A signal subspace approach for interference locations in adaptive antenna arrays

Closed-loop adaptive weights corresponding to different mainbeam directions are shown to have sufficient information which can be processed by eigenstructure methods to yield the signal and noise subspaces without the need for an estimate of the covariance matrix. Since adaptive algorithms can be implemented using continuous-time adaptive loops, locating the interferences using only the adaptive weights provides an option to avoid sampling and, in turn, eliminates the need for the data snap shots. This option is important to consider when operating at high frequency and with large signal bandwidth. The combined adaptive-eigenstructure approach is presented using exact statistics and the assumption of narrow-band uncorrelated jamming sources.<>