# Questions tagged [filters]

In signal processing, a filter is a device or process that transforms a signal by selectively choosing specific frequencies and leaving others with appropriate gain or as it is.

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### Why is time domain low pass filter the "sinc" shape?

I'm looking at low pass filters, and I see that the time domain representation of an "ideal" filter resembles the shape above whereas the frequency domain is a box. I also get the as you ...
• 51
25 views

### Why is time domain low pass filter the "sinc" shape?

I'm looking at low pass filters, and I see that the time domain representation of an "ideal" filter resembles the shape above whereas the frequency domain is a box. I also get the as you ...
• 51
11 views

### 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 ...
15 views

### Is there any way of calculating the portion of signal lost as we keep on reducing the passband edge frequency of a band-pass filter?

Any kind of references would be appreciable.
1 vote
59 views

### Which filter is suitable for reducing noise in feature detection?

I have a feature detection algorithm that is called FAST - Feature Accelerated Segmented Test. It's a very fast algorithm for finding feature points, e.g "corners" inside an image. Here is ...
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1 vote
23 views

### RLS Adaptive Filter for estimating signal

I am currently working on a project where i am to estimate a signal x_T using x_1 and x_2 with an RLS filter. I have a problem where i don't quite get the results i am looking for. I think there is a ...
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### Understand basic Impulse Response from Impulse, can you help me visualizing it?

I was looking at this graph from The Scientist and Engineer's Guide to Digital Signal Processing, copyright ©1997-1998 by Steven W. Smith: where basically it shows how differnt representations can ...
• 35
118 views

### How to interpret integer coefficients for a filter generated by Matlab

I have always used high-performance 32-bit microcontrollers with hardware FPU support. To calculate the coefficients of digital filters, I used the fdatool package in Matlab. I used single-precision ...
• 43
1 vote
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### Why lag compensator is preferred over PI for sinusoidal reference?

In this post, LJSilver mentioned that a PI compensator is not appropriate for a constantly changing reference, such as a sinusoidal waveform. In this scenario, a lag compensator is considered the ...
• 131
25 views

### Filter response weighted formula representation

I am trying to represent a filter response numerically using the formula shown in the end. I know its electromagnetic response. Could you please help me understand how to make in Matlab such filter ...
• 171
58 views

### 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 ...
36 views

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. ...
30 views

### 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 ...
1 vote
83 views

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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
57 views

### 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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### Why the difference of a vectorized VS non-vectorized FIR convolution differ?

I have an FIR filter that is a low pass at 11025Hz for 44100Hz, 461 taps. The reference implementation, i.e. naive convolution, works as expected. Now I've written a vectorized implementation to take ...
• 284
1 vote