DSP Implementation of a Distributed Acoustical Beamformer on a Wireless Sensor Platform

In this paper, we consider the use of Compaq iPAQ 3760s, equipped with a built-in microphone and an external wireless card, for acoustic acquisition and processing to perform a distributed acoustical beamforming. Time synchronization among the microphones is achieved by the ReferenceBroadcast Synchronization method. Two beamforming algorithms, based on the time difference of arrivals (TDOAs) among the microphones followed by a least-squares estimation, and the maximum-likelihood (ML) parameter estimation method, are used to perform source detection, enhancement, localization, delay-steered beamforming, and direction-of-arrival estimation. Experimental beamforming results using the iPAQs and the wireless network are reported. 1