We discuss the use of multi-rate FIR filters in radio frequency (RF) transient spectroscopy as well as the implementation challenges these multi-rate filters face when used in this application to reduce the sampling rate (decimation) and raise the sampling rate (interpolation). On a Texas Instruments TMS320-C30 DSP processor, all implementation measurements given here were carried out.
An innovative adaptive line enhancer (ALE) structure is presented in this work. The adaptive filter's auto regressive-moving average (ARMA) structure is based on traditional Laguerre orthogonal functions. The orthogonal set's poles' frequencies and radii allow for tuning. Higher-order statistics are used to tune these terms in this contribution. Fourth-order cumulants' qualities are used to help with harmonic retrieval of the sinusoids embedded in the input signal.