Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

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.

0
votes
0answers
20 views

Impulse response of discrete time system

I am learning about discrete systems and in this derivation something struck me as quite odd. Solving for $A_0$ in this equation seems dubious as it ignored all other values of $n$. For example, at $n=...
1
vote
0answers
207 views

How to envelope a non periodic Impulse signal?

I want to analyse a trc oscilloscope file, find impulses and envelope them. In the end I want to plot the envelope. data file (trc): https://ufile.io/z4m4d Code: (Python) ...
1
vote
0answers
36 views

How far can numerical differentiation be accurate for sinusoids?

Suppose you have samples of uniform interval of a sinusoidal signal that is some sum of sinusoids. Forget about aliasing, as the signal is bandlimited. If we have infinite number of samples at ...
1
vote
1answer
72 views

Is it possible to get the envelope of a signal via FIR filter?

I was reading an article about ultrasonic signals, and I read in it that it is possible to get the envelope of a signal by using a band pass FIR filter. My question: Is it possible to get the envelope ...
1
vote
2answers
529 views

How to Classify a Kernel as Low Pass Filter (LPF) or High Pass Filter (HPF)? How to Transform an LPF Kernel into HPF Kernel?

The filter impulse response is [1/9 1/9 1/9;1/9 1/9 1/9;1/9 1/9 1/9]. how do i determine whether it is an Low pass filter or a high pass filter. If this is a low pass filter how do i convert it to a ...
0
votes
4answers
73 views

Can I use IIR or FIR to get a sliding mean?

My output signal shall be computed by (meta code): o = 0 # or some arbitrary initial value for i in input: o = (o * 99 + i) / 100 print o I call this a "...
-2
votes
1answer
182 views

Finite moving average filter

I am trying to solve this problem but I need a lot of help. Below are my answers for the separate parts, please check and tell me where I am wrong because I am weak on the fundamental concepts of this....
0
votes
1answer
2k views

Find the impulse response of an LTI system?

why there is a 3/2 in the (b) problem? Does the impulse response even exist?
0
votes
1answer
50 views

follow up to previous question “ is this an impulse response or step response”

This question is a follow up to the gorgeous explanation of how the leaky integrator model becomes a differential equation. The link to that question and answer is below. should this be viewed as an ...
1
vote
2answers
153 views

should this be viewed as an impulse response or step response

I'm trying to teach myself the relation between simple discrete ODE's and the impulse response-step response concept. Getting back to the question: I don't expect anyone to read the whole thing but I'...
0
votes
2answers
97 views

Typical filter orders

I am on my first DSP project where I want to implement lowpass/highpass filters for ECG application. I have started from MATLAB to give me orders and coefficients for my desired specs. I prefer to go ...
0
votes
1answer
161 views

Proper method for generating Channel coefficients in MATLAB

I am trying to estimate the coefficients of a Moving average model using popular estimation method such as Least Squares (LS). For educational purposes, I am trying to see if LS can work well when the ...
1
vote
2answers
992 views

Memory for FIR and IIR [closed]

I have doubt regarding memory of FIR and IIR, I have read that output of FIR depends upon present and previous inputs, while output of IIR depends upon, present and previous inputs as well as previous ...
0
votes
0answers
48 views

Difference between MFB bound and ML bound for ISI channels?

I am considering a straight forward simulation setup in matlab. I am transmitting a random sequence $\mathbf{x}$ of $\{+1,-1\}$ over a two-tap ISI channel $\mathbf{h}=[h_0 \hspace{2mm} h_1]$. The ...
1
vote
2answers
109 views

Is this an infinite response or a finite response?

If you're given $h[n] = 1$ for every even number of $n$, otherwise it'll be 0. Is that considered an infinite response or a finite response and how do you know?
1
vote
2answers
139 views

Why are there no poles for finite length signals

My professor recently said something along the lines of, "finite length signals can't have poles because poles correspond to recursive difference equations which correspond to infinite length signals."...
0
votes
3answers
561 views

FIR analog low-pass filter?

