Burst start/end phase error

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Alexander Chemeris alexander.chemeris at gmail.com
Thu Dec 13 14:04:41 UTC 2012


On Fri, Dec 7, 2012 at 12:28 PM, Thomas Tsou <tom at tsou.cc> wrote:
> On Wed, Dec 5, 2012 at 10:13 PM, Thomas Tsou <tom at tsou.cc> wrote:
>> Please try the last commit at
>>
>>   git://github.com/ttsou/openbts-p2.8.git laurent
>>
>> I tested with 4 samples per symbol as we did in the past. Reducing the
>> start/end phase error involved adding bits so that there is no partial
>> phase transition to/from nothing. We then zero out the excess bits
>> with a simple power mask.
>
> It turns out that the transmit tester likes this signal, but my
> handsets do not; they do not even recognize it. Perhaps this form of
> testing is not as reliable as I thought.
>
> So I reverted the commit to handle start/end phase errors. I also
> setup the correlators with single pulse (I see no benefit for the more
> complicated modulator on receive), and set timing for 4sps. I receive
> RA and normal bursts fine. The start/end transients will need to be
> handled a different way.

Ok, we've tested 'laurent' branch and it works great for both Rx and Tx, thanks!

Have you had any success with fixing ramp up / ramp down issue?

--
Regards,
Alexander Chemeris.
CEO, Fairwaves LLC / ООО УмРадио
http://fairwaves.ru




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