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: "beamforming tradeoffs for initial ue discovery in millimeter wave mimo systems"
  Abstract: Millimeter-wave (mmW) multi-input multi-output (MIMO) systems have gained increasing traction toward the goal of meeting the high data-rate requirements in next-generation wireless systems. The focus of this work is on low-complexity beamforming approaches for initial user equipment (UE) discovery in such systems. Toward this goal, we first note the structure of the optimal beamformer with per-antenna gain and phase control and establish the structure of good beamformers with per-antenna phase-only control. Learning these right singular vector (RSV)-type beamforming structures in mmW systems is fraught with considerable complexities such as the need for a non-broadcast system design, the sensitivity of the beamformer approximants to small path length changes, inefficiencies due to power amplifier backoff, etc. To overcome these issues, we establish a physical interpretation between the RSV-type beamformer structures and the angles of departure/arrival (AoD/AoA) of the dominant path(s) capturing the scattering environment. This physical interpretation provides a theoretical underpinning to the emerging interest on directional beamforming approaches that are less sensitive to small path length changes. While classical approaches for direction learning such as MUltiple SIgnal Classification (MUSIC) have been well-understood, they suffer from many practical difficulties in a mmW context such as a non-broadcast system design and high computational complexity. A simpler broadcast-based solution for mmW systems is the adaptation of limited feedback-type directional codebooks for beamforming at the two ends. We establish fundamental limits for the best beam broadening codebooks and propose a construction motivated by a virtual subarray architecture that is within a couple of dB of the best tradeoff curve at all useful beam broadening factors. We finally provide the received   ${\text{SNR}}$   loss-UE discovery latency tradeoff with the proposed beam broadening constructions. Our results show that users with a reasonable link margin can be quickly discovered by the proposed design with a smooth roll-off in performance as the link margin deteriorates. While these designs are poorer in performance than the RSV learning approaches or MUSIC for cell-edge users, their low-complexity that leads to a broadcast system design makes them a useful candidate for practical mmW systems.

Connected through hyperedge HE-1 (induced by source paper "statistical blockage modeling and robustness of beamforming in millimeter wave systems"):
  with members:
    - "how to dimension 5g network when users are distributed on roads modeled by poisson line process"
    - "millimeter wave mimo prototype measurements and experimental results"
    - "small scale local area and transitional millimeter wave propagation for 5g communications"
    - "rapid fading due to human blockage in pedestrian crowds at 5g millimeter wave frequencies"
    - "millimeter wave human blockage at 73 ghz with a simple double knife edge diffraction model and extension for directional antennas"
    - "millimeter wave cellular wireless networks potentials and challenges"
    - "spatially sparse precoding in millimeter wave mimo systems"
    - "five disruptive technology directions for 5g"

Connected through hyperedge HE-2 (induced by source paper "hand and body blockage measurements with form factor user equipment at 28 ghz"):
  with members:
    - "statistical blockage modeling and robustness of beamforming in millimeter wave systems"
    - "millimeter wave mimo prototype measurements and experimental results"
    - "small scale local area and transitional millimeter wave propagation for 5g communications"
    - "rapid fading due to human blockage in pedestrian crowds at 5g millimeter wave frequencies"
    - "millimeter wave human blockage at 73 ghz with a simple double knife edge diffraction model and extension for directional antennas"
    - "directional beamforming for millimeter wave mimo systems"
    - "spatially sparse precoding in millimeter wave mimo systems"
    - "millimeter wave beamforming for wireless backhaul and access in small cell networks"

Connected through hyperedge HE-3 (induced by source paper "beam codebook design for 5g mmwave terminals"):
  with members:
    - "statistical blockage modeling and robustness of beamforming in millimeter wave systems"
    - "over sampling codebook based hybrid minimum sum mean square error precoding for millimeter wave 3d mimo"
    - "millimeter wave mimo prototype measurements and experimental results"
    - "hierarchical codebook design for beamforming training in millimeter wave communication"
    - "codebook design for millimeter wave channel estimation with hybrid precoding structure"
    - "channel estimation and hybrid precoding for millimeter wave cellular systems"
    - "what will 5g be"
    - "designing unimodular codes via quadratic optimization"

Connected through hyperedge HE-4 (induced by source paper "evolution of physical layer communications research in the post 5g era"):
  with members:
    - "statistical blockage modeling and robustness of beamforming in millimeter wave systems"
    - "deep learning coordinated beamforming for highly mobile millimeter wave systems"
    - "channel reconstruction based hybrid precoding for millimeter wave multi user mimo systems"
    - "millimeter wave mimo prototype measurements and experimental results"
    - "directional beamforming for millimeter wave mimo systems"

Connected through hyperedge HE-5 (induced by source paper "antenna placement and performance tradeoffs with hand blockage in millimeter wave systems"):
  with members:
    - "statistical blockage modeling and robustness of beamforming in millimeter wave systems"
    - "5g new radio unveiling the essentials of the next generation wireless access technology"
    - "millimeter wave mimo prototype measurements and experimental results"
    - "five disruptive technology directions for 5g"

Connected through hyperedge HE-6 (induced by source paper "versatile compressive mmwave hybrid beamformer codebook design framework"):
  with members:
    - "channel estimation for hybrid architecture based wideband millimeter wave systems"
    - "channel estimation and hybrid precoding for millimeter wave cellular systems"
    - "structured compressed sensing from theory to applications"

Connected through hyperedge HE-7 (induced by source paper "multi cell hybrid millimeter wave systems pilot contamination and interference mitigation"):
  with members:
    - "a multi beam noma framework for hybrid mmwave systems"
    - "massive mimo has unlimited capacity"
    - "optimal resource allocation for power efficient mc noma with imperfect channel state information"
    - "massive mimo performance tdd versus fdd what do measurements say"
    - "coverage analysis for millimeter wave networks the impact of directional antenna arrays"
    - "where when and how mmwave is used in 5g and beyon"
    - "multi user precoding and channel estimation for hybrid millimeter wave systems"
    - "small scale local area and transitional millimeter wave propagation for 5g communications"

Connected through hyperedge HE-8 (induced by source paper "channel reconstruction based hybrid precoding for millimeter wave multi user mimo systems"):
  with members:
    - "millimeter wave mimo prototype measurements and experimental results"
    - "common codebook millimeter wave beam design designing beams for both sounding and communication with uniform planar arrays"
    - "directional beamforming for millimeter wave mimo systems"
    - "investigation of prediction accuracy sensitivity and parameter stability of large scale propagation path loss models for 5g wireless communications"
    - "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"
    - "limited feedback hybrid precoding for multi user millimeter wave systems"
    - "channel estimation and hybrid precoding for millimeter wave cellular 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)