Eigenvalue-Driven Switching Framework for Two-Microphone Beamforming Under Multi-Interferer Conditions

This paper proposes a switching mode beamforming (SMVB) technique for a two-microphone array setup in a multi-source acoustic environment with one dominant target and two interferers. The proposed method adaptively switches between a robust minimum variance beamformer (RMVB) and a linearly constrained minimum variance (LCMV) beamformer based on the eigenvalue characteristics of the spatial covariance matrix. The eigenvalue distribution is used to infer the signal environment and select the appropriate beamforming strategy. Simulation results show that the proposed SMVB method outperforms conventional MVDR, RMVB, and LCMV beamformers in terms of interference suppression and target signal preservation, achieving improved output signal-to-interference-plus-noise ratio (SINR) and overall signal quality.