Hi Guys, I have a question for any of you who have studied Hogenauer's original paper on cascaded integrator-comb (CIC) digital filters. E. Hogenauer, E. "An Economical Class of Digital Filters For Decimation and Interpolation," IEEE Trans. Acoust. Speech and Signal Proc., Vol. ASSP-29, April 1981, pp. 155-162. I'm having a disagreement with the a signal processing engineer. One of us thinks that Hogenauer's 'Bmax' variable in Hogenauer's Equation (11) represents the number of bits in a binary word. The other one of us thinks that the 'Bmax' variable represents the index of the most significant bit in a binary word. To illustrate our difference of opinions: in one interpretation, for an 8-bit binary word, Bmax = 8. In the other interpretation Bmax = 7. Do any of you have an opinion on what is the definition of Hogenauer's 'Bmax' variable? This is not just a friendly disagreement. We'd like to know the true definition of 'Bmax' in preparation for an upcoming DSP publication. Thanks for your help. [-Rick-]
A CIC decimation filter question.
Started by ●February 10, 2012
Reply by ●February 10, 20122012-02-10
On Feb 10, 12:59�pm, Rick Lyons <R.Lyons@_BOGUS_ieee.org> wrote:> Hi Guys, > � I have a question for any of you who have studied > Hogenauer's original paper on cascaded integrator-comb > (CIC) digital filters. > > � � E. Hogenauer, E. "An Economical Class of Digital > � � Filters For Decimation and Interpolation," IEEE > � � Trans. Acoust. Speech and Signal Proc., Vol. ASSP-29, > � � April 1981, pp. 155-162. > > I'm having a disagreement with the a signal processing > engineer. �One of us thinks that Hogenauer's 'Bmax' > variable in Hogenauer's Equation (11) represents the > number of bits in a binary word. �The other one of us > thinks that the 'Bmax' variable represents the index > of the most significant bit in a binary word. > > To illustrate our difference of opinions: in one > interpretation, for an 8-bit binary word, Bmax = 8. > In the other interpretation Bmax = 7. > > Do any of you have an opinion on what is the definition > of Hogenauer's 'Bmax' variable? > > This is not just a friendly disagreement. We'd like > to know the true definition of 'Bmax' in preparation > for an upcoming DSP publication. > > Thanks for your help. > [-Rick-]Can you reveal to us, before hand, the weighting function or fuzzy logic algorithm you will use to determine which of you are correct based upon the inputs from comp.dsp :-)
Reply by ●February 10, 20122012-02-10
On 2/10/12 12:59 PM, Rick Lyons wrote:> > I have a question for any of you who have studied > Hogenauer's original paper on cascaded integrator-comb > (CIC) digital filters. > > E. Hogenauer, E. "An Economical Class of Digital > Filters For Decimation and Interpolation," IEEE > Trans. Acoust. Speech and Signal Proc., Vol. ASSP-29, > April 1981, pp. 155-162. >i wouldn't mind being a Johnny-come-lately and read the paper, but i don't have it and i am not even sure i can get it if i roll over to the local university. if it's online-only, students and faculty with accounts will be able to get it free, but i won't. if it's on paper (doubtful 3 decades old) i can read it at the UVM library. but, being IEEE Transaction, it might be too obtuse to read anyway. if you got it on pdf, would you mind sneaking me a copy? -- r b-j rbj@audioimagination.com "Imagination is more important than knowledge."
Reply by ●February 10, 20122012-02-10
Rick Lyons wrote:> > Hi Guys, > I have a question for any of you who have studied > Hogenauer's original paper on cascaded integrator-comb > (CIC) digital filters. > > E. Hogenauer, E. "An Economical Class of Digital > Filters For Decimation and Interpolation," IEEE > Trans. Acoust. Speech and Signal Proc., Vol. ASSP-29, > April 1981, pp. 155-162. > > I'm having a disagreement with the a signal processing > engineer. One of us thinks that Hogenauer's 'Bmax' > variable in Hogenauer's Equation (11) represents the > number of bits in a binary word. The other one of us > thinks that the 'Bmax' variable represents the index > of the most significant bit in a binary word. > > To illustrate our difference of opinions: in one > interpretation, for an 8-bit binary word, Bmax = 8. > In the other interpretation Bmax = 7. > > Do any of you have an opinion on what is the definition > of Hogenauer's 'Bmax' variable?I haven't read the paper yet; I just printed it and I taking it with me as I'm going out to eat. My first impression based on quotes like these "If the number of bits in the input data stream is Bin, then the register growth can be used to calculate Bmax, the most significant bit at the filter output." "Not only is Bmax the MSB at the filter output, but it is also the MSB for all stages of the filter." He also mentions just after equation 11 that the LSB is 0. is that Bmax refers to the MSB which I nearly always take as zero based. My preliminary vote is Bmax=7 in your hypothetical.> This is not just a friendly disagreement. We'd like > to know the true definition of 'Bmax' in preparation > for an upcoming DSP publication.Sliderules at ten paces :)
Reply by ●February 11, 20122012-02-11
On Fri, 10 Feb 2012 10:06:32 -0800 (PST), brent <bulegoge@columbus.rr.com> wrote:>On Feb 10, 12:59�pm, Rick Lyons <R.Lyons@_BOGUS_ieee.org> wrote: >> Hi Guys, >> � I have a question for any of you who have studied >> Hogenauer's original paper on cascaded integrator-comb >> (CIC) digital filters.[Snipped by Lyons]> >Can you reveal to us, before hand, the weighting function or fuzzy >logic algorithm you will use to determine which of you are correct >based upon the inputs from comp.dsp :-)Hi Brent, Ha ha. Nothing that complicated. I'll just compare the number of votes for definition# 1 versus definition#2. See Ya', [-Rick-]
Reply by ●February 11, 20122012-02-11
