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: "layered downlink precoding for c ran systems with full dimensional mimo"
  Abstract: The implementation of a cloud radio access network (C-RAN) with full dimensional (FD) multiple-input multiple-output (MIMO) is faced with the challenge of controlling the fronthaul overhead for the transmission of baseband signals as the number of horizontal and vertical antennas grows larger. This paper proposes to leverage the special low-rank structure of the FD-MIMO channel, which is characterized by a time-invariant elevation component and a time-varying azimuth component, by means of a layered precoding approach, to reduce the fronthaul overhead. According to this scheme, separate precoding matrices are applied for the azimuth and elevation channel components, with different rates of adaptation to the channel variations and correspondingly different impacts on the fronthaul capacity. Moreover, we consider two different central unit (CU)–radio unit (RU) functional splits at the physical layer, namely, the conventional C-RAN implementation and an alternative one in which coding and precoding are performed at the RUs. Via numerical results, it is shown that the layered schemes significantly outperform conventional nonlayered schemes, particularly in the regime of low fronthaul capacity and a large number of vertical antennas.

Connected through hyperedge HE-1 (induced by source paper "optimization of massive full dimensional mimo for positioning and communication"):
  with members:
    - "channel estimation and performance analysis of one bit massive mimo systems"
    - "a pessimistic approximation for the fisher information measure"
    - "sectoring in multi cell massive mimo systems"
    - "positioning for the internet of things a 3gpp perspective"
    - "downlink achievable rate analysis in massive mimo systems with one bit dacs"
    - "optimal fronthaul quantization for cloud radio positioning"
    - "parallel and distributed methods for nonconvex optimization part ii applications"
    - "quantized precoding for massive mu mimo"

Connected through hyperedge HE-2 (induced by source paper "hybrid precoding for massive mimo systems in cloud ran architecture with capacity limited fronthauls"):
  with members:
    - "an overview of signal processing techniques for millimeter wave mimo systems"
    - "recent advances in cloud radio access networks system architectures key techniques and open issues"
    - "on the number of rf chains and phase shifters and scheduling design with hybrid analog digital beamforming"
    - "channel covariance estimation in massive mimo frequency division duplex systems"
    - "hybrid beamforming for massive mimo a survey"
    - "regularized zf in cooperative broadcast channels under distributed csit a large system analysis"
    - "limited feedback hybrid precoding for multi user millimeter wave systems"
    - "fronthaul constrained cloud radio access networks insights and challenges"

Connected through hyperedge HE-3 (induced by source paper "degrees of freedom in wireless interference networks with cooperative transmission and backhaul load constraints"):
  with members:
    - "conferencing in wyner s asymmetric interference network effect of number of rounds"
    - "network mimo transmitters with no csi can still be very useful"
    - "cloud based topological interference management a case with no cooperative transmission gain"
    - "cell associations that maximize the average uplink downlink degrees of freedom"
    - "cloud radio access network virtualizing wireless access for dense heterogeneous systems"
    - "performance of cloud radio networks"
    - "topological interference management with transmitter cooperation"
    - "aligned image sets under channel uncertainty settling a conjecture by lapidoth shamai and wigger on the collapse of degrees of freedom under finite precision csit"

Connected through hyperedge HE-4 (induced by source paper "cell associations that maximize the average uplink downlink degrees of freedom"):
  with members:
    - "conferencing in wyner s asymmetric interference network effect of number of rounds"
    - "performance of cloud radio networks"
    - "on uplink downlink duality for cellular ia"
    - "degrees of freedom of uplink downlink multiantenna cellular networks"
    - "cellular interference alignment"
    - "dynamic interference management"
    - "degrees of freedom of interference channels with comp transmission and reception"

Connected through hyperedge HE-5 (induced by source paper "swipt in 3 d bipolar ad hoc networks with sectorized antennas"):
  with members:
    - "millimeter wave energy harvesting"
    - "simultaneous wireless information and power transfer in modern communication systems"
    - "wireless networks with rf energy harvesting a contemporary survey"
    - "cooperative energy harvesting networks with spatially random users"
    - "mimo broadcasting for simultaneous wireless information and power transfer"
    - "transmission capacity of ad hoc networks with spatial diversity"

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)