Multichannel Sparse Recovery for Constant Modulus Signals via ℓ_{∞ 1} Minimization

Compressed sensing techniques have extensive applications in radar signal processing. Convex optimization approaches, such as ℓ_2,1 minimization, are used for multichannel sparse signal recovery. However, when jointly sparse signals also exhibit the constant modulus (CM) property, ℓ_2,1 minimization cannot utilize this prior information. In this article, we focus on utilizing ℓ_{∞ 1} minimization to recover sparse signals with the CM property. We first establish a sufficient recovery condition for jointly sparse signals. Based on the duality theory, our main theorem sheds light on the superiority of ℓ_{∞ 1} minimization over ℓ_{2, 1} minimization in the CM signal recovery. In addition, we provide an average-case analysis for ℓ_∞1 minimization. These results are applicable to the direction-of-arrival estimation with a nonuniform linear array and have practical relevance. A fast algorithm based on the alternating direction method of multipliers is proposed, and extensive numerical simulations are carried out to validate the results obtained.