System and method for improving time domain processed sensor signals

• US 20070046278A1
• Filed: 08/26/2005
• Published: 03/01/2007
• Est. Priority Date: 08/26/2005
• Status: Active Grant

• Current Assignee: Dolby Laboratories Licensing Corporation (Dolby Laboratories Incorporated)
• Original Assignee: Step Communications Corporation
• Inventors: Taenzer, Jon
• Granted Patent: US 7,436,188 B2
• Time in Patent Office: Days
• US Class Current: 324/76.770
• CPC Class Codes: G10K 11/341 Circuits therefor

Abstract

Noise discrimination in signals from a plurality of sensors is conducted by enhancing the phase difference in the signals such that off-axis pick-up is suppressed while on-axis pick-up is enhanced. Alternatively, attenuation/expansion are applied to the signals in a phase difference dependent manner, consistent with suppression of off-axis pick-up and on-axis enhancement. Nulls between sensitivity lobes are widened, effectively narrowing the sensitivity lobes and improving directionality and noise discrimination.

Claims

1. A method for time domain processing of signals from a plurality of sensors, the method comprising:

obtaining from the plurality of sensors a plurality of corresponding input signals each representable by an input vector having phase and magnitude components;

applying each of the input signals to each filter of a bank of bandpass frequency discrimination filters, such that each filter of said bank generates a plurality of filtered signals each of which corresponds to an input signal from a sensor;

generating, for each filter, an instantaneous phase angle difference value representative of the phase angle difference between the plurality of filtered signals from that filter;

enhancing the phase component of each filtered signal by an enhancement value which is a function of the instantaneous phase angle difference value associated with that filter to thereby obtain enhanced output signals; and

combining the enhanced output signals.

2. A method for time domain processing of signals from a plurality of sensors, the method comprising:

obtaining from the plurality of sensors a plurality of corresponding input signals;

applying the input signals to a bank of bandpass frequency discrimination filters to thereby obtain a filtered signal from each filter;

generating phase angle difference values from the filtered signals; and

attenuating each of the plurality of input signals by an attenuation factor which is a function of the phase angle difference values; and

combining the plurality of attenuated input signals.

3. The method of claim 2, wherein the attenuation factor is derived from a look-up table.