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: "framework for link level energy efficiency optimization with informed transmitter"
  Abstract: The dramatic increase of network infrastructure comes at the cost of rapidly increasing energy consumption, which makes optimization of energy efficiency (EE) an important topic. Since EE is often modeled as the ratio of rate to power, we present a mathematical framework called fractional programming that provides insight into this class of optimization problems, as well as algorithms for computing the solution. The main idea is that the objective function is transformed to a weighted sum of rate and power. A generic problem formulation for systems dissipating transmit-independent circuit power in addition to transmit-dependent power is presented. We show that a broad class of EE maximization problems can be solved efficiently, provided the rate is a concave function of the transmit power. We elaborate examples of various system models including time-varying parallel channels. Rate functions with an arbitrary discrete modulation scheme are also treated. The examples considered lead to water-filling solutions, but these are different from the dual problems of power minimization under rate constraints and rate maximization under power constraints, respectively, because the constraints need not be active. We also demonstrate that if the solution to a rate maximization problem is known, it can be utilized to reduce the EE problem into a one-dimensional convex problem.

Connected through hyperedge HE-1 (induced by source paper "distributed power control with partial channel state information performance characterization and design"):
  with members:
    - "interference coordination via power domain channel estimation"
    - "ultra dense small cell networks turning density into energy efficiency"
    - "a survey of energy efficient techniques for 5g networks and challenges ahead"
    - "coordination in distributed networks via coded actions with application to power control"
    - "coded power control performance analysis"
    - "robust precoding for network mimo with hierarchical csit"
    - "a game theoretic analysis for energy efficient heterogeneous networks"
    - "mac with action dependent state information at one encoder"

Connected through hyperedge HE-2 (induced by source paper "mixed monotonic programming for fast global optimization"):
  with members:
    - "optimization of weighted individual energy efficiencies in interference networks"
    - "efficient global optimal resource allocation in non orthogonal interference networks"
    - "energy efficient power control a look at 5g wireless technologies"
    - "resource allocation for energy efficient 3 way relay channels"
    - "robust monotonic optimization framework for multicell miso systems"
    - "achieving global optimality for weighted sum rate maximization in the k user gaussian interference channel with multiple antennas"
    - "mapel achieving global optimality for a non convex wireless power control problem"
    - "optimal linear precoding strategies for wideband non cooperative systems based on game theory part ii algorithms"

Connected through hyperedge HE-3 (induced by source paper "a new relation between energy efficiency and spectral efficiency in wireless communications systems"):
  with members:
    - "energy efficient scheduling and power allocation in downlink ofdma networks with base station coordination"
    - "joint energy and spectrum cooperation for cellular communication systems"
    - "cost aware green cellular networks with energy and communication cooperation"

Connected through hyperedge HE-4 (induced by source paper "system level modeling and optimization of the energy efficiency in cellular networks a stochastic geometry framework"):
  with members:
    - "effect of densification on cellular network performance with bounded pathloss model"
    - "modeling and analysis of cellular networks using stochastic geometry a tutorial"
    - "enhanced cellular coverage and throughput using rateless codes"
    - "area spectral efficiency analysis and energy consumption minimization in multiantenna poisson distributed networks"
    - "stochastic geometric analysis of energy efficient dense cellular networks"
    - "the intensity matching approach a tractable stochastic geometry approximation to system level analysis of cellular networks"
    - "a survey of energy efficient techniques for 5g networks and challenges ahead"
    - "spatial spectrum and energy efficiency of random cellular networks"

Connected through hyperedge HE-5 (induced by source paper "efficient global optimal resource allocation in non orthogonal interference networks"):
  with members:
    - "optimization of weighted individual energy efficiencies in interference networks"
    - "distributed optimization for coordinated beamforming in multicell multigroup multicast systems power minimization and sinr balancing"
    - "energy efficient beam coordination strategies with rate dependent processing power"
    - "energy efficient power control a look at 5g wireless technologies"
    - "optimal achievable rates for interference networks with random codes"
    - "resource allocation for energy efficient 3 way relay channels"
    - "instantaneous relaying for the 3 way relay channel with circular message exchanges"
    - "wireless information and power transfer energy efficiency optimization in ofdma systems"

Connected through hyperedge HE-6 (induced by source paper "a learning approach for low complexity optimization of energy efficiency in multicarrier wireless networks"):
  with members:
    - "a brief introduction to machine learning for engineers"
    - "energy efficient power control a look at 5g wireless technologies"
    - "a survey of energy efficient techniques for 5g networks and challenges ahead"
    - "learning to be green robust energy efficiency maximization in dynamic mimo ofdm systems"
    - "transmit without regrets online optimization in mimo ofdm cognitive radio systems"
    - "distributed learning policies for power allocation in multiple access channels"
    - "energy efficient power control in impulse radio uwb wireless networks"

Connected through hyperedge HE-7 (induced by source paper "joint queue aware and channel aware delay optimal scheduling of arbitrarily bursty traffic over multi state time varying channels"):
  with members:
    - "on optimizing power allocation for reliable communication over fading channels with uninformed transmitter"
    - "optimum transmission rate in fading channels with markovian sources and qos constraints"
    - "delay optimal scheduling of arbitrarily bursty traffic over multi state time varying channels"
    - "what will 5g be"
    - "the impact of qos constraints on the energy efficiency of fixed rate wireless transmissions"

Connected through hyperedge HE-8 (induced by source paper "fractional programming for communication systems part i power control and beamforming"):
  with members:
    - "fractional programming for communication systems part ii uplink scheduling via matching"
    - "energy efficient power control a look at 5g wireless technologies"
    - "achieving maximum energy efficiency in multi relay ofdma cellular networks a fractional programming approach"

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)