## Higher order Bessel filter

Started by in comp.dsp15 years ago 10 replies

Can anybody give me an idea on how to implement nth order bessel filter with cascaded biquad sections? I am able to implement higher order...

Can anybody give me an idea on how to implement nth order bessel filter with cascaded biquad sections? I am able to implement higher order Butterworth with cascaded biquads by following equations given in the link http://www.musicdsp.org/files/Audio-EQ-Cookbook.txt I found that to design filter coefficients for the biquads, Q has to be changed in the equation Alpha = alpha = sin(w0...

## KB-Window

Started by in comp.dsp17 years ago 9 replies

What is the identity (formula) of a Kaiser-Bessel window. I need something like W[n] = F(n,alpha)= .........?

What is the identity (formula) of a Kaiser-Bessel window. I need something like W[n] = F(n,alpha)= .........?

## Anti-Aliasing filter

Started by in comp.dsp14 years ago 12 replies

If you are estimating time-delay bewteen two microphones would it be better to use a Bessel filter for anti-aliasing rather than a Butterworth...

If you are estimating time-delay bewteen two microphones would it be better to use a Bessel filter for anti-aliasing rather than a Butterworth due to the approximate linear phase. Wang King

## bartlet

Started by in comp.dsp15 years ago 2 replies

hi folks, i have a term project about high-pass bessel filter with fstop = 200Hz and fPass = 400Hz, there's no big deal in "iir" design, i...

hi folks, i have a term project about high-pass bessel filter with fstop = 200Hz and fPass = 400Hz, there's no big deal in "iir" design, i could overcome it, but at the "fir" design i was asked to perform this by a "bartlett window" and my brain is almost to explode, i can't find any articles, any techniques and unfortunately there's no assistants to help me (and as we all know "if you don't know ...

## how to get rid of ringing with IIR notch filters?

Started by in comp.dsp19 years ago 20 replies

Hello, I have an IIR notch filter ( i.e. bandstop ), that rings like crazy whenever a transient signal comes through ... which is very...

Hello, I have an IIR notch filter ( i.e. bandstop ), that rings like crazy whenever a transient signal comes through ... which is very unwanted for my application. Anybody have any ideas how to get around this? I have to stick with IIR form filters. I've tried all the various standard design flavors, i.e. Butterworth, Bessel, Elliptic, etc ... but they all seem to ring unacceptably abou...

## newbie filter question

Started by in comp.dsp18 years ago 13 replies

Hi everyone, Just got handed a 600000 line software application with lots of DSP. I am trying to understand a few things and as I am new to...

Hi everyone, Just got handed a 600000 line software application with lots of DSP. I am trying to understand a few things and as I am new to DSP, it is a bit complicated. Here is a scenario. There is a signal that is being fed into a cascaded Bessel filter bank that splits it into 0-60 Hz, 60-120 Hz, 120-180 Hz, 180-240 Hz uptil 480 Hz... i.e. in bands of 60 Hz. After this, the output ...

## Help on cascaded filter freq correction

Started by in comp.dsp18 years ago 2 replies

I've figured out the cutoff frequency correction factor necessary to force a 2-pole Bessel lowpass filter to exhibit 3 dB of power attenuation...

I've figured out the cutoff frequency correction factor necessary to force a 2-pole Bessel lowpass filter to exhibit 3 dB of power attenuation at the cutoff frequency I specify, for a single pass of the filter. The problem is, if I stack up multiple passes, I can't seem to get it right. Here's what I've done so far. Filter response function H = W^2 / (W^2 + 3W + 3) [1] This w...

## pdf of product of two dependent rv

Started by in comp.dsp16 years ago 1 reply

Hello, I am facing problem in finding the pdf of Z= AB+CD, where A, B, C, D are independent normal random variables with...

Hello, I am facing problem in finding the pdf of Z= AB+CD, where A, B, C, D are independent normal random variables with zero mean and uneqaul variances. I could bale to find out the pdf's of each term (i.e. AB or CD). It is a well known result that AB has a pdf of modified Bessel function of the second kind. If we add two random variables having the pdf of " modified...

