HA adaptive array with a novel DOA estimation method applicable to TDMA communication systems

The applications of adaptive arrays based on the digital beamforming technique are widely considered for various communication systems. However, the adaptive control algorithm of the array antennas under TDMA systems requires particular consideration due to the fact that it employs intermittent signals. The Howells-Applebaum (1976) algorithm is one of the control algorithms of such adaptive arrays which utilize the direction of arrival (DOA) of the desired signal as a reference. It is expected that the HA algorithm is suitable for TDMA systems. This algorithm requires a DOA estimation system. Many DOA estimation algorithms have been presented conventionally. However, most of them require heavy computational load. Therefore, a simpler DOA estimation algorithm with less precision would be preferred. In this paper, first, we suggest a novel DOA estimation algorithm which takes advantage of the features of the TDMA signals. Second, the performance of the adaptive array with the HA algorithm for TDMA communication systems is evaluated through computer simulations and experiments.