Method and apparatus for accommodating device and/or signal mismatch in a sensor array
View Patent ↗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.
1. A method for accommodating device and/or signal mismatch in a sensor array system having a plurality of sensors generating a plurality of input signals including first and second sensors generating first and second input signals, the plurality of input signals being representable, at at least one frequency, by input signal vectors each having a phase component and a magnitude component, including first and second input signal vectors, the method comprising:
generating the first and second input signals from the first and second sensors;
processing the first and second input signals, said processing including, at the at least one frequency, using the magnitudes of the first and second input vectors to obtain corresponding first and second magnitude matched vectors, the first and second magnitude matched vectors:
A) each having a magnitude that is substantially equal to a mathematical mean of the magnitudes of two or more of said input signal vectors;
B) each having a phase that is substantially equal to the phase of a respective one of the first and second input signal vectors; and
C) having a phase relationship that is representable as a vector phase difference;
enhancing the vector phase difference by modifying the phase of at least one of the first and second magnitude matches vectors, thereby generating at least one modified magnitude matched vectors, said enhancing being a function of the vector phase difference of the first and second magnitude matched vectors, and including increasing or decreasing the vector phase difference in a frequency-dependent manner; and
generating an output signal that is a function of the modified magnitude matched vector.
2. The method of claim 1 , wherein increasing the vector phase difference is effected using an expansion function.
3. A method for accommodating device and/or signal mismatch in a sensor array system having a plurality of sensors generating a plurality of input signals including first and second sensors generating first and second input signals, the plurality of input signals representable, at at least one frequency, by input signal vectors each having a phase component and a magnitude component, including first and second input signal vectors, the method comprising:
generating the first and second input signals from the first and second sensors;
processing the first and second input signals, said processing including, at the at least one frequency, using the magnitudes of the first and second input vectors to obtain corresponding first and second magnitude matched vectors, the first and second magnitude matched vectors:
A) each having a magnitude that is substantially equal to a mathematical mean of the magnitudes of two or more of said input signal vectors;
B) each having a phase that is substantially equal to the phase of a respective one of the first and second input vectors; and,
C) having a phase relationship that is representable as a vector phase difference; enhancing the vector phase difference of the first and second magnitude matched vectors by modification of the phase of at least one of the first and second magnitude matched vectors, thereby creating at least one modified magnitude matched vector; and,
generating an output signal with a magnitude that is a function of the modified magnitude matched vector.
4. A method for accommodating device and/or signal mismatch in a sensor array system having an array system sensitivity beam pattern and a plurality of sensors generating a plurality of input signals including first and second sensors generating first and second input signals representable, at at least one frequency, by input vectors each having a phase component and a magnitude component, including first and second input vectors, the method comprising:
generating the first and second input signals from the first and second sensors
processing the first and second input signals, said processing including, at the at least one frequency, using the magnitudes of first and second input vectors to obtain corresponding first and second magnitude matched vectors, the first and second magnitude matched vectors having:
A) a magnitude of each equal to a mathematical mean of the magnitudes of two or more input signal vectors;
B) a phase equal to the respective phase of the first and second input vectors; and
C) a phase relationship between the first and second magnitude matched vectors representable as a vector phase difference; enhancing the vector phase difference of the first and second magnitude matched vectors by modification of the phase of at least one of the first and second magnitude matched vectors, thereby creating at least one modified magnitude matched vector, with such enhancing being a function of the vector phase difference of the first magnitude matched vector and the second magnitude matched vector, and a function of an adjustable sharpness parameter for adjusting shape of the array system sensitivity beam pattern; and
generating an output signal whose magnitude is a function of the modified magnitude matched vector.
5. The method of claim 4 , wherein the adjustable sharpness parameter is applied multiplicatively.