Subband coding for fast controller implementation: The general case

This papers concerns a new wavelet packet based design methodology for efficient implementation of digital controllers that operate at very high sampling rates, but for reasons of compactness are fabricated on VLSI chips with limited surface area. The original problem was posed in [1]. We argue that this brings about a. fundamental tradeoff between sampling speed, accuracy due to signal quantization, and the chip area. Here we reconcile this tradeoff using multirate subband coding techniques, that exploit spectral disparities in the closed loop signals. A precise optimization problem was formulated in [1] but only a very restrictive solution given. In this paper we provide a more general solution to the problem.