Iterative l1 minimization for non convex compressed sensing
An algorithmic framework, based on the difference of convex functions algorithm, is proposed for minimizing a class of concave sparse metrics for compressed sensing problems. The resulting algorithm iterates a sequence of l1 minimization problems. An exact sparse recovery theory is established to show that the proposed framework always improves on the basis pursuit (l1 minimization) and inherits robustness from it. Numerical examples on success rates of sparse solution recovery illustrate further that, unlike most existing non convex compressed sensing solvers in the literature, our method always out performs basis pursuit, no matter how ill conditioned the measurement matrix is. Moreover, the iterative l1 algorithms lead by a wide margin the state of the art algorithms on l1/2 and logarithimic minimizations in the strongly coherent (highly ill conditioned) regime, despite the same objective functions.
ArXiv