Hi Alexander,
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.
Thomas
Thanks Thomas, I'll try this.
Did you test receive side with this patch?
On Thu, Dec 6, 2012 at 7:13 AM, Thomas Tsou tom@tsou.cc wrote:
Hi Alexander,
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.
Thomas
On Wed, Dec 5, 2012 at 10:55 PM, Alexander Chemeris alexander.chemeris@gmail.com wrote:
Thanks Thomas, I'll try this.
Did you test receive side with this patch?
No, the E4406 was plugged in the entire time.
Thomas
On Thu, Dec 6, 2012 at 8:55 AM, Thomas Tsou thomastsou@gmail.com wrote:
On Wed, Dec 5, 2012 at 10:55 PM, Alexander Chemeris alexander.chemeris@gmail.com wrote:
Thanks Thomas, I'll try this.
Did you test receive side with this patch?
No, the E4406 was plugged in the entire time.
Got it. Waiting for the receive side test.
-- Regards, Alexander Chemeris. CEO, Fairwaves LLC / ООО УмРадио http://fairwaves.ru
On Wed, Dec 5, 2012 at 10:13 PM, Thomas Tsou tom@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.
Thomas
On Fri, Dec 7, 2012 at 12:28 PM, Thomas Tsou tom@tsou.cc wrote:
On Wed, Dec 5, 2012 at 10:13 PM, Thomas Tsou tom@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
On Thu, Dec 13, 2012 at 9:04 AM, Alexander Chemeris alexander.chemeris@gmail.com wrote:
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?
No, not yet. I tried some other combinations that worked fine on the signal tester, but the handset still wasn't happy. I'm not yet sure why.
Thomas
On Fri, Dec 14, 2012 at 7:10 AM, Thomas Tsou tom@tsou.cc wrote:
On Thu, Dec 13, 2012 at 9:04 AM, Alexander Chemeris alexander.chemeris@gmail.com wrote:
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?
No, not yet. I tried some other combinations that worked fine on the signal tester, but the handset still wasn't happy. I'm not yet sure why.
Did you check power mask with the signal tester, or phase error too? May be differential modulation is somehow broken by this change?
-- Regards, Alexander Chemeris. CEO, Fairwaves LLC / ООО УмРадио http://fairwaves.ru
On Thu, Dec 13, 2012 at 11:16 PM, Alexander Chemeris alexander.chemeris@gmail.com wrote:
No, not yet. I tried some other combinations that worked fine on the signal tester, but the handset still wasn't happy. I'm not yet sure why.
Did you check power mask with the signal tester, or phase error too? May be differential modulation is somehow broken by this change?
The modified case I measured earlier was improved in power mask and phase error, but just failed in real testing. There is an overall phase rotation from the added bits, but this technically shouldn't matter - and adding only the trailing bits also caused the failure condition. My guess is that this is ramp/power related and not directly due to modulation.
My power shaping profile was really a coarse guesstimate, so that may be a factor. But I'm surprised it doesn't work because having no power profile seems to work quite well (without the extra bits).
Thomas
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Thomas Tsou