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How to caulate the Frequency Sample Response of IIR Filter?

Started by cweston in comp.dsp1 hour ago 1 reply

This has probably been answered already but how does one the 'DFT' samples of an IIR filter from the 'b' and 'a' coefficients. For a FIR,...

This has probably been answered already but how does one the 'DFT' samples of an IIR filter from the 'b' and 'a' coefficients. For a FIR, this is trivial. if b_n are the coefficients which are by definition finite in length. The DFT would be easily calculated as DFT = F*b_n where F is the DFT matrix. How would one specify and calculate each frequency bin amplitude and phase for an I...


Liftering, what is it actually?

Started by proffy in comp.dsp8 hours ago

I want to know the physical significance of liftering process. with Ci as ith feature element in the feature vector, the liftering changes Ci...

I want to know the physical significance of liftering process. with Ci as ith feature element in the feature vector, the liftering changes Ci as Ci = (1 + (N/2)sin((pi*n)/N))*Ci What is it actually doing to a signal? Mathematically it is amplifying the signal. But then, why do we need such an amplification in terms of number of frames? --------------------------------------- P...


In memoriam - Vladimir Vassilevsky

Started by Rick Lyons in comp.dsp2 days ago 25 replies

Hi, In the Russian culture it's traditional to formally remember a deceased family member, or friend, 40 days after the day of their...

Hi, In the Russian culture it's traditional to formally remember a deceased family member, or friend, 40 days after the day of their passing. Today it's been 40 days since Vladimir Vassilevsky left this world. My memory of Vlad, as his friends called him, is that he was a highly skilled engineer. Over the years of exchanging signal processing ideas with Vlad I had the distinct...


I/Q modulation and phase noise sensitivity

Started by Peter Mairhofer in comp.dsp2 days ago 7 replies

Hi, I am observing something that is very counter-intuitive to me: I/Q modulation is very susceptible to phase noise? In an experiment I...

Hi, I am observing something that is very counter-intuitive to me: I/Q modulation is very susceptible to phase noise? In an experiment I plot "phase noise" vs. "SNR" and see a constant slope of ~20dB/dec. I use a real baseband signal, multiply it by cos(2*pi*fc*t) and then multiply it again by cos(2*pi*fc*t + phi(t)) where phi represents the phase noise. Finally, a simple image filter. I...


Automatic (no user-parameters) envelope/peak follower

Started by mavavilj in comp.dsp4 days ago 12 replies

I'm looking for known algorithms that do envelope/peak following with no user-specified attack or release times. Specifically I'm interested in...

I'm looking for known algorithms that do envelope/peak following with no user-specified attack or release times. Specifically I'm interested in what kind of algorithms something like: http://i.stack.imgur.com/gT4dw.png could be using (based on how it looks like). --------------------------------------- Posted through http://www.DSPRelated.com


Thoughts on a 'Companion' FIR Filter Design

Started by cweston in comp.dsp4 days ago 5 replies

I have and interesting design that involves designing two filters that are very related. (I call them companion not to confuse the word...

I have and interesting design that involves designing two filters that are very related. (I call them companion not to confuse the word with matched) Filter 1 is set by the system. That is H(jw_1) in some frequency band cannot be changed (both magnitude and phase over some frequency band) - lets call it w0 - w1. The out of band frequency response can be arbitrary over the out of band frequency...


Fire Codes

Started by Rob Doyle in comp.dsp5 days ago 15 replies

I was studying the schematic of a 1970's era washing machine sized disk drive [1] wondering how it performed ECC. Everything was built out...

I was studying the schematic of a 1970's era washing machine sized disk drive [1] wondering how it performed ECC. Everything was built out of simple SSI TTL circuitry. The disk controller had a 13-bit register that provided the "Error Position" and another 12-bit register that provided the "Error Pattern". I couldn't find any explanation for how this circuit worked in any of the disk drive...


MATLAB - Digital Filtering in Second Order Sections - Scale Values

Started by Lightbulb85 in comp.dsp6 days ago 7 replies

Hi Everyone, I am struggling to manually apply the scale values to a digital filter I designed in MATLAB using fdatool. I generated the filter...

Hi Everyone, I am struggling to manually apply the scale values to a digital filter I designed in MATLAB using fdatool. I generated the filter (IIR band stop filter consisting of four second order sections) and exported it as an object. I can use MATLAB's "filter" function to filter my data correctly. As a precursor to implementing the filter in C and embedding it onto a hardware device, I...


LFCC (Linear Frequency Cepstral Coefficients)

Started by Biruntha Gnaneswaran in comp.dsp7 days ago

It is used to extract the features in audio signal. It has steps Signal Normalization, Compute FFT power spectrum, Compute autoregressive model...

It is used to extract the features in audio signal. It has steps Signal Normalization, Compute FFT power spectrum, Compute autoregressive model analysis, Convert LPC to cepstra , Apply DCT and Convert to cepstra, Apply lifter to matrix of cepstra, Calculate the deltas of a output mel sequence . Can anyone briefly explain about LFCC and it's steps? Thankyou


Need help in determining entropy of four coins - skewed distribution

Started by Anonymous in comp.dsp1 week ago 8 replies

All, I used to be a student of channel capacity years back. Now I am trying to teach concepts of information, entropy and channel capacity to...

All, I used to be a student of channel capacity years back. Now I am trying to teach concepts of information, entropy and channel capacity to my high-school kid for a school math project. I am coming across a situation in which the entropy of an (unequiprobable) event is coming out to be GREATER than had it been equiprobable. I am clearly wrong somewhere. Where? Background: (re


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