Concurrent nulling and locations of multiple interferences in adaptive antenna arrays

An approach for concurrent nulling and location (CANAL) of multiple interferences impinging on an array antenna is presented. It is based on the principle of constructing the signal and the noise subspaces from the nulling weights which correspond to different steering directions. In this respect, the data snapshots and their estimated covariance matrix are not required. As in the MUSIC algorithm, the basis of the noise subspace is then used to form a spectrum in which the peak locations define the estimated angles of arrivals. Applebaum optimum weights are employed to delineate the properties of the proposed approach under the assumption of narrowband uncorrelated jamming sources, and providing that the number of steering directions exceeds the number of interferences. CANAL is presented for the general case of unknown noise power. The effect of the desired signal presence on the performance Is discussed