US 2014/0177869 A1 · ADAPTIVE PHASE DISCOVERY

Abstract

In an adaptive phase discovery system a first audio signal is received via a first microphone and a second signal is received via a second microphone. Corresponding audio frames of the first and second signals are each transformed into the frequency domain and a plurality of frequency sub-bands are generated. A phase is determined for each frequency sub-band in each signal. Instantaneous phase differences are determined between the signals at each of the frequency sub-bands. Lower frequency instantaneous phase differences are filtered over time to determine current phase differences at lower frequencies. When SNR is high in lower frequency sub-bands, lower frequency sub-band phase differences are tracked to the higher frequency sub-bands. The tracked higher frequency phase differences are filtered over time to determine phase differences for the current frame. The phase differences may be used to rotate phases in each sub-band and sum signals and/or to reject off-axis signals.

Claims27

Dependent claims

A method for determining phase difference, the method comprising:

determining a phase of a first signal and a phase of a second signal;
determining an instantaneous phase difference between said first signal and said second signal based on said phase of said first signal and said phase of said second signal;
filtering said instantaneous phase difference over time for frequencies below a specified frequency threshold;
and
estimating a phase difference between said first signal and said second signal at one or more frequencies above said specified frequency threshold, based on said filtered phase difference of frequencies below said specified frequency threshold.

2 more elements

Dependencies are inferred from the claim text.

Adaptive phase discovery

Life of this patent

Adaptive phase discovery

Life of this patent

Abstract

Claims27