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: "linear precoding in cooperative mimo cellular networks with limited coordination clusters"
  Abstract: In a cooperative multiple-antenna downlink cellular network, maximization of a concave function of user rates is considered. A new linear precoding technique called soft interference nulling (SIN) is proposed, which performs at least as well as zero-forcing (ZF) beamforming. All base stations share channel state information, but each user's message is only routed to those that participate in the user's coordination cluster. SIN precoding is particularly useful when clusters of limited sizes overlap in the network, in which case traditional techniques such as dirty paper coding or ZF do not directly apply. The SIN precoder is computed by solving a sequence of convex optimization problems. SIN under partial network coordination can outperform ZF under full network coordination at moderate SNRs. Under overlapping coordination clusters, SIN precoding achieves considerably higher throughput compared to myopic ZF, especially when the clusters are large.

Connected through hyperedge HE-1 (induced by source paper "stochastic modeling and analysis of user centric network mimo systems"):
  with members:
    - "a stochastic analysis of network mimo systems"
    - "user centric intercell interference nulling for downlink small cell networks"
    - "adaptive multicell 3d beamforming in multi antenna cellular networks"
    - "a tractable model for noncoherent joint transmission base station cooperation"
    - "sparse beamforming and user centric clustering for downlink cloud radio access network"
    - "location aware cross tier coordinated multipoint transmission in two tier cellular networks"
    - "analytical modeling of uplink cellular networks"
    - "network mimo with linear zero forcing beamforming large system analysis impact of channel estimation and reduced complexity scheduling"

Connected through hyperedge HE-2 (induced by source paper "adaptive hybrid beamforming with massive phased arrays in macro cellular networks"):
  with members:
    - "hybrid beamforming for massive mimo a survey"
    - "massive mimo testbed implementation and initial results in system model validation"

Connected through hyperedge HE-3 (induced by source paper "uplink performance of multi antenna cellular networks with co operative base stations and user centric clustering"):
  with members:
    - "ergodic spectral efficiency in mimo cellular networks"
    - "on a user centric base station cooperation scheme for reliable communications"
    - "full duplex cloud ran with uplink downlink remote radio head association"
    - "heterogeneous cellular networks with spatio temporal traffic delay analysis and scheduling"
    - "cooperative base station coloring for pair wise multi cell coordination"
    - "the world s first real time testbed for massive mimo design implementation and validation"
    - "uplink and downlink rate analysis of a full duplex c ran with radio remote head association"
    - "distributed massive mimo in cellular networks impact of imperfect hardware and number of oscillators"

Connected through hyperedge HE-4 (induced by source paper "layered group sparse beamforming for cache enabled green wireless networks"):
  with members:
    - "fog aided wireless networks for content delivery fundamental latency tradeoffs"
    - "flexible cache aided networks with backhauling"
    - "an efficient global algorithm for single group multicast beamforming"
    - "content centric sparse multicast beamforming for cache enabled cloud ran"
    - "cache aided interference channels"
    - "5g wireless backhaul networks challenges and research advances"
    - "two layer feature reduction for sparse group lasso via decomposition of convex sets"
    - "backhaul limited asymmetric cooperation for mimo cellular networks via semidefinite relaxation"

Connected through hyperedge HE-5 (induced by source paper "fronthaul compression and transmit beamforming optimization for multi antenna uplink c ran"):
  with members:
    - "fog computing based radio access networks issues and challenges"
    - "fronthaul constrained cloud radio access networks insights and challenges"
    - "distributed fronthaul compression and joint signal recovery in cloud ran"
    - "optimal fronthaul compression for synchronization in the uplink of cloud radio access networks"
    - "cloud radio access network virtualizing wireless access for dense heterogeneous systems"
    - "heterogeneous cloud radio access networks a new perspective for enhancing spectral and energy efficiencies"
    - "optimized backhaul compression for uplink cloud radio access network"
    - "sparse beamforming and user centric clustering for downlink cloud radio access network"

Connected through hyperedge HE-6 (induced by source paper "cooperative base station coloring for pair wise multi cell coordination"):
  with members:
    - "a stochastic geometry framework for analyzing pairwise cooperative cellular networks"
    - "spectral efficiency of dynamic coordinated beamforming a stochastic geometry approach"
    - "user centric intercell interference nulling for downlink small cell networks"
    - "a tractable model for noncoherent joint transmission base station cooperation"
    - "location aware cross tier coordinated multipoint transmission in two tier cellular networks"
    - "interference coordination random clustering and adaptive limited feedback"
    - "fundamental limits of cooperation"
    - "a tractable approach to coverage and rate in cellular networks"

Connected through hyperedge HE-7 (induced by source paper "two scale stochastic control for multipoint communication systems with renewables"):
  with members:
    - "power delay tradeoff with predictive scheduling in integrated cellular and wi fi networks"
    - "decentralized energy allocation for wireless networks with renewable energy powered base stations"
    - "cooperative energy trading in comp systems powered by smart grids"
    - "group sparse beamforming for green cloud ran"
    - "optimal power cost management using stored energy in data centers"
    - "stability and capacity regions or discrete time queueing networks"
    - "networked mimo with clustered linear precoding"

Connected through hyperedge HE-8 (induced by source paper "comp meets smart grid a new communication and energy cooperation paradigm"):
  with members:
    - "information and energy cooperation in cognitive radio networks"
    - "base station sleeping and resource allocation in renewable energy powered cellular networks"
    - "energy cooperation in energy harvesting communications"
    - "throughput maximization for the gaussian relay channel with energy harvesting constraints"
    - "energy cooperation in cellular networks with renewable powered base stations"
    - "planning of cellular networks enhanced by energy harvesting"
    - "throughput optimal policies for energy harvesting wireless transmitters with non ideal circuit power"
    - "delay aware bs discontinuous transmission control and user scheduling for energy harvesting downlink coordinated mimo 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)