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: "joint spectrum and power allocation for multi node cooperative wireless systems"
  Abstract: Energy efficiency is a growing concern for wireless networks, not only due to the emerging traffic demand from smart devices, but also because of the dependence on the traditional unsustainable energy and the overall environmental concerns. The urgent call for reducing power consumption while meeting system requirements has motivated increasing research efforts on green radio. In this paper, we investigate a new joint spectrum and power allocation scheme for a cooperative downlink multi-user system using the frequency division multiple access scheme, in which arbitrary M base stations (BSs) coordinately allocate their resources to each user equipment (UE). With the assumption that multi-BS UE (user being served by multi-BS) would require the same amount of spectrum from these BSs, we conclude that when the number of multi-BS UEs is limited by M-1, the resource allocation scheme can always guarantee the minimum overall transmit power consumption while meeting the throughput requirement of each UE and also each BS's power constraint. Then, to decide the clusters of multi-BS UEs and the clusters of individual-BS UEs (users being served by individual BSs), we propose a UE-BS association scheme and a complexity reduction scheme. Finally, a novel joint spectrum and power allocation algorithm is proposed to minimize the total power consumption. Simulation results are presented to verify the optimality of the derived schemes.

Connected through hyperedge HE-1 (induced by source paper "joint spectrum allocation and structure optimization in green powered heterogeneous cognitive radio networks"):
  with members:
    - "backhaul aware user association and resource allocation for energy constrained hetnets"
    - "toward hierarchical mobile edge computing an auction based profit maximization approach"
    - "wireless networks with energy harvesting and power transfer joint power and time allocation"
    - "optimal cooperative power allocation for energy harvesting enabled relay networks"
    - "on green energy powered cognitive radio networks"
    - "qos aware base station selections for distributed mimo links in broadband wireless networks"
    - "maximizing system throughput by cooperative sensing in cognitive radio networks"

Connected through hyperedge HE-2 (induced by source paper "content caching and distribution in smart grid enabled wireless networks"):
  with members:
    - "greendelivery proactive content caching and push with energy harvesting based small cells"
    - "green energy aware avatar migration strategy in green cloudlet networks"
    - "complexity analysis of joint subcarrier and power allocation for the cellular downlink ofdma system"
    - "on green energy powered cognitive radio networks"
    - "the throughput outage tradeoff of wireless one hop caching networks"
    - "on tractability aspects of optimal resource allocation in ofdma systems"

Connected through hyperedge HE-3 (induced by source paper "on green energy powered cognitive radio networks"):
  with members:
    - "optimal cooperative power allocation for energy harvesting enabled relay networks"
    - "a traffic load balancing framework for software defined radio access networks powered by hybrid energy sources"
    - "network utility aware traffic loading balancing in backhaul constrained cache enabled small cell networks with hybrid power supplies"
    - "rf energy harvesting enabled power sharing in relay networks"
    - "throughput maximization for the gaussian relay channel with energy harvesting constraints"
    - "a learning theoretic approach to energy harvesting communication system optimization"
    - "relaying protocols for wireless energy harvesting and information processing"
    - "wideband spectrum sensing for cognitive radio networks a survey"

Connected through hyperedge HE-4 (induced by source paper "optimal cooperative power allocation for energy harvesting enabled relay networks"):
  with members:
    - "rf energy harvesting enabled power sharing in relay networks"
    - "power allocation strategies in energy harvesting wireless cooperative networks"
    - "on green energy powered cognitive radio networks"
    - "throughput maximization for the gaussian relay channel with energy harvesting constraints"
    - "relaying protocols for wireless energy harvesting and information processing"
    - "optimal save then transmit protocol for energy harvesting wireless transmitters"
    - "optimal energy allocation for wireless communications with energy harvesting constraints"
    - "transmission with energy harvesting nodes in fading wireless channels optimal policies"

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)