A Novel Improved Symmetric Coprime MIMO Array for DOA Estimation of Coherent Signals

Compared to the traditional passive detection co-prime array, coprime MIMO array has the advantage of detecting coherent signals. Compared to other coprime MIMO arrays, the symmetric coprime MIMO array (SCMA) has more subarrays, making it more flexible. However, the SCMA array contains a significant amount of redundancy. In this paper, a new improved SCMA structure is proposed, which not only reduces the redundancy of the SCMA but also utilizes the information from the redundant sensors to obtain more degrees of freedom (DoFs) and a larger virtual aperture, thereby improving the estimation accuracy. Simulation results demonstrate the superiority of the proposed structure.