# Questions tagged [finite-impulse-response]

A finite impulse response (FIR) filter is a type of a signal processing filter whose impulse response is of finite duration.

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### Is this FIR filter considered symmetric?

My goal is to generate linear phase FIR filters. Currently, I am generating an array of frequency response magnitudes for the positive frequencies and then I mirror those with the complex conjugate. ...
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1 vote
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### Confused About Relationship Between Number of Points and Solving Wiener Filter Coefficients in Time Domain vs Fourier Domain

I'm interested in computing M, FIR filter taps / coefficients using a Wiener filter approach with known signal and noise timestreams. I know of two ways to compute the coefficients: one in the Fourier ...
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### Compress filter coeficients?

if we have a FIR with 100 coefficients, is there a method to "compress" the length? so for example, have a similar response with 50 coefficients? I am ok with the response degrading within ...
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This is mine code for fir_filter_design in python. But I'm getting wrong output for low-pass, band-pass, and high-pass magnitude response. ...
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### I'm struggling to understand the FIR Filter and its application

I'm new to GNU Radio, and I was watching this video However, I didn't quite understand the purpose of the FIR Filter. I know what decimation or downsampling is because I have the book "Digital ...
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### Design a lowpass filter cutoff and sampling frequency is given

Design a FIR low pass filter with cutoff frequency of 1 𝑘𝐻𝑧 and sampling frequency of 4 𝑘𝐻𝑧 with 11 samples using Fourier series method. Realize the filter with suitable structure. Determine the ...
659 views

### Algorithm to "serialize" impulse responses

New user to dsp.stackexchange here. I'd like to know what's a quick and effective way to take 2 impulse responses and create one that's equivalent to both of these "in series" for audio ...
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### FIR filter design with nonlinear phase from measured amplitude and phase responses

I am having trouble when design FIR filter fitting to the complex data (i.e., amplitude and phase responses from measurements). I did try to use Matt. L's lslevin method here since this method is to ...
1 vote
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### On FFT, interpolating signal vs extending signal in time

When we interpolate, then FFT the output will have more bins. When we extend the signal in time, Then FFT output will have more bins too but: Interpolation increases max bin frequency but time ...
1 vote
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### Does block-based FIR filtering necessarily imply using the DFT?

Assume I want to filter a stream of data with a rather small FIR filter (in the order of 16 to 64 coefficients). In any case I have to split the input stream into chunks (blocks) of data. Searching ...
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### Impulse response aquired by ifft seems to require circshift

On the system below: I have found W by inputing 20-1000 frequency and found amplitude and phase for each frequency. I've tested for minimum phase and none min S. But the answer is not logical for me. ...
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### Total delay of cascade FIR filters

I have a doubt regarding the total delay in terms of taps for cascade filters. Imagine that I have an SOS IIR Filter (2 delays) and an FIR filter of 10 taps (10 delays) and another of 20 taps (20 ...
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### Impulse Response for an Input-Output Pair

Given an input-output pair of a LTI system \begin{gather*} x[ n] \ =\ 2\delta [ n+2] -\delta [ n+1] +\delta [ n-1]\\ y[ n] \ =\ 4 \delta [ n+2] +\ 4\delta [ n+1] -\delta [ n-1] \end{gather*} My ...
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### Kaiser window but desired frequency response extends beyond pi?

Passband : 0 to 0.5π Stopband : 0.7π to 2π Is there a way to reduce this to a 0 to π scale? If I had to guess, we should be able to simply divide the edge frequencies by 2 and use the time scaling ...
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1 vote
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### Modeling an Acoustic Reflection from a Wall - a Paradox?

I am trying to simulate the reflection of a sound ray, that goes from a sound source, bounces off a wall, and is received by a microphone. The wall has a an absorption coefficient, and a specular ...
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### Integral Calculation in Matlab for Filter Optimization

I am trying to calculate the area under my FIR filter kernel using trapz but I'm getting weird results. The reason I want to know the area is eventually I would ...
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### How does rate reduction work in a decimator with even valued gain?

Cascaded integrator-comb (CIC) filters are used in decimators, and decimators with a gain that is a power of 2 are popular (at least at my workplace) because the gain can be normalized with a right ...
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### FIR filters: is it possible to manipulate phase without change in magnitude response

Here's response of FIR design: which shows SPL 0dB and here's a wave file exported from ( DRC ) FIR design software: FIR48kHz.wav. Audio software (internally uses FFTW routines) where this filter is ...
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### Troubleshooting distortion in room impulse response measurements:

I am collecting data for a project, where I am measuring the room impulse response by playing a sine sweep from a speaker (QSC K8 1KW Active Loudspeaker) and measuring it from the other side of the ...
1 vote
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### Stringent filter requirements

I am trying to resample a signal using Matlab's resample function. The documentation explains that conceptually, it is upsampling by p, then applying an interpolation filter, then downsampling by q, ...
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### Implementing the NMCFLMS Algorithm for a 2 channel WGN input signal

I am just trying to implement the Normalised Multi-channel Frequency Domain Least Mean Square (NMCFLMS) algorithm for a simple 5 tap filter to estimate the filter coefficients of a 2 channel system ...
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### Can Synchrosqueezing be use to Derive IIR Filter From Impulse Response

I am looking for alternate solutions to determine the IIR filter coefficients from the impulse response, or more specifically determine the closest IIR filter for a given FIR filter. Much of this is ...
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### What is the position of all zeros of a minimum phase, Type 1 Linear Phase FIR Filter?

Let me write down all the facts that I know of. In context of the z plane: Minimum phase system: All zeros and poles of such a system lie inside the unit circle. Linear phase FIR filter: For every ...
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### Linear phase impulse response causes non linear phase frequency response in GNU Octave/ Matlab

Assume linear phase FIR symteric impulse response like [1 2 3 4 5 5 4 3 2 1],shoud resault in a frequency response with linear phase negative sloped phase. but it ...
150 views

### Subtract Lowpass from Wire to Get Allpass

One technique to make a high pass filter is to subtract a lowpass filter from a wire (meaning subtract the output of the filter from the input as I have demonstrated in this post). What lowpass can ...
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