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: "joint base station clustering and beamforming for non orthogonal multicast and unicast transmission with backhaul constraints"
  Abstract: The demand for providing multicast services in cellular networks is continuously and fastly increasing. In this work, we propose a non-orthogonal transmission framework based on layered-division multiplexing (LDM) to support multicast and unicast services concurrently in cooperative multi-cell cellular networks with limited backhaul capacity. We adopt a two-layer LDM structure where the first layer is intended for multicast services, the second layer is for unicast services, and the two layers are superposed with different beamformers. Each user decodes the multicast message first, subtracts it, and then decodes its dedicated unicast message. We formulate a joint multicast and unicast beamforming problem with adaptive base station clustering that aims to maximize the weighted sum of the multicast rate and the unicast rate under per-BS power and backhaul constraints. To solve the problem, we first develop a branch-and-bound algorithm to find its global optimum. We then reformulate the problem as a sparse beamforming problem and propose a low-complexity algorithm based on convex-concave procedure. Simulation results demonstrate the significant superiority of the proposed LDM-based non-orthogonal scheme over orthogonal schemes in terms of the achievable multicast-unicast rate region.

Connected through hyperedge HE-1 (induced by source paper "energy efficient hybrid precoding design for integrated multicast unicast millimeter wave communications with swipt"):
  with members:
    - "hybrid precoding based millimeter wave massive mimo noma with simultaneous wireless information and power transfer"
    - "joint optimization of computation and communication power in multi user massive mimo systems"
    - "energy efficient transceiver design for hybrid sub array architecture mimo systems"
    - "energy efficient power allocation in millimeter wave massive mimo with non orthogonal multiple access"
    - "joint beamforming and broadcasting in massive mimo"
    - "an overview of signal processing techniques for millimeter wave mimo systems"
    - "on the spectral efficiency and security enhancements of noma assisted multicast unicast streaming"
    - "energy efficiency optimization of 5g radio frequency chain systems"

Connected through hyperedge HE-2 (induced by source paper "rate splitting for multi antenna non orthogonal unicast and multicast transmission spectral and energy efficiency analysis"):
  with members:
    - "energy efficiency of rate splitting multiple access and performance benefits over sdma and noma"
    - "rate splitting multiple access for coordinated multi point joint transmission"
    - "rate splitting for multi antenna non orthogonal unicast and multicast transmission"
    - "gaussian message passing for overloaded massive mimo noma"
    - "rate splitting multiple access for downlink communication systems bridging generalizing and outperforming sdma and noma"
    - "rate splitting for max min fair multigroup multicast beamforming in overloaded systems"
    - "optimal dof region of the k user miso bc with partial csit"
    - "generalized multicast multibeam precoding for satellite communications"

Connected through hyperedge HE-3 (induced by source paper "two layered superposition of broadcast multicast and unicast signals in multiuser ofdma systems"):
  with members:
    - "rate splitting for multi antenna non orthogonal unicast and multicast transmission"
    - "rate splitting for multi antenna non orthogonal unicast and multicast transmission spectral and energy efficiency analysis"
    - "a survey on non orthogonal multiple access for 5g networks research challenges and future trends"
    - "energy efficient joint unicast and multicast beamforming with multi antenna user terminals"
    - "joint beamforming and broadcasting in massive mimo"
    - "on the spectral efficiency and security enhancements of noma assisted multicast unicast streaming"
    - "rate splitting for mimo wireless networks a promising phy layer strategy for lte evolution"
    - "on the performance of non orthogonal multiple access in 5g systems with randomly deployed users"

Connected through hyperedge HE-4 (induced by source paper "rate splitting for multi antenna non orthogonal unicast and multicast transmission"):
  with members:
    - "rate splitting multiple access for downlink communication systems bridging generalizing and outperforming sdma and noma"
    - "energy efficient joint unicast and multicast beamforming with multi antenna user terminals"
    - "sum rate maximization for linearly precoded downlink multiuser miso systems with partial csit a rate splitting approach"
    - "rate splitting for mimo wireless networks a promising phy layer strategy for lte evolution"
    - "sum rate maximization for mu miso with partial csit using joint multicasting and broadcasting"

Connected through hyperedge HE-5 (induced by source paper "multi tenant c ran with spectrum pooling downlink optimization under privacy constraints"):
  with members:
    - "optimization of massive full dimensional mimo for positioning and communication"
    - "inter operator base station coordination in spectrum shared millimeter wave cellular networks"
    - "cross layer design for downlink multihop cloud radio access networks with network coding"
    - "on the optimal fronthaul compression and decoding strategies for uplink cloud radio access networks"
    - "multivariate fronthaul quantization for downlink c ran"
    - "content centric sparse multicast beamforming for cache enabled cloud ran"
    - "robust group sparse beamforming for multicast green cloud ran with imperfect csi"
    - "cloud radio access network virtualizing wireless access for dense heterogeneous systems"

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)