A Novel Data Transformation Approach for DOA Estimation With 3-D Antenna Arrays in the Presence of Mutual Coupling

In antenna array applications, mutual coupling (MC) is an important error source that should be corrected. In previous works, MC parameters are estimated by using a data transformation approach, where the unknown coupling coefficients are extracted into a single vector so that the parameter estimation is done accordingly. While this is an effective way to estimate the MC coefficients, this approach is only considered for the antenna arrays with special geometries such as linear, circular, and rectangular. In this letter, we introduce a new data transformation approach that is applicable for a general array geometry, namely 3-D arrays. The proposed approach is based on the decomposition of the MC matrix in terms of the unknown distinct MC coefficients. The performance of the proposed technique is evaluated through simulations for different 3-D arrays, and it is compared to the theoretical performance bounds. It is shown that the proposed technique can be used effectively for 3-D array structures with high estimation accuracy.