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: "cooperative algorithms for mimo amplify and forward relay networks"
  Abstract: Interference is a common impairment in wireless communication systems. Multi-hop relay networks use a set of intermediate nodes called relays to facilitate communication between multiple transmitters and multiple receivers through multiple hops. Relay based communication is especially sensitive to interference because the interference impacts both the received signal at the relay, and the received signal at the destination. Interference alignment is a signaling technique that provides high multiplexing gain in the interference channel. In this paper, inspired by an algorithmic approach for interference alignment, three cooperative algorithms are proposed to find suboptimal solutions for end-to-end sum-rate maximization problem in a multiple-antenna amplify-and-forward (AF) relay interference channel. The first algorithm aims at minimizing the sum power of enhanced noise from the relays and interference at the receivers. The second and third algorithms aim at minimizing matrix-weighted sum mean square errors with either equality or inequality power constraints to utilize a connection between mean square error and mutual information. The resulting iterative algorithms are convergent to points that we conjecture to be stationary points of the corresponding problems. Simulations show that the proposed algorithms achieve higher end-to-end sum-rates and multiplexing gains that existing strategies for AF relays, decode-and-forward relays, and direct transmission. The first algorithm outperforms the other algorithms at high signal-to-noise ratio (SNR) but performs worse than them at low SNR. Thanks to power control, the third algorithm outperforms the second algorithm at the cost of additional overhead.

Connected through hyperedge HE-1 (induced by source paper "optimal relaying beamforming in multiple access broadcast channel mabc bidirectional cognitive radio networks in presence of interferers"):
  with members:
    - "a reputation based stackelberg game model to enhance secrecy rate in spectrum leasing to selfish iot devices"
    - "resource allocation and outage analysis for an adaptive cognitive two way relay network"
    - "spectrum sharing in cooperative cognitive radio networks a matching game framework"
    - "energy efficient power allocation in cognitive radio systems with imperfect spectrum sensing"
    - "relay selection and resource allocation for two way df af cognitive radio networks"
    - "cognitive radio an information theoretic perspective"

Connected through hyperedge HE-2 (induced by source paper "relaying strategies for wireless powered mimo relay networks"):
  with members:
    - "distributed power splitting for swipt in relay interference channels using game theory"
    - "joint wireless information and power transfer for an autonomous multiple antenna relay system"
    - "joint power splitting and antenna selection in energy harvesting relay channels"
    - "joint wireless information and power transfer in a three node autonomous mimo relay network"
    - "joint resource optimization for multicell networks with wireless energy harvesting relays"
    - "user cooperation in wireless powered communication networks"
    - "power allocation strategies in energy harvesting wireless cooperative networks"
    - "relaying protocols for wireless energy harvesting and information processing"

Connected through hyperedge HE-3 (induced by source paper "interference alignment in mimo interference channels using sdp relaxation"):
  with members:
    - "degrees of freedom of the k user m times n mimo interference channel"

Connected through hyperedge HE-4 (induced by source paper "energy efficiency optimization in relay assisted mimo systems with perfect and statistical csi"):
  with members:
    - "energy efficiency optimization for mimo broadcast channels"
    - "joint source and relay precoding designs for mimo two way relaying based on mse criterion"
    - "power allocation in two hop amplify and forward mimo relay systems with qos requirements"
    - "framework for link level energy efficiency optimization with informed transmitter"
    - "energy efficient precoding for multiple antenna terminals"
    - "energy efficient resource allocation in multiuser mimo systems a game theoretic framework"
    - "on the capacity and diversity multiplexing tradeoff of the two way relay channel"
    - "energy efficient communications in cdma networks a game theoretic analysis considering operating costs"

Connected through hyperedge HE-5 (induced by source paper "mimo beamforming design towards maximizing mutual information in wireless sensor network"):
  with members:
    - "joint transceiver design for wireless sensor networks through block coordinate descent optimization"

Connected through hyperedge HE-6 (induced by source paper "low complexity sum rate maximization for single and multiple stream mimo af relay networks"):
  with members:
    - "approximate ergodic capacity of a class of fading 2 user 2 hop networks"
    - "on the degrees of freedom achievable through interference alignment in a mimo interference channel"
    - "on feasibility of interference alignment in mimo interference networks"
    - "on feasibility of interference alignment in mimo interference networks"

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)