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 "pilot power allocation through user grouping in multi cell massive mimo systems"):
  Abstract: In this paper, we propose a relative channel estimation error (RCEE) metric, and derive closed-form expressions for its expectation    $\rm {Exp}_{rcee}$    and the achievable uplink rate holding for any number of base station antennas    $M$   , with the least squares (LS) and minimum mean squared error (MMSE) methods. It is found that RCEE and    $\rm {Exp}_{rcee}$    converge to the same constant value when    $M\rightarrow \infty $   , which renders the pilot power allocation (PPA) substantially simplified and a PPA algorithm is proposed to minimize the average    $\rm {Exp}_{rcee}$    per user under a total pilot power budget    $P$    in multi-cell massive multiple-input multiple-output systems. Numerical results show that the PPA algorithm brings considerable gains for the LS estimation compared with equal PPA (EPPA), while the gains are significant only with large frequency reuse factor (FRF) for the MMSE estimation. Moreover, for large FRF and large    $P$   , the performance of the LS approaches to that of the MMSE. Besides, a scheduling strategy is proposed to allocate pilot power in the whole system, which can approach the optimal performance. For the achievable uplink rate, the PPA scheme and improves the minimum achievable uplink rate compared with the EPPA scheme.

Includes members:
  Member "power allocation schemes for multicell massive mimo systems":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "on the pilot contamination attack in multi cell multiuser massive mimo networks")
  Member "channel estimation in massive mimo systems":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "super resolution blind channel and signal estimation for massive mimo with one dimensional antenna array")
  Member "uplink pilot and data power control for single cell massive mimo systems with mrc":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "optimal pilot and payload power control in single cell massive mimo systems")
  Member "massive mimo with non ideal arbitrary arrays hardware scaling laws and circuit aware design":
    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 "multipair full duplex relaying with massive arrays and linear processing":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "angle aware user cooperation for secure massive mimo in rician fading channel")
  Member "power scaling of uplink massive mimo systems with arbitrary rank channel means":
    also connected through other hyperedges:
      - Hyperedge HE-6 (induced by source paper "spectral efficiency of one bit sigma delta massive mimo")
  Member "dealing with interference in distributed large scale mimo systems a statistical approach":
    also connected through other hyperedges:
      - Hyperedge HE-7 (induced by source paper "covariance aided csi acquisition with non orthogonal pilots in massive mimo a large system performance analysis")
  Member "massive mimo multicasting in noncooperative cellular networks":
    also connected through other hyperedges:
      - Hyperedge HE-8 (induced by source paper "joint unicast and multi group multicast transmission in massive mimo systems")

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)