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 beamforming and broadcasting in massive mimo"
  Abstract: The downlink of a massive MIMO system is considered for the case in which the base station must concurrently serve two categories of terminals: one group to which imperfect instantaneous channel state information (CSI) is available and one group to which no CSI is available. Motivating applications include broadcasting of public channels and control information in wireless networks. A new technique is developed and analyzed: joint beamforming and broadcasting (JBB), by which the base station beamforms to the group of terminals to which CSI is available, and broadcasts to the other group of terminals, to which no CSI is available. The broadcast information does not interfere with the beamforming as it is placed in the nullspace of the channel matrix collectively seen by the terminals targeted by the beamforming. JBB is compared to orthogonal access (OA) by which the base station partitions the time-frequency resources into two disjunct parts, one for each group of terminals. It is shown that JBB can substantially outperform OA in terms of required total radiated power for given rate targets.

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 base station clustering and beamforming for non orthogonal multicast and unicast transmission with backhaul constraints"
    - "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 "non orthogonal unicast and broadcast transmission via joint beamforming and ldm in cellular networks"):
  with members:
    - "distributed optimization for coordinated beamforming in multicell multigroup multicast systems power minimization and sinr balancing"
    - "rate splitting for multi antenna non orthogonal unicast and multicast transmission spectral and energy efficiency analysis"
    - "admm based fast algorithm for multi group multicast beamforming in large scale wireless systems"
    - "celltv on the benefit of tv distribution over cellular networks a case study"
    - "coordinated multicast beamforming in multicell networks"
    - "distributed robust multicell coordinated beamforming with imperfect csi an admm approach"
    - "robust linear precoder design for multi cell downlink transmission"

Connected through hyperedge HE-3 (induced by source paper "joint unicast and multi group multicast transmission in massive mimo systems"):
  with members:
    - "large system analysis of power normalization techniques in massive mimo"
    - "hybrid precoding for multi group physical layer multicasting"
    - "max min fair transmit precoding for multi group multicasting in massive mimo"
    - "multigroup multicast precoding in massive mimo"
    - "reducing the computational complexity of multicasting in large scale antenna systems"
    - "hybrid precoding for physical layer multicasting"
    - "on the spectral efficiency and security enhancements of noma assisted multicast unicast streaming"
    - "massive mimo ten myths and one critical question"

Connected through hyperedge HE-4 (induced by source paper "estimation and mitigation of channel non reciprocity in massive mimo"):
  with members:
    - "performance analysis of multi user massive mimo downlink under channel non reciprocity and imperfect csi"
    - "analysis of massive mimo with hardware impairments and different channel models"
    - "massive mimo for next generation wireless systems"
    - "scalable synchronization and reciprocity calibration for distributed multiuser mimo"
    - "five disruptive technology directions for 5g"
    - "massive mu mimo downlink tdd systems with linear precoding and downlink pilots"
    - "channel estimation and linear precoding in multiuser multiple antenna tdd systems"
    - "pilot contamination and precoding in multi cell tdd systems"

Connected through hyperedge HE-5 (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 base station clustering and beamforming for non orthogonal multicast and unicast transmission with backhaul constraints"
    - "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-6 (induced by source paper "symbol level and multicast precoding for multiuser multiantenna downlink a survey classification and challenges"):
  with members:
    - "channel estimation and performance analysis of one bit massive mimo systems"
    - "an overview on resource allocation techniques for multi user mimo systems"
    - "spatio temporal waveform design for multiuser massive mimo downlink with 1 bit receivers"
    - "coordinate update algorithms for robust power loading for the mu miso downlink with outage constraints"
    - "energy efficient symbol level precoding in multiuser miso based on relaxed detection region"
    - "robust transmission in downlink multiuser miso systems a rate splitting approach"
    - "adaptive pilot clustering in heterogeneous massive mimo networks"
    - "a rate splitting strategy for max min fair multigroup multicasting"

Connected through hyperedge HE-7 (induced by source paper "max min fair transmit precoding for multi group multicasting in massive mimo"):
  with members:
    - "large system analysis of power normalization techniques in massive mimo"
    - "multigroup multicast precoding in massive mimo"
    - "reducing the computational complexity of multicasting in large scale antenna systems"
    - "no downlink pilots are needed in tdd massive mimo"
    - "massive mimo ten myths and one critical question"
    - "multicast multigroup beamforming for per antenna power constrained large scale arrays"
    - "massive mimo performance evaluation based on measured propagation data"
    - "massive mimo multicasting in noncooperative cellular networks"

Connected through hyperedge HE-8 (induced by source paper "joint base station clustering and beamforming for non orthogonal multicast and unicast transmission with backhaul constraints"):
  with members:
    - "energy efficient joint unicast and multicast beamforming with multi antenna user terminals"
    - "an efficient global algorithm for single group multicast beamforming"
    - "robust transmission in downlink multiuser miso systems a rate splitting approach"
    - "rate splitting for mimo wireless networks a promising phy layer strategy for lte evolution"
    - "content centric sparse multicast beamforming for cache enabled cloud ran"
    - "sum rate maximization for mu miso with partial csit using joint multicasting and broadcasting"
    - "sparse beamforming and user centric clustering for downlink cloud radio access network"

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)