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: "efficient transmit beamspace design for search free based doa estimation in mimo radar"
  Abstract: In this paper, we address the problem of transmit beamspace design for multiple-input multiple-output (MIMO) radar with colocated antennas in application to direction-of-arrival (DOA) estimation. A new method for designing the transmit beamspace matrix that enables the use of search-free DOA estimation techniques at the receiver is introduced. The essence of the proposed method is to design the transmit beamspace matrix based on minimizing the difference between a desired transmit beampattern and the actual one while enforcing the constraint of uniform power distribution across the transmit array elements. The desired transmit beampattern can be of arbitrary shape and is allowed to consist of one or more spatial sectors. The number of transmit waveforms is even but otherwise arbitrary. To allow for simple search-free DOA estimation algorithms at the receive array, the rotational invariance property is established at the transmit array by imposing a specific structure on the beamspace matrix. Semidefinite programming relaxation is used to approximate the proposed formulation by a convex problem that can be solved efficiently. We also propose a spatial-division based design (SDD) by dividing the spatial domain into several subsectors and assigning a subset of the transmit beams to each subsector. The transmit beams associated with each subsector are designed separately. Simulation results demonstrate the improvement in the DOA estimation performance offered by using the proposed joint and SDD transmit beamspace design methods as compared to the traditional MIMO radar technique.

Connected through hyperedge HE-1 (induced by source paper "transmit array interpolation for doa estimation via tensor decomposition in 2 d mimo radar"):
  with members:
    - "transmit radiation pattern invariance in mimo radar with application to doa estimation"
    - "transmit energy focusing for doa estimation in mimo radar with colocated antennas"
    - "phased mimo radar a tradeoff between phased array and mimo radars"

Connected through hyperedge HE-2 (induced by source paper "ambiguity function of the transmit beamspace based mimo radar"):
  with members:
    - "spatial compressive sensing for mimo radar"
    - "moving target parameters estimation in noncoherent mimo radar systems"
    - "transmit energy focusing for doa estimation in mimo radar with colocated antennas"
    - "optimal joint target detection and parameter estimation by mimo radar"
    - "mimo radar using compressive sampling"
    - "phased mimo radar a tradeoff between phased array and mimo radars"
    - "diversity integration tradeoffs in mimo detection"

Connected through hyperedge HE-3 (induced by source paper "transmit radiation pattern invariance in mimo radar with application to doa estimation"):
  with members:
    - "transmit energy focusing for doa estimation in mimo radar with colocated antennas"
    - "phased mimo radar a tradeoff between phased array and mimo radars"

Connected through hyperedge HE-4 (induced by source paper "colocated mimo radar waveform design for transmit beampattern formation"):
  with members:
    - "transmit energy focusing for doa estimation in mimo radar with colocated antennas"

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)