Method for asynchronous impulse response measurement between separately clocked systems

摘要

A method for measuring acoustic impulse response of a Device Under Test (DUT) addresses sample rate variations by determining clock rate differences between the DUT and test system, and making adjustments to compensate for the different clock rates. An interrogation signal is generated with two “events” spaced a known number of samples apart, at the nominal sampling rate of the DUT. The interrogation signal is played through the DUT and recorded by a measurement system. The number of samples between the two “events” is measured in the sampled signal to determine the shift introduced by the different clock rates. The adjustment is then applied to either the original frequency response measurement signal by adjusting the sampling rate of a frequency response measurement signal to compensate for the different clock rates, or to the measured signal before averaging, to align the samples and prevent cancelling.

主权项

1. A method for avoiding cancelling in asynchronous measurement integration when a measurement system and a Device Under Test (DUT) have different clock rates, the method comprising:
generating a measurement data signal; providing the measurement data signal to the DUT; broadcasting the measurement data signal by the DUT; recording the broadcasted measurement data signal; integrating the recorded broadcasted measurement data signal to reduce noise; and before integrating the recorded broadcasted measurement data signal:
determining a difference in clock rates between the DUT and the measurement system; andcompensating for the difference in clock rates to avoid cancelling elements of the measurement data signal.