# Tagged Questions

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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### What is the best technique for implementing high sample rate FIR filters on FPGAs? [closed]

What is the best technique for implementing FIR filters in SERDES implementations for GSPS applications? Are poly-phase filters (non-decimated) the best technique?
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### 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 ...
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### Very-short Hilbert transform FIR (or “recursive”) approximations

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. ...
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### What is the meaning of the delay in a FIR filter

I'm using a C# library that has the FIR filter implemented and I'd like to know what's the meaning of the ${z^{-1}}$ operation (delay) mathematically. The triangle is multiplication, the circle is ...
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### Sine-weighted moving average on non-periodic, stationary signal

I am looking for -or trying to create- a filter with a piece-wise monotonic second derivative in such a way that when placed on a non-periodic input signal, changes in sign of the second derivative ...
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### parametric eq with FIR filters

Are there any good published approach for designing parametric EQs as FIR filters. The standard techniques discussed in DSP textbooks are frequency-domain-sampling or using Parks-McClellan, which ...
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### FIR filter with linear phase, 4 types

I know there are 4 types of FIR filters with linear phase, i.e. constant group delay: (M = length of impulse response) Impulse response symmetrical, M = odd Imp. resp. symmetrical, M = even Imp. ...
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### Calculating an impulse response in a stable environment

I would like to estimate the impulse response of a simple environment (room, two speakers, one microphone). I am aware of the issues/limitations of working with "near" LTI systems. That said, I have a ...
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### How to calculate signal which is not changed by a filter?

Suppose that there is a FIR filter F and a signal S. The filtered signal is the convolution of F and S, F * S. The problem: how to calculate a signal S' such that F * S' = S' (the filtered version ...
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### FIR design : compute coefficients for the same frequency response at another sampling frequency

I would like to know if there's a standard way to obtain the FIR coefficients for a sampling frequency $F'$ when the coefficients are for a sampling frequency $F$. I would like to implement the ...
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### A Simple Lowpass Filter Behaving so Strangely

I don't know much about filter design. After reading a few articles on wikipedia I am playing with filter design and I see something weird and would like some help in understanding what exactly is ...
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### Downsample Equiripple FIR filter

I am designing some Downsampling filters using the remez exchange algorithm (Matlab FDAtool). I see that some times i get a spike at the first and last coefficients. does anybody knows why is that? my ...
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### Do FFT-based filtering methods add intrinsic latency to a real time algorithm?

In a current audio processing application, I am working entirely in the time domain using IIR filters. This is so I can use an audio buffer of just 3 or 4 samples and can guarantee that there will be ...
### With respect to the dirac delta function, what does $\delta [x + 2A, y - A]$
I have come across the following function and I'm trying to figure out what it really is. I have this function: $f[x, y] = \delta [x + 2A, y - A] - \delta [x - A, y + A]$. The $\delta$ is ...