Re: [Discuss-gnuradio] Arbitrary resampler question on gnuradio 3.7.2.1

[George]

Hi Tom, 

You are right increasing the number of taps by 100 is not the case, after I 
debugged the results a bit more.
The problem seems to be in the number of samples consumed as you mentioned 
above.

The full definition for the filter I am using is 
firdes.root_raised_cosine(nfilts, 1.0, 1.0/nfilts, rolloff, int(11*spb*nfilts))
where nfilts=32, rolloff=0.35 and spb =4

Thanks,
-George

On Dec 18, 2013, at 5:54 PM, Tom Rondeau <address@hidden> wrote:

> On Tue, Dec 17, 2013 at 9:06 PM, George <address@hidden> wrote:
>> Hello all,
>> 
>> Considering a simple gnuradio flowgraph as the following
>> 
>> Random source -> chunks2symbols -> complex2float -> float2complex -> 
>> pfb_arb_resampler-> USRP sink
>> 
>> which used to work without any problem in the older gnuradio distributions, 
>> in the newer 3.7.2.1 seems that the conversion above (from complex to float 
>> and float to complex) introduces a problem, that has to do with USRP 
>> transmissions.
>> 
>> However, when I increased the number of taps used for the root raised cosine 
>> filter in pfb_arb_resampler by a factor of 100, everything seems to work 
>> properly.
>> 
>> Note that if the conversions float2complex and complex2float miss everything 
>> works.
>> 
>> Any ideas why?
>> 
>> Thanks,
>> -George
> 
> Bug it the pfb_arb_resampler. I was trying to be too conscientious
> about calls to work but made an assumption in the forecast function
> that's not always correct. I'm testing a few things out, still, but I
> should push this fix soon.
> 
> Still, your behavior of the filter length (increasing it by 100, that
> is) doesn't fit with what I'm seeing. What's the full filter
> definition you're using for the block?
> 
> Tom