Quantize an analog signal
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Shravan Kumar Pasupuleti
el 10 de Abr. de 2012
Comentada: Walter Roberson
el 27 de Mayo de 2019
I have an analog signal(ECG) ranging in amplitude from 0.1 to 2.5 and I want to quantize it, to convert the ECG signal into bit stream. The problem I am facing is I don't know what parameters in quantize function will lead to the required quantization range.
Can anyone help me in how to do this using quantize function and what should be the parameters that will lead me to the required range of quantization values.
1 comentario
Walter Roberson
el 27 de Mayo de 2019
Due to the laws of the USA, we are not permitted to discuss encryption.
Respuestas (3)
Rick Rosson
el 12 de Abr. de 2012
Quantize Function
function y = quantize(x)
xMin = 0.1;
xMax = 2.5;
N = 64;
y = floor( N * log(x/xMin) / log(xMax/xMin) ) ;
end
Test Script
x = 0.1 + 2.4*rand(100,1);
y = quantize(x);
scatter(x,y);
HTH.
Rick
5 comentarios
Walter Roberson
el 26 de Mzo. de 2019
The above code assumes non-negative numbers (notice the log() calls).
Neha Gupta, are you looking for uniform quantization, or non-uniform? If you want non-uniform, then how do you want to determine the widths of the bins ?
Image Analyst
el 27 de Mzo. de 2019
Why not use imquantize() from the Image Processing Toolbox where you can specify the edges of the ranges to quantize?
Rick Rosson
el 10 de Abr. de 2012
- How many quantization levels do you want to have?
- Do you want uniformly spaced levels, or non?
- Is the signal signed or unsigned?
2 comentarios
Rick Rosson
el 12 de Abr. de 2012
Is the value of the signal always greater than zero (one-sided), or is it less than zero some of the time (two-sided)?
Image Analyst
el 17 de Mzo. de 2013
If it's already in MATLAB then it's already been quantized. This just changes the quantization to some other quantization. I got the impression he had an analog signal that he needed to quantize (digitize). For that he'd probably need the Data Acquisition Toolbox and an appropriate A-to-D converter device, such as those from Measurement Computing Corporation (like I use) or any of the others listed here. That will take the actual input analog voltage signal and digitize it into a MATLAB variable.
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