jrn@me.utoronto.ca ("John R. Nickerson") (10/05/89)
>jj@alice.UUCP (alice!jj) writes: >The original paper on the subject (as far as I know) >from the original patent holders, is Esteban and Galand, "Application >of Quadrature Mirror Filters to Split Band Voice Coding >Schemes", proc ASSP 1977, pp 191-195. This work opened the door for a plethora of papers on split band vocoders. I was involved with algorithm development for these devices (for a small now defunct company) although now I am now interested in QMF's for musical processing. >For an explanatory reference, see Jayant and Noll, >"Digital Coding of Waveforms", Pages 496 to 499. Lovely book, wish I could afford it. >For an ICASSP-level discussion, see J D. Johnston, >"A Filter Family Designed for Use in Quadrature Mirror >Filter Banks", Proc. ICASSP 1980, pp291-294. This paper >also has some coefficients in case you don't want to design >your own. I tried designing my own and found it was a real bear since the Method described by J.D. Johnston is open loop ( ie. operator intervention) with the Hooke and Jeaves Algorithm which I obtained from Huester, J.L., Mize, J.H., "Optimization Techniques with Fortran", McGraw-Hill, N.Y. 1973. Some day I would like to try this again with a more modern optimization algorithm. >R. V. Cox has done an 'n' band (n .ge. 2) version, >in ASSP Transactions, Vol ASSP-34 #5, Oct 86, pp 1090-1096, >"The Design of Uniformly and Non-uniformly spaced Pseudo-Quadrature >Mirror Filters". I took a look through a collection of papers on the subject and found a couple of others that may help especialy in the generation of the coefficients: Rothweiller, J.H., "Polyphase Quadrature Filters. A New Subband Coding Technique", Proc. 1983 IEEE Conf. on ASSP pp. 1280-1283. Nussbaumer, H.J., Vetterli, M., "Pseudo Quadrature Mirror Filters", in Digital Signal Processing-84, edited by V. Cappellini and A.G. Constantinides, Elsevier Science Publishers B.V., 1986 pp. 8-11. Hope this helps, J.R. -- Disclaimer: "I'm gonna hit the highway like a battering ram on a Silver Black Phantom Bike" ... Bat out of Hell John R. Nickerson, University of Toronto (416) 978-7020 UUNET:...uunet!utai!me!jrn USENET: jrn@me.utoronto.ca BITNET: jrn@ME.UTORONTO