Gael Sapience, Tomoyuki Aono, Keisuke Higuchi and Takashi Ohira
Concurrent Criterion - and Algorithm - Diversity Blind Adaptive Beamforming of an Espar Antenna
Abstract:As an ESPAR (Electronically Steerable Parasitic Array Radiator) antenna has only a single-port output and parasitic elements surrounded with it, the simple configuration of it causes difficulties to apply the beamforming techniques of conventional adaptive array antennas. Several adaptive beamforming algorithms and criteria for ESPAR antennas have been proposed, though any combination of an algorithm and a criterion cannot overcome the trade-off problem between its fast convergence and its stability.
This paper presents a new blind adaptive beamforming scheme using concurrent algorithm and criterion diversity. Using algorithm diversity switching two algorithms (Steepest Gradient Algorithm and Sequential Random Algorithm), each of them using criterion diversity (M2M4 and MMMC), was found to provide faster blind beamforming with a more stable convergence.
Key words: ESPAR antenna, Blind adaptive beamforming, Steepest Gradient Algorithm, Sequential Random Algorithm, criterion diversity