An Enhanced Multi-ULA Sparse Array With Improved DOA Estimation Performance

In this letter, we introduce a novel sparse array (SA) architecture consisting of five uniform linear arrays (ULAs), referred to as the enhanced multi-ULA SA (EMUSA). A closed-form expression is provided to define the sensor positions of the EMUSA, as well as derivations for its uniform degrees of freedom (uDOFs) and the first three values of its weight function. Theoretical analysis demonstrates that EMUSA outperforms existing SAs in terms of achievable uDOFs, with the first three values of its weight function equal to 1 when the number of sensors is at least 18. Simulation results indicate that the proposed EMUSA exhibits significant advantages over existing SAs regarding uDOFs, coupling leakage (CL), and direction of arrival (DOA) estimation performance.