A novel unitary beamspace recursive least squares algorithm for fast adaptive beamforming

A novel unitary beamspace recursive least squares (UB-RLS) algorithm for fast adaptive beamforming is proposed in this paper. Firstly, a kind of random unitary transformation matrix is designed. Secondly, with these matrices, the feed signals are transformed into a low-dimensional space named the unitary beamspace (UB) and the computation complexity is accordingly decreased. Finally, the RLS algorithm is applied for the beamspace to realize adaptive beamforming and the whole processing is called the UB-RLS algorithm. As a result, a good signal of interest (SOI) extraction and interferences nulling performance is obtained. Simulation experiments show the merits of the proposed algorithm against the other two, the UB-LMS algorithm and the UB-MVDR algorithm.