## merging FIR filter with feedforward IIR coeffecients?

Started by in comp.dsp15 years ago 2 replies

Hello I have a 7 tap FIR which performs sinx compensation. This is followed by a second order IIR group delay equalisation which corrects the...

Hello I have a 7 tap FIR which performs sinx compensation. This is followed by a second order IIR group delay equalisation which corrects the D/A reconstruction filters response. I am tight on space in my DSP so want to know if it is possible to remove the 3 feedforward coeffecients from the IIR section and combine them into the 7 TAP fir inverse sinx filter Thanks in advance for any tips an...

## FIR filter response

Started by in comp.dsp15 years ago 19 replies

Hi all, Here's a newbie type question, but one which I haven't seen fully explained elsewhere. Lets say I have a 1000 tap bandpass FIR...

Hi all, Here's a newbie type question, but one which I haven't seen fully explained elsewhere. Lets say I have a 1000 tap bandpass FIR filter centred on 100kHz and 10kHz wide. We'll assume it's perfect (flat passband). The group delay is 2.5mS. I put a 95kHz continuous sine wave signal at the input, and (after a short delay) it appears as a continuous output at the same level and freque...

## Minimum phase vice versa minimum phase

Started by in comp.dsp15 years ago 10 replies

Hello, I'm actually confused with minimum phase. I know actually two applications for minimum phase: 1. A FIR filter is designed and the...

Hello, I'm actually confused with minimum phase. I know actually two applications for minimum phase: 1. A FIR filter is designed and the result typically is a time domain signal (or taps) with a symmetric structure = linear phase This filter can be converted to a minimum phase filter e.g. by methods described at dspguru. So for example Hilbert transforms are often used. If I do a FFT t...

## Unit circle and location of zeros ...

Started by in comp.dsp15 years ago 2 replies

I need to solve the following problem: I was given frequency response of some FIR filter, consisting of two plots Magnitude response and Phase...

I need to solve the following problem: I was given frequency response of some FIR filter, consisting of two plots Magnitude response and Phase response. - From Magnitude response plot I can easily identify number and polar angles of zeros. There are 5 zeros in my case. One of them located on the unit circle. - From Phase response plot I can see that filter is mixed phase, which means th...

## what kind of digital filter is this

Started by in comp.dsp15 years ago 3 replies

Hello all, I found the following digital filter algortihm Function filter(input: extended):exteded; begin x[0]:= (input+...

Hello all, I found the following digital filter algortihm Function filter(input: extended):exteded; begin x[0]:= (input+ a*x[-1]+b*x[-2]); filter:= (c*x[0]+d*x[-1]+e*x[-2]); x[-2]:= x[-1]; x[-1]:= x[0]; end; Can anybody tell my what type it is? Is it a IIR or a FIR filter, or something special? Thanks in advance em

## Inverse FIR computation

Started by in comp.dsp15 years ago 6 replies

Hello all, I am trying to compute the inverse of an FIR filter: something that would reverse the effect of the first filter. I just want to...

Hello all, I am trying to compute the inverse of an FIR filter: something that would reverse the effect of the first filter. I just want to make sure my steps are correct: - take the FFT of the FIR - compute complex 1/f (in the frequency domain) - invert back into the time domain. (IFFT) - circular shift to adjust for the aliasing - window the data Does that seem right? --Shafik ...

## How to compsensate for FIR filter delay?

Started by in comp.dsp15 years ago 5 replies

How can I go about compensating for FIR filter integer delay, for the case of M even (odd length filter)? How about for M odd? I'm trying...

How can I go about compensating for FIR filter integer delay, for the case of M even (odd length filter)? How about for M odd? I'm trying to implement a FIR differentiator in Matlab, first using a Kaiser window, and then other windows with varying lengths for comparison. Thanks, Brandon

## Bitplane approach to FIR filter architecture

Started by in comp.dsp15 years ago 4 replies

Hi all, Has anyone heard about the bitplane approach to implement FIR filters? Regards.

Hi all, Has anyone heard about the bitplane approach to implement FIR filters? Regards.

## Simply FIR question

Started by in comp.dsp15 years ago 7 replies

Hi there, I have a 1024 coef FIR filter bank, which I use to filter a cosine signal. I have calculated the stop-band supression to be -35dBs...

Hi there, I have a 1024 coef FIR filter bank, which I use to filter a cosine signal. I have calculated the stop-band supression to be -35dBs but this sounds really high to me. The filters turning point is at 0.1f, where f is the sampling frequency. For example, if I feed the FIR with a frequency of 0.25f, I get a signal out with amplitude 1*10^-6. Does this sound correct? Is there a fu...

## ANN: Free FIR Design program with full source

Started by in comp.dsp15 years ago 1 reply

Hellow all DSP junkies and fellow Netlanders, After reading this newsgroup for a while and having benefited from it, I thought I contribute...

Hellow all DSP junkies and fellow Netlanders, After reading this newsgroup for a while and having benefited from it, I thought I contribute something back. I have taken the guts of two free C/C++ programs that generated FIR filter coefficients and hand translated them into Visual Basic 6.0. I also put a GUI front end on them and the result is a nice program that can use the Sinc impulse r...

## is there a way to convert Matlab code direct to TI TMS320C54x...?

Started by in comp.dsp15 years ago 6 replies

I noticed that Mathworks has simulink target for TMS C2000 and C6000... Does that mean that my TMS320C5410 EVM cannot be used by converting...