Is there a way to construct FIR analog low-pass filter? (By this, I believe I am asking for no-pole analog low-pass filter, in terms of Laplace transform.)
0
votes
2answers
79 views

Optimizing Two Parallel IIR Filter Sweeps

Got an audio related question here; So I have two IIR low pass filters that work in parallel to do a filter sweep. Basically: ...
2
votes
2answers
132 views

Equalizing frequency response in software

I'm playing audio through a speaker which I know to have a non-flat frequency response, with particularly poor response in the low ($<1\textrm{ kHz}$) ranges. My plan to get around this problem is ...
1
vote
1answer
406 views

Is an FIR filters 'transition width' frequency dependent?

I was recently brushing up on some FIR filter design and was browsing the Wikipedia page. A claim in the article caught my attention: The main disadvantage of FIR filters is that considerably more ...
1
vote
1answer
101 views

How do multirate systems introduce 'efficiency' in computation?

I've started reading more into multirate systems recently and am somewhat confused. The concepts introduced seem to make sense, that is, how the decimation and interpolation can change certain ...
2
votes
0answers
194 views

Scipy.signal.dimpulse(system): how to translate a StateSpace to a “system”? [closed]

The command scipy.signal.dimpulse(system, x0=None, t=None, n=None) does not seem to accept a scipy StateSpace as an input to its ...
1
vote
0answers
353 views

Upsampling with FIR filter causing discontinuity at start of new buffer [closed]

I have implemented an oversampling algorithm for an audio signal in C++ which is producing a distortion of the signal at the start of a buffer. The algorithm is wrapped in a class with methods for up ...
1
vote
1answer
809 views

Approximation of Hilbert Transform Using Very Short Hilbert Transform FIR / IIR Filter

Hilbert transform is a quite sensitive topic here, since Gabor's paper, Theory of Communication, J. Inst. Electr. Engineering, London, 1946. Perhaps even more important than the Fourier transform. ...
1
vote
1answer
64 views

FIR filter : $h(n)$ is palindrome?

I study condition for fix if filter is a linear phase,but it's not clear in my mind! I have this $h(n)$: $$h(n) = \begin{cases} \left(\frac{1}{2}\right)^{n} & 0<n<N-1 \\[2ex] 0 & \text{...
1
vote
2answers
451 views

Root raised cosine pulse shaping peak value

I am using a FIR filter to generate Root Raised Cosine pulse for an IQ modulator. How can I predict the peak value at the output, depending on the roll-off factor of the pulse ? Knowing that : FIR ...
0
votes
2answers
170 views

Interpolated impulse response for fraction delay?

I need to find a way to create some fractional delay in a signal processing application that I am working on. Separately to this, I have been messing around with basic filter design (despite reading ...
2
votes
1answer
1k views

FIR filter design and implementation - sample rate and number of taps

I have been designing and using IIR filters to process audio for a while now but want to design some FIR filters for delay equalization. I have done some preliminary work using the following approach: ...
0
votes
1answer
46 views

finite impulse response filter

I am not specialist in DSP,I am dealing with geophysical time-series(electromagenteic sources).After converting to frequency domain,my friend is trying to filter with FIR(45-65Hz) to get rid of AC ...
0
votes
0answers
143 views

DSP Library IIR and FIR filters

Me and a coworker are currently in the process of making an audio dsp library. We are wondering what some good FIR and IIR filters to use were. I know ALOT of them but what do you guys think in best/...
3
votes
2answers
1k views

Determining which Filter from a Z-Plane Plots?

How do i determine which FIR filter (LP, HP, BS, BP) it is from looking at it's z-plane plot?
1
vote
1answer
464 views

Why does the impulse response determine the transfer function of a system? [closed]

why does it describe the transfer function.. How come? Especially for LTI systems. I thinking about the theory about how come an impulse input can provide information about a complete system.. As it ...
0
votes
1answer
265 views

FIR difference equation vs convolution summation

I'm sorry if my question is too simple, but I am self-studying FIR because we have to report it in our class. I am using the book of Proakis and Manolakis as reference. Under 7.2 Structures for FIR ...
2
votes
1answer
514 views

Multi-Stage digital FIR filter vs Single stage FIR filter. Which is better?