Started by in comp.dsp18 years ago 4 replies

hi! All, i would like some info on implementing cascade form IIR filters...does matlab support it???...as far as i can understand...

hi! All, i would like some info on implementing cascade form IIR filters...does matlab support it???...as far as i can understand butter,cheby1,cheby2,bessel,ellip generate coefficients in the direct form...how do i implement the cascade form... TIA bngguy

## filtering of noise signal

Started by in comp.dsp11 years ago 2 replies

how to filter a noise signal using iir filter coefficients-- cybyshev or bessel, band is between 45hz to 65hz, sampling frequency 1000hz if...

how to filter a noise signal using iir filter coefficients-- cybyshev or bessel, band is between 45hz to 65hz, sampling frequency 1000hz if 240 hz pure signal noise +signal =270 hz----> iir filter-----> 240hz

## Modulation transfer function

Started by in comp.dsp15 years ago

Hi, I have a doubt regarding 1 other project. I have to get the modulation transfer function of an image (and the same image defocused)....

Hi, I have a doubt regarding 1 other project. I have to get the modulation transfer function of an image (and the same image defocused). The defocus is either induced by constructing a bessel filter (similar to airy functions, defocus created by unfocused thin lens). Even though I already designed the filter, I am currently using a webcam to get the defocus by altering the focus of the le...

## IIR BandPass nominator

Started by in comp.dsp11 years ago 7 replies

Hello everybody, I have problem with nominator of H(z) of bandpass filter. I develop musical open-source software (non-commercional) and I...

Hello everybody, I have problem with nominator of H(z) of bandpass filter. I develop musical open-source software (non-commercional) and I wrote my filter-design algorithms based on polynomials (without complex aritmetic). I have all working well (Bessel, Butterworth, Chebyshev, inverse Chebyshev and Cauer's elliptic filters Low, High Band pass and band Reject). Now I decided do rewrite my al...

## Digital filter woes

Started by in comp.dsp10 years ago 15 replies

I'm trying to design an LP IIR digital filter but not having much luck. The bandwidth of my filter is too low. The filter specifications are:...

I'm trying to design an LP IIR digital filter but not having much luck. The bandwidth of my filter is too low. The filter specifications are: pass, stop and sampling frequencies 4.8, 8.5 and 30 KHz respectively; maximum pass band ripple 0.5 dB and minimum stop band attenuation 30 dB; filter type Bessel. I obtained the poles and zeros with the Python Scipy function iirdesign. There are seven p...

## FIR all pass and Bessel Function unit sample response

Started by in comp.dsp13 years ago 3 replies

Once upon a time I wrote a nonlinear program to compute the unit sample response (i.e. to "design") FIR filters with the following...

Once upon a time I wrote a nonlinear program to compute the unit sample response (i.e. to "design") FIR filters with the following characteristics: 1) Minimax solution to all pass. 2) The unit sample response could not be the trivial single unit sample - rather, it had to have: a) "length" b) the samples had to be in a magnitude range something like from 1 to 2.5 with arbitrary s...

## THD digital FM demod

Started by in comp.dsp15 years ago 3 replies

Hi, I have designed a digital FM demodulator... I have a 70 MHz FI signal that I downconvert to baseband This demodulator works fine with...

Hi, I have designed a digital FM demodulator... I have a 70 MHz FI signal that I downconvert to baseband This demodulator works fine with Analog Bessel 24 order filter on I and Q signals before demodulating. When I change this filter with a digital FIR filter (phase lineartity) I have a -50 dB THD My message signal is a pure 10 MHz filter sine My -50 dB THD is due to a 20 Hz sine...

## Frequency Modulation Spectra

Started by in comp.dsp14 years ago 18 replies

The frequency spectrum of an FM signal with a sinusoidal modulating signal is a discrete infinite frequency series where the carrier and...

The frequency spectrum of an FM signal with a sinusoidal modulating signal is a discrete infinite frequency series where the carrier and sidebands are given by the Bessel functions, which are themselves a function of the modulation index. But when the FM signal is modulated by TWO sinusoidal signals, is the spectrum represented by TWO infinite frequency series? Or is the spectrum mo...

## phase error variance to rms phase error

Started by in comp.dsp12 years ago 2 replies

hello, i have an expression that gives the phase error variance of QPSK system as follows:\ phase error...

hello, i have an expression that gives the phase error variance of QPSK system as follows:\ phase error variance=(Aif/sqrt(2*pi*n))*I0(-Aif/2*n) here, Aif=IF amplitude, n=noise component variance, I0=modified bessel function of the 1st kind How can i calculate rms phase error of that system from this phase error variance thanks