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: "energy efficiency optimization for mimo ofdm mobile multimedia communication systems with qos constraints"
  Abstract: It is widely recognized that, in addition to the quality-of-service (QoS), energy efficiency is also a key parameter in designing and evaluating mobile multimedia communication systems, which has catalyzed great interest in recent literature. In this paper, an energy-efficiency model is first proposed for multiple-input–multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) mobile multimedia communication systems with statistical QoS constraints. Employing the channel-matrix singular value decomposition (SVD) method, all subchannels are classified by their channel characteristics. Furthermore, the multichannel joint optimization problem in conventional MIMO-OFDM communication systems is transformed into a multitarget single-channel optimization problem by grouping all subchannels. Therefore, a closed-form solution of the energy-efficiency optimization is derived for MIMO-OFDM mobile multimedia communication systems. As a consequence, an energy-efficiency optimized power allocation (EEOPA) algorithm is proposed to improve the energy efficiency of MIMO-OFDM mobile multimedia communication systems. Simulation comparisons validate that the proposed EEOPA algorithm can guarantee the required QoS with high energy efficiency in MIMO-OFDM mobile multimedia communication systems.

Connected through hyperedge HE-1 (induced by source paper "on the effective capacity of an underwater acoustic channel under impersonation attack"):
  with members:
    - "impersonation detection in line of sight underwater acoustic sensor networks"
    - "physical layer authentication in mission critical mtc networks a security and delay performance analysis"
    - "channel impulse response based distributed physical layer authentication"
    - "effective capacity of delay constrained cognitive radio links exploiting primary feedback"
    - "effective capacity of two hop wireless communication systems"
    - "effective capacity analysis of cognitive radio channels for quality of service provisioning"
    - "using the physical layer for wireless authentication in time variant channels"

Connected through hyperedge HE-2 (induced by source paper "neural networks in hybrid precoding for millimeter wave massive mimo systems"):
  with members:
    - "deep learning based channel estimation for beamspace mmwave massive mimo systems"
    - "energy efficiency of mmwave massive mimo precoding with low resolution dacs"
    - "an introduction to deep learning for the physical layer"
    - "energy efficiency challenges of 5g small cell networks"
    - "energy efficiency optimization of 5g radio frequency chain systems"
    - "spatial spectrum and energy efficiency of random cellular networks"
    - "user mobility evaluation for 5g small cell networks based on individual mobility model"
    - "deep residual learning for image recognition"

Connected through hyperedge HE-3 (induced by source paper "a novel jt comp scheme in 5g fractal small cell networks"):
  with members:
    - "ultra reliable uav communication using altitude and cooperation diversity"
    - "downlink small cell base station cooperation strategy in fractal small cell networks"
    - "wireless fractal cellular networks"
    - "spatial spectrum and energy efficiency of random cellular networks"
    - "user mobility evaluation for 5g small cell networks based on individual mobility model"
    - "5g ultra dense cellular networks"
    - "a stochastic geometry framework for analyzing pairwise cooperative cellular networks"
    - "5g wireless backhaul networks challenges and research advances"

Connected through hyperedge HE-4 (induced by source paper "performance analysis of urban mmwave multi hop v2v communications with shifted exponential distribution headway"):
  with members:
    - "5g software defined vehicular networks"
    - "energy efficiency challenges of 5g small cell networks"
    - "multi hop links quality analysis of 5g enabled vehicular networks"
    - "energy efficiency optimization of 5g radio frequency chain systems"
    - "spatial spectrum and energy efficiency of random cellular networks"
    - "user mobility evaluation for 5g small cell networks based on individual mobility model"
    - "5g ultra dense cellular networks"
    - "5g wireless backhaul networks challenges and research advances"

Connected through hyperedge HE-5 (induced by source paper "computing resource allocation of mobile edge computing networks based on potential game theory"):
  with members:
    - "energy efficient resource allocation for cache assisted mobile edge computing"
    - "spatial spectrum and energy efficiency of random cellular networks"
    - "5g ultra dense cellular networks"
    - "5g wireless backhaul networks challenges and research advances"
    - "energy efficiency evaluation of cellular networks based on spatial distributions of traffic load and power consumption"
    - "a tractable approach to coverage and rate in cellular networks"

Connected through hyperedge HE-6 (induced by source paper "energy efficiency optimization of 5g radio frequency chain systems"):
  with members:
    - "on the number of rf chains and phase shifters and scheduling design with hybrid analog digital beamforming"
    - "limited feedback hybrid precoding for multi user millimeter wave systems"
    - "5g ultra dense cellular networks"
    - "5g wireless backhaul networks challenges and research advances"
    - "channel estimation and hybrid precoding for millimeter wave cellular systems"
    - "impact of transceiver power consumption on the energy efficiency of zero forcing detector in massive mimo systems"
    - "spatially sparse precoding in millimeter wave mimo systems"
    - "optimal design of energy efficient multi user mimo systems is massive mimo the answer"

Connected through hyperedge HE-7 (induced by source paper "energy efficient small cell with spectrum power trading"):
  with members:
    - "fundamental green tradeoffs progresses challenges and impacts on 5g networks"
    - "an overview of sustainable green 5g networks"
    - "energy efficient resource allocation for wireless powered communication networks"
    - "a traffic load balancing framework for software defined radio access networks powered by hybrid energy sources"
    - "quantifying potential energy efficiency gain in green cellular wireless networks"
    - "joint energy and spectrum cooperation for cellular communication systems"
    - "energy efficient resource allocation in ofdma systems with hybrid energy harvesting base station"
    - "achieving maximum energy efficiency in multi relay ofdma cellular networks a fractional programming approach"

Connected through hyperedge HE-8 (induced by source paper "5g multimedia massive mimo communications systems"):
  with members:
    - "spatial spectrum and energy efficiency of random cellular networks"
    - "5g ultra dense cellular networks"
    - "5g wireless backhaul networks challenges and research advances"
    - "massive mimo for next generation wireless systems"
    - "massive mu mimo downlink tdd systems with linear precoding and downlink pilots"
    - "scaling up mimo opportunities and challenges with very large arrays"

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)