On Sequences with Good Correlation Properties: A New Perspective

The so-called merit factor approach (MFA) to radar binary sequence design has led to several theoretical contributions in fairly diverse research areas including information theory, computer science, combinatorial optimization, and analytical number theory. However, the pragmatic motivation of this approach is shown here to be questionable. Specifically, the MFA -which basically aims at minimizing the clutter effect on radar performance -implicitly assumes the use of a least-squares (LS) receiver that is optimal only when there is no clutter. This apparent inconsistency in the problem formulation can be eliminated by using a more general optimal instrumental-variables (IV) receiver in lieu of the LS receiver. The IV receiver proposed here is shown to reject clutter much more efficiently than the LS receiver. Additionally, the binary sequence design problem associated with the IV receiver is shown to have an interesting form that is likely to attract the attention of the readers previously interested in the MFA.