Can anyone provide an insight to select a filter structure out of multi-stage and single stage FIR filter?(it will be great help if references are also provided) Let's say I have to make 50 tap filter....
1
vote
0answers
53 views

non-standard error function for adaptive filter

I want to create an adaptive filter. Its coefficients have this general shape: When the input signal for the filter is a sine wave, the filter behaves the desired way if the look-back window is set ...
2
votes
1answer
330 views

Low order sinc interpolation vs. polynomial interpolation for variable fractional delay

I'm implementing a variable fractional delay element for use in online audio processing. Applications include ie. Karplus-Strong synthesis, flanger, chorus, echo, vibrato. I'm not oversampling, so ...
0
votes
0answers
208 views

BandPass and StopBand FIR filters (Hamming) is not working

I have two groups of 3 frequencies of tone (music), First Group Tones: 39 (77.7817 Hz), 40 (82.4069 Hz) and 41 (87.3070 Hz). Second Group ...
0
votes
2answers
4k views

Why is this MATLAB butterworth filter giving me wrong results

Given a 128 Hz signal, in MATLAB I entered the following command ...
0
votes
1answer
1k views

FIR vs IIR complexity

IIR filters have feedback whereas FIR filters don't use feedback. Then why is it said that FIR filters sometimes have the disadvantage that they require more memory and/or calculation to achieve a ...
3
votes
3answers
22k views

Group delay of the FIR filter

For an FIR filter, with symmetrical tap values $h[N-1-n]=h[n]$, why is the group delay $\frac{N-1}{2} T$ (where $N$ is the number of taps of the FIR filter and $T$ is the sampling time)? Why is ...
0
votes
3answers
591 views

FIR / IIR and Wavelets

I am a self-learner of DSP by reading various books. I have accomplished basic understanding of Signals - CT and DT and a few transforms. I recently started to learn FIR / IIR Filters. The part that ...
1
vote
0answers
1k views

Using Python with scipy.signal firwin, how do I know how many taps/coefficients should be used?

I need to alter an FIR filter which I know very little about. I have a signal which need to be altered, and looking at a Python script used for this task, I see that it uses Scipy's signal library, ...
1
vote
0answers
93 views

Deriving finite impulse response for polylogarithm

As a part of my research i have to use the following z-transform in matlab 'filter' function so as to derive the convoluted signal from the original one. $$\frac{1}{{\rm Li}_{k}(z^{-1}e^{-b})}$$ ...
0
votes
0answers
67 views

Backward propagation of error in FIR Neural Networks

FIR Networks are a really great kind of Neural Networks. It allows very precise predictions of missing samples for example when ones wants to reconstruct missing signals or adaptive noise ...
0
votes
1answer
170 views

Understanding IIR , Low Pass, High Pass, Chebyshev, Elliptic Filter? [closed]

I see these terms everyday in every lecture, I do read stuff from wikipedia, follow lecture notes, study solved exercises. All in all I do have a rough idea about these, I know a little from ...
0
votes
2answers
1k views

FIR-Decimation and Low-pass filter (taps vs number of input points vs number of decimation stages)

I am new to digital filters and trying to understand parameters behind them. Scenario I am trying to get DC value from signals sampled at 100kHz sampling rate. such high frequency is used due to ...
1
vote
2answers
322 views

Linear-phase lowpass filters: frequency responses alignment

These two filters have very similar frequency responses, but those responses are not identical except at a single frequency $\omega_0$. I want to find $\omega_0$. One way I've seen that done is like ...
0
votes
1answer
90 views

Calculating Signal Approximation Error (Theoretical signal - Real hardware signal)?

I've got a FIR filter, which I developed in IC. Now, when I got my results, I ended up with two signals: Theoretical signal calculated through MATLAB as a response to my input. Real response given by ...
2
votes
1answer
447 views

Creating a time domain filter from a frequency domain plot

In figure 11.23 of Monzingo's Introduction to Adaptive Arrays, the author uses a sinewave in the frequency domain to model the amplitude ripple in the passband of a channel of a receiver. What does ...
0
votes
2answers
654 views

Bandpass Filter window length: filter “in phase” with sinusoidal input

Say you have a bandpass filter and you place it on 40 discretely sampled points from a sinusoid with a period of 40. Why is the bandpass filter (green curve on the image) only "in phase" with the ...