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 optimal power allocation for downlink non orthogonal multiple access systems"
  Abstract: Non-orthogonal multiple access (NOMA) enables power-domain multiplexing via successive interference cancellation (SIC) and has been viewed as a promising technology for 5G communication. The full benefit of NOMA depends on resource allocation, including power allocation and channel assignment, for all users, which, however, leads to mixed integer programs. In the literature, the optimal power allocation has only been found in some special cases, while the joint optimization of power allocation and channel assignment generally requires exhaustive search. In this paper, we investigate resource allocation in downlink NOMA systems. As the main contribution, we analytically characterize the optimal power allocation with given channel assignment over multiple channels under different performance criteria. Specifically, we consider the maximin fairness, weighted sum rate maximization, sum rate maximization with quality of service (QoS) constraints, and energy efficiency maximization with weights or QoS constraints in NOMA systems. We also take explicitly into account the order constraints on the powers of the users on each channel, which are often ignored in the existing works, and show that they have a significant impact on SIC in NOMA systems. Then, we provide the optimal power allocation for the considered criteria in closed or semi-closed form. We also propose a low-complexity efficient method to jointly optimize channel assignment and power allocation in NOMA systems by incorporating the matching algorithm with the optimal power allocation. Simulation results show that the joint resource optimization using our optimal power allocation yields better performance than the existing schemes.

Connected through hyperedge HE-1 (induced by source paper "downlink analysis of noma enabled cellular networks with 3gpp inspired user ranking"):
  with members:
    - "downlink analysis for the typical cell in poisson cellular networks"
    - "noma in the uplink delay analysis with imperfect csi and finite length coding"
    - "meta distribution of downlink non orthogonal multiple access noma in poisson networks"
    - "downlink non orthogonal multiple access noma in poisson networks"
    - "stochastic geometry based uplink analysis of massive mimo systems with fractional pilot reuse"
    - "accuracy of distance based ranking of users in the analysis of noma systems"
    - "non orthogonal multiple access in large scale heterogeneous networks"
    - "a survey on non orthogonal multiple access for 5g networks research challenges and future trends"

Connected through hyperedge HE-2 (induced by source paper "power efficient irs assisted noma"):
  with members:
    - "multi antenna covert communications in random wireless networks"
    - "resource allocation for secure irs assisted multiuser miso systems"
    - "beamforming optimization for wireless network aided by intelligent reflecting surface with discrete phase shifts"
    - "intelligent reflecting surface assisted non orthogonal multiple access"
    - "smart radio environments empowered by ai reconfigurable meta surfaces an idea whose time has come"
    - "a vision of 6g wireless systems applications trends technologies and open research problems"
    - "a simple design of irs noma transmission"
    - "a speculative study on 6g"

Connected through hyperedge HE-3 (induced by source paper "a note on decoding order in optimizing multi cell noma"):
  with members:
    - "a robust machine learning method for cell load approximation in wireless networks"
    - "a framework for optimizing multi cell noma delivering demand with less resource"
    - "resource optimization with load coupling in multi cell noma"
    - "energy aware wireless relay selection in load coupled ofdma cellular networks"
    - "load optimization with user association in cooperative and load coupled lte networks"
    - "dynamic user clustering and power allocation for uplink and downlink non orthogonal multiple access noma systems"
    - "elementary properties of positive concave mappings with applications to network planning and optimization"
    - "power and channel allocation for non orthogonal multiple access in 5g systems tractability and computation"

Connected through hyperedge HE-4 (induced by source paper "fundamentals of power allocation strategies for downlink multi user noma with target rates"):
  with members:
    - "leveraging edge caching in noma systems with qos requirements"
    - "on the power allocation limits for downlink multi user noma with qos"
    - "joint beamforming and power allocation in downlink noma multiuser mimo networks"
    - "a fair power allocation approach to noma in multiuser siso systems"
    - "joint power allocation and beamforming for non orthogonal multiple access noma in 5g millimeter wave communications"
    - "a fair individual rate comparison between mimo noma and mimo oma"
    - "capacity comparison between mimo noma and mimo oma with multiple users in a cluster"
    - "a new noma approach for fair power allocation"

Connected through hyperedge HE-5 (induced by source paper "power allocation in cache aided noma systems optimization and deep reinforcement learning approaches"):
  with members:
    - "resource allocation in noma based fog radio access networks"
    - "non orthogonal multiple access common myths and critical questions"
    - "joint power allocation and beamforming for non orthogonal multiple access noma in 5g millimeter wave communications"
    - "noma assisted wireless caching strategies and performance analysis"
    - "a survey of downlink non orthogonal multiple access for 5g wireless communication networks"
    - "non orthogonal multiple access in multi cell networks theory performance and practical challenges"
    - "adam a method for stochastic optimization"
    - "fundamental limits of caching in wireless d2d networks"

Connected through hyperedge HE-6 (induced by source paper "distributed cluster formation and power bandwidth allocation for imperfect noma in dl hetnets"):
  with members:
    - "optimal resource allocation for power efficient mc noma with imperfect channel state information"
    - "joint rate control and power allocation for non orthogonal multiple access systems"
    - "sub channel assignment power allocation and user scheduling for non orthogonal multiple access networks"
    - "optimal joint power and subcarrier allocation for full duplex multicarrier non orthogonal multiple access systems"
    - "dynamic user clustering and power allocation for uplink and downlink non orthogonal multiple access noma systems"
    - "power and channel allocation for non orthogonal multiple access in 5g systems tractability and computation"
    - "non orthogonal multiple access noma for downlink multiuser mimo systems user clustering beamforming and power allocation"

Connected through hyperedge HE-7 (induced by source paper "user pairing link selection and power allocation for cooperative noma hybrid vlc rf systems"):
  with members:
    - "on optimizing vlc networks for downlink multi user transmission a survey"
    - "non orthogonal multiple access for mobile vlc networks with random receiver orientation"
    - "dc bias and power allocation in cooperative vlc networks for joint information and energy transfer"
    - "a survey on non orthogonal multiple access for 5g networks research challenges and future trends"
    - "non orthogonal multiple access for visible light communications"
    - "cooperative non orthogonal multiple access with simultaneous wireless information and power transfer"

Connected through hyperedge HE-8 (induced by source paper "blind signal classification analysis and impact on user scheduling and power allocation in nonorthogonal multiple access"):
  with members:
    - "bi directional cooperative noma without full csit"
    - "optimal user scheduling and power allocation for millimeter wave noma systems"
    - "quadrature amplitude modulation division for multiuser miso broadcast channels"
    - "fairness for non orthogonal multiple access in 5g systems"
    - "a general mimo framework for noma downlink and uplink transmission based on signal alignment"
    - "what will 5g be"

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)