I have completed my Ph.D. studies on July 31, 1998. In the thesis you may find the fundamental connection between the problems of optimal subband coding and the principal component filter banks. This connection simplifies most of the optimality results in the case of uniform orthonormal filter banks, and leads to the new optimality results in the case of nonuniform filter banks.
Wavelets belong to the class of nonuniform filter banks.
At iBiquity Digital Corporation , I am working in the area of digital communications utilizing digital signal processing algorithms and hardware.