4 Optimum Beamforming for Wideband Non-stationary Signals

Abstract

Array processing techniques strive for extraction of maximum information from a propagating wave field using groups of sensors, which are located at distinct spatial locations. The sensors transduce propagating waves into signals describing both a finite spatial and a temporal aperture. In accordance with temporal sampling which leads to the discrete time domain, spatial sampling by sensor arrays forms the discrete space domain. Thus, with sensor arrays, signal processing operates in a multi-dim ensional space-time domain. The processor which combines temporal and spatial filtering using sensor arrays is called a beamformer. Many properties and techniques which are known from temporal FIR filtering directly translate t o beamforming based on finite spatial apertures¹.