Help using butterworth filters

Started by cool...@hotmail.com in Matlab DSP17 years ago 1 reply

Hello, I'm currently taking an Electrical Engineering class but I'm a Mathematics Graduate student so I'm missing some of the screws that put...

Hello, I'm currently taking an Electrical Engineering class but I'm a Mathematics Graduate student so I'm missing some of the screws that put this whole shebang together so I'm having some trouble with some probably very basic things for all of you. Anyways, I'm trying to construct 7 butterworth bandpass filters but they're not coming out how I want them to. I'm used to using the fir1 filter


Interpolation

Started by muyeen NAWAZ in Matlab DSP19 years ago 1 reply

Hi I' m looking for a good interpolation filter. I need to know what method of interpolation is used the matlab function...

Hi I' m looking for a good interpolation filter. I need to know what method of interpolation is used the matlab function interp(.). Is it the sum of sinc(.) type of interpolation? kindly advise. regards Muyeen Nawaz


2D IIR filter

Started by Hugo de Paula in Matlab DSP19 years ago

Hi, Does anyone know a tool or script which helps us design 2D IIR filters in Matlab? I would be specially interested in...

Hi, Does anyone know a tool or script which helps us design 2D IIR filters in Matlab? I would be specially interested in Chebychev Type I filters but others may be useful too. Thank you in advance. Hugo


sigma delta

Started by ms_venka in Matlab DSP15 years ago

hi i am currently working on sigma delta modulator and finding some problems with the decimation filter design........ can any one please...

hi i am currently working on sigma delta modulator and finding some problems with the decimation filter design........ can any one please suggest me some useful links where i can find the complete design?


decimation filter for sigma-delta

Started by Pavel Yermolenko in Matlab DSP21 years ago

Hello I will be grateful to anyone who could help me to resolve the problem concerned sample rate conversion. I have tried to...

Hello I will be grateful to anyone who could help me to resolve the problem concerned sample rate conversion. I have tried to simulate in Simulink famous Hogenauer structure: integrator ? downsample ? differentiator. But the results of simulations are different from ones of cl


Using Butter.m function 's' option

Started by elbe...@infinito.it in Matlab DSP16 years ago

Which differences between [A,B] = butter(1,0.5) and [A,B] = butter(1,0.5,'s') ? It's written 's' is for analog filter: what difference between...

Which differences between [A,B] = butter(1,0.5) and [A,B] = butter(1,0.5,'s') ? It's written 's' is for analog filter: what difference between using or not 's' option?


ILS algorith For FMT

Started by srin...@yahoo.co.in in Matlab DSP17 years ago

Dear All; I have to work with FMT (filtered Multitone modulation) . any body worked with ILS algorithm for designing the filter banks....

Dear All; I have to work with FMT (filtered Multitone modulation) . any body worked with ILS algorithm for designing the filter banks. If anybody worked with this one please send me the Matlab code. Thanks in Advance. Regards


Drivate of noisy signal

Started by raffaelemalutta in Matlab DSP20 years ago

Hallo evedybody. I'm working with Simulink (discrete time) and I've to derivate a noisy signal. What is the best way to do...

Hallo evedybody. I'm working with Simulink (discrete time) and I've to derivate a noisy signal. What is the best way to do this? Anyone could suggest me a proper choise for cefficients of a derivative filter? (for example: [z(n) + 3z(n-1) -3z(n-2) -z(


Windowing in the Frequency Domain

Started by Rajmathi S in Matlab DSP12 years ago

Hello Mark, ? The output seems to be okay. I don't see any problem with it. May be you should remove the db conversion part and see the...

Hello Mark, ? The output seems to be okay. I don't see any problem with it. May be you should remove the db conversion part and see the output. ? plot(handles. convolution_ axes,f1, 20*log10(abs( convo))); %log plot of the filter Also, the confusion could be because of the x-axis being viewed from 0 to Fs (0 to N) and not from -Fs/2 to Fs/2 (-N/2 to N/2). ? Hope this helps. ? Regards, ...


8PSK modulation for EDGE

Started by sylv...@yahoo.fr in Matlab DSP16 years ago

Hi everybody I\'ve got a problem in matlab when generating bits With my short program, modulus of bits pass by 0 which is not required of course...

Hi everybody I\'ve got a problem in matlab when generating bits With my short program, modulus of bits pass by 0 which is not required of course even if i rotate then of 3*pi/8 Can someone help me please? %%%%generation and rotation of bits%%%%%%%? for(l=1:n) q=floor(8*rand()); a(l) = exp(i*pi/8*(2*q + 3*l)); end %%%%gaussian filter thanks to http://www.tropian.com/tech/tech_doc...


rounding off the coefficients

Started by Appalayagari Sreedhar in Matlab DSP19 years ago 1 reply

Dear all, Happy New Year. I am designing a FIR filter i want to study the finite wordlength effects, i want to reduce...

