# Tag Info

### Why is a linear phase important?

Let me add the following graphic to the great answers already given, with the intention of a specific and clear answer to the question posed. The other answers detail what linear phase is, this ...
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Accepted

### Why is a linear phase important?

A linear phase filter will preserve the waveshape of the signal or component of the input signal (to the extent that's possible, given that some frequencies will be changed in amplitude by the action ...
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### Why is a linear phase important?

Just to add to what's already been said, you can see this intuitively by looking at the following sinusoid with monotonically increasing frequency. Shifting this signal to the right or left will ...
• 481
Accepted

### Filter Order Rule of Thumb

My favorite "Rule of thumb" for the order of a low-pass FIR filter is the "fred harris rule of thumb": $$N=\frac{f_s}{\Delta f}\cdot\frac{\rm atten_{dB}}{22}$$ where $\Delta f$ ...
• 37.6k
Accepted

### FIR Filter Design: Window vs Parks McClellan and Least Squares

I agree that the windowing filter design method is not one of the most important design methods anymore, and it might indeed be the case that it is overrepresented in traditional textbooks, probably ...
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### FIR Filter Design: Window vs Parks McClellan and Least Squares

Windowed Sinc filters can be adaptively generated on the fly on processors barely powerful enough to run the associated FIR filter. Windowed Sinc filters can be generated in finite bounded time. The ...
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### FIR Filter Design: Window vs Parks McClellan and Least Squares

I'll show here one benefit of a windowed design and a trick to get the same benefit from Parks–McClellan. For half-band, quarter-band etc. filters windowing retains the time-domain zeros of the ...
• 12.5k
Accepted

### Educational purpose - What is the correct way to simulate a multipath fading channel which has ISI

Lets say we want to transmit a sequence of discrete data $\left\lbrace x[n] \right\rbrace$. But because we are living in analog world, the sequence must be modulated. Call $T_s$ is symbol duration ...
• 5,780
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### How to Classify a Kernel as Low Pass Filter (LPF) or High Pass Filter (HPF)? How to Transform an LPF Kernel into HPF Kernel?

General We assume 2 modes of filters: LPF or HPF. Classifying Filter Type Usually, if it is a well planned LPF and well Planned HPF a simple test will do. Calculate the sum of all coefficients. The ...
• 41.2k
Accepted

### Why a pair of complex-conjugate zeros provide a nulling filter? (FIR filter case)

The unit circle on the z-plane represents the frequency axis, similar to the imaginary axis $j\Omega$ on the s-plane for the Laplace Transform in the continuous time case. So the frequency response of ...
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So, from the discussion in the comments it's clear you know most you need to know. The window method for FIR filter design is based on this idea: We know the "ideal" frequency response $H(f)$ we ...