human: Given a hyperedge-centered hypergraph: <hypergraph>, where the center hyperedge is induced by one source paper and its member nodes are the cited papers.

Details of the hypergraph:
Center hyperedge (induced by source paper "energy efficiency optimization in relay assisted mimo systems with perfect and statistical csi"):
  Abstract: A framework for energy-efficient resource allocation in a single-user, amplify-and-forward (AF), relay-assisted, multiple-input-multiple-output (MIMO) system is devised in this paper. Previous results in this area have focused on rate maximization or sum power minimization problems, whereas fewer results are available when bits/Joule energy efficiency (EE) optimization is the goal. Here, the performance metric to optimize is the ratio between the system's achievable rate and the total consumed power. The optimization is carried out with respect to the source and relay precoding matrices, subject to quality-of-service (QoS) and power constraints. Such a challenging non-convex optimization problem is tackled by means of fractional programming and alternating maximization algorithms, for various channel state information (CSI) assumptions at the source and relay. In particular the scenarios of perfect CSI and those of statistical CSI for either the source-relay or the relay-destination channel are addressed. Moreover, sufficient conditions for beamforming optimality are derived, which is useful in simplifying the system design. Numerical results are provided to corroborate the validity of the theoretical findings.

Includes members:
  Member "cooperative algorithms for mimo amplify and forward relay networks":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "optimal relaying beamforming in multiple access broadcast channel mabc bidirectional cognitive radio networks in presence of interferers")
  Member "energy efficiency optimization for mimo broadcast channels":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "energy efficiency optimization for downlink massive mimo with statistical csit")
  Member "joint source and relay precoding designs for mimo two way relaying based on mse criterion":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "utility energy efficiency oriented user association with power control in heterogeneous networks")
  Member "power allocation in two hop amplify and forward mimo relay systems with qos requirements":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "convex separable problems with linear constraints in signal processing and communications")
  Member "framework for link level energy efficiency optimization with informed transmitter":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "distributed power control with partial channel state information performance characterization and design")
  Member "energy efficient precoding for multiple antenna terminals":
    also connected through other hyperedges:
      - Hyperedge HE-6 (induced by source paper "decision set optimization and energy efficient mimo communications")
  Member "energy efficient resource allocation in multiuser mimo systems a game theoretic framework":
    also connected through other hyperedges:
      - Hyperedge HE-7 (induced by source paper "totally distributed energy efficient transmission in mimo interference channels")
  Member "on the capacity and diversity multiplexing tradeoff of the two way relay channel":
    also connected through other hyperedges:
      - Hyperedge HE-8 (induced by source paper "degrees of freedom of the mimo three way channel with node intermittency")

Question: Please tell me which class the source paper 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)