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: "block orthogonal space time code structure and its impact on qrdm decoding complexity reduction"
  Abstract: Full-rate space time codes (STCs) with rate number of transmit antennas have high multiplexing gain, but high decoding complexity even when decoded using reduced-complexity decoders such as sphere or QRDM decoders. In this paper, we introduce a new code property of STC called block-orthogonal property, which can be exploited by QR-decomposition-based decoders to achieve significant decoding complexity reduction without performance loss. We show that such complexity reduction principle can benefit the existing algebraic codes such as Perfect and DjABBA codes due to their inherent (but previously undiscovered) block-orthogonal property. In addition, we construct and optimize new full-rate block-orthogonal STC (BOSTC) that further maximize the QRDM complexity reduction potential. Simulation results of bit error rate (BER) performance against decoding complexity show that the new BOSTC outperforms all previously known codes as long as the QRDM decoder operates in reduced-complexity mode, and the code exhibits a desirable complexity saturation property.

Connected through hyperedge HE-1 (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    - "space time encoded miso broadcast channel with outdated csit an error rate and diversity performance analysis"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-2 (induced by source paper "circular sphere decoding a low complexity detection for mimo systems with general two dimensional signal constellations"):
  with members:
    - "sparsity aware sphere decoding algorithms and complexity analysis"
    - "soft input soft output single tree search sphere decoding"

Connected through hyperedge HE-3 (induced by source paper "revisited design criteria for stbcs with reduced complexity ml decoding"):
  with members:
    - "achieving low complexity maximum likelihood detection for the 3d mimo code"
    - "construction of block orthogonal stbcs and reducing their sphere decoding complexity"
    - "fast decodable asymmetric space time codes from division algebras"
    - "iterated space time code constructions from cyclic algebras"
    - "a family of fast decodable mido codes from crossed product algebras over q"
    - "optimization of fast decodable full rate stbc with non vanishing determinants"
    - "quadratic forms and space time block codes from generalized quaternion and biquaternion algebras"
    - "group decodable space time block codes with code rate 1"

Connected through hyperedge HE-4 (induced by source paper "construction of block orthogonal stbcs and reducing their sphere decoding complexity"):
  with members:
    - "fast decodable asymmetric space time codes from division algebras"
    - "minimizing the complexity of fast sphere decoding of stbcs"
    - "four group decodable space time block codes"
    - "fast maximum likelihood decoding of the golden code"
    - "multi group ml decodable collocated and distributed space time block codes"
    - "on fast decodable space time block codes"
    - "high rate multi symbol decodable stbcs from clifford algebras"
    - "multigroup decodable stbcs from clifford algebras"

Connected through hyperedge HE-5 (induced by source paper "a new family of low complexity stbcs for four transmit antennas"):
  with members:
    - "a novel construction of multi group decodable space time block codes"
    - "optimization of fast decodable full rate stbc with non vanishing determinants"
    - "on the average complexity of sphere decoding in lattice space time coded mimo channel"
    - "group decodable space time block codes with code rate 1"
    - "four group decodable space time block codes"
    - "on fast decodable space time block codes"

Connected through hyperedge HE-6 (induced by source paper "minimizing the complexity of fast sphere decoding of stbcs"):
  with members:
    - "construction of block orthogonal stbcs and reducing their sphere decoding complexity"
    - "fast decodable asymmetric space time codes from division algebras"
    - "iterated space time code constructions from cyclic algebras"
    - "optimization of fast decodable full rate stbc with non vanishing determinants"
    - "quadratic forms and space time block codes from generalized quaternion and biquaternion algebras"
    - "group decodable space time block codes with code rate 1"
    - "four group decodable space time block codes"
    - "fast maximum likelihood decoding of the golden code"

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)