Robust Adaptive Beamforming for Flexible Conformal Array with Parameter Errors and Mutual Coupling

The flexible conformal array (FCA) with variable array structure is modeled as an array which is composed of two splice rings whose radius that are named controlling parameters (CPs) can be changed by users. Since the performance of (FCA) is sensitive to the errors of controlling parameters, an adaptive beamforming (ABF) method which is called multiple domain interference-plus-noise covariance matrix reconstruction and steering vector estimation (MD-SV) is proposed to compensate them associated with other types of errors. The ABF procedure is mainly consisted of multi-dimensional integral and CPs estimation stages, that is to estimate the perturbational steering vector and approximate it using alternative optimization. Simply, the first stage is implemented by a discrete sum in multidomain including CP and angle domains, and the second stage of SV estimation is fulfilled by an alternative optimization procedure. Simulation results demonstrate that the proposed method achieves well performance under multiple mismatches over a wide range of input signal-to-noise ratios.