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: "mimo relaying broadcast channels with linear precoding and quantized channel state information feedback"
  Abstract: Multi-antenna relaying has emerged as a promising technology to enhance the system performance in cellular networks. However, when precoding techniques are utilized to obtain multi-antenna gains, the system generally requires channel state information (CSI) at the transmitters. We consider a linear precoding scheme in a MIMO relaying broadcast channel with quantized CSI feedback from both two-hop links. With this scheme, each remote user feeds back its quantized CSI to the relay, and the relay sends back the quantized precoding information to the base station (BS). An upper bound on the rate loss due to quantized channel knowledge is first characterized. Then, in order to maintain the rate loss within a predetermined gap for growing SNRs, a strategy of scaling quantization quality of both two-hop links is proposed. It is revealed that the numbers of feedback bits of both links should scale linearly with the transmit power at the relay, while only the bit number of feedback from the relay to the BS needs to grow with the increasing transmit power at the BS. Numerical results are provided to verify the proposed strategy for feedback quality control.

Connected through hyperedge HE-1 (induced by source paper "ergodic rate analysis of cooperative ambient backscatter communication"):
  with members:
    - "cooperative ambient backscatter communications for green internet of things"
    - "riding on the primary a new spectrum sharing paradigm for wireless powered iot devices"

Connected through hyperedge HE-2 (induced by source paper "hybrid precoding architecture for massive multiuser mimo with dissipation sub connected or fully connected structures"):
  with members:
    - "on performance of quantized transceiver in multiuser massive mimo downlinks"
    - "spectral and energy efficiency of multi pair massive mimo relay network with hybrid processing"
    - "multiuser millimeter wave beamforming strategies with quantized and statistical csit"
    - "two dimensional aod and aoa acquisition for wideband millimeter wave systems with dual polarized mimo"
    - "hybrid analog digital precoding revisited under realistic rf modeling"
    - "alternating minimization algorithms for hybrid precoding in millimeter wave mimo systems"
    - "an overview of signal processing techniques for millimeter wave mimo systems"
    - "linear precoding of data and artificial noise in secure massive mimo systems"

Connected through hyperedge HE-3 (induced by source paper "cache placement in two tier hetnets with limited storage capacity cache or buffer"):
  with members:
    - "optimal fairness aware time and power allocation in wireless powered communication networks"
    - "energy efficient resource allocation in machine to machine communications with multiple access and energy harvesting for iot"
    - "cooperative edge caching in user centric clustered mobile networks"
    - "association and load optimization with user priorities in load coupled heterogeneous networks"
    - "on consideration of content preference and sharing willingness in d2d assisted offloading"
    - "stochastic content centric multicast scheduling for cache enabled heterogeneous cellular networks"
    - "caching at the wireless edge design aspects challenges and future directions"
    - "wireless caching technical misconceptions and business barriers"

Connected through hyperedge HE-4 (induced by source paper "robust mmse precoding for multiuser mimo relay systems using switched relaying and side information"):
  with members:
    - "multi branch tomlinson harashima precoding design for mu mimo systems theory and algorithms"
    - "a general robust linear transceiver design for multi hop amplify and forward mimo relaying systems"
    - "adaptive distributed space time coding based on adjustable code matrices for cooperative mimo relaying 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)