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: "hybrid beamforming via the kronecker decomposition for the millimeter wave massive mimo systems"
  Abstract: Despite its promising performance gain, the realization of mmWave massive MIMO still faces several practical challenges. In particular, implementing massive MIMO in the digital domain requires hundreds of RF chains matching the number of antennas. Furthermore, designing these components to operate at the mmWave frequencies is challenging and costly. These motivated the recent development of hybrid-beamforming where MIMO processing is divided for separate implementation in the analog and digital domains, called the analog and digital beamforming, respectively. Analog beamforming using a phase array introduces uni-modulus constraints on the beamforming coefficients, rendering the conventional MIMO techniques unsuitable and call for new designs. In this paper, we present a systematic design framework for hybrid beamforming for multi-cell multiuser massive MIMO systems over mmWave channels characterized by sparse propagation paths. The framework relies on the decomposition of analog beamforming vectors and path observation vectors into Kronecker products of factors being uni-modulus vectors. Exploiting properties of Kronecker mixed products, different factors of the analog beamformer are designed for either nulling interference paths or coherently combining data paths. Furthermore, a channel estimation scheme is designed for enabling the proposed hybrid beamforming. The scheme estimates the AoA of data and interference paths by analog beam scanning and data-path gains by analog beam steering. The performance of the channel estimation scheme is analyzed. In particular, the AoA spectrum resulting from beam scanning, which displays the magnitude distribution of paths over the AoA range, is derived in closed-form. It is shown that the inter-cell interference level diminishes inversely with the array size, the square root of pilot sequence length and the spatial separation between paths.

Connected through hyperedge HE-1 (induced by source paper "rate splitting for multi antenna downlink precoder design and practical implementation"):
  with members:
    - "rate splitting unifying sdma oma noma and multicasting in miso broadcast channel a simple two user rate analysis"
    - "on linearly precoded rate splitting for mimo broadcast channels"
    - "linearly precoded rate splitting optimality and non optimality for mimo broadcast channels"
    - "rate splitting multiple access for downlink communication systems bridging generalizing and outperforming sdma and noma"
    - "sum rate maximization for linearly precoded downlink multiuser miso systems with partial csit a rate splitting approach"
    - "robust transmission in downlink multiuser miso systems a rate splitting approach"
    - "a rate splitting strategy for massive mimo with imperfect csit"
    - "large system analysis of base station cooperation for power minimization"

Connected through hyperedge HE-2 (induced by source paper "channel estimation and hybrid beamforming for reconfigurable intelligent surfaces assisted thz communications"):
  with members:
    - "secure wireless communication via intelligent reflecting surface"
    - "capacity characterization for intelligent reflecting surface aided mimo communication"
    - "intelligent reflecting surface meets ofdm protocol design and rate maximization"
    - "intelligent reflecting surface design for mimo system by maximizing sum path gains"
    - "channel estimation and transmission for intelligent reflecting surface assisted thz communications"
    - "energy efficient multi user miso communication using low resolution large intelligent surfaces"
    - "achievable rate maximization by passive intelligent mirrors"
    - "intelligent reflecting surface enhanced wireless network via joint active and passive beamforming"

Connected through hyperedge HE-3 (induced by source paper "a framework on hybrid mimo transceiver design based on matrix monotonic optimization"):
  with members:
    - "spectral and energy efficiency of multi pair massive mimo relay network with hybrid processing"
    - "a new view of multi user hybrid massive mimo non orthogonal angle division multiple access"
    - "hybrid analog digital beamforming for massive mimo systems"
    - "hybrid analog and digital beamforming for mmwave ofdm large scale antenna arrays"
    - "codebook based hybrid precoding for millimeter wave multiuser systems"
    - "a novel hybrid beamforming algorithm with unified analog beamforming by subspace construction based on partial csi for massive mimo ofdm systems"
    - "hybrid beamforming for large antenna arrays with phase shifter selection"
    - "hybrid digital and analog beamforming design for large scale antenna arrays"

Connected through hyperedge HE-4 (induced by source paper "low complexity separable beamformers for massive antenna array systems"):
  with members:
    - "energy efficiency of mmwave massive mimo precoding with low resolution dacs"
    - "overview of full dimension mimo in lte advanced pro"
    - "nonlinear adaptive algorithms on rank one tensor models"
    - "massive mimo for next generation wireless systems"

Connected through hyperedge HE-5 (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"
    - "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"
    - "massive mimo for next generation wireless systems"

Connected through hyperedge HE-6 (induced by source paper "spectral efficiency optimization for millimeter wave multiuser mimo systems"):
  with members:
    - "penalty dual decomposition method for nonsmooth nonconvex optimization"
    - "joint source relay design for full duplex mimo af relay systems"
    - "an overview of signal processing techniques for millimeter wave mimo systems"
    - "hybrid digital and analog beamforming design for large scale antenna arrays"
    - "limited feedback hybrid precoding for multi user millimeter wave systems"
    - "near optimal hybrid processing for massive mimo systems via matrix decomposition"
    - "hybrid block diagonalization for massive multiuser mimo systems"
    - "mmwave massive mimo based wireless backhaul for the 5g ultra dense network"

Connected through hyperedge HE-7 (induced by source paper "hybrid beamforming for 5g millimeter wave multi cell networks"):
  with members:
    - "opportunistic downlink interference alignment for multi cell mimo networks"
    - "a novel millimeter wave channel simulator and applications for 5g wireless communications"
    - "spatially sparse precoding in millimeter wave mimo systems"
    - "base station cooperation on the downlink large system analysis"

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)