Optimum noise reduction of conjugate quadrature filter bank

This paper considers design of L-infinity- and L-2-optimal CQF bank which reduces the influence of the additive noise on the output in an optimal fashion. To deal with this design problem, we first give a glance at the characterization of solutions set of the so-called Smith-Barnwell equation, whereby we derive the explicit expression of all optimum solutions for the deterministic-but-unknown disturbance. We also treat the stochastic noise case, and show that the average power of the output due to the channel noise cannot be controlled by the choice of filters. Numerical examples are given to illustrate the results developed in the paper. (C) 2000 Elsevier Science B.V. All rights reserved.