human: Given a hyperedge-centered hypergraph: <hypergraph>, where the center hyperedge is induced by one source paper and its member nodes are the cited papers.

Details of the hypergraph:
Center hyperedge (induced by source paper "localization efficiency in massive mimo systems"):
  Abstract: In the next generation of wireless systems, Massive MIMO offers high angular resolution for localization. By virtue of large number of antennas, users' angle of arrival can be estimated with high accuracy. As Massive MIMO antenna array can be very large, the channels seen by different antennas might differ from each other, however, this does not rule out the possibility of the Angle of Arrival (AoA) estimation. We show that Cramer-Rao Lower Bound (CRLB) in multi-user independent, identically distributed (i.i.d) channels does exist and regardless of channel distribution, it converges toward a closed-form expression. Then, we redefine a localization efficiency function for a multi-user scenario and numerically optimize it with respect to the number of antennas. We prove when only a subset of the available antennas is used, CRLB can be minimized with respect to which set of antennas is used. An antenna selection strategy that minimizes CRLB is proposed. As a benchmark, we apply the proposed antenna selection scheme to the MUltiple SIgnal Classification (MUSIC) algorithm and study its efficiency. Numerical results validate the accuracy of our analysis and show significant improvement in efficiency when the proposed antenna selection strategy is employed.

Includes members:
  Member "localization in ultra narrow band iot networks design guidelines and tradeoffs":
    also connected through other hyperedges:
      (none)
  Member "massive mimo based localization and mapping exploiting phase information of multipath components":
    also connected through other hyperedges:
      (none)
  Member "employing antenna selection to improve energy efficiency in massive mimo systems":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "joint transmit and circuit power minimization in massive mimo with downlink sinr constraints when to turn on massive mimo")
  Member "tracking of wideband multipath components in a vehicular communication scenario":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "on the effectiveness of otfs for joint radar and communication")
  Member "massive mimo in real propagation environments do all antennas contribute equally":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "amplitude and phase estimation for absolute calibration of massive mimo front ends")
  Member "massive mimo for next generation wireless systems":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "joint power control and lsfd for wireless powered cell free massive mimo")
  Member "what will 5g be":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "5g network slicing using sdn and nfv a survey of taxonomy architectures and future challenges")
  Member "optimal design of energy efficient multi user mimo systems is massive mimo the answer":
    also connected through other hyperedges:
      - Hyperedge HE-6 (induced by source paper "rate splitting multiple access for multi antenna downlink communication systems spectral and energy efficiency tradeoff")

Question: Please tell me which class the source paper 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)