## Forums comp.dsp

## POTSBAND Design filter

inHi, Can anyone give introduction about POTSBAND Design filter? and what the purpose of this filter??? I found matlab code for this...

Hi, Can anyone give introduction about POTSBAND Design filter? and what the purpose of this filter??? I found matlab code for this filter, function [b,a]=bandfilter(fs, f1, f2) %POTSBAND Design filter for 300-3400 telephone bandwidth [B,A]=(FS) %Input: FS=sample frequency in Hz %Output: B/A is a discrete time bandpass filter with a passband gain of 1 %The filter meets the specifications o...

## I/Q modulation and phase noise sensitivity

inHi, 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...

## How to caulate the Frequency Sample Response of IIR Filter?

inThis 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?

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

inHi, 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...

## Automatic (no user-parameters) envelope/peak follower

inI'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

inI 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

inI 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

inHi 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)

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