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: "tree structured random vector quantization for limited feedback wireless channels"
  Abstract: We consider the quantization of a transmit beamforming vector in multiantenna channels and of a signature vector in code division multiple access (CDMA) systems. Assuming perfect channel knowledge, the receiver selects for a transmitter the vector that maximizes the performance from a random vector quantization (RVQ) codebook, which consists of independent isotropically distributed unit-norm vectors. The quantized vector is then relayed to the transmitter via a rate-limited feedback channel. The RVQ codebook requires an exhaustive search to locate the selected entry. To reduce the search complexity, we apply generalized Lloyd or k-dimensional (kd)-tree algorithms to organize RVQ entries into a tree. In examples shown, the search complexity of tree-structured (TS) RVQ can be a few orders of magnitude less than that of the unstructured RVQ for the same performance. We also derive the performance approximation for TS-RVQ in a large system limit, which predicts the performance of a moderate-size system very well.

Connected through hyperedge HE-1 (induced by source paper "machine learning based signal detection for pmh signals in load modulated mimo system"):
  with members:
    - "what will 5g be"
    - "low complexity hybrid precoding in massive multiuser mimo systems"

Connected through hyperedge HE-2 (induced by source paper "on optimizing feedback interval for temporally correlated mimo channels with transmit beamforming and finite rate feedback"):
  with members:
    - "on transmit beamforming for miso ofdm channels with finite rate feedback"
    - "training sequence design for feedback assisted hybrid beamforming in massive mimo systems"
    - "ensemble properties of rvq based limited feedback beamforming codebooks"
    - "on the minimum differential feedback for time correlated mimo rayleigh block fading channels"
    - "optimization of training and feedback overhead for beamforming over block fading channels"
    - "capacity of a multiple antenna fading channel with a quantized precoding matrix"
    - "limited feedback beamforming over temporally correlated channels"

Connected through hyperedge HE-3 (induced by source paper "waveform design for wireless power transfer with limited feedback"):
  with members:
    - "large scale multiantenna multisine wireless power transfer"
    - "prototyping and experimentation of a closed loop wireless power transmission with channel acquisition and waveform optimization"
    - "low complexity adaptive multisine waveform design for wireless power transfer"
    - "waveform optimization for radio frequency wireless power transfer"
    - "waveform design for wireless power transfer"
    - "a general design framework for mimo wireless energy transfer with limited feedback"
    - "waveform optimization for large scale multi antenna multi sine wireless power transfer"
    - "communications and signals design for wireless power transmission"

Connected through hyperedge HE-4 (induced by source paper "joint wireless information and energy transfer with reduced feedback in mimo interference channels"):
  with members:
    - "simultaneous information and power transfer for broadband wireless systems"
    - "wireless information and power transfer in multiuser ofdm systems"
    - "relaying protocols for wireless energy harvesting and information processing"
    - "optimal scheduling and power allocation for two hop energy harvesting communication systems"
    - "wireless information transfer with opportunistic energy harvesting"
    - "multi user diversity vs accurate channel state information in mimo downlink channels"
    - "enabling wireless power transfer in cellular networks architecture modeling and deployment"
    - "robust beamforming for wireless information and power transmission"

Connected through hyperedge HE-5 (induced by source paper "statistical precoder design for space time frequency block codes in multiuser miso mc cdma systems"):
  with members:
    - "distributed linear precoder optimization and base station selection for an uplink heterogeneous network"
    - "sparsity enhanced decision feedback equalization"
    - "how much multiuser diversity is required for energy limited multiuser systems"

Connected through hyperedge HE-6 (induced by source paper "variable length channel quantizers for maximum diversity and array gains"):
  with members:
    - "very low rate variable length channel quantization for minimum outage probability"
    - "distributed beamforming in wireless multiuser relay interference networks with quantized 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)