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: "low complexity sum rate maximization for single and multiple stream mimo af relay networks"
  Abstract: A multiple-antenna amplify-and-forward two-hop interference network with multiple links and multiple relays is considered. We optimize transmit precoders, receive decoders and relay AF matrices to maximize the achievable sum rate. Under per user and total relay sum power constraints, we propose an efficient algorithm to maximize the total signal to total interference plus noise ratio (TSTINR). Computational complexity analysis shows that our proposed algorithm for TSTINR has lower complexity than the existing weighted minimum mean square error (WMMSE) algorithm. We analyze and confirm by simulations that the TSTINR, WMMSE and the total leakage interference plus noise (TLIN) minimization models with per user and total relay sum power constraints can only transmit a single data stream for each user. Thus we propose a novel multiple stream TSTINR model with requirement of orthogonal columns for precoders, in order to support multiple data streams and thus utilize higher Degrees of Freedom. Multiple data streams and larger multiplexing gains are guaranteed. Simulation results show that for single stream models, our TSTINR algorithm outperforms the TLIN algorithm generally and outperforms WMMSE in medium to high Signal-to-Noise-Ratio scenarios; the system sum rate significantly benefits from multiple data streams in medium to high SNR scenarios.

Connected through hyperedge HE-1 (induced by source paper "grouping based interference alignment with ia cell assignment in multi cell mimo mac under limited feedback"):
  with members:
    - "user selection in mimo interfering broadcast channels"
    - "what will 5g be"
    - "limited feedback design for interference alignment on mimo interference networks with heterogeneous path loss and spatial correlations"
    - "interference alignment with quantized grassmannian feedback in the k user constant mimo interference channel"
    - "spatial degrees of freedom of the multicell mimo multiple access channel"
    - "on feasibility of interference alignment in mimo interference networks"
    - "downlink interference alignment"
    - "interference alignment under limited feedback for mimo interference channels"

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)