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 efficient large scale distributed antenna system l das for multiple users"
  Abstract: Large-scale distributed-antenna system (L-DAS) with very large number of distributed antennas, possibly up to a few hundred antennas, is considered. A few major issues of the L-DAS, such as high latency, energy consumption, computational complexity, and large feedback (signaling) overhead, are identified. The potential capability of the L-DAS is illuminated in terms of an energy efficiency (EE) throughout the paper. We firstly and generally model the power consumption of an L-DAS, and formulate an EE maximization problem. To tackle two crucial issues, namely the huge computational complexity and large amount of feedback (signaling) information, we propose a channel-gain-based antenna selection (AS) method and an interference-based user clustering (UC) method. The original problem is then split into multiple subproblems by a cluster, and each cluster's precoding and power control are managed in parallel for high EE. Simulation results reveal that i) using all antennas for zero-forcing multiuser multiple-input multiple-output (MU-MIMO) is energy inefficient if there is nonnegligible overhead power consumption on MU-MIMO processing, and ii) increasing the number of antennas does not necessarily result in a high EE. Furthermore, the results validate and underpin the EE merit of the proposed L-DAS complied with the AS, UC, precoding, and power control by comparing with non-clustering L-DAS and colocated antenna systems.

Connected through hyperedge HE-1 (induced by source paper "energy efficient downlink transmission for multicell massive das with pilot contamination"):
  with members:
    - "joint power allocation and user association optimization for massive mimo systems"
    - "asymptotic orthogonality analysis of time domain sparse massive mimo channels"
    - "interference management in 5g reverse tdd hetnets with wireless backhaul a large system analysis"
    - "large scale mimo relaying techniques for physical layer security af or df"
    - "large system analysis of cognitive radio network via partially projected regularized zero forcing precoding"
    - "joint power and antenna selection optimization in large cloud radio access networks"
    - "impact of transceiver power consumption on the energy efficiency of zero forcing detector in massive mimo systems"
    - "massive mimo for next generation wireless systems"

Connected through hyperedge HE-2 (induced by source paper "cell free massive mimo versus small cells"):
  with members:
    - "cell free massive mimo uniformly great service for everyone"
    - "deploying dense networks for maximal energy efficiency small cells meet massive mimo"
    - "harmonized cellular and distributed massive mimo load balancing and scheduling"
    - "a comparative study of downlink mimo cellular networks with co located and distributed base station antennas"
    - "large scale mimo versus network mimo for multicell interference mitigation"
    - "dealing with interference in distributed large scale mimo systems a statistical approach"
    - "interference reduction in multi cell massive mimo systems i large scale fading precoding and decoding"
    - "downlink mimo hetnets modeling ordering results and performance analysis"

Connected through hyperedge HE-3 (induced by source paper "downlink rate analysis for virtual cell based large scale distributed antenna systems"):
  with members:
    - "spectral efficiency of dynamic coordinated beamforming a stochastic geometry approach"
    - "a comparative study of downlink mimo cellular networks with co located and distributed base station antennas"
    - "joint power and antenna selection optimization in large cloud radio access networks"
    - "what will 5g be"
    - "interference coordination random clustering and adaptive limited feedback"
    - "scaling up mimo opportunities and challenges with very large arrays"
    - "asymptotic rate analysis of downlink multi user systems with co located and distributed antennas"
    - "networked mimo with clustered linear precoding"

Connected through hyperedge HE-4 (induced by source paper "energy efficient transmission for multicast services in miso distributed antenna systems"):
  with members:
    - "heterogeneous cloud radio access networks a new perspective for enhancing spectral and energy efficiencies"
    - "what will 5g be"
    - "large system analysis of linear precoding in correlated miso broadcast channels under limited feedback"
    - "green cellular networks a survey some research issues and challenges"

Connected through hyperedge HE-5 (induced by source paper "low complexity antenna selection for low target rate users in dense cloud radio access networks"):
  with members:
    - "cooperative base station coloring for pair wise multi cell coordination"
    - "large scale convex optimization for dense wireless cooperative networks"
    - "the complexity rate tradeoff of centralized radio access networks"
    - "a stochastic geometry framework for analyzing pairwise cooperative cellular networks"
    - "spectral efficiency of dynamic coordinated beamforming a stochastic geometry approach"
    - "the role of computational outage in dense cloud based centralized radio access networks"
    - "user centric intercell interference nulling for downlink small cell networks"
    - "joint power and antenna selection optimization in large cloud radio access networks"

Connected through hyperedge HE-6 (induced by source paper "performance analysis and location optimization for massive mimo systems with circularly distributed antennas"):
  with members:
    - "dealing with interference in distributed large scale mimo systems a statistical approach"
    - "scaling up mimo opportunities and challenges with very large arrays"
    - "on capacity of large scale mimo multiple access channels with distributed sets of correlated antennas"
    - "achieving massive mimo spectral efficiency with a not so large number of antennas"
    - "large system analysis of linear precoding in correlated miso broadcast channels under limited feedback"
    - "on the precoder design of flat fading mimo systems equipped with mmse receivers a large system approach"
    - "energy and spectral efficiency of very large multiuser mimo systems"

Connected through hyperedge HE-7 (induced by source paper "fingerprinting based positioning in distributed massive mimo systems"):
  with members:
    - "cell free massive mimo uniformly great service for everyone"
    - "a comparative study of downlink mimo cellular networks with co located and distributed base station antennas"
    - "massive mimo for next generation wireless systems"
    - "gaussian processes for nonlinear signal processing an overview of recent advances"

Connected through hyperedge HE-8 (induced by source paper "principal component analysis pca based massive mimo channel feedback"):
  with members:
    - "antenna grouping based feedback compression for fdd based massive mimo systems"
    - "kronecker product correlation model and limited feedback codebook design in a 3d channel model"
    - "scaling up mimo opportunities and challenges with very large arrays"
    - "large system analysis of linear precoding in correlated miso broadcast channels under limited feedback"

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)