On the correction of linear time-varying systems by means of time-varying FIR filters

In this paper, methods for the design of time-varying finite impulse response (FIR) filters which facilitate the correction of time-varying systems are presented. The two possible cases where an undesired time-varying system requires either preprocessing or postprocessing are considered. In particular, we show how the methods from [1], [2] can be used for the precorrection of time-varying systems. Though, these presented methods allow for the correction of systems exhibiting periodically recurring time-varying behavior, these techniques can also be applied to the non-periodic case. A mixed-signal application is presented to verify the viability of the presented precorrection case. To this end, a system model for non-uniform zero-order-hold (ZOH) signals in a digital-to-analog converter (DAC) is introduced. Finally, numerical simulations are performed to illustrate the increase of performance when the proposed precorrection is employed.