The Joint Optimization of Channel Equalization and Wideband Adaptive Beamforming Based on Partially Calibrated Arrays and Real Steering Vectors

Wideband digital beamforming technology is widely employed in radar and communication applications. However, non-ideal frequency response characteristics of power devices and suboptimal antenna performance result in inconsistencies in the amplitude and phase responses of the channels, significantly degrading the performance of beamformers. These inconsistencies lead to mismatched array steering vectors, causing a frequency-domain constraint matrix that fails to align with the real steering vectors in the desired direction, ultimately resulting in a beam pointing deviations. Furthermore, when the wideband signals of interest are present in the covariance matrix of the received signal, the performance of interference nulling is significantly degraded. To address these challenges, a combined space-time filter, namely, channel equalization and wideband adaptive beamforming (CE-WABF), which is obtained by the joint optimization of real steering vectors and reconstructing the interference-plus-noise covariance matrix, is proposed in this paper. In addition, a wideband interference location algorithm (WBILA) based on partially calibrated arrays is proposed for CE-WABF to estimate wideband interference directions with reduced computational complexity and maintained accuracy. Simulation results demonstrate the advantages of proposed algorithm.