Abstract
Covariance Matrix Tapers (CMT) widen the beampattern notches of an adaptive beamformer to improve the suppression of moving interferers. If the bearing rate of a moving interferer is known, then the ideal notch width can be found. In practice, the bearing rate is an unknown and often time-varying parameter. To address this challenge, we previously proposed a universal CMT beamformer that blends the array weights across a set of fixed notch width CMT beamformers. This universal beamformer suppressed moving interferers well in simulations. This talk presents experimental results from a 31 microphone uniform line array with a 750 Hz moving interferer at a range of 10 meters. We evaluated two scenarios with the interferer moving at different speeds. In the first experiment, the interferer moved 40deg in 814 snapshots (approximately 0.05 deg/snapshot) while in the second experiment, the interferer moved 30° in the same time. Both experiments had 25 dB INR at a single sensor. The experiments confirm that the universal CMT beamformer adapts to the best notch width for moving interferers. The results also show that the universal beamformer matches or exceeds the performance of the best fixed notch width CMT beamformer. [Work supported by ONR 321US.]