):
  with members:
    - "hybrid spatio temporal artificial noise design for secure mimome ofdm systems"
    - "principles of physical layer security in multiuser wireless networks a survey"
    - "power allocation and time domain artificial noise design for wiretap ofdm with discrete inputs"

Connected through hyperedge HE-2 (induced by source paper "the secrecy capacity of gaussian mimo channels with finite memory full version"):
  with members:
    - "on the capacity of narrowband plc channels"
    - "principles of physical layer security in multiuser wireless networks a survey"
    - "full rank solutions for the mimo gaussian wiretap channel with an average power constraint"
    - "source channel coding theorems for the multiple access relay channel"
    - "private broadcasting over independent parallel channels"
    - "for the grid and through the grid the role of power line communications in the smart grid"
    - "towards the secrecy capacity of the gaussian mimo wire tap channel the 2 2 1 channel"
    - "the capacity region of the degraded finite state broadcast channel"

Connected through hyperedge HE-3 (induced by source paper "hybrid spatio temporal artificial noise design for secure mimome ofdm systems"):
  with members:
    - "physical layer security in heterogeneous cellular networks"
    - "artificial noise aided secure multi antenna transmission with limited feedback"
    - "massive mimo for next generation wireless systems"
    - "principles of physical layer security in multiuser wireless networks a survey"
    - "power allocation and time domain artificial noise design for wiretap ofdm with discrete inputs"
    - "filter design with secrecy constraints the mimo gaussian wiretap channel"
    - "secure transmission with artificial noise over fading channels achievable rate and optimal power allocation"

Connected through hyperedge HE-4 (induced by source paper "vandermonde subspace frequency division multiplexing for two tiered cognitive radio networks"):
  with members:
    - "from spectrum pooling to space pooling opportunistic interference alignment in mimo cognitive networks"
    - "power control in two tier femtocell networks"
    - "mimo broadcast channel optimization under general linear constraints"
    - "vandermonde frequency division multiplexing for cognitive radio"
    - "femtocell networks a survey"

Connected through hyperedge HE-5 (induced by source paper "diversity multiplexing tradeoff for the multiple antenna wire tap channel"):
  with members:
    - "opportunistic secrecy with a strict delay constraint"
    - "interference alignment for secrecy"
    - "mimo wiretap channels with arbitrarily varying eavesdropper channel states"
    - "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"
    - "on the compound mimo broadcast channels with confidential messages"
    - "on the delay limited secrecy capacity of fading channels"
    - "discrete memoryless interference and broadcast channels with confidential messages secrecy rate regions"

Connected through hyperedge HE-6 (induced by source paper "on the compound mimo broadcast channels with confidential messages"):
  with members:
    - "capacity bounds for broadcast channels with confidential messages"
    - "secrecy capacity region of a multi antenna gaussian broadcast channel with confidential messages"
    - "on the secrecy capacity of fading channels"

Connected through hyperedge HE-7 (induced by source paper "on the 3 receiver broadcast channel with degraded message sets and confidential messages"):
  with members:
    - "secrecy capacity of a class of broadcast channels with an eavesdropper"

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)