Eigen Domain Interference Rejection Combining Algorithm for MIMO Systems

In this letter, we investigate an eigen domain interference rejection combining (E-IRC) algorithm for multiple-input-multiple-output (MIMO) systems suffering from narrowband interference (NBI). The received signals are transformed into the eigen domain, which is obtained by eigenvalue decomposition of the time domain autocorrelation matrix of the NBI, and the interference is rejected in the eigen domain via multiple antennas. V-BLAST and Alamouti schemes are considered in this letter. For the V-BLAST scheme, the E-IRC algorithm is an extension of the one for SIMO system. For the Alamouti scheme, we redesign the transmission codeword, which can preserve the orthogonality in the eigen domain, and propose an NBI rejection algorithm based on the spatial whitening filter.