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: "uplink sounding reference signal coordination to combat pilot contamination in 5g massive mimo"
  Abstract: To guarantee the success of massive multiple-input multiple-output (MIMO), one of the main challenges to solve is the efficient management of pilot contamination. Allocation of fully orthogonal pilot sequences across the network would provide a solution to the problem, but the associated overhead would make this approach infeasible in practical systems. Ongoing fifth-generation (5G) standardisation activities are debating the amount of resources to be dedicated to the transmission of pilot sequences, focussing on uplink sounding reference signals (UL SRSs) design. In this paper, we extensively evaluate the performance of various UL SRS allocation strategies in practical deployments, shedding light on their strengths and weaknesses. Furthermore, we introduce a novel UL SRS fractional reuse (FR) scheme, denoted neighbour-aware FR (FR-NA). The proposed FR-NA generalizes the fixed reuse paradigm, and entails a tradeoff between i) aggressively sharing some UL SRS resources, and ii) protecting other UL SRS resources with the aim of relieving neighbouring BSs from pilot contamination. Said features result in a cell throughput improvement over both fixed reuse and state-of-the-art FR based on a cell-centric perspective.

Connected through hyperedge HE-1 (induced by source paper "enabling ultra reliable wireless communications for factory automation with distributed mimo"):
  with members:
    - "ultra reliable and low latency wireless communication tail risk and scale"

Connected through hyperedge HE-2 (induced by source paper "5g massive mimo architectures self backhauled small cells versus direct access"):
  with members:
    - "performance analysis for practical unmanned aerial vehicle networks with los nlos transmissions"
    - "performance of massive mimo self backhauling for ultra dense small cell deployments"
    - "performance of dynamic and static tdd in self backhauled millimeter wave cellular networks"
    - "joint backhaul access analysis of full duplex self backhauling heterogeneous networks"
    - "analysis of massive mimo enabled downlink wireless backhauling for full duplex small cells"
    - "the new frontier in ran heterogeneity multi tier drone cells"
    - "performance impact of los and nlos transmissions in dense cellular networks"
    - "performance analysis of massive mimo for cell boundary users"

Connected through hyperedge HE-3 (induced by source paper "understanding uav cellular communications from existing networks to massive mimo"):
  with members:
    - "cellular connected uav potentials challenges and promising technologies"
    - "supporting uav cellular communications through massive mimo"
    - "the essential guide to realizing 5g connected uavs with massive mimo"
    - "the sky is not the limit lte for unmanned aerial vehicles"
    - "a tutorial on uavs for wireless networks applications challenges and open problems"
    - "interference mitigation methods for unmanned aerial vehicles served by cellular networks"
    - "reshaping cellular networks for the sky the major factors and feasibility"
    - "massive mimo for communications with drone swarms"

Connected through hyperedge HE-4 (induced by source paper "supporting uav cellular communications through massive mimo"):
  with members:
    - "reshaping cellular networks for the sky the major factors and feasibility"
    - "massive mimo for communications with drone swarms"
    - "cell edge aware precoding for downlink massive mimo cellular networks"
    - "massive mimo unlicensed a new approach to dynamic spectrum access"
    - "a stochastic geometry model of backhaul and user coverage in urban uav networks"
    - "pilot contamination is not a fundamental asymptotic limitation in massive mimo"
    - "wireless communications with unmanned aerial vehicles opportunities and challenges"
    - "operating massive mimo in unlicensed bands for enhanced coexistence and spatial reuse"

Connected through hyperedge HE-5 (induced by source paper "enhanced multiuser superposition transmission through structured modulation"):
  with members:
    - "cell edge aware precoding for downlink massive mimo cellular networks"
    - "lattice partition multiple access a new method of downlink non orthogonal multiuser transmissions"
    - "the application of mimo to non orthogonal multiple access"
    - "fairness for non orthogonal multiple access in 5g systems"
    - "a general mimo framework for noma downlink and uplink transmission based on signal alignment"
    - "large system analysis of linear precoding in miso broadcast channels with confidential messages"

Connected through hyperedge HE-6 (induced by source paper "performance of massive mimo self backhauling for ultra dense small cell deployments"):
  with members:
    - "analysis of massive mimo enabled downlink wireless backhauling for full duplex small cells"
    - "performance impact of los and nlos transmissions in dense cellular networks"
    - "towards 1 gbps ue in cellular systems understanding ultra dense small cell deployments"
    - "energy efficient design of mimo heterogeneous networks with wireless backhaul"
    - "small cell in band wireless backhaul in massive mimo systems a cooperation of next generation techniques"
    - "scaling up mimo opportunities and challenges with very large arrays"

Connected through hyperedge HE-7 (induced by source paper "downlink performance of uplink fractional power control in 5g massive mimo systems"):
  with members:
    - "joint pilot design and uplink power allocation in multi cell massive mimo systems"
    - "massive mimo ten myths and one critical question"
    - "massive mimo for next generation wireless systems"
    - "five disruptive technology directions for 5g"

Connected through hyperedge HE-8 (induced by source paper "indoor massive mimo deployments for uniformly high wireless capacity"):
  with members:
    - "cell edge aware precoding for downlink massive mimo cellular networks"
    - "massive mimo unlicensed for high performance indoor networks"
    - "enhancing coexistence in the unlicensed band with massive mimo"
    - "massive mimo unlicensed a new approach to dynamic spectrum access"
    - "cell free massive mimo versus small cells"
    - "a stochastic analysis of network mimo systems"
    - "operating massive mimo in unlicensed bands for enhanced coexistence and spatial reuse"
    - "towards 1 gbps ue in cellular systems understanding ultra dense small cell deployments"

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)