FFT-based sonar array beamforming without corner turning

Abstract

The concept of ldquocorner turningrdquo has been, for many decades, at the heart of array beamforming via Fourier transforms. As widely reported in the open literature (both for sonars and radars), corner turning operations in the computational sequence Lttemporal Fourier transforms rarr data cube corner turning rarr spatial Fourier transformsGt, constitute a major obstacle to achieve high-performance and lower power dissipation (by reducing the number memory accesses). To date, leading industry providers still include explicit corner turning stages in their computational flow architectures for multidimensional array processing. The emergence of ultra-low power multicore processors opens unprecedented opportunities for implementing sophisticated signal processing algorithms faster and within a much lower energy budget. In that context, the primary innovation reported in this paper addresses the development of a computational scheme that avoids altogether the corner turning stage. We discuss its implementation on an IBM Cell multicore processor (Sony PS3) and provide preliminary timing results.