Minimal complexity blind interference mitigation via Non-Eigen Decomposition beamforming

This paper evaluates the ultra low complexity non-eigen decomposition (NED) algorithm for adaptive interference mitigation. Current blind beamforming algorithms require computational complexity too high for many target applications. NED does not rely on the eignenvalues and eigenvectors used by conventional algorithms and requires significantly less computations, with a total computational load of O(4M-4) per snapshot for a system with M receiving antennas by approximating the cross correlation vector of the received signals in the reference and other antennas. The weight vector is a function of only the cross correlation vector and initial guess and does not require a step size. This technique requires neither a training sequence nor an assumption of incoherency among impinging signals. Simulations show that NED achieves comparable performance as other blind beamforming algorithms in nulling interference sources The smart antenna structure for NED implementation in spread spectrum and OFDM system will also be discussed.