Delay Coprime Array: A New Sparse Linear Array for Fast and Robust DOA Estimation

In this letter, we propose a new sparse linear array (SLA), termed delay coprime array (DCA), and correspondingly develop a low-complexity direction of arrival (DOA) estimation algorithm. In terms of structure, unlike existing SLAs (e.g., coprime array), DCA is composed of two “large-spaced” uniform linear arrays (ULAs) with a shifted distance that is coprime with the inter-element spacing in the ULAs. In terms of algorithm, the proposed algorithm involves ambiguity and de-ambiguity stages and significantly improves estimation accuracy due to the active use of phase ambiguity instead of hastily suppressing ambiguity. Numerical results demonstrate that DOA estimation with DCA has comparable performance as the existing DOA estimation with SLAs, but with much lower computational complexity and simpler configuration. Admittedly, since the proposed method achieves fast calculation without using difference co-array, it loses the ability to identify more sources. Yet, owing to the low complexity and simple configuration, DCA and the corresponding algorithm are expected to play a role in DOA estimation.