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: "omnidirectional space time block coding for common information broadcasting in massive mimo systems"
  Abstract: In this paper, we design space-time block codes (STBCs) to broadcast the common information omnidirectionally in a massive MIMO downlink. To reduce the burden of the downlink channel estimation and achieve partial spatial diversity from base station (BS) transmit antennas, we propose channel-independently precoded low-dimensional STBC. The precoding matrix and the signal constellation in the low-dimensional STBC are jointly designed to guarantee omnidirectional coverage at any instant time and sufficiently utilize the power amplifier capacities of BS transmit antennas, and at the same time, achieve the full diversity of the low-dimensional STBC. Under this framework, several designs are presented. To provide transmit diversity order of two, a precoded Alamouti code is proposed, which has a fast symbol-wise maximum-likelihood (ML) decoding. To provide transmit diversity order of four, three types of STBCs are proposed, being referred to as precoded orthogonal STBC (OSTBC), precoded quasi-orthogonal STBC (QOSTBC), and precoded coordinate interleaved orthogonal design (CIOD), respectively. The last two codes have the same complexity for pair-wise ML decoding, while precoded QOSTBC has a higher coding gain when the bit rate is lower than or equal to 4 bps/Hz, and precoded CIOD has a higher coding gain when the bit rate is higher than 4 bps/Hz. Precoded OSTBC has a higher decoding complexity and a lower coding gain than the other two codes, since in the precoded OSTBC the information symbols need to be jointly designed and decoded. Moreover, a precoded no-zero-entry Toeplitz code and a precoded no-zero-entry overlapped Alamouti code are also proposed. These two codes can achieve a higher diversity order with linear receivers.

Connected through hyperedge HE-1 (induced by source paper "space time block coding based beamforming for beam squint compensation"):
  with members:
    - "effect of wideband beam squint on codebook design in phased array wireless systems"

Connected through hyperedge HE-2 (induced by source paper "omnidirectional precoding and combining based synchronization for millimeter wave massive mimo systems"):
  with members:
    - "bdma for millimeter wave terahertz massive mimo transmission with per beam synchronization"
    - "low complexity channel estimation for millimeter wave systems with hybrid a d antenna processing"
    - "beamforming tradeoffs for initial ue discovery in millimeter wave mimo systems"
    - "directional cell discovery in millimeter wave cellular networks"
    - "coverage and rate analysis for millimeter wave cellular networks"
    - "downlink training techniques for fdd massive mimo systems open loop and closed loop training with memory"
    - "spatially sparse precoding in millimeter wave mimo systems"
    - "millimeter wave mimo channel tracking systems"

Connected through hyperedge HE-3 (induced by source paper "performance of in band transmission of system information in massive mimo systems"):
  with members:
    - "optimal pilot and payload power control in single cell massive mimo systems"
    - "joint beamforming and broadcasting in massive mimo"
    - "broadbeam for massive mimo systems"
    - "massive mimo ten myths and one critical question"
    - "hybrid beamforming for massive mimo a survey"
    - "massive mimo performance evaluation based on measured propagation data"
    - "massive mimo multicasting in noncooperative cellular networks"

Connected through hyperedge HE-4 (induced by source paper "energy efficient beamforming for massive mimo public channel"):
  with members:
    - "performance analysis of mixed adc massive mimo systems over rician fading channels"
    - "joint beamforming and broadcasting in massive mimo"
    - "on the spectral efficiency of massive mimo systems with low resolution adcs"
    - "broadbeam for massive mimo systems"
    - "transmit radiation pattern invariance in mimo radar with application to doa estimation"
    - "spatially sparse precoding in millimeter wave mimo systems"

Connected through hyperedge HE-5 (induced by source paper "power efficient hybrid beamforming for massive mimo public channel"):
  with members:
    - "performance analysis of mixed adc massive mimo systems over rician fading channels"
    - "joint beamforming and broadcasting in massive mimo"
    - "broadbeam for massive mimo systems"
    - "transmit radiation pattern invariance in mimo radar with application to doa estimation"
    - "spatially sparse precoding in millimeter wave mimo 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)