I noticed that Mathworks has simulink target for TMS C2000 and C6000... Does that mean that my TMS320C5410 EVM cannot be used by converting simulink code into TI code? I am also wondering what can I do if I want to convert Matlab code directly into TI code? Is that an option to convert Matlab code directly into TI code to work in CCS? For example, for a 40-tap FIR filter, my Matlab ...

## inverse of an FIR filter

Started by in comp.dsp15 years ago 25 replies

Hi Folks, I read that the inverse of an FIR filter is always an IIR filter. I have no idea how to prove this mathematically. If anybody could...

Hi Folks, I read that the inverse of an FIR filter is always an IIR filter. I have no idea how to prove this mathematically. If anybody could tell me where to start, I'd be more than happy. I'm a DSP newbie, please do excuse me if the question is a little stupid. Thanks, Karthik.

## FIR Filter Help

Started by in comp.dsp15 years ago 44 replies

Hi, I would like to apply a FIR filter to my frequency sample array. Specifically, I want to use a band-pass filter against my data, but...

Hi, I would like to apply a FIR filter to my frequency sample array. Specifically, I want to use a band-pass filter against my data, but I'm pretty new to DSP and I'm not sure exactly how to integrate this. First, I have a complex array of frequency data (real, imaginary). Second, I've used a FIR design program to come up with the following information: -Rectangular window FIR filter ...

## Beginers question on nos of taps

Started by in comp.dsp15 years ago 20 replies

Hi, How do the number of taps of an IIR or FIR filter corelate to the order of the filter?? Lets say I have a 2nd order Low pass Butterworth...

Hi, How do the number of taps of an IIR or FIR filter corelate to the order of the filter?? Lets say I have a 2nd order Low pass Butterworth filter, does that mean the nos of taps will be 2?? Also will the number of taps vary with the corner frequency. Thanks -Glidden This message was sent using the Comp.DSP web interface on www.DSPRelated.com

## FIR timing problem?

Started by in comp.dsp15 years ago 2 replies

Hello Everybody! It's my first post on this forum, can anyone help me? I'm newbie on DSP and I'm using TMS320C5402 DSK Board... I've used...

Hello Everybody! It's my first post on this forum, can anyone help me? I'm newbie on DSP and I'm using TMS320C5402 DSK Board... I've used the codec.c digital loopback example to implement my own FIR filter as someone told already in a post from this forum. The problem it's that I think it's not working as it should... I'm going to attach the code for you guys to take a look... After the i...

## Question about computing a "moving variance"

Started by in comp.dsp15 years ago 57 replies

Hi Guys, I've been tryin' to figure something out and darnit, I just can't seem to find a satisfying answer. Maybe one of you guys...

Hi Guys, I've been tryin' to figure something out and darnit, I just can't seem to find a satisfying answer. Maybe one of you guys will help me. You recall the idea of a moving averager built with a tapped delay-line FIR filter like the 8-point moving averager shown below in Figure 1. (All the "b" coefficients are equal to 1/8th.) Each new y(n) output is the average of the c...

## HELP with ADSP-21161 Ez-Kit !!!

Started by in comp.dsp15 years ago 3 replies

Hi! Have someone programier a fir filter for this ADSP-21161 EZ-Kit and for 96kHz sample rate? I am new in the DSP world. Have someone...

Hi! Have someone programier a fir filter for this ADSP-21161 EZ-Kit and for 96kHz sample rate? I am new in the DSP world. Have someone worked with the ADSP-21161 EZ-Kit? I need to program a correlation. That?s mean a matched filter, als a fir filter? I need 96kHz sample rate for the AD. That?s mean I2S mode but there is not a lot of examples for I2S mode configuration. I need Help!...

## New to DSP (FIR implementation help)

Started by in comp.dsp14 years ago 2 replies

Hi guys/gals I'm new to DSP pogramming but am familiar to the high level concepts. I know how the output of a FIR filter is computed and how...

Hi guys/gals I'm new to DSP pogramming but am familiar to the high level concepts. I know how the output of a FIR filter is computed and how to generate the coeficients and tap count. I'm using ScopeFIR and have generated a 100 tap low pass filter. I have "quantized the coefficents to 16 bits because I'm planning to use this on the DsPic 30F6014. The 16bit A2D I'll be sampling out...

## ringing: minimum vs linear phase

Started by in comp.dsp14 years ago 33 replies

In my experience, if a minimum phase FIR filter does (doesn't) ring then the linear phase equivalent of that filter also will (won't)...

In my experience, if a minimum phase FIR filter does (doesn't) ring then the linear phase equivalent of that filter also will (won't) ring. Anybody have any counterexamples or else a proof that the above is always true? John

## Tunable FIR filter spectral nulls?

Started by in comp.dsp15 years ago 8 replies

All, Looking for any help here from my DSP cronies. I am analyzing a method of filtering a periodic pulsed sinusoid signal with a bandpass...

All, Looking for any help here from my DSP cronies. I am analyzing a method of filtering a periodic pulsed sinusoid signal with a bandpass FIR filter and have hit a stumbling block! As you know, the spectrum of the pulsed periodic sinusoid results in line spectra based on the pulse length (PW) and repetition rate (PRF). The line spectra are separated in the freq. domain by the PRF rate....