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: "physical layer mimo relaying"
  Abstract: The physical-layer network coding (PNC) approach provides improved performance in many scenarios over "traditional" relaying techniques or network coding. This work addresses the generalization of PNC to wireless scenarios where network nodes have multiple antennas. We use a recent matrix decomposition, which allows, by linear pre- and post-processing, to simultaneously transform both channel matrices to triangular forms, where the diagonal entries, corresponding to both channels, are equal. This decomposition, in conjunction with precoding, allows to convert any two-input multiple-access channel (MAC) into parallel MACs, over which single-antenna PNC may be used. The technique is demonstrated using the two-way relay channel with multiple antennas. For this case it is shown that, in the high signal-to-noise regime, the scheme approaches the cut-set bound, thus establishing the asymptotic network capacity.

Connected through hyperedge HE-1 (induced by source paper "the dirty mimo multiple access channel"):
  with members:
    - "joint unitary triangularization for gaussian multi user mimo networks"
    - "joint unitary triangularization for mimo networks"
    - "multiple input multiple output two way relaying a space division approach"
    - "lattice strategies for the dirty multiple access channel"

Connected through hyperedge HE-2 (induced by source paper "joint unitary triangularization for gaussian multi user mimo networks"):
  with members:
    - "joint unitary triangularization for mimo networks"
    - "rateless coding for gaussian channels"
    - "approximately universal codes over slow fading channels"

Connected through hyperedge HE-3 (induced by source paper "multiple input multiple output two way relaying a space division approach"):
  with members:
    - "eigen direction alignment based physical layer network coding for mimo two way relay channels"
    - "compute and forward harnessing interference through structured codes"
    - "optimal beamforming for two way multi antenna relay channel with analogue network coding"
    - "the case for structured random codes in network capacity theorems"
    - "physical network coding in two way wireless relay channels"
    - "capacity of a class of modulo sum relay channels"

Connected through hyperedge HE-4 (induced by source paper "joint unitary triangularization for mimo networks"):
  with members:
    - "hybrid digital analog codes for source channel broadcast of gaussian sources over gaussian channels"
    - "analog matching of colored sources to colored channels"
    - "robust joint source channel coding for delay limited applications"
    - "a framework for designing mimo systems with decision feedback equalization or tomlinson harashima precoding"

Connected through hyperedge HE-5 (induced by source paper "modulation for mimo networks with several users"):
  with members:
    - "joint unitary triangularization for mimo networks"
    - "rateless coding for gaussian channels"

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)