Blind multiband signal reconstruction: compressed sensing for analog signals

  • Authors:
  • Moshe Mishali;Yonina C. Eldar

  • Affiliations:
  • Technion-Israel Institute of Technology, Haifa, Israel;Technion-Israel Institute of Technology, Haifa, Israel

  • Venue:
  • IEEE Transactions on Signal Processing
  • Year:
  • 2009

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Abstract

We address the problem of reconstructing a multi-band signal from its sub-Nyquist pointwise samples, when the band locations are unknown. Our approach assumes an existing multi-coset sampling. To date, recovery methods for this sampling strategy ensure perfect reconstruction either when the band locations are known, or under strict restrictions on the possible spectral suppprts. In this paper, only the number of bands and their widths are assumed without any other limitations on the support. We describe how to choose the parameters of the multicoset sampling so that a unique multiband signal matches the given samples. To recover the signal, the continuous recontruction is replaced by a single finite-dimensional problem without the need for discretization. The resulting problem is studied within the framework of compressed sensing, and thus can be solved efficiently using known tractable algorithms from this emerging area. We also develop a theoretical lower bound on the average sampling rate required for blind signal reconstruction, which is twice the minimal rate of known-spectrum recovery. Our method ensures perfect reconstruction for a wide class of signals sampled at the minimal rate, and provides a first systematic study of compressed sensig in a truly analog setting. Numerical experiments are presented demonstrating blind sampling and reconstruction with minimal sampling rate.