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: "space constrained massive mimo hitting the wall of favorable propagation"
  Abstract: The recent development of the massive multiple-input multiple-output (MIMO) paradigm, has been extensively based on the pursuit of favorable propagation: in the asymptotic limit, the channel vectors become nearly orthogonal and inter-user interference tends to zero [1]. In this context, previous studies have considered fixed inter-antenna distance, which implies an increasing array aperture as the number of elements increases. Here, we focus on a practical, space-constrained topology, where an increase in the number of antenna elements in a fixed total space imposes an inversely proportional decrease in the inter-antenna distance. Our analysis shows that, contrary to existing studies, inter-user interference does not vanish in the massive MIMO regime, thereby creating a saturation effect on the achievable rate.

Connected through hyperedge HE-1 (induced by source paper "spectral efficiency of one bit sigma delta massive mimo"):
  with members:
    - "one bit sigma delta mimo precoding"
    - "a framework for one bit and constant envelope precoding over multiuser massive miso channels"
    - "quantized constant envelope precoding with psk and qam signaling"
    - "one bit precoding and constellation range design for massive mimo with qam signaling"
    - "one bit sphere decoding for uplink massive mimo systems with one bit adcs"
    - "1 bit massive mu mimo precoding in vlsi"
    - "throughput analysis of massive mimo uplink with low resolution adcs"
    - "channel estimation and performance analysis of one bit massive mimo systems"

Connected through hyperedge HE-2 (induced by source paper "spatial characterization of holographic mimo channels"):
  with members:
    - "degrees of freedom of holographic mimo channels"
    - "large system analysis of massive mimo with optimal m mmse processing"
    - "beyond massive mimo the potential of data transmission with large intelligent surfaces"
    - "massive mimo has unlimited capacity"
    - "optimal pilot and payload power control in single cell massive mimo systems"
    - "a generalized spatial correlation model for 3d mimo channels based on the fourier coefficients of power spectrums"
    - "on landau s eigenvalue theorem and information cut sets"
    - "optimal design of energy efficient multi user mimo systems is massive mimo the answer"

Connected through hyperedge HE-3 (induced by source paper "theoretical performance limits of massive mimo with uncorrelated rician fading channels"):
  with members:
    - "massive mimo with spatially correlated rician fading channels"
    - "massive mimo has unlimited capacity"
    - "performance analysis of mixed adc massive mimo systems over rician fading channels"
    - "on the spectral efficiency of massive mimo systems with low resolution adcs"
    - "pilot contamination is not a fundamental asymptotic limitation in massive mimo"
    - "asymptotic analysis of multicell massive mimo over rician fading channels"
    - "achievable rate of rician large scale mimo channels with transceiver hardware impairments"
    - "massive mimo ten myths and one critical question"

Connected through hyperedge HE-4 (induced by source paper "antenna arrays for line of sight massive mimo half wavelength is not enough"):
  with members:
    - "massive mimo ten myths and one critical question"
    - "massive mimo performance evaluation based on measured propagation data"
    - "aspects of favorable propagation in massive mimo"
    - "massive mimo for next generation wireless systems"
    - "optimal design of energy efficient multi user mimo systems is massive mimo the answer"
    - "five disruptive technology directions for 5g"
    - "scaling up mimo opportunities and challenges with very large arrays"
    - "achieving massive mimo spectral efficiency with a not so large number of antennas"

Connected through hyperedge HE-5 (induced by source paper "uplink analysis of large mu mimo systems with space constrained arrays in ricean fading"):
  with members:
    - "on the role of transmit correlation diversity in multiuser mimo systems"
    - "multi user massive mimo communication systems based on irregular antenna arrays"
    - "on the spectral efficiency of space constrained massive mimo with linear receivers"
    - "power scaling of uplink massive mimo systems with arbitrary rank channel means"
    - "massive mimo for next generation wireless systems"
    - "millimeter wave channel modeling and cellular capacity evaluation"
    - "scaling up mimo opportunities and challenges with very large arrays"
    - "performance analysis of macrodiversity mimo systems with mmse and zf receivers in flat rayleigh fading"

Connected through hyperedge HE-6 (induced by source paper "on the spectral efficiency of space constrained massive mimo with linear receivers"):
  with members:
    - "on the spectral efficiency of massive mimo systems with low resolution adcs"
    - "achievable rate of rician large scale mimo channels with transceiver hardware impairments"
    - "the impact of physical channel on performance of subspace based channel estimation in massive mimo systems"
    - "massive mimo with non ideal arbitrary arrays hardware scaling laws and circuit aware design"
    - "power scaling of uplink massive mimo systems with arbitrary rank channel means"
    - "massive mimo for next generation wireless systems"
    - "what will 5g be"
    - "energy and spectral efficiency of very large multiuser mimo systems"

Connected through hyperedge HE-7 (induced by source paper "exploiting known interference as green signal power for downlink beamforming optimization"):
  with members:
    - "constructive multiuser interference in symbol level precoding for the miso downlink channel"
    - "rethinking the role of interference in wireless networks"
    - "a multicast approach for constructive interference precoding in miso downlink channel"
    - "massive mimo for next generation wireless systems"
    - "transmit designs for the mimo broadcast channel with statistical csi"
    - "scaling up mimo opportunities and challenges with very large arrays"
    - "generic optimization of linear precoding in multibeam satellite systems"

Connected through hyperedge HE-8 (induced by source paper "asymptotic orthogonality analysis of time domain sparse massive mimo channels"):
  with members:
    - "super resolution sparse mimo ofdm channel estimation based on spatial and temporal correlations"
    - "scaling up mimo opportunities and challenges with very large arrays"
    - "estimation of sparse mimo channels with common support"

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)