Adaptive centre-frequency bandpass state-space digital filters and their l2-sensitivity analysis

This paper explores an adaptive centre-frequency bandpass state-space digital filter by expanding a sign algorithm into the gradient-based method. To this end, a simple method for deriving a bandpass state-space digital filter with tuneable centre-frequency from a prototype low-pass filter and low-pass/bandpass transformation is presented. An adaptive iterative algorithm is then developed by expanding a sign algorithm into the gradient-based method. Also, (Formula presented.) -sensitivities for the bandpass state-space digital filter with tuneable centre-frequency are analysed where an (Formula presented.) -sensitivity measure for evaluating the whole (Formula presented.) -sensitivities is deduced. Numerical experiments are included to demonstrate the validity and effectiveness of the adaptive centre-frequency bandpass state-space digital filter and the (Formula presented.) -sensitivity analysis. © 2024 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.