Implementation of sub-aperture sampling into adaptive beamforming using the conjugate gradient algorithm

The conjugate gradient algorithm, as presented by Boray and Srinath (see IEEE Transaction on Circuits and Systems, vol.39, no.1, p.1-10, 1992) has been shown to be effective when applied to adaptive beamforming. However, data over several snapshots must be suitably averaged in order to generate the required conjugate directions for rapid covergence of the beamformer. In this paper, sub-aperture sampling is used as an alternative to temporal smoothing as a means of eliminating the requirement to store several snapshots. Simulation results are presented to demonstrate the performance of the technique.