US Patent 7970151 Hybrid beamforming

A system such as a speakerphone may include a processor, memory and an array of microphones. The processor may be configured (via program instructions stored in the memory) to perform automatic echo cancellation, self calibration and beam forming. In particular, the processor may receive input signals from the microphone array and operate on the input signals with a highly directed virtual beam which is a composite of two or more beams which are restricted to respective frequency ranges. The two or more beams may include beams of different kinds, e.g., superdirective beams and delay-and-sum beams.