about cic filter problem

Started by liux...@yahoo.cn in Matlab DSP11 years ago 4 replies

Hello all, In the book of "understanding of digital signal processing", it is said that cic filter has a inherent problem which is cic filter...

Hello all, In the book of "understanding of digital signal processing", it is said that cic filter has a inherent problem which is cic filter can not remove the outband imgage clearly and the image will be folded into the real signal when decimation especially when stage of cic filter is very small. But there is an integrater ahead of decimation. Is the integrater a good low pass filter enoug...


Filter design using Remez Exchange Algorithm

Started by himab_g in Matlab DSP14 years ago

Hi I am new to filter design. I have to design Smith-Barnwell Filters for lengths N= 4,8,16,31,64.. using Remez Exchange Algorithm. ...

Hi I am new to filter design. I have to design Smith-Barnwell Filters for lengths N= 4,8,16,31,64.. using Remez Exchange Algorithm. These are the steps to design the filter (1) design an equiripple half-band filter using the Remez exchange (2) make the filter frequency response positive-definite (3) spectral factorization This i


filter and downsample

Started by egan_nc in Matlab DSP16 years ago 2 replies

Hi, I designed a filter using remezord function. When I filtered the input first and downsampled later, the filter works fine. ...

Hi, I designed a filter using remezord function. When I filtered the input first and downsampled later, the filter works fine. out2a=filter(h1,1,out1a); out2b=downsample(out2a,4); But when I downsampled first and then fitlered it later the output is incorrect. out2a


Problem in Bandpass filter, passband reappear after half sampling frequency

Started by Henry Chang in Matlab DSP17 years ago 3 replies

Hi all, I am beginner in digital filter design. Currently, I am designing a bandpass filter cut-off at 500hz and 1.8khz, with...

Hi all, I am beginner in digital filter design. Currently, I am designing a bandpass filter cut-off at 500hz and 1.8khz, with sampling frequency 6k Hz. I use butterworth filter with order 6 according to the specification. However, when I try to plot the signal, there is


Decimation filter magnitude response.

Started by usu_...@yahoo.com in Matlab DSP9 years ago 2 replies

I designed a CIC decimation filter, and am trying to plot its frequency response. Given below are the specifications of the filter. Sampling...

I designed a CIC decimation filter, and am trying to plot its frequency response. Given below are the specifications of the filter. Sampling Freq fclk: 1.4MHz Decimation D: 100 Input bits: 3 Output bits: 24 Order: 3 Question: What is the proper way to plot the magnitude the freq response of the filter? I did the following: If I send in 102400 samples into the filter, I get 1...


filter constants

Started by sheppa28 in Matlab DSP12 years ago

In the following Matlab routine: == %*********************************************** % BandPass...

In the following Matlab routine: == %*********************************************** % BandPass Filter %*********************************************** Wn = [1.5, 9]/(Fs/2); [b,a] = ellip(6,0.1,40,Wn); data = filter(b,a,fr_in); %*********************************************** %******************************************* % Plot the rms of the compressed data %*********************...


question for filter implementation

Started by nasim ahmed in Matlab DSP14 years ago

hi guys, This is nasim, i am working as a DSP engg. in chennai ( india ). My work is to convert many matlab functions in C. just like linkage,...

hi guys, This is nasim, i am working as a DSP engg. in chennai ( india ). My work is to convert many matlab functions in C. just like linkage, cluster and to implement filter in C. Here, i am facing a problem in implementation filter. basically i am not able to convert the "filtfilt" function in C. bcos of "filter" function that is used in "filtfilt'. In matlab filter


State Variable Filter in DSP

Started by rver...@hotmail.com in Matlab DSP13 years ago

Dear all, I am very new to DSP and I need to construct a High Pass, State Variable Filter. I have taken the filter strucuture from the...

Dear all, I am very new to DSP and I need to construct a High Pass, State Variable Filter. I have taken the filter strucuture from the following link: http://www.earlevel.com/Digital%20Audio/StateVar.html I have constructed the Filter in Simulink and it works fine. However I wish to model it as an m-file. I am having severe problems in devising the equation that will calculate the output...


circular high pass filter

Started by enriquefergosa in Matlab DSP16 years ago

Hallo, I need help. I would like to do a 2D circular high pass filter using the matlab function FSPECIAL('DISK', RADIUS) but, this ...

Hallo, I need help. I would like to do a 2D circular high pass filter using the matlab function FSPECIAL('DISK', RADIUS) but, this function is a low pass filter really. How could I change from low to high pass filter using this function?. I tried to do this filter doing my ow


Decimation Filter Specification Object

Started by usu_...@yahoo.com in Matlab DSP9 years ago

Hello, Thanks for a helpful forum. I have two questions. 1. I am trying to implement a simple FIR filter. All I do is sum 100 samples of the...

