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: "transmit antenna correlation in spatial multiplexing systems"
  Abstract: In this letter we present a transmit antenna correlation in spatial multiplexing systems with channel state information at the transmitter (CSIT) of a multiple-input multiple-output (MIMO) correlated channel. Indeed, high correlation degrades system capacity and performance. Most related work has thus far considered in the statistical channel model such as Kronecker model with an approximate Toeplitz form of the transmitter or receiver side correlation for measuring the Power Azimuth Spectral (PAS), but channel capacity has not been well studied. The Toeplitz assumption of the correlation matrix restricts the actual configuration of MIMO systems to a linear structure for a uniform linear array (ULA). Therefore, we only propose an optimal circulant assumption of a novel transmit correlation matrix in this letter to significantly reduce arithmetic complexity and spectral norms. We use this result to maximize ergodic capacity and minimize average bit error rate (BER) in spatial multiplexing (SM) systems with a zero-forcing (ZF) linear receiver. Simulation results show that the proposed method can achieve significant performance enhancement versus conventional equal power transmission

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)