On Fri, 10 Feb 2012 13:18:46 -0500, robert bristow-johnson <rbj@audioimagination.com> wrote:>On 2/10/12 12:59 PM, Rick Lyons wrote: >> >> I have a question for any of you who have studied >> Hogenauer's original paper on cascaded integrator-comb >> (CIC) digital filters. >> >> E. Hogenauer, E. "An Economical Class of Digital >> Filters For Decimation and Interpolation," IEEE >> Trans. Acoust. Speech and Signal Proc., Vol. ASSP-29, >> April 1981, pp. 155-162. >> > >i wouldn't mind being a Johnny-come-lately and read the paper, but i >don't have it and i am not even sure i can get it if i roll over to the >local university. if it's online-only, students and faculty with >accounts will be able to get it free, but i won't. if it's on paper >(doubtful 3 decades old) i can read it at the UVM library. but, being >IEEE Transaction, it might be too obtuse to read anyway. > >if you got it on pdf, would you mind sneaking me a copy?Hi Robert, Your slightest wish is my most stern command. See Ya', [-Rick-]
Reply by ●February 11, 20122012-02-11
On Fri, 10 Feb 2012 15:26:27 -0500, stan <smoore@exis.net> wrote:>Rick Lyons wrote: >> >> Hi Guys, >> I have a question for any of you who have studied >> Hogenauer's original paper on cascaded integrator-comb >> (CIC) digital filters. >>[Snipped by Lyons]> >I haven't read the paper yet; I just printed it and I taking it with >me as I'm going out to eat. > >My first impression based on quotes like these > >"If the number of bits in the input data stream is Bin, then >the register growth can be used to calculate Bmax, the most >significant bit at the filter output." > >"Not only is Bmax the MSB at the filter output, but it is also >the MSB for all stages of the filter." > >He also mentions just after equation 11 that the LSB is 0. > >is that Bmax refers to the MSB which I nearly always take as zero >based. My preliminary vote is Bmax=7 in your hypothetical. > > >Sliderules at ten paces :)Hi Stan, Thanks for going to the trouble to give me your opinion. Your thoughts are duly noted. The origin of my question is that Prentice Hall Publishing has asked me to review a manuscript for a potential DSP book. In that manuscript, the author gives a definition of Bmax that differs from my definition of Bmax. This uncertainty is now like 'a burr under my saddle'. I'd sure like to resolve this question. See Ya', [-Rick-]
Reply by ●February 11, 20122012-02-11
On 2/10/12 3:26 PM, stan wrote: ...> My first impression based on quotes like these > > "If the number of bits in the input data stream is B_in, then > the register growth can be used to calculate B_max, the most > significant bit at the filter output." > > "Not only is B_max the MSB at the filter output, but it is also > the MSB for all stages of the filter." > > He also mentions just after equation 11 that the LSB is 0. >i think they mean that the *index* of the LSB is 0. like this: B_max X = SUM{ x_n * 2^n } n=0 x_n = 0 or 1 and is the "nth bit" in the word.> is that B_max refers to the MSB which I nearly always take as zero > based. My preliminary vote is B_max=7 in your hypothetical.i would agree. i think that the smoking pistol is the "- 1" term that resides in Eq. 11. i believe that the word width of the output is B_max + 1. but that's just my first impression.> >> This is not just a friendly disagreement. We'd like >> to know the true definition of 'B_max' in preparation >> for an upcoming DSP publication. > > Sliderules at ten paces :)well, don't bring a sliderule to a gunfight. i've tried that a few different times and have lost each and every time. (at least i have the consolation of being "right". dead, but right.) -- r b-j rbj@audioimagination.com "Imagination is more important than knowledge."
Reply by ●February 11, 20122012-02-11
robert bristow-johnson wrote:> i would agree. i think that the smoking pistol is the "- 1" term > that resides in Eq. 11. i believe that the word width of the output > is B_max + 1. but that's just my first impression.I thought that was important too.>> Sliderules at ten paces :) > > well, don't bring a sliderule to a gunfight. i've tried that a few > different times and have lost each and every time. (at least i have the > consolation of being "right". dead, but right.)Kevlar case? With todays focus on teams, it seems but a short step to a Roman Phalanx kind of technique. Somehow brings to mind my favorite usenet argument: self deprecating engineer statment offended party makes speech about professionalism and need to stop self deprecating pack senses weakness and circles, someone uses "nerd" offended party reponds with OED definition of the word "nerd" someone points out that only a nerd would look up "nerd" in OED someone else mentions "anal retentive" someone asks if "anal retentive" needs a hyphen the crowd dispersed instantly
Reply by ●February 11, 20122012-02-11
Rick Lyons wrote:> On Fri, 10 Feb 2012 15:26:27 -0500, stan <smoore@exis.net> wrote:> Thanks for going to the trouble to give me > your opinion. Your thoughts are duly noted.No problem.> The origin of my question is that Prentice Hall > Publishing has asked me to review a manuscript > for a potential DSP book. In that manuscript, > the author gives a definition of Bmax that differs > from my definition of Bmax. This uncertainty is > now like 'a burr under my saddle'. I'd sure > like to resolve this question.A very quick internet scan turned up different equations last night. I still don't know if it's off by one error or 0 vs 1 based indexing. FWIW, I would typically go to your book to refresh myself before reading that paper. If I could suggest, this seems to scream out for a worked example (in the book) to mitigate the ambiguity no matter who is correct. The fact that at least two knowledgeable people see it different removes any doubt about the existence of ambiguity and the goal is clarity. Of course a good smackdown cage match every now and then is good for the soul.