Frequency domain noise cancellation with a desired null based acoustic devices, systems, and methods

摘要

Frequency domain signal extraction methods and apparatuses include receiving a reference signal, which contains mostly undesired audio and is substantially void of desired audio. The reference signal is decomposed into at least two reference frequency components. Filtering the at least two reference frequency components with at least two adaptive filters to form at least two filtered reference frequency components. The filtered reference frequency components are recombined in an IFFT component, to produce a filtered reference signal. A delayed signal is input to an adder. The delayed signal contains desired audio and undesired audio. The filtered reference signal is subtracted from the delayed signal to form an output signal containing desired audio. The output signal is decomposed into at least two frequency components. The filtering is adapted with the at least two frequency components. The filtering is inhibited intermittently with the at least two adaptive filters to prevent cancellation of the desired audio. In some implementations, frequency sub-bands are employed. In some implementations, an acoustic element with a Cardioid beam pattern is used to acquire the reference signal.

主权项

1. A system for signal extraction in a frequency domain, comprising:
a reference FFT component, the reference FFT component receives a first signal which contains mostly undesired audio, substantially void of desired audio, the reference FFT component decomposes the first signal into at least two reference frequency components; a primary FFT component, the primary FFT component receives a second signal which contains delayed desired audio and undesired audio, the primary FFT component decomposes the second signal into at least two primary frequency components; at least two adaptive filters, each of the at least two reference frequency components is filtered by a corresponding adaptive filter of the at least two adaptive filters to provide filtered reference frequency components; at least two adders, each of the at least two primary frequency components is input into a corresponding adder of the at least two adders, wherein a corresponding filtered reference frequency component is subtracted from a corresponding primary frequency component in the corresponding adder, an output from the corresponding adder is fed back to the corresponding adaptive filter to provide information that is used during the filtering at the corresponding adaptive filter; an inhibit component, the inhibit component includes inhibit logic and uses inputs from the at least two primary frequency components and the at least two reference frequency components to control the at least two adaptive filters; and an IFFT component, each output from the at least two adders is input into the IFFT component and recombined to form a recombined signal, the recombined signal is output as desired audio.