The frequency hop auto-tune module is interfaced between the acquisition
module and the rest of the post-processing modules, as shown below.
The frequency hop auto-tune module applies a configurable cyclic
frequency-hopping algorithm, such that on each measurement cycle a different sampling
frequency is used. Several preconfigured frequencies are implemented in turn during
consecutive measurement cycles.
Where ‘n’ frequencies are included in the cycle, an ‘n’-point median filter is applied to
the output data.
To perform auto-tuning, the signals measured on each sensor node are
recorded for each selected frequency. When one frequency shows greater variance than the
others, that frequency is removed from the measurement sequence and replaced with
another.
