Digital signal-processing structure and methodology featuring engine-instantiated, wave-digital-filter componentry, and fabrication thereof

• US 20050050126A1
• Filed: 08/28/2003
• Published: 03/03/2005
• Est. Priority Date: 08/28/2003
• Status: Active Grant

• Current Assignee: Acoustic Processing Technology Incorporated
• Original Assignee: Acoustic Processing Technology Incorporated
• Inventors: Sidman, Steven B., Curtis, Thomas E.
• Granted Patent: US 7,363,334 B2
• Time in Patent Office: Days
• US Class Current: 708/300
• CPC Class Codes: H03H 17/0201 Wave digital filters

Abstract

Digital signal-processing structure and methodology which feature a time-slice-based digital fabricating engine, and software operating structure operatively associated with that engine structured to operate the engine in a time-slice-based fabrication mode wherein the engine, in a time-differentiated and instantiating manner, functions to fabricate a time-succession of individual, composite wave digital filters. Each of these filters takes the form of (1) a concatenated assembly including one to a plurality of upstream, early-stage, decimate-by-two, signal-processing agencies connected in a cascade series arrangement, with each such agency possessing a first transfer function having a first transition bandwidth, and (2) a single, downstream, later-stage, decimate-by-two, signal-processing agency which possesses a second transfer function having a transition bandwidth which is less than the mentioned first transition bandwidth.

Claims

1. Digital signal-processing structure comprising

a Type-II wave digital filter (WDF) agency taking the form of a concatenated series of four 5^th-Order elliptical sections, including three, upstream input sections which are non-decimating sections, and a single, downstream output section which is a decimating section, said agency having input and output sides operatively coupled to said input and output sections, respectively, and

signal input and output structures operatively connected, respectively, to said input and output sides.

2. The structure of claim 1 which further includes a time-slice-based, digital fabricating engine, and said Type-II agency is an instantiated fabrication product of said engine.

3. The structure of claim 1, wherein each of said sections is structurally characterized, at least in part, by fixed-value Gamma multiplication factors.

4. The structure of claim 2, wherein each of said sections is structurally characterized, at least in part, by fixed-value Gamma multiplication factors.

5. The structure of claim 1, wherein said WDF agency is, as a whole, effectively a decimate-by-two agency.

6. The structure of claim 2, wherein said WDF agency is, as a whole, effectively a decimate-by-two agency.

7. The structure of claim 1, wherein each of said sections is alike in the sense of being characterized by a pair of parallel branches, each of which branches is characterized by a single, fixed-value Gamma multiplication factor.

8. The structure of claim 7, wherein, with respect to the two branches in a section, the characterizing Gamma multiplication factors are different.

9. The structure of claim 1, wherein each of said non-decimating sections is characterized by a pair of parallel branches which differ, at least in part, by the presence in one only of these branches of a delay element.

10. The structure of claim 7, wherein said branches in said non-decimating sections differ, at least in part, by the presence in one only of these branches of a delay element.

11. The structure of claim 10, wherein, with respect to the two branches in each said non-decimating section, the characterizing Gamma multiplication factors are different.

12. The structure of claim 1, wherein said decimating and non-decimating sections differ, at least in part, by the presence in said decimating sections of two selectable, mutually exclusive through-paths.

13. The structure of claim 1, wherein said signal input structure includes at least one Type-I wave digital filter (WDF) agency taking the form of a concatenated series of two 5^th-Order elliptical sections, the first of which is an upstream, non-decimating section, and the second of which is a downstream, decimating section, said at least one Type-I agency and said Type-II agency collectively forming a composite WDF.

14. The structure of claim 13 which further includes a time-slice-based digital fabricating engine, and said Type-I and Type-II agencies are instantiated fabrication products of said engine

15. The structure of claim 14 which is disposed in a setting, wherein (a) said Type-I agency is connected to the output side of a plural-channel signal feed structure by way of which, on a per channel basis, signals to be processed are fed initially to said Type-I agency, and (b) the performance of said engine is such that, for each signal fed for processing from each channel, the engine fabricates a time-sliced and phased, associated composite WDF.

16. Digital signal-processing structure comprising,

a time-slice-based digital fabricating engine, and

software operating structure operatively associated with said engine, structured to operate the engine in a time-slice-based fabrication mode wherein the engine, in a time-differentiated and instantiating manner, functions to fabricate a time-succession of individual, composite wave digital filters.

