Wideband Beamspace Processing Using Orthogonal Modal Beamformers

We introduce a novel beamspace processing structure that can be used for narrowband or wideband sources located either in nearfield or farfield of a sensor array. Main features of the new structure are: (i) a single parameter is used to steer the processor to any desired radial distance; (ii) a set of fixed frequency invariant orthogonal beamformers are used to transform array data into beamspace; and (iii) consequently, only a single set of beamspace weights are needed to process wideband beamspace data. The utility of the novel structure is illustrated by applications in interference cancellation and direction/range estimation.