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: "cloud radio access network virtualizing wireless access for dense heterogeneous systems"
  Abstract: Cloud Radio Access Network (C-RAN) refers to the virtualization of base station functionalities by means of cloud computing. This results in a novel cellular architecture in which low-cost wireless access points, known as radio units (RUs) or remote radio heads (RRHs), are centrally managed by a reconfigurable centralized "cloud", or central, unit (CU). C-RAN allows operators to reduce the capital and operating expenses needed to deploy and maintain dense heterogeneous networks. This critical advantage, along with spectral efficiency, statistical multiplexing and load balancing gains, make C-RAN well positioned to be one of the key technologies in the development of 5G systems. In this paper, a succinct overview is presented regarding the state of the art on the research on C-RAN with emphasis on fronthaul compression, baseband processing, medium access control, resource allocation, system-level considerations and standardization efforts.

Connected through hyperedge HE-1 (induced by source paper "joint 3d maneuver and power adaptation for secure uav communication with comp reception"):
  with members:
    - "efficient local map search algorithms for the placement of flying relays"
    - "secrecy transmission in large scale uav enabled wireless networks"
    - "cognitive uav communication via joint maneuver and power control"
    - "beyond 5g with uavs foundations of a 3d wireless cellular network"
    - "comp in the sky uav placement and movement optimization for multi user communications"
    - "on the number and 3d placement of drone base stations in wireless cellular networks"
    - "optimal 3d trajectory design and resource allocation for solar powered uav communication systems"
    - "securing uav communications via joint trajectory and power control"

Connected through hyperedge HE-2 (induced by source paper "integer forcing architectures for uplink cloud radio access networks"):
  with members:
    - "achievability performance bounds for integer forcing source coding"
    - "green heterogeneous cloud radio access networks potential techniques performance trade offs and challenges"
    - "on the optimal fronthaul compression and decoding strategies for uplink cloud radio access networks"
    - "outage behavior of integer forcing with random unitary pre processing"
    - "fronthaul compression and transmit beamforming optimization for multi antenna uplink c ran"
    - "system architecture and key technologies for 5g heterogeneous cloud radio access networks"
    - "optimized backhaul compression for uplink cloud radio access network"
    - "successive integer forcing and its sum rate optimality"

Connected through hyperedge HE-3 (induced by source paper "caching at base stations with multi cluster multicast wireless backhaul via accelerated first order algorithm"):
  with members:
    - "caching at base stations with heterogeneous user demands and spatial locality"
    - "optimized base station cache allocation for cloud radio access network with multicast backhaul"
    - "modeling analysis and optimization of coded caching in small cell networks"
    - "noisy broadcast networks with receiver caching"
    - "caching at the wireless edge design aspects challenges and future directions"
    - "content centric sparse multicast beamforming for cache enabled cloud ran"
    - "cloud radio access networks with coded caching"
    - "analysis and optimization of caching and multicasting in large scale cache enabled wireless networks"

Connected through hyperedge HE-4 (induced by source paper "hybrid precoder design for cache enabled millimeter wave radio access networks"):
  with members:
    - "hybrid beamforming based on implicit channel state information for millimeter wave links"
    - "two level transmission scheme for cache enabled fog radio access networks"
    - "optimized base station cache allocation for cloud radio access network with multicast backhaul"
    - "spatial and frequency wideband effects in millimeter wave massive mimo systems"
    - "joint precoding and rrh selection for user centric green mimo c ran"
    - "energy efficient transceiver design for hybrid sub array architecture mimo systems"
    - "joint design of digital and analog processing for downlink c ran with large scale antenna arrays"
    - "codebook based hybrid precoding for millimeter wave multiuser systems"

Connected through hyperedge HE-5 (induced by source paper "joint design of fronthauling and hybrid beamforming for downlink c ran systems"):
  with members:
    - "channel diagonalization for cloud radio access"
    - "stochastic successive convex optimization for two timescale hybrid precoding in massive mimo"
    - "energy efficiency maximization for c rans discrete monotonic optimization penalty and ell _ 0 approximation methods"
    - "hybrid analog digital beamforming for massive mimo systems"
    - "multi user precoding and channel estimation for hybrid millimeter wave systems"
    - "hybrid precoding for massive mimo systems in cloud ran architecture with capacity limited fronthauls"
    - "alternating minimization algorithms for hybrid precoding in millimeter wave mimo systems"
    - "subspace estimation and decomposition for large millimeter wave mimo systems"

Connected through hyperedge HE-6 (induced by source paper "interference mitigation via rate splitting and common message decoding in cloud radio access networks"):
  with members:
    - "energy efficiency of rate splitting multiple access and performance benefits over sdma and noma"
    - "rate splitting for multi antenna non orthogonal unicast and multicast transmission"
    - "cross layer design for downlink multihop cloud radio access networks with network coding"
    - "content centric sparse multicast beamforming for cache enabled cloud ran"
    - "optimality of treating interference as noise a combinatorial perspective"
    - "fronthaul constrained cloud radio access networks insights and challenges"
    - "cloud radio access networks with coded caching"
    - "what will 5g be"

Connected through hyperedge HE-7 (induced by source paper "joint agc and receiver design for large scale mu mimo systems with coarsely quantized signals and c rans"):
  with members:
    - "throughput analysis of massive mimo uplink with low resolution adcs"
    - "branch and bound precoding for multiuser mimo systems with 1 bit quantization"
    - "widely linear precoding for large scale mimo with iqi algorithms and performance analysis"
    - "uplink interference reduction in large scale antenna systems"
    - "full duplex cloud radio access network stochastic design and analysis"
    - "iterative detection and decoding algorithms for mimo systems in block fading channels using ldpc codes"
    - "robust adaptive beamforming based on low rank and cross correlation techniques"
    - "adaptive reduced rank receive processing based on minimum symbol error rate criterion for large scale multiple antenna systems"

Connected through hyperedge HE-8 (induced by source paper "robust baseband compression against congestion in packet based fronthaul networks using multiple description coding"):
  with members:
    - "hybrid data sharing and compression strategy for downlink cloud radio access network"
    - "reliable and low latency fronthaul for tactile internet applications"
    - "fronthaul compression and transmit beamforming optimization for multi antenna uplink c ran"
    - "content centric sparse multicast beamforming for cache enabled cloud ran"
    - "joint precoding and multivariate backhaul compression for the downlink of cloud radio access networks"
    - "robust and efficient distributed compression for cloud radio access networks"
    - "minimum expected distortion in gaussian source coding with fading side information"

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)