Problems associated with correlation-loop adaptive antennas employing hard limiting

Adaptive control methods based upon Wiener optimization theory have received a great deal of attention in recent years. However, their use is often restricted because the generation of a desired signal replica for a reference signal approach or the computation of an accurate look direction for a steering vector scheme is impossible for many existing systems. Important is the case in which the received desired signal is weaker than a known power level, as may be obtained with satellite communication and navigation systems. The present investigation is concerned with the sensitivity threshold for a discrete-time gradient descent algorithm. It is shown that the application of generalized limiting leads to problems associated with controlling the sensitivity threshold of power inversion arrays.