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: "interference reduction in multi cell massive mimo systems i large scale fading precoding and decoding"
  Abstract: A wireless massive MIMO system entails a large number (tens or hundreds) of base station antennas serving a much smaller number of users, with large gains in spectral-efficiency and energy-efficiency compared with conventional MIMO technology. Until recently it was believed that in multi-cellular massive MIMO system, even in the asymptotic regime, as the number of service antennas tends to infinity, the performance is limited by directed inter-cellular interference. This interference results from unavoidable re-use of reverse-link training sequences (pilot contamination) by users in different cells. #R##N#We devise a new concept that leads to the effective elimination of inter-cell interference in massive MIMO systems. This is achieved by outer multi-cellular precoding, which we call Large-Scale Fading Precoding (LSFP). The main idea of LSFP is that each base station linearly combines messages aimed to users from different cells that re-use the same training sequence. Crucially, the combining coefficients depend only on the slow-fading coefficients between the users and the base stations. Each base station independently transmits its LSFP-combined symbols using conventional linear precoding that is based on estimated fast-fading coefficients. Further, we derive estimates for downlink and uplink SINRs and capacity lower bounds for the case of massive MIMO systems with LSFP and a finite number of base station antennas.

Connected through hyperedge HE-1 (induced by source paper "max min rate of cell free massive mimo uplink with optimal uniform quantization"):
  with members:
    - "on the uplink throughput of zero forcing in cell free massive mimo with coarse quantization"
    - "ubiquitous cell free massive mimo communications"
    - "on the energy efficiency of limited backhaul cell free massive mimo"
    - "cell free massive mimo with limited backhaul"
    - "on the performance of backhaul constrained cell free massive mimo with linear receivers"
    - "cooperative access networks optimum fronthaul quantization in distributed massive mimo and cloud ran"
    - "network deployment for maximal energy efficiency in uplink with multislope path loss"
    - "enhanced max min sinr for uplink cell free massive mimo systems"

Connected through hyperedge HE-2 (induced by source paper "jamming resistant receivers for the massive mimo uplink"):
  with members:
    - "jamming resistant receivers for massive mimo"
    - "pilot contamination is not a fundamental asymptotic limitation in massive mimo"
    - "subverting massive mimo by smart jamming"
    - "secure massive mimo transmission with an active eavesdropper"
    - "jamming aided secure communication in massive mimo rician channels"
    - "physical layer security for massive mimo an overview on passive eavesdropping and active attacks"
    - "worst case jamming on mimo gaussian channels"
    - "securing massive mimo at the physical layer"

Connected through hyperedge HE-3 (induced by source paper "pilot reuse factor with large scale fading precoding for massive mimo"):
  with members:
    - "massive mimo ten myths and one critical question"
    - "interference reduction in multi cell massive mimo systems ii downlink analysis for a finite number of antennas"
    - "massive mu mimo downlink tdd systems with linear precoding and downlink pilots"

Connected through hyperedge HE-4 (induced by source paper "sectoring in multi cell massive mimo systems"):
  with members:
    - "interference reduction in multi cell massive mimo systems ii downlink analysis for a finite number of antennas"
    - "massive mimo for next generation wireless systems"

Connected through hyperedge HE-5 (induced by source paper "uplink interference reduction in large scale antenna systems"):
  with members:
    - "robust pilot decontamination based on joint angle and power domain discrimination"
    - "channel acquisition for massive mimo ofdm with adjustable phase shift pilots"

Connected through hyperedge HE-6 (induced by source paper "cell free massive mimo versus small cells"):
  with members:
    - "cell free massive mimo uniformly great service for everyone"
    - "deploying dense networks for maximal energy efficiency small cells meet massive mimo"
    - "harmonized cellular and distributed massive mimo load balancing and scheduling"
    - "a comparative study of downlink mimo cellular networks with co located and distributed base station antennas"
    - "large scale mimo versus network mimo for multicell interference mitigation"
    - "dealing with interference in distributed large scale mimo systems a statistical approach"
    - "energy efficient large scale distributed antenna system l das for multiple users"
    - "downlink mimo hetnets modeling ordering results and performance analysis"

Connected through hyperedge HE-7 (induced by source paper "robust pilot decontamination based on joint angle and power domain discrimination"):
  with members:
    - "pilot decontamination through pilot sequence hopping in massive mimo systems"
    - "fractional pilot reuse in massive mimo systems"
    - "dealing with interference in distributed large scale mimo systems a statistical approach"
    - "blind pilot decontamination"
    - "joint spatial division and multiplexing opportunistic beamforming and user grouping"
    - "a coordinated approach to channel estimation in large scale multiple antenna systems"
    - "large system analysis of linear precoding in correlated miso broadcast channels under limited feedback"
    - "energy and spectral efficiency of very large multiuser mimo systems"

Connected through hyperedge HE-8 (induced by source paper "massive mimo pilot retransmission strategies for robustification against jamming"):
  with members:
    - "linear precoding of data and artificial noise in secure massive mimo systems"
    - "subverting massive mimo by smart jamming"
    - "jamming aided secure communication in massive mimo rician channels"
    - "physical layer security for massive mimo an overview on passive eavesdropping and active attacks"
    - "securing massive mimo at the physical layer"
    - "energy and spectral efficiency of very large multiuser mimo systems"
    - "pilot contamination and precoding in multi cell tdd 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)