Re: Stucked on a trivial interpolation issue

[Christophe Seguinot]

First answer to myself :

• I should have used an empty value for parameter taps. This only works for Rational resampler, not for interpolation.

Question:

• How can I interpolate without filtering to obtain a linear interpolation giving
  
• 1 1 1 / 1 1 1 / 1 1 1 / 1 1 1 / -1 -1 -1/ -1 -1 -1/ -1 -1 -1/

On 23/03/2020 17:46, Christophe Seguinot wrote:

Hi

I'm stucked on a trivial interpolation problem.

I was trying to interpolate a binary source ( in the attached flowgraph I've witched to a rectangular wave source to analyse and explain my problem).

• So I've a rectangular source with 4 sample/period : 1 1 1 1 -1 -1 -1-1 1... .
• I interpolate whith a 3 interpolation factor
• I was guessiong to obtain : 1 1 1 / 1 1 1 / 1 1 1 / 1 1 1 / -1 -1 -1/ -1 -1 -1/ -1 -1 -1/ ...(/ used to separate group of 3 samples)
  
• Instead I get: 1 0 0 / 1 0 0 /1 0 0 /1 0 0 /-1 0 0 /-1 0 0 /-1 0 0 /-1 0 0 /

This seems wrong as compared to paragraph "E2.3. A Note on Resampling" on this GNURadio Wiki  tutorial

Does I made something wrong, or Does I've been infected by Covid19.

Sincerely,

Christophe confined at home since 7 days (North of France)