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: "to code or not to code in multi hop relay channels"
  Abstract: Multi-hop relay channels use multiple relay stages, each with multiple relay nodes, to facilitate communication between a source and destination. Previously, distributed space-time coding was used to maximize diversity gain. Assuming a low-rate feedback link from the destination to each relay stage and the source, this paper proposes end-to-end antenna selection strategies as an alternative to distributed space-time coding. One-way (where only the source has data for destination) and two-way (where the destination also has data for the source) multi-hop relay channels are considered with both the full-duplex and half duplex relay nodes. End-to-end antenna selection strategies are designed and proven to achieve maximum diversity gain by using a single antenna path (using single antenna of the source, each relay stage and the destination) with the maximum signal-to-noise ratio at the destination. For the half-duplex case, two single antenna paths with the two best signal-to-noise ratios in alternate time slots are used to overcome the rate loss with half-duplex nodes, with a small diversity gain penalty. Finally to answer the question, whether to code (distributed space-time code) or not (the proposed end-to-end antenna selection strategy) in a multi-hop relay channel, end-to-end antenna selection strategy and distributed space-time coding is compared with respect to several important performance metrics.

Connected through hyperedge HE-1 (induced by source paper "achievable rate regions and outer bounds for a multi pair bi directional relay network"):
  with members:
    - "the multi way relay channel"
    - "capacity of the gaussian two way relay channel to within 1 2 bit"
    - "the mimo wireless switch relaying can increase the multiplexing gain"
    - "capacity region of the deterministic multi pair bi directional relay network"
    - "bits through relay cascades with half duplex constraint"
    - "broadcast capacity region of two phase bidirectional relaying"
    - "on the capacity and diversity multiplexing tradeoff of the two way relay channel"
    - "bi directional half duplex protocols with multiple relays"

Connected through hyperedge HE-2 (induced by source paper "end to end joint antenna selection strategy and distributed compress and forward strategy for relay channels"):
  with members:
    - "dmt of multi hop cooperative networks part ii half duplex networks with full duplex performance"
    - "nonregenerative mimo relaying with optimal transmit antenna selection"
    - "relay subset selection in wireless networks using partial decode and forward transmission"
    - "diversity of mimo multihop relay channels"
    - "a simple cooperative diversity method based on network path selection"
    - "optimal space time codes for the mimo amplify and forward cooperative channel"

Connected through hyperedge HE-3 (induced by source paper "dmt of multi hop cooperative networks part i basic results"):
  with members:
    - "multi hop cooperative wireless networks diversity multiplexing tradeoff and optimal code design"
    - "diversity and degrees of freedom of cooperative wireless networks"
    - "dmt of multi hop cooperative networks part ii half duplex networks with full duplex performance"
    - "the case for structured random codes in network capacity theorems"
    - "approximate capacity of gaussian relay networks"
    - "a deterministic approach to wireless relay networks"
    - "interference alignment on the deterministic channel and application to fully connected awgn interference networks"
    - "approximately universal space time codes for the parallel multi block and cooperative dynamic decode and forward channels"

Connected through hyperedge HE-4 (induced by source paper "bi directional half duplex protocols with multiple relays"):
  with members:
    - "capacity region of the deterministic multi pair bi directional relay network"
    - "broadcast capacity region of two phase bidirectional relaying"
    - "on the capacity and diversity multiplexing tradeoff of the two way relay channel"
    - "achievable rate regions for bi directional relaying"
    - "capacity of gaussian mimo bidirectional broadcast channels"
    - "performance bounds for bi directional coded cooperation protocols"
    - "a simple cooperative diversity method based on network path selection"

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)