Adaptive beamforming for noise reduction

Claim 1

An adaptive noise cancelling apparatus comprising: A. a receiving array including a plurality of spatially disposed sensors, each for receiving an input signal, comprising at least one of a component of target signal and a component of a noise signal, and for generating a signal representative of said input signal, B. primary signal means coupled with said receiving array for generating a primary signal representative of a first selected combination of one or more of said input-representative signals, C. reference signal means coupled with said receiving array for producing one or more signals representative of a second selected combination of said input-representative signals, D. adaptive filter means coupled to said reference signal means for generating a noise-approximating signal as a function of one or more noise component-representative signals produced during a selected period of time, E. output means coupled to said primary signal means and to said adaptive filter means for subtracting said noise-approximating signal from said primary signal to generate an output signal representative of said target signal, F. adaptation controlling means coupled with said receiving array for generating an SNR signal representative of a relative strength of said target signal to said noise signal, said adaptation controlling means including means coupled with said output means for generating an adaptation signal as a function of said output signal on said SNR signal, and G. modification means coupled with said adaptation controlling means and with said adaptive filter means for responding to said adaptation signal to selectively modify said noise-approximating signal to minimize a difference between it and one or more selected noise components of said primary signal.