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: "reduced complexity sphere decoding"
  Abstract: In Multiple-Input Multiple-Output (MIMO) systems, Sphere Decoding (SD) can achieve performance equivalent to full search Maximum Likelihood (ML) decoding, with reduced complexity. Several researchers reported techniques that reduce the complexity of SD further. In this paper, a new technique is introduced which decreases the computational complexity of SD substantially, without sacrificing performance. The reduction is accomplished by deconstructing the decoding metric to decrease the number of computations and exploiting the structure of a lattice representation. Furthermore, an application of SD, employing a proposed smart implementation with very low computational complexity is introduced. This application calculates the soft bit metrics of a bit-interleaved convolutional-coded MIMO system in an efficient manner. Based on the reduced complexity SD, the proposed smart implementation employs the initial radius acquired by Zero-Forcing Decision Feedback Equalization (ZF-DFE) which ensures no empty spheres. Other than that, a technique of a particular data structure is also incorporated to efficiently reduce the number of executions carried out by SD. Simulation results show that these approaches achieve substantial gains in terms of the computational complexity for both uncoded and coded MIMO systems.

Connected through hyperedge HE-1 (induced by source paper "bit interleaved coded multiple beamforming with perfect coding"):
  with members:
    - "precoding by pairing subchannels to increase mimo capacity with discrete input alphabets"
    - "reduced complexity decoding for bit interleaved coded multiple beamforming with constellation precoding"
    - "golden coded multiple beamforming"
    - "constellation precoded beamforming"
    - "constellation precoded multiple beamforming"
    - "mimo precoding with x and y codes"
    - "bit interleaved coded multiple beamforming with constellation precoding"
    - "diversity analysis of bit interleaved coded multiple beamforming"

Connected through hyperedge HE-2 (induced by source paper "multiple beamforming with perfect coding"):
  with members:
    - "reduced complexity decoding for bit interleaved coded multiple beamforming with constellation precoding"
    - "constellation precoded beamforming"
    - "constellation precoded multiple beamforming"
    - "bit interleaved coded multiple beamforming with constellation precoding"
    - "diversity analysis of bit interleaved coded multiple beamforming"
    - "fast maximum likelihood decoding of the golden code"
    - "reduced complexity sphere decoding for square qam via a new lattice representation"
    - "perfect space time codes with minimum and non minimum delay for any number of antennas"

Connected through hyperedge HE-3 (induced by source paper "reduced complexity decoding for bit interleaved coded multiple beamforming with constellation precoding"):
  with members:
    - "bit interleaved coded multiple beamforming with constellation precoding"
    - "diversity analysis of bit interleaved coded multiple beamforming"
    - "reduced complexity sphere decoding for square qam via a new lattice representation"

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)