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: "hierarchical interference mitigation for massive mimo cellular networks"
  Abstract: We propose a hierarchical interference mitigation scheme for massive MIMO cellular networks. The MIMO precoder at each base station (BS) is partitioned into an inner precoder and an outer precoder. The inner precoder controls the intra-cell interference and is adaptive to local channel state information (CSI) at each BS (CSIT). The outer precoder controls the inter-cell interference and is adaptive to channel statistics. Such hierarchical precoding structure reduces the number of pilot symbols required for CSI estimation in massive MIMO downlink and is robust to the backhaul latency. We study joint optimization of the outer precoders, the user selection, and the power allocation to maximize a general concave utility which has no closed-form expression. We first apply random matrix theory to obtain an approximated problem with closed-form objective. Then using the hidden convexity of the problem, we propose an iterative algorithm to find the optimal solution for the approximated problem. We also obtain a low complexity algorithm with provable convergence. Simulations show that the proposed design has significant gain over various state-of-the-art baselines.

Connected through hyperedge HE-1 (induced by source paper "joint path selection and rate allocation framework for 5g self backhauled mm wave networks"):
  with members:
    - "path selection and rate allocation in self backhauled mmwave networks"
    - "ultra reliable communication in 5g mmwave networks a risk sensitive approach"
    - "energy efficient interactive beam alignment for millimeter wave networks"
    - "ultra reliable and low latency wireless communication tail risk and scale"
    - "toward low latency and ultra reliable virtual reality"
    - "millimeter wave v2v communications distributed association and beam alignment"
    - "capacity scaling of cellular networks impact of bandwidth infrastructure density and number of antennas"
    - "joint load balancing and interference mitigation in 5g heterogeneous networks"

Connected through hyperedge HE-2 (induced by source paper "reduced dimension design of mimo over the air computing for data aggregation in clustered iot networks"):
  with members:
    - "broadband analog aggregation for low latency federated edge learning extended version"
    - "wirelessly powered data aggregation for iot via over the air functional computation beamforming and power control"
    - "blind over the air computation and data fusion via provable wirtinger flow"
    - "hybrid beamforming via the kronecker decomposition for the millimeter wave massive mimo systems"
    - "inference from randomized transmissions by many backscatter sensors"
    - "alternating minimization algorithms for hybrid precoding in millimeter wave mimo systems"
    - "communication efficient learning of deep networks from decentralized data"
    - "over the air function computation in sensor networks"

Connected through hyperedge HE-3 (induced by source paper "downlink precoding with mixed statistical and imperfect instantaneous csi for massive mimo systems"):
  with members:
    - "massive mimo with imperfect channel covariance information"
    - "a rate splitting strategy for massive mimo with imperfect csit"
    - "massive mimo ten myths and one critical question"
    - "two stage subspace constrained precoding in massive mimo cellular systems"
    - "power scaling of uplink massive mimo systems with arbitrary rank channel means"
    - "dealing with interference in distributed large scale mimo systems a statistical approach"
    - "pilot beam pattern design for channel estimation in massive mimo systems"
    - "two tier precoding for fdd multi cell massive mimo time varying interference networks"

Connected through hyperedge HE-4 (induced by source paper "stochastic successive convex optimization for two timescale hybrid precoding in massive mimo"):
  with members:
    - "joint power allocation and user association optimization for massive mimo systems"
    - "a parallel decomposition method for nonconvex stochastic multi agent optimization problems"
    - "hybrid digital and analog beamforming design for large scale antenna arrays"
    - "hybrid beamforming for massive mimo a survey"
    - "limited feedback hybrid precoding for multi user millimeter wave systems"
    - "joint power and antenna selection optimization in large cloud radio access networks"
    - "spatially sparse precoding in millimeter wave mimo systems"
    - "low complexity hybrid precoding in massive multiuser mimo systems"

Connected through hyperedge HE-5 (induced by source paper "an overview on resource allocation techniques for multi user mimo systems"):
  with members:
    - "low complexity downlink user selection for massive mimo systems"
    - "alternating minimization algorithms for hybrid precoding in millimeter wave mimo systems"
    - "an overview of signal processing techniques for millimeter wave mimo systems"
    - "user association in 5g networks a survey and an outlook"
    - "cell free massive mimo versus small cells"
    - "mu mimo mac protocols for wireless local area networks a survey"
    - "on the number of rf chains and phase shifters and scheduling design with hybrid analog digital beamforming"
    - "hybrid digital and analog beamforming design for large scale antenna arrays"

Connected through hyperedge HE-6 (induced by source paper "joint load balancing and interference mitigation in 5g heterogeneous networks"):
  with members:
    - "optimal hierarchical radio resource management for hetnets with flexible backhaul"
    - "ultra reliable and low latency communication in mmwave enabled massive mimo networks"
    - "user association in 5g networks a survey and an outlook"
    - "joint in band backhauling and interference mitigation in 5g heterogeneous networks"
    - "interference management in 5g reverse tdd hetnets with wireless backhaul a large system analysis"
    - "large system analysis of cognitive radio network via partially projected regularized zero forcing precoding"
    - "cooperative interference mitigation algorithm in heterogeneous networks"
    - "an overview of load balancing in hetnets old myths and open problems"

Connected through hyperedge HE-7 (induced by source paper "ultra reliable and low latency communication in mmwave enabled massive mimo networks"):
  with members:
    - "when mmwave communications meet network densification a scalable interference coordination perspective"
    - "downlink cell association and load balancing for joint millimeter wave microwave cellular networks"
    - "joint in band backhauling and interference mitigation in 5g heterogeneous networks"
    - "massive mimo for next generation wireless systems"
    - "millimeter wave channel modeling and cellular capacity evaluation"
    - "large system analysis of linear precoding in correlated miso broadcast channels under limited feedback"

Connected through hyperedge HE-8 (induced by source paper "on the role of transmit correlation diversity in multiuser mimo systems"):
  with members:
    - "a codebook based limited feedback system for large scale mimo"
    - "massive mimo meets hetnet interference coordination through spatial blanking"
    - "joint spatial division and multiplexing for mm wave channels"
    - "a coordinated approach to channel estimation in large scale multiple antenna systems"
    - "network mimo with linear zero forcing beamforming large system analysis impact of channel estimation and reduced complexity scheduling"
    - "multiuser mimo achievable rates with downlink training and channel state 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)