A SIMPLE, FAST ADAPTIVE ALGORITHM FOR BROAD-BAND NULL STEERING ARRAYS

A simple algorithm is presented and investigated for adaptively steering the broad-band null in a two-element power inversion array which employs a tapped delay line filter as the processing element. Basically, by performing a simple signal trasformation, the algorithm constrains some of the filter weights so that a variable lenght delay line is being approximated in the maximally flat sense. By using the least mean square (LMS) algorithm to adjust the weights controlling the length and gain of the delay line, a broad-band null is then adaptively formed to track and reject the broad-band jammer. As studied analytically and by using simulation results, the convergence begavior of the algorithm is fast and depends only on the tolerable level of misadjustment noise. Yet, its implementation complexity is comparable to that of using the LMS algorithm directly.