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: "a non orthogonal distributed space time coded protocol part i signal model and design criteria"
  Abstract: In this two-part series of papers, a generalized non-orthogonal amplify and forward (GNAF) protocol which generalizes several known cooperative diversity protocols is proposed. Transmission in the GNAF protocol comprises of two phases - the broadcast phase and the cooperation phase. In the broadcast phase, the source broadcasts its information to the relays as well as the destination. In the cooperation phase, the source and the relays together transmit a space-time code in a distributed fashion. The GNAF protocol relaxes the constraints imposed by the protocol of Jing and Hassibi on the code structure. In Part-I of this paper, a code design criteria is obtained and it is shown that the GNAF protocol is delay efficient and coding gain efficient as well. Moreover GNAF protocol enables the use of sphere decoders at the destination with a non-exponential Maximum likelihood (ML) decoding complexity. In Part-II, several low decoding complexity code constructions are studied and a lower bound on the Diversity-Multiplexing Gain tradeoff of the GNAF protocol is obtained.

Connected through hyperedge HE-1 (induced by source paper "cascaded orthogonal space time block codes for wireless multi hop relay networks"):
  with members:
    - "multi hop cooperative wireless networks diversity multiplexing tradeoff and optimal code design"
    - "dmt of multi hop cooperative networks part ii half duplex networks with full duplex performance"
    - "algebraic distributed space time codes with low ml decoding complexity"
    - "diversity of mimo multihop relay channels"
    - "a non orthogonal distributed space time coded protocol part ii code construction and dm g tradeoff"
    - "optimal space time codes for the mimo amplify and forward cooperative channel"
    - "approximately universal optimality over several dynamic and non dynamic cooperative diversity schemes for wireless networks"

Connected through hyperedge HE-2 (induced by source paper "distributed space time codes for cooperative networks with partial csi"):
  with members:
    - "towards the optimal amplify and forward cooperative diversity scheme"
    - "high date rate single symbol ml decodable distributed stbcs for cooperative networks"
    - "a non orthogonal distributed space time coded protocol part ii code construction and dm g tradeoff"
    - "approximately universal codes over slow fading channels"
    - "on the achievable diversity multiplexing tradeoffs in half duplex cooperative channels"

Connected through hyperedge HE-3 (induced by source paper "multi group ml decodable collocated and distributed space time block codes"):
  with members:
    - "four group decodable space time block codes"
    - "high rate single symbol decodable precoded dstbcs for cooperative networks"
    - "high rate multi symbol decodable stbcs from clifford algebras"
    - "algebraic distributed differential space time codes with low decoding complexity"

Connected through hyperedge HE-4 (induced by source paper "noncoherent low decoding complexity space time codes for wireless relay networks"):
  with members:
    - "algebraic distributed space time codes with low ml decoding complexity"
    - "signal set design for full diversity low decoding complexity differential scaled unitary stbcs"
    - "single symbol decodable differential space time modulation based on qo stbc"

Connected through hyperedge HE-5 (induced by source paper "single symbol ml decodable distributed stbcs for partially coherent cooperative networks"):
  with members:
    - "four group decodable space time block codes"

Connected through hyperedge HE-6 (induced by source paper "a non orthogonal distributed space time coded protocol part ii code construction and dm g tradeoff"):
  with members:
    - "towards the optimal amplify and forward cooperative diversity scheme"
    - "approximately universal codes over slow fading 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)