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: "direction finding algorithms based on joint iterative subspace optimization"
  Abstract: In this paper, a reduced-rank scheme with joint iterative optimization is presented for direction of arrival estimation. A rank-reduction matrix and an auxiliary reduced-rank parameter vector are jointly optimized to calculate the output power with respect to each scanning angle. Subspace algorithms to estimate the rank-reduction matrix and the auxiliary vector are proposed. Simulations are performed to show that the proposed algorithms achieve enhanced performance over existing algorithms in the studied scenarios.

Connected through hyperedge HE-1 (induced by source paper "study of coarse quantization aware block diagonalization algorithms for mimo systems with low resolution"):
  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"
    - "linear precoding with low resolution dacs for massive mu mimo ofdm downlink"
    - "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"
    - "quantized precoding for massive mu mimo"
    - "adaptive reduced rank receive processing based on minimum symbol error rate criterion for large scale multiple antenna systems"

Connected through hyperedge HE-2 (induced by source paper "study of compressed randomized utv decompositions for low rank matrix approximations in data science"):
  with members:
    - "subspace orbit randomized decomposition for low rank matrix approximations"
    - "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"
    - "coherence pursuit fast simple and robust principal component analysis"
    - "practical sketching algorithms for low rank matrix approximation"
    - "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"
    - "fast randomized singular value thresholding for low rank optimization"

Connected through hyperedge HE-3 (induced by source paper "compressed sensing with probability based prior information"):
  with members:
    - "subspace orbit randomized decomposition for low rank matrix approximations"
    - "compressed sensing mri reconstruction using a generative adversarial network with a cyclic loss"
    - "masked signal decomposition using subspace representation and its applications"
    - "on collaborative compressive sensing systems the framework design and algorithm"
    - "widely linear precoding for large scale mimo with iqi algorithms and performance analysis"
    - "joint sensing matrix and sparsifying dictionary optimization for tensor compressive sensing"
    - "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"

Connected through hyperedge HE-4 (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"
    - "cloud radio access network virtualizing wireless access for dense heterogeneous systems"

Connected through hyperedge HE-5 (induced by source paper "study of robust distributed diffusion rls algorithms with side information for adaptive networks"):
  with members:
    - "maximum total correntropy diffusion adaptation over networks with noisy links"
    - "decentralized rls with data adaptive censoring for regressions over large scale networks"
    - "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"
    - "robust adaptive beamforming using a low complexity shrinkage based mismatch estimation algorithm"
    - "diffusion least mean p power algorithms for distributed estimation in alpha stable noise environments"
    - "distributed pareto optimization via diffusion strategies"
    - "diffusion strategies outperform consensus strategies for distributed estimation over adaptive networks"

Connected through hyperedge HE-6 (induced by source paper "study of adaptive activity aware constellation list based detection for massive machine type communications"):
  with members:
    - "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"
    - "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"
    - "compressed sensing for wireless communications useful tips and tricks"
    - "adaptive reduced rank receive processing based on minimum symbol error rate criterion for large scale multiple antenna systems"
    - "robust adaptive beamforming using a low complexity shrinkage based mismatch estimation algorithm"
    - "adaptive reduced rank lcmv beamforming algorithms based on joint iterative optimization of filters design and analysis"

Connected through hyperedge HE-7 (induced by source paper "compressed randomized utv decompositions for low rank approximations and big data applications"):
  with members:
    - "high dimensional low rank plus sparse matrix decomposition"
    - "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"
    - "coherence pursuit fast simple and robust principal component analysis"
    - "practical sketching algorithms for low rank matrix approximation"
    - "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"
    - "fast randomized singular value thresholding for low rank optimization"

Connected through hyperedge HE-8 (induced by source paper "distributed low rank adaptive algorithms based on alternating optimization and applications"):
  with members:
    - "widely linear precoding for large scale mimo with iqi algorithms and performance analysis"
    - "robust adaptive beamforming based on low rank and cross correlation techniques"
    - "dictionary learning over distributed models"
    - "adaptive reduced rank receive processing based on minimum symbol error rate criterion for large scale multiple antenna systems"
    - "robust adaptive beamforming using a low complexity shrinkage based mismatch estimation algorithm"
    - "single bit and reduced dimension diffusion strategies over distributed networks"
    - "adaptive distributed space time coding based on adjustable code matrices for cooperative mimo relaying systems"
    - "mimo radar using compressive sampling"

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.DS(Data Structures and Algorithms)