Linked Questions

21
votes
3answers
6k views

FIR Filter Design: Window vs Parks McClellan and Least Squares

Are there any advantages to use a window approach over Parks-McClellan (further abbreviated here as PMcC) or Least Squares algorithms for FIR filter design of a low pass filter? Assume with today's ...
18
votes
2answers
1k views

How can I design Nyquist interpolation filters with the Parks-McClellan algorithm?

We can easily design interpolation filters that obey certain frequency-domain constraints using the Parks-McClellan algorithm. However, it's not immediately clear how to enforce time-domain ...
4
votes
4answers
2k views

Algorithm for 1d spline interpolation suitable for 8 bit microcontroler

What is a concise, fast, down to earth algorithm for doing (or closely approximating) spline interpolation on a 1d continuous stream of data? (Edit1: The paragraph below equates to saying "the ...
2
votes
3answers
1k views

How to design very narrow, sharp lowpass filters - Only DC needed?

I asked exact the same here one year ago: One year ago question I asked this question again here, because after one year, I have learned more about DSP and am thinking ways to improve it. Filter ...
4
votes
5answers
207 views

Reconstructing/interpolating small regions of a bandlimited signal by taking the fewest possible samples

I have a signal which is bandlimited and can be sampled at arbitrary continuous positions. The value at any position is given by an expensive computation. I need to do some further computation on ...
1
vote
2answers
274 views

Sinc interpolation of pure sine wave sampled just at Nyquist frequency

Following this question: Shannon-Nyquist theorem reconstruct 1Hz sine wave from 2 samples could you explain the algorithm to apply for sinc interpolation to avoid the "sawtooth" effect due to linear ...
3
votes
2answers
236 views

Tetrahedral microphone array beamforming

I have a microphone array of 4 channels taken as channels [6,10,22,26] from Eigenmike spherical microphone array. I wish to do 3D beamforming and create $8\times 4$ beams, 4-elevations with 8 ...
1
vote
2answers
129 views

Drawbacks of upsampling using polynomial interpolation

I've come across an upsampler that uses polynomial interpolation and no filter. What are the drawbacks to this? I looks more efficient than filtering.
1
vote
1answer
107 views

How to implement sinc interpolation

I'm trying to write my own high quality audio sample rate converter. I barely know anything about signal processing though so I need help. From what I understand I need to sum together normalized sinc ...
-1
votes
1answer
90 views

Basic upsampling of a signal

I've been learning about the (Fast) Fourier Transform and it's uses. Using the formula: $$FFT(concatenate(IFFT(signal), 0^\text{increase}))$$ I was able to go from this signal: to this: by settings $...
0
votes
2answers
67 views

Why the plots of spline and cubic interpolation are exactly same? [closed]

I am trying to watch difference between cubic interpolation and spline interpolation using matlab plot but i am getting same plots in both cases using interp1 ...
0
votes
2answers
110 views

Interpolation and harmonics

A real valued causal sequence $x1[n]$ exists with length of the sequence being $N$. Valid indices of x conform to $0 \le n \le N-1 $ The DFT of x[n] is: $$ X1[k] = \sum_{n=0}^{N-1} x1[n].e^{-j.2.\...
0
votes
1answer
62 views

“plot” command for continous time signal in matlab?uses interpolation?

We know digital computer cannot deal with continuous time signals directly. But then how MATLAB "plot" command works? Does that uses interpolation technique to show an apparently continous time ...