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: "robust transceiver with tomlinson harashima precoding for amplify and forward mimo relaying systems"
  Abstract: In this paper, robust transceiver design with Tomlinson-Harashima precoding (THP) for multi-hop amplify-and-forward (AF) multiple-input multiple-output (MIMO) relaying systems is investigated. At source node, THP is adopted to mitigate the spatial intersymbol interference. However, due to its nonlinear nature, THP is very sensitive to channel estimation errors. In order to reduce the effects of channel estimation errors, a joint Bayesian robust design of THP at source, linear forwarding matrices at relays and linear equalizer at destination is proposed. With novel applications of elegant characteristics of multiplicative convexity and matrix-monotone functions, the optimal structure of the nonlinear transceiver is first derived. Based on the derived structure, the transceiver design problem reduces to a much simpler one with only scalar variables which can be efficiently solved. Finally, the performance advantage of the proposed robust design over non-robust design is demonstrated by simulation results.

Connected through hyperedge HE-1 (induced by source paper "hybrid transceiver optimization for multi hop communications"):
  with members:
    - "hybrid beamforming for millimeter wave systems using the mmse criterion"
    - "majorization minimization aided hybrid transceivers for mimo interference channels"
    - "hybrid precoding architecture for massive multiuser mimo with dissipation sub connected or fully connected structures"
    - "hybrid beamforming with selection for multiuser massive mimo systems"
    - "spectral efficiency optimization for millimeter wave multiuser mimo systems"
    - "spectral and energy efficiency of multi pair massive mimo relay network with hybrid processing"
    - "multi user precoding and channel estimation for hybrid millimeter wave systems"
    - "alternating minimization algorithms for hybrid precoding in millimeter wave mimo systems"

Connected through hyperedge HE-2 (induced by source paper "a framework on hybrid mimo transceiver design based on matrix monotonic optimization"):
  with members:
    - "hybrid beamforming via the kronecker decomposition for the millimeter wave massive mimo systems"
    - "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"

Connected through hyperedge HE-3 (induced by source paper "unified overview of matrix monotonic optimization for mimo transceivers"):
  with members:
    - "a framework for joint design of pilot sequence and linear precoder"
    - "on weighted mse model for mimo transceiver optimization"
    - "a framework for transceiver designs for multi hop communications with covariance shaping constraints"
    - "fifty years of mimo detection the road to large scale mimos"
    - "convex separable problems with linear constraints in signal processing and communications"
    - "matrix monotonic optimization for mimo systems"
    - "miso capacity with per antenna power constraint"

Connected through hyperedge HE-4 (induced by source paper "a survey on mimo transmission with discrete input signals technical challenges advances and future trends"):
  with members:
    - "asymptotic performance analysis of a k hop amplify and forward relay mimo channel"
    - "iterative distributed minimum total mse approach for secure communications in mimo interference channels"
    - "asymptotic analysis of su mimo channels with transmitter noise and mismatched joint decoding"
    - "secure massive mimo transmission with an active eavesdropper"
    - "interference aligned space time transmission with diversity for the 2 times 2 x network"
    - "space time encoded miso broadcast channel with outdated csit an error rate and diversity performance analysis"
    - "high snr asymptotics of mutual information for discrete constellations with applications to bicm"
    - "differential distributed space time coding with imperfect synchronization in frequency selective channels"

Connected through hyperedge HE-5 (induced by source paper "noncoherent relaying in energy harvesting communication systems"):
  with members:
    - "resource allocation in wireless networks with rf energy harvesting and transfer"
    - "wireless powered communication opportunities and challenges"
    - "wireless powered relays in cooperative communications time switching relaying protocols and throughput analysis"
    - "energy harvesting noncoherent cooperative communications"
    - "wireless networks with rf energy harvesting a contemporary survey"
    - "power allocation strategies in energy harvesting wireless cooperative networks"
    - "simultaneous information and energy transfer in large scale networks with without relaying"
    - "cooperative energy harvesting networks with spatially random users"

Connected through hyperedge HE-6 (induced by source paper "energy harvesting noncoherent cooperative communications"):
  with members:
    - "wireless networks with rf energy harvesting a contemporary survey"
    - "power allocation strategies in energy harvesting wireless cooperative networks"
    - "simultaneous information and energy transfer in large scale networks with without relaying"
    - "throughput maximization in wireless powered communication networks"
    - "a general robust linear transceiver design for multi hop amplify and forward mimo relaying systems"
    - "cooperative energy harvesting networks with spatially random users"
    - "matrix monotonic optimization for mimo systems"
    - "simultaneous information and power transfer for broadband wireless systems"

Connected through hyperedge HE-7 (induced by source paper "a framework for transceiver designs for multi hop communications with covariance shaping constraints"):
  with members:
    - "evolution toward 5g multi tier cellular wireless networks an interference management perspective"
    - "beamforming for miso interference channels with qos and rf energy transfer"
    - "a general robust linear transceiver design for multi hop amplify and forward mimo relaying systems"
    - "matrix monotonic optimization for mimo systems"
    - "a tutorial on the optimization of amplify and forward mimo relay systems"
    - "transceiver design for dual hop nonregenerative mimo ofdm relay systems under channel uncertainties"
    - "ergodic capacity analysis of amplify and forward mimo dual hop systems"

Connected through hyperedge HE-8 (induced by source paper "tomlinson harashima precoding for multiuser mimo systems with quantized csi feedback and user scheduling"):
  with members:
    - "eigen based transceivers for the mimo broadcast channel with semi orthogonal user selection"
    - "antenna combining for the mimo downlink channel"
    - "mimo broadcast channels with finite rate 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)