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 complexity of joint subcarrier and power allocation for multi user ofdma systems"
  Abstract: Consider a multi-user Orthogonal Frequency Division Multiple Access (OFDMA) system where multiple users share multiple discrete subcarriers, but at most one user is allowed to transmit power on each subcarrier. To adapt fast traffic and channel fluctuations and improve the spectrum efficiency, the system should have the ability to dynamically allocate subcarriers and power resources to users. Assuming perfect channel knowledge, two formulations for the joint subcarrier and power allocation problem are considered in this paper: the first is to minimize the total transmission power subject to quality of service constraints and the OFDMA constraint, and the second is to maximize some system utility function (including the sum-rate utility, the proportional fairness utility, the harmonic mean utility, and the min-rate utility) subject to the total transmission power constraint per user and the OFDMA constraint. In spite of the existence of various heuristics approaches, little is known about the computational complexity status of the above problem. This paper aims to fill this theoretical gap, i.e., characterizing the complexity of the joint subcarrier and power allocation problem for the multi-user OFDMA system. It is shown in this paper that both formulations of the joint subcarrier and power allocation problem are strongly NP-hard. The proof is based on a polynomial time transformation from the so-called 3-dimensional matching problem. Several subclasses of the problem which can be solved to global optimality or $\epsilon$-global optimality in polynomial time are also identified. These complexity results suggest that there are not polynomial time algorithms which are able to solve the general joint subcarrier and power allocation problem to global optimality (unless P$=$NP), and determining an approximately optimal subcarrier and power allocation strategy is more realistic in practice.

Connected through hyperedge HE-1 (induced by source paper "harq cc enabled noma designs with outage probability constraints"):
  with members:
    - "on energy efficient noma designs for heterogeneous low latency downlink transmissions"
    - "on the performance of noma with hybrid arq"
    - "a survey on non orthogonal multiple access for 5g networks research challenges and future trends"
    - "joint beamforming and power splitting control in downlink cooperative swipt noma systems"
    - "sub channel assignment power allocation and user scheduling for non orthogonal multiple access networks"
    - "what will 5g be"
    - "on the performance of non orthogonal multiple access in 5g systems with randomly deployed users"
    - "coordinated beamforming for multiuser miso interference channel under rate outage constraints"

Connected through hyperedge HE-2 (induced by source paper "subcarrier pairing as channel gain tailoring joint resource allocation for relay assisted secure ofdma with untrusted users"):
  with members:
    - "jammer assisted resource allocation in secure ofdma with untrusted users"
    - "utility regions for df relay in ofdma based secure communication with untrusted users"
    - "ofdma based df secure cooperative communication with untrusted users"
    - "secure communications in noma system subcarrier assignment and power allocation"
    - "principles of physical layer security in multiuser wireless networks a survey"
    - "joint subcarrier pairing and power allocation for ofdm transmission with decode and forward relaying"
    - "power and subcarrier allocation for physical layer security in ofdma based broadband wireless networks"

Connected through hyperedge HE-3 (induced by source paper "jammer assisted resource allocation in secure ofdma with untrusted users"):
  with members:
    - "principles of physical layer security in multiuser wireless networks a survey"
    - "secrecy sum rates for multi user mimo regularized channel inversion precoding"
    - "on tractability aspects of optimal resource allocation in ofdma systems"
    - "interference assisted secret communication"
    - "power and subcarrier allocation for physical layer security in ofdma based broadband wireless networks"
    - "a quantitative measure of fairness and discrimination for resource allocation in shared computer systems"

Connected through hyperedge HE-4 (induced by source paper "weighted sum rate maximization in multi carrier noma with cellular power constraint"):
  with members:
    - "optimal joint subcarrier and power allocation in noma is strongly np hard"
    - "optimal joint power and subcarrier allocation for mc noma systems"
    - "power and channel allocation for non orthogonal multiple access in 5g systems tractability and computation"
    - "a new noma approach for fair power allocation"
    - "complexity analysis of joint subcarrier and power allocation for the cellular downlink ofdma system"

Connected through hyperedge HE-5 (induced by source paper "optimal joint subcarrier and power allocation in noma is strongly np hard"):
  with members:
    - "power and channel allocation for non orthogonal multiple access in 5g systems tractability and computation"
    - "complexity analysis of joint subcarrier and power allocation for the cellular downlink ofdma system"
    - "on the performance of non orthogonal multiple access in 5g systems with randomly deployed users"

Connected through hyperedge HE-6 (induced by source paper "a survey of downlink non orthogonal multiple access for 5g wireless communication networks"):
  with members:
    - "power efficient resource allocation for mc noma with statistical channel state information"
    - "analysis and design of secure massive mimo systems in the presence of hardware impairments"
    - "nonorthogonal multiple access in large scale underlay cognitive radio networks"
    - "design of massive mimo noma with limited feedback"
    - "optimal joint power and subcarrier allocation for mc noma systems"
    - "secrecy sum rate maximization in non orthogonal multiple access"
    - "relay selection for cooperative noma"
    - "non orthogonal multiple access for visible light communications"

Connected through hyperedge HE-7 (induced by source paper "power and channel allocation for non orthogonal multiple access in 5g systems tractability and computation"):
  with members:
    - "noma an information theoretic perspective"
    - "optimal joint power and subcarrier allocation for mc noma systems"
    - "fairness for non orthogonal multiple access in 5g systems"
    - "uplink non orthogonal multiple access for 5g wireless networks"
    - "what will 5g be"
    - "on the performance of non orthogonal multiple access in 5g systems with randomly deployed users"
    - "on tractability aspects of optimal resource allocation in ofdma systems"
    - "gaussian interference channel capacity to within one bit"

Connected through hyperedge HE-8 (induced by source paper "sub channel assignment power allocation and user scheduling for non orthogonal multiple access networks"):
  with members:
    - "collaborative smartphone sensing using overlapping coalition formation games"
    - "matching theory for priority based cell association in the downlink of wireless small cell networks"
    - "on the performance of non orthogonal multiple access in 5g systems with randomly deployed users"
    - "matching with externalities for context aware user cell association in small cell networks"
    - "peer effects and stability in matching markets"
    - "a quantitative measure of fairness and discrimination for resource allocation in shared computer systems"

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)