Abstract
The authors present a method for determining the effects of envelope modulated interference on an LMS (least mean square) adaptive array. The interference is assumed to have periodic envelope modulation with a bandwidth small compared to the carrier frequency. For such interference, the method allows one to calculate the periodic steady-state behavior of the array weights and the resulting array performance. As an example, computed are the effects of an ordinary amplitude modulated (AM) interference signal on the array. It is shown that such interference causes the array to modulate the desired signal envelope but not its phase. With a DPSK desired signal, AM interference is found to have about the same effect on bit error probability as CW interference. (Author)