Re: [Discuss-gnuradio] Fractional Resampler discards samples

[Andrej Rode]

Thanks for the reply

> 03.02.2016 22:36, Andrej Rode wrote:
> > (with a resampling rate of 1 and a phase offset) also
> 
> I presume that's "... and a ZERO phase offset", right?

Yes, you guessed right somehow I left the word zero out.

> So I used the source, Luke, and
> 
>  1. these are not the resamplers you're looking for (probably), unless
>     you're really going for non-rational ($\frac1\pi$) or really
>     really-close-to-1 ratios, and
>  2. the point where the phase delay is implemented is by using the MMSE
>     interpolator[1], which really is just a set of FIRs, from which the
>     right one is selected by definition of the µ to use.

I have not selected this resampler by myself and just recognised some weird 
behaviour in the channel model block. 

I have just ran some tests and it seems there is not just a delay:
(again resampling rate=1.0 phase offset=0)

First five input samples:

[(1+0j), (0.9980267284282716+0.06279051952931337j), 
(0.9921147013144779+0.12533323356430426j), 
(0.9822872507286887+0.18738131458572463j), 
(0.9685831611286311+0.2486898871648548j)]

First five output samples:

((0.9822872281074524+0.187381312251091j), 
(0.9685831665992737+0.24868988990783691j), 
(0.9510565400123596+0.30901700258255005j), 
(0.9297764897346497+0.3681245446205139j), 
(0.9048270583152771+0.4257792830467224j))

A delay would be something I expect but completely removing samples? Is it 
possible the first 3 samples are used to initialize the filter? Maybe I can 
also dig through the source but not until evening.

Regards, 
Andrej

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