17. The signal-processing structure of claim 16, wherein each of said fabricated, composite wave digital filters takes the form of a cascade series arrangement including an upstream, Type-I, decimate-by-two, wave digital filter (WDF) agency having an output side connected to an input side in a downstream, Type II, decimate-by-two, WDF agency

18. The signal-processing structure of claim 16, wherein each of said fabricated, composite wave digital filters takes the form of a cascade series arrangement including an upstream plurality of cascade-series-connected, Type-I, decimate-by-two, wave digital filter (WDF) agencies collectively having an output region, and a downstream, Type-II decimate-by-two, WDF agency having an input side operatively connected to said output region.

19. Digital signal-processing structure comprising

a plurality of early-stage, decimate-by-two, signal-processing agencies connected in a cascade series arrangement, said agencies each being associated with a first transfer function having a first transition bandwidth, and each having an output, and

a later-stage, decimate-by-two, signal-processing agency selectively coupleable to different ones of said outputs, said later-stage agency being associated with a second transfer function having a transition bandwidth which is less than said first transition bandwidth.

20. The structure of claim 19, wherein said second transition bandwidth is steeper than said first transition bandwidth.

21. The structure of claim 19, wherein said later-stage agency takes the form of Type-II, decimate-by-two, wave digital filter (WDF) agency.

22. The structure of claim 21, wherein each of said plurality of early-stage agencies takes the form of a Type-I, decimate-by-two, WDF agency.

23. Digital signal-processing structure comprising

a time-slice-based fabricating engine operable over an extent of time, and during a defined span within such a time extent, to fabricate/realize, as an integral structural and functional portion of itself,

a pair of signal input and output zones, and

interposed said zones, at least one time-slice-instantiated wave digital filter assembly (WDFA) which is structured to intake and process a signal presented to said input zone, and to furnish to said output zone a WDFA-processed version of such an in-taken signal.

24. The structure of claim 23, wherein said engine, over and within such a time extent, is operable to fabricate/realize a plurality of time-successive, differentiated WFDAs.

25. The structure of claim 23, wherein said WDFA comprises a Type-I wave digital filter (WDF) agency.

26. The structure of claim 23, wherein said WDFA comprises a Type-II wave digital filter (WDF) agency.

27. The structure of claim 23, wherein said WDFA comprises a composite Type-I and Type-II wave digital filter (WDF) agency arrangement in which the Type-I agency is disposed upstream relative to the Type-II agency.

28. A digital signal-processing method comprising

providing a time-slice-based digital fabricating engine,

utilizing that engine, instantiating in time-spaced phases wave digital filter (WDF) structure, and

during said instantiating, feeding a signal through, and processing that signal by, such phase-instantiated WDF structure.

29. The signal-processing method of claim 28, wherein said instantiating includes phased fabricating of a Type-II WDF agency which includes an effective concatenation of three, non-decimating, 5^th-Order elliptical sections followed by a single, decimating, 5^th-Order elliptical section.

30. The signal-processing method of claim 28, wherein said instantiating includes phased fabricating of a Type-I WDF agency which includes an effective concatenation of a single, non-decimating, 5^th-Order elliptical section followed by a single, decimating, 5^th-Order elliptical section.

31. The signal-processing method of claim 28, wherein said instantiating, from the point of view of a signal being processed in accordance with the method, includes, first, phased fabricating of a Type-I WDF agency which includes an effective concatenation of a single, non-decimating, 5^th-Order elliptical section followed by a single, decimating, 5^th-Order elliptical section, and second, phased fabricating of a Type-II WDF agency which includes an effective concatenation of three, non-decimating, 5^th-Order elliptical sections followed by a single, decimating, 5^th-Order elliptical section.

32. Signal-processing structure comprising

a computer-based, electronic engine designed to fabricate, in an instantiated manner, different, time-successive, 5^th-Order elliptical wave digital filter (WDF) sections through which a signal to be processed passes, each said section including a pair of branches possessing assigned, Gamma-factor multipliers, with one branch in each said pair optionally including a delay element, and

control code structure operatively and drivingly connected to said engine, constructed to operate the engine in a fashion which includes instructing the engine, with regard to the fabrication of each said WDF section, and with further regard to the formation of each said branch in that section, what value Gamma factors to define for, and to assign to, the multipliers in the section, and whether or not to include a delay element in said one branch in the section.

33. A method associated with digital signal processing for fabricating, by instantiation, a defined branch of a 5^th-Order, wave-digital-filter, elliptical section, said method comprising

associating a digital fabricating engine with selected control code which is employable to operate the engine in a time-sliced, instantiation-fabrication mode of operation that is effective to cause the engine to produce such a section branch, and

following said associating, and the utilizing the selected, associated control code, operating the engine under control of the code to instantiate/create the defined branch.