Advanced adaptive null steering concepts for GPS

The problem of protecting the GPS signal from interference is addressed. A number of null steering techniques for use in conjunction with antenna arrays are compared and contrasted in terms of efficient use of available degrees of freedom and computational complexity. The techniques investigated range from the simple well known power minimization approach to a subspace constrained power minimization method that makes use of DOA estimates provided by a 2D version of ESPRIT. Limitations of the methods are addressed as well.