Multiple beam broadband beamforming: filter design and real-time implementation

In this paper the design and implementation of a truly broadband beamformer is described. Using only a limited number of microphones a beamformer has been developed with a reasonably homogeneous beampattern over the entire speech bandwidth. The solution is obtained as the result of a filter-and-sum operation. Beams are steered towards different listening-directions and for each direction a set of spatio-temporal filters had to be designed. All beams operate in parallel and a beam-selection procedure picks out the beam with the most prominent speech signal. The complete system has been implemented in real-time using 1 MOTOROLA-56001 and 4 TMS-320C40 processors.