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: "secure communication in the low snr regime"
  Abstract: Secrecy capacity of a multiple-antenna wiretap channel is studied in the low signal-to-noise ratio (SNR) regime. Expressions for the first and second derivatives of the secrecy capacity with respect to SNR at SNR = 0 are derived. Transmission strategies required to achieve these derivatives are identified. In particular, it is shown that it is optimal in the low-SNR regime to transmit in the maximal-eigenvalue eigenspace of Phi = H_m* H_m - N_m/N_e H_e* H_e where H_m and H_e denote the channel matrices associated with the legitimate receiver and eavesdropper, respectively, and N_m and N_e are the noise variances at the receiver and eavesdropper, respectively. Energy efficiency is analyzed by finding the minimum bit energy required for secure and reliable communications, and the wideband slope. Increased bit energy requirements under secrecy constraints are quantified. Finally, the impact of fading is investigated, and the benefits of fading in terms of energy efficiency are shown.

Connected through hyperedge HE-1 (induced by source paper "secure transmission with large numbers of antennas and finite alphabet inputs"):
  with members:
    - "physical layer security for spectrum sharing systems"
    - "linear precoding of data and artificial noise in secure massive mimo systems"
    - "a survey on wireless security technical challenges recent advances and future trends"
    - "secure massive mimo transmission with an active eavesdropper"
    - "large scale mimo relaying techniques for physical layer security af or df"
    - "multi antenna relay aided wireless physical layer security"
    - "low complexity mimo precoding with discrete signals and statistical csi"
    - "linear precoding for the mimo multiple access channel with finite alphabet inputs and statistical csi"

Connected through hyperedge HE-2 (induced by source paper "secure transmission of delay sensitive data over wireless fading channels"):
  with members:
    - "secure communications in the presence of a buffer aided wireless powered relay with self energy recycling"
    - "a survey on wireless security technical challenges recent advances and future trends"
    - "joint power control in wiretap interference channels"
    - "cross layer scheduling for ofdma based cognitive radio systems with delay and security constraints"
    - "opportunistic secrecy with a strict delay constraint"
    - "energy efficient optimization for physical layer security in multi antenna downlink networks with qos guarantee"
    - "secure wireless communication and optimal power control under statistical queueing constraints"
    - "analysis of energy efficiency in fading channels under qos constraints"

Connected through hyperedge HE-3 (induced by source paper "rank deficient solutions for optimal signaling over wiretap mimo channels"):
  with members:
    - "an algorithm for global maximization of secrecy rates in gaussian mimo wiretap channels"
    - "on the optimal precoding for mimo gaussian wire tap channels"
    - "secrecy results for compound wiretap channels"
    - "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"
    - "transmitter optimization for achieving secrecy capacity in gaussian mimo wiretap channels"
    - "the secrecy capacity of the mimo wiretap channel"

Connected through hyperedge HE-4 (induced by source paper "large scale mimo secure transmission with finite alphabet inputs"):
  with members:
    - "secure massive mimo transmission with an active eavesdropper"
    - "linear precoding for the mimo multiple access channel with finite alphabet inputs and statistical csi"
    - "massive mimo for next generation wireless systems"
    - "linear precoder design for mimo interference channels with finite alphabet signaling"
    - "on secrecy rate analysis of mimo wiretap channels driven by finite alphabet input"
    - "precoding by pairing subchannels to increase mimo capacity with discrete input alphabets"

Connected through hyperedge HE-5 (induced by source paper "an algorithm for global maximization of secrecy rates in gaussian mimo wiretap channels"):
  with members:
    - "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"
    - "transmitter optimization for achieving secrecy capacity in gaussian mimo wiretap channels"
    - "the secrecy capacity of the mimo wiretap channel"

Connected through hyperedge HE-6 (induced by source paper "low power secret key agreement over ofdm"):
  with members:
    - "coding with scrambling concatenation and harq for the awgn wire tap channel a security gap analysis"
    - "exploiting channel diversity in secret key generation from multipath fading randomness"
    - "secret sharing ldpc codes for the bpsk constrained gaussian wiretap channel"
    - "increasing physical layer security through scrambled codes and arq"
    - "on a family of circulant matrices for quasi cyclic low density generator matrix codes"
    - "non systematic codes for physical layer security"
    - "efficient reconciliation protocol for discrete variable quantum key distribution"

Connected through hyperedge HE-7 (induced by source paper "on the fast fading multiple antenna gaussian broadcast channel with confidential messages and partial csit"):
  with members:
    - "on secrecy rate analysis of mimo wiretap channels driven by finite alphabet input"
    - "cognitive radio with partial channel state information at the transmitter"
    - "on the achievable rate of the fading dirty paper channel with imperfect csit"
    - "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)