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: "low complexity polynomial channel estimation in large scale mimo with arbitrary statistics"
  Abstract: This paper considers pilot-based channel estimation in large-scale multiple-input multiple-output (MIMO) communication systems, also known as “massive MIMO”, where there are hundreds of antennas at ...

Connected through hyperedge HE-1 (induced by source paper "channel estimation for spatially temporally correlated massive mimo systems with one bit adcs"):
  with members:
    - "channel estimation for one bit massive mimo systems exploiting spatio temporal correlations"
    - "channel estimation and performance analysis of one bit massive mimo systems"
    - "bayes optimal joint channel and data estimation for massive mimo with low precision adcs"
    - "hybrid architectures with few bit adc receivers achievable rates and energy rate tradeoffs"
    - "mixed adc massive mimo detectors performance analysis and design optimization"
    - "channel estimation in broadband millimeter wave mimo systems with few bit adcs"
    - "near maximum likelihood detector and channel estimator for uplink multiuser massive mimo systems with one bit adcs"
    - "channel estimation techniques for quantized distributed reception in mimo systems"

Connected through hyperedge HE-2 (induced by source paper "massive mimo with spatially correlated rician fading channels"):
  with members:
    - "covariance matrix estimation for massive mimo"
    - "uplink spectral efficiency of massive mimo with spatially correlated rician fading"
    - "covariance matrix estimation in massive mimo"
    - "impact of line of sight and unequal spatial correlation on uplink mu mimo systems"
    - "massive mimo pilot decontamination and channel interpolation via wideband sparse channel estimation"
    - "massive mimo with imperfect channel covariance information"
    - "asymptotic analysis of multicell massive mimo over rician fading channels"
    - "power scaling of uplink massive mimo systems with arbitrary rank channel means"

Connected through hyperedge HE-3 (induced by source paper "power efficient resource allocation in c rans with sinr constraints and deadlines"):
  with members:
    - "joint energy minimization and resource allocation in c ran with mobile cloud"
    - "base station on off switching in 5g wireless networks approaches and challenges"
    - "recent advances in cloud radio access networks system architectures key techniques and open issues"
    - "joint optimization of cloud and edge processing for fog radio access networks"
    - "energy efficiency of downlink transmission strategies for cloud radio access networks"
    - "inter tier interference suppression in heterogeneous cloud radio access networks"
    - "energy efficient resource assignment and power allocation in heterogeneous cloud radio access networks"
    - "large scale convex optimization for ultra dense cloud ran"

Connected through hyperedge HE-4 (induced by source paper "massive mimo has unlimited capacity"):
  with members:
    - "massive mimo pilot decontamination and channel interpolation via wideband sparse channel estimation"
    - "massive mimo with imperfect channel covariance information"
    - "robust pilot decontamination based on joint angle and power domain discrimination"
    - "pilot contamination is not a fundamental asymptotic limitation in massive mimo"
    - "massive mimo with multi cell mmse processing exploiting all pilots for interference suppression"
    - "massive mimo in real propagation environments do all antennas contribute equally"
    - "massive mimo performance evaluation based on measured propagation data"
    - "pilot reuse for massive mimo transmission over spatially correlated rayleigh fading channels"

Connected through hyperedge HE-5 (induced by source paper "a bilinear equalizer for massive mimo systems"):
  with members:
    - "massive mimo has unlimited capacity"
    - "uplink interference reduction in large scale antenna systems"
    - "massive mimo with imperfect channel covariance information"
    - "robust pilot decontamination based on joint angle and power domain discrimination"
    - "cell free massive mimo versus small cells"
    - "cell free massive mimo uniformly great service for everyone"
    - "massive mimo for maximal spectral efficiency how many users and pilots should be allocated"
    - "scaling up mimo opportunities and challenges with very large arrays"

Connected through hyperedge HE-6 (induced by source paper "linear shrinkage estimation of covariance matrices using low complexity cross validation"):
  with members:
    - "low rank covariance assisted downlink training and channel estimation for fdd massive mimo systems"

Connected through hyperedge HE-7 (induced by source paper "pilot power allocation through user grouping in multi cell massive mimo systems"):
  with members:
    - "power allocation schemes for multicell massive mimo systems"
    - "channel estimation in massive mimo systems"
    - "uplink pilot and data power control for single cell massive mimo systems with mrc"
    - "massive mimo with non ideal arbitrary arrays hardware scaling laws and circuit aware design"
    - "multipair full duplex relaying with massive arrays and linear processing"
    - "power scaling of uplink massive mimo systems with arbitrary rank channel means"
    - "dealing with interference in distributed large scale mimo systems a statistical approach"
    - "massive mimo multicasting in noncooperative cellular networks"

Connected through hyperedge HE-8 (induced by source paper "massive mimo pilot decontamination and channel interpolation via wideband sparse channel estimation"):
  with members:
    - "low complexity massive mimo subspace estimation and tracking from low dimensional projections"
    - "robust pilot decontamination based on joint angle and power domain discrimination"
    - "channel acquisition for massive mimo ofdm with adjustable phase shift pilots"
    - "rrh based massive mimo with on the fly pilot contamination control"
    - "pilot contamination is not a fundamental asymptotic limitation in massive mimo"
    - "cell free massive mimo uniformly great service for everyone"
    - "linear precoding based on polynomial expansion large scale multi cell mimo systems"
    - "massive mimo for next generation wireless 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)