Power-Aware Acoustic Processing

We investigated the tradeoffs between accuracy and battery-energy longevity of acoustic beamforming on disposable sensor nodes subject to varying key parameters: 1) number of microphones, 2) duration of sampling, 3) number of search angles, and 4) CPU clock speed. Beyond finding the most energy efficient implementation of the beamforming algorithm at a specified accuracy, we seek to enable application-level selection of accuracy based on the energy required to achieve this accuracy. Our energy measurements were taken on the HiDRA node, provided by Rockwell Science Center, employing a 133-MHz StrongARM processor. We compared the accuracy and energy of our time-domain beamformer to a Fourier-domain algorithm provided by the Army Research Laboratory (ARL). With statistically identical accuracy, we measured a 300x improvement in energy efficiency of the CPU relative to this baseline. We also present other algorithms under development that combine results from multiple nodes to provide mor...

• Type: Conference
• Year: 2003
• Where: IPSN
• Authors: Ronald Riley, Brian Schott, Joseph Czarnaski, Sohil Thakkar
• Keywords: Disposable Sensor Nodes, Energy Efficient Implementation, Identical Accuracy, IPSN 2003, Sensor Networks