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: "optimization of integer forcing precoding for multi user mimo downlink"
  Abstract: Integer-forcing (IF) precoding is an alternative to linear precoding for multi-user (MU) multiple-input-multiple-output (MIMO) channels. IF precoding can be viewed as a generalization of lattice-reduction-aided (LRA) precoding where symbol-level detection is replaced by codeword-level decoding, allowing achievable rate expressions to be derived explicitly. A particular form of IF precoding that is asymptotically optimal for high SNR is the regularized diagonally-scaled IF (RDIF) scheme, which is specified by a diagonal scaling matrix $\mathbf{D}$ and an integer-valued effective channel matrix $\mathbf{A}$. Optimal values for these parameters have been found (analytically) only for the case of $K = 2$ users. In this paper, a low-complexity method is proposed to find good parameters for the RDIF scheme for $K > 2$ users. The proposed method computes matrix $\mathbf{D}$ by solving a relaxed optimization problem and then matrix $\mathbf{A}$ by the application of the LLL algorithm---which, in this particular case, is shown to converge with a fixed number of iterations, resulting in an overall complexity of $\mathcal{O}(K^3)$. Simulation results show that the proposed method achieves 1a higher sum rate than choosing $\mathbf{D} = \mathbf{I}$ (as in LRA precoding) and significantly outperforms traditional linear precoding in all simulated scenarios1

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)