Hello, Thanks for a helpful forum. I have two questions. 1. I am trying to implement a simple FIR filter. All I do is sum 100 samples of the input to get the output. Y = X(100) + X(99)..........X(1). I want to create a filter object for this filter. The question is - Do I use a FORM I, or a FORM II structure, i.e, do I use dfilt.df1, or dfilt.df2 function in matlab? 2. I...


sampling freq for combined filter

Started by egan_nc in Matlab DSP16 years ago 1 reply

Hi, Can anybody please tell me how to set up the sampling freq for a combined filters. The sampling freq for the input signal to...

Hi, Can anybody please tell me how to set up the sampling freq for a combined filters. The sampling freq for the input signal to the first filter h1 is 1.5Mhz, the output of the first filter is then downsampled to 96khz and feed into the second filter h2. h12 is the convolution


Halfband and FIR filter for decimation

Started by feyzakent in Matlab DSP9 years ago

Hi, I want to design a decimation filter for a Sigma-Delta modulator. The modulator input is 20Khz sinus signal. And this signal is oversampled...

Hi, I want to design a decimation filter for a Sigma-Delta modulator. The modulator input is 20Khz sinus signal. And this signal is oversampled to 2.5Mhz. So decimation ratio is about 64. First I designed a CIC filter which has a decimation ratio of 16. After a halfband filter and an FIR filter. So halfband filter output is 80 Khz, FIR filter output is 40 khz. Anyway, I want to design halfband ...


Re: gain scaling of comb filter

Started by wuqi...@yahoo.cn in Matlab DSP10 years ago

Hi, have you get your answer? I am a beginner of this field. I am in a project that have to use the CIC filter. The gain of the filter also puzzle...

Hi, have you get your answer? I am a beginner of this field. I am in a project that have to use the CIC filter. The gain of the filter also puzzle me a lot. In matlab, I could just divide by 1/gain(CIC) before or after the CIC to scale the gain of this filter to 0 dB. But I don't know how to implement it in verilog or in the hardware. Also I don't know whether is it necessary. > > > > H


Re: For Loop Execution

Started by Joe Sababa in Matlab DSP18 years ago

--- bakoguz <> wrote: > I have a problem of for loops. > I saw the messages about them but it did not help > me. > I want to...

--- bakoguz <> wrote: > I have a problem of for loops. > I saw the messages about them but it did not help > me. > I want to filter my matrix(actually an image) by a > filter > and I want to convolve(2D) my filter with my image. > If I use


Problem in design filter -- Is it possible to avoid the division operation?

Started by Henry Chang in Matlab DSP17 years ago 2 replies

Hi all, Currently, I am designing low-pass filter that will be implemented in mcu processor and the result filter response is...

Hi all, Currently, I am designing low-pass filter that will be implemented in mcu processor and the result filter response is like this: -6 -4 -2 -z + 3z - 3z + 1 h = --------------------------------------------------- -6 -5 -4 -3 -2 -1 z + 6z + 17z - 29z + 3


Unknown Filter Type

Started by larkjon in Matlab DSP15 years ago 1 reply

Hi, I may have inadvertly posted this twice. If so, I apologize. I've "inherited" the following filter: Yn = Yn-1...

Hi, I may have inadvertly posted this twice. If so, I apologize. I've "inherited" the following filter: Yn = Yn-1 + C(Xn-Xn-1)^2 - C(Xn-Xn-1)(Yn-1) Where Yi are outputs Xi are inputs C is a constant The filter perfo


FIR or IIR?

Started by "kian.zarrin" in Matlab DSP12 years ago 1 reply

Hallow, please help me about choosing FIR or IIR filters I have a DSP/FPGA system to process signal and I want to design a filter to filter my...

Hallow, please help me about choosing FIR or IIR filters I have a DSP/FPGA system to process signal and I want to design a filter to filter my input signal. I need to know which one is better for me, FIR filter or IIR filter. For my application I need to meet all the requirements below: 1) Low ripple 2) Linear Phase response 4) Sharpness: to block noise 5) Complexity (inherent group pha...


digital filters

Started by Sergio Dominguez in Matlab DSP15 years ago

Hi all, I have written a digital filter (quite simple and generic) as a*s^2+b*s+c ___________ d*s^2+e*s+f The...

Hi all, I have written a digital filter (quite simple and generic) as a*s^2+b*s+c ___________ d*s^2+e*s+f The filter discretized using Tusting. The code is verified and seems to be fine. Now, if have the filter K*S _____________


Implementation of Linear phase IIR filter

Started by sham ganth in Matlab DSP16 years ago 6 replies

Sir, Iam trying to implement Linear phase IIR filter. My problem is that i want to reset the state variable of the Elliptic...

Sir, Iam trying to implement Linear phase IIR filter. My problem is that i want to reset the state variable of the Elliptic lowpass filter i want your suggestions in doing that task. If anyone came across ftpsite of Linear phase iir filter source code please send me. Thanks in


Bandpass filter

Started by jk_meher in Matlab DSP11 years ago

Hi, I have to design a band pass filter followed by a decimator in some application .Design of digital band pass filter is ok.But how to...

Hi, I have to design a band pass filter followed by a decimator in some application .Design of digital band pass filter is ok.But how to implement filter followed by decimator using matlab? J.K.Meher