Estimating Partially Observed Graph Signals by Learning Spectrally Concentrated Graph Kernels


Turhan G., VURAL E.

31st IEEE International Workshop on Machine Learning for Signal Processing, MLSP 2021, Gold-Coast, Australia, 25 - 28 October 2021, vol.2021-October identifier identifier

  • Publication Type: Conference Paper / Full Text
  • Volume: 2021-October
  • Doi Number: 10.1109/mlsp52302.2021.9596282
  • City: Gold-Coast
  • Country: Australia
  • Keywords: Graph dictionary learning, graph signal processing, sparse representations, graph kernels, multiple graph domains
  • Middle East Technical University Affiliated: Yes

Abstract

© 2021 IEEE.Graph models provide flexible tools for the representation and analysis of signals defined over irregular domains such as social or sensor networks. However, in real applications data observations are often not available over the whole graph, due to practical problems such as sensor failure or connection loss. In this paper, we study the estimation of partially observed graph signals on multiple graphs. We learn a sparse representation of partially observed graph signals over spectrally concentrated graph dictionaries. Our dictionary model consists of several sub-dictionaries each of which is generated from a Gaussian kernel centered at a certain graph frequency in order to capture a particular spectral component of the graph signals at hand. The problem of jointly learning the spectral kernels and the sparse codes is solved with an alternating optimization approach. Finally, the incomplete entries of the given graph signals are estimated using the learnt dictionaries and the sparse coefficients. Experimental results on synthetic and real graph data sets suggest that the proposed method yields promising performance in comparison to reference solutions.