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: "cognitive beamforming made practical effective interference channel and learning throughput tradeoff"
  Abstract: This paper studies the transmit strategy for a secondary link or the so-called cognitive radio (CR) link under opportunistic spectrum sharing with an existing primary radio (PR) link. It is assumed that the CR transmitter is equipped with multi-antennas, whereby transmit precoding and power control can be jointly deployed to balance between avoiding interference at the PR terminals and optimizing performance of the CR link. This operation is named as cognitive beamforming (CB). Unlike prior study on CB that assumes perfect knowledge of the channels over which the CR transmitter interferes with the PR terminals, this paper proposes a practical CB scheme utilizing a new idea of effective interference channel (EIC), which can be efficiently estimated at the CR transmitter from its observed PR signals. Somehow surprisingly, this paper shows that the learning-based CB scheme with the EIC improves the CR channel capacity against the conventional scheme even with the exact CR-to-PR channel knowledge, when the PR link is equipped with multi-antennas but only communicates over a subspace of the total available spatial dimensions. Moreover, this paper presents algorithms for the CR to estimate the EIC over a finite learning time. Due to channel estimation errors, the proposed CB scheme causes leakage interference at the PR terminals, which leads to an interesting learning-throughput tradeoff phenomenon for the CR, pertinent to its time allocation between channel learning and data transmission. This paper derives the optimal channel learning time to maximize the effective throughput of the CR link, subject to the CR transmit power constraint and the interference power constraints for the PR terminals.

Connected through hyperedge HE-1 (induced by source paper "a practical spectrum sharing scheme for cognitive radio networks design and experiments"):
  with members:
    - "an efficient precoder design for multiuser mimo cognitive radio networks with interference constraints"
    - "nonorthogonal multiple access in large scale underlay cognitive radio networks"
    - "coordinated shared spectrum precoding with distributed csit"
    - "interference mitigation for cognitive radio mimo systems based on practical precoding"

Connected through hyperedge HE-2 (induced by source paper "primary channel gain estimation for spectrum sharing in cognitive radio networks"):
  with members:
    - "optimal power allocation for fading channels in cognitive radio networks ergodic capacity and outage capacity"
    - "on active learning and supervised transmission of spectrum sharing based cognitive radios by exploiting hidden primary radio feedback"
    - "design of learning based mimo cognitive radio systems"

Connected through hyperedge HE-3 (induced by source paper "totally distributed energy efficient transmission in mimo interference channels"):
  with members:
    - "energy efficiency optimization in relay assisted mimo systems with perfect and statistical csi"
    - "what will 5g be"
    - "distributed optimal beamformers for cognitive radios robust to channel uncertainties"
    - "the mimo iterative waterfilling algorithm"
    - "competitive design of multiuser mimo systems based on game theory a unified view"
    - "energy efficient resource allocation in multiuser mimo systems a game theoretic framework"
    - "energy efficient communications in cdma networks a game theoretic analysis considering operating costs"
    - "energy efficient resource allocation in wireless networks"

Connected through hyperedge HE-4 (induced by source paper "cooperative cognitive relaying under primary and secondary quality of service satisfaction"):
  with members:
    - "beamforming and rate allocation in miso cognitive radio networks"
    - "exploiting multi antennas for opportunistic spectrum sharing in cognitive radio networks"
    - "collaborative beamforming for distributed wireless ad hoc sensor networks"

Connected through hyperedge HE-5 (induced by source paper "on the throughput and energy efficiency of cognitive mimo transmissions"):
  with members:
    - "cognitive radio transmission under qos constraints and interference limitations"
    - "performance analysis of cognitive radio systems under qos constraints and channel uncertainty"
    - "optimal spectrum sharing in mimo cognitive radio networks via semidefinite programming"
    - "from spectrum pooling to space pooling opportunistic interference alignment in mimo cognitive networks"
    - "mimo wireless communications under statistical queueing constraints"
    - "effective capacity analysis of cognitive radio channels for quality of service provisioning"
    - "design of learning based mimo cognitive radio systems"
    - "exploiting multi antennas for opportunistic spectrum sharing in cognitive radio networks"

Connected through hyperedge HE-6 (induced by source paper "the one bit null space learning algorithm and its convergence"):
  with members:
    - "interference mitigation for cognitive radio mimo systems based on practical precoding"
    - "optimal spectrum sharing in mimo cognitive radio networks via semidefinite programming"
    - "on active learning and supervised transmission of spectrum sharing based cognitive radios by exploiting hidden primary radio feedback"
    - "design of learning based mimo cognitive radio systems"
    - "exploiting multi antennas for opportunistic spectrum sharing in cognitive radio networks"
    - "cognitive mimo radio"

Connected through hyperedge HE-7 (induced by source paper "interference mitigation for cognitive radio mimo systems based on practical precoding"):
  with members:
    - "pareto region characterization for rate control in multi user systems and nash bargaining"
    - "design of learning based mimo cognitive radio systems"
    - "exploiting multi antennas for opportunistic spectrum sharing in cognitive radio networks"
    - "cognitive mimo radio"

Connected through hyperedge HE-8 (induced by source paper "throughput optimal policies for energy harvesting wireless transmitters with non ideal circuit power"):
  with members:
    - "green cellular networks a survey some research issues and challenges"
    - "optimal energy allocation for wireless communications with energy harvesting constraints"
    - "a general framework for the optimization of energy harvesting communication systems with battery imperfections"
    - "framework for link level energy efficiency optimization with informed transmitter"
    - "transmission with energy harvesting nodes in fading wireless channels optimal policies"
    - "optimum transmission policies for battery limited energy harvesting nodes"
    - "optimal packet scheduling in an energy harvesting communication system"

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)