Dear all, Happy New Year. I am designing a FIR filter i want to study the finite wordlength effects, i want to reduce the bit size for representing the coefficient, but to reduce that i want to know exactly with how many bits the coefficeint is gener


Image procesing

Started by cesar acosta in Matlab DSP14 years ago

HI, I want to "filter" an image and only left a color, in other words, i want to supress all color that arent the color choosen. I have...

HI, I want to "filter" an image and only left a color, in other words, i want to supress all color that arent the color choosen. I have read the both demo of image segmentation but i really dont understand it. Any ideas ?? Thanks in anvance. Regars, Cesar Acosta


Test Signal !!

Started by Anonymous in Matlab DSP18 years ago 2 replies

Hi Everyone.....Well this is Nitin here and I am doing my MS from the University of Hartford. Actually , I wanted to know, suppose...

Hi Everyone.....Well this is Nitin here and I am doing my MS from the University of Hartford. Actually , I wanted to know, suppose I have designed a Butterworth filterusing the "Butter" command in Matlab and "Buttord" for finding the order of the Filter ...


Adaptive Filtering of QAM Signals

Started by Mahdi in Matlab DSP19 years ago

Hi everybody, I have a QAM signal corrupted by a colored/AWGN noise. I would like to filter it. The problem is that QAM has not...

Hi everybody, I have a QAM signal corrupted by a colored/AWGN noise. I would like to filter it. The problem is that QAM has not constant spectrum. Anybody has or has seen a solution? tnx 2 much, Mehdi


Problems with Butterworth f. when order>=10

Started by adap...@yahoo.co.jp in Matlab DSP13 years ago 2 replies

Hello everybody. Thank you always for your help. I have a question regarding Butterworth filters with order > =10. I was out of the office,...

Hello everybody. Thank you always for your help. I have a question regarding Butterworth filters with order > =10. I was out of the office, so couldn't use MATLAB. Instead I used Octave. I tried to do the following: > [b a]=butter(10,0.015); > y=filter(b,a,x); for a original signal x.(a sin signal) Now when ploting I can see this gives me a filtered signal (although a little strange


Re: plz help

Started by Jeff Brower in Matlab DSP18 years ago

Reshma- I have posted your question on the MATLAB Yahoo Group. -Jeff Reshma Jacob wrote: > > Hello Sir, > i am...

Reshma- I have posted your question on the MATLAB Yahoo Group. -Jeff Reshma Jacob wrote: > > Hello Sir, > i am trying to implement the yule walk filter in C++.i have the IEEE paper"the > modified yulewalker method of ARMA


Filter translation

Started by Anonymous in Matlab DSP21 years ago

Hi, I'm using MATLAB for demodulating an amplitude modulated signal. I am using a synchronous demodulator: I multiply the...

Hi, I'm using MATLAB for demodulating an amplitude modulated signal. I am using a synchronous demodulator: I multiply the signal by exp(j*wc*t) in phase with the signal and then I apply a low-pass. BEFORE being demodulated, the signal passes by a transfer function


cremez usage confusion

Started by Appalayagari Sreedhar in Matlab DSP19 years ago 2 replies

Hi, I am trying to design a Nonlinear FIR filter, i am confused with the inputs to be given, i have fresp in that,i...

Hi, I am trying to design a Nonlinear FIR filter, i am confused with the inputs to be given, i have fresp in that,i gave the inputs as follows b = cremez(20,[0 0.375 0.5 1],[0.01 0.1]); ignoring the fresp but the coefficeints i obtained are sy


Multi-rate Fir Filter Design

Started by c r in Matlab DSP20 years ago 1 reply

I am designing an audio equalizer in Matlab, and I want to do it with a multirate setup, but I do not want to sample the input wave...

I am designing an audio equalizer in Matlab, and I want to do it with a multirate setup, but I do not want to sample the input wave more than once, so if I have a sampling of say 50khz, I was wondering what the best way to decimate the signal would be in order to make it work.  I plan on implementing th


Butterworth Gain in Matlab

Started by kili...@hotmail.com in Matlab DSP16 years ago

Hello guys, I was trying to demodulate an AM modulated signal in matlab. Obviously if the signal has an Amplitude A, after demodulation it will...

Hello guys, I was trying to demodulate an AM modulated signal in matlab. Obviously if the signal has an Amplitude A, after demodulation it will be A/2. So to recover the same signal I need an LPF, which has a DC gain 2. Is that right? I've tried the following code but was not succesful. Multiplying the coefficients with a scalar. [b,a]=butter(6,0.02); k=2; c=k*b; output=filter(c,a,demod); ...