New Recursive Adaptive Beamforming Algorithms for Uniform Concentric Spherical Arrays with Frequency Invariant Characteristics

This paper proposes a new recursive adaptive beamforming algorithms for uniform concentric spherical array (UCSA) having nearly frequency invariant (FI) characteristics. New recursive adaptive beamforming algorithms based on the least mean square (LMS) algorithm and the generalized sidelobe canceller (GSC) structure are proposed. Simulation results show that the proposed adaptive FI-UCSA beamformer requires much fewer variable taps than the conventional UCSA for the same steady-state performance, while offering much faster convergence speed. Simulation results also show that the proposed FI-UCSA has uniform resolutions around both the elevation and azimuth angles.