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: "effect of transmission correlations on the performance of general space time codes in single keyhole channels"
  Abstract: The effect of spatial correlation of Rayleigh fading channel has been extensively studied in literatures. In Rayleigh channel, it has been shown that the transmission correlations always degrade the performance of space-time codes in high SNR regimes. In this correspondence, however, we show that when MIMO channels experience single-keyhole conditions, the effect of spatial correlations between transmission antennas is more sophisticated for non-orthogonal space-time codes: when $M>N$ (the number of transmission antennas greater than the receiving antennas), depending on how the correlation matrix $\mathbf{A}$ beamforms the code words difference matrix $\mathbf{\Delta}$, the performance of space-time codes can be either degraded or improved in the high SNR regimes. In particular, we provide a new measure which is based on the eigenvalues of $\mathbf{\Delta}$, and the numbers of transmission and receiving antennas, to exam if there exist some correlation matrices that can improve the performance of space-time codes in high SNR regimes. Previous studies on the effect of spatial correlation over single-keyhole conditions only concentrated on the cases when the space-time codes are orthogonal, while our new measure is for general space-time codes, and can also be used to explain the previous findings for orthogonal cases.

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)