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Alexander Chemeris alexander.chemeris at gmail.comThis is pure host side UHD update (UHD driver as you call it). Sent from my Android device. -- Regards, Alexander Chemeris CEO, Fairwaves LLC http://fairwaves.ru 20.03.2013 16:47 пользователь "Craig Reading" <craig.reading1 at gmail.com> написал: > Alexander > > Is this a firmware update or UHD driver update? If firmware would it be > possible to upload an image? > > Regards > Craig > > Begin forwarded message: > > *From:* umtrx-request at lists.osmocom.org > *Date:* 19 March 2013 20:36:34 GMT > *To:* umtrx at lists.osmocom.org > *Subject:* *UmTRX Digest, Vol 9, Issue 16* > *Reply-To:* umtrx at lists.osmocom.org > > Send UmTRX mailing list submissions to > umtrx at lists.osmocom.org > > To subscribe or unsubscribe via the World Wide Web, visit > http://lists.osmocom.org/cgi-bin/mailman/listinfo/umtrx > or, via email, send a message with subject or body 'help' to > umtrx-request at lists.osmocom.org > > You can reach the person managing the list at > umtrx-owner at lists.osmocom.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of UmTRX digest..." > > > Today's Topics: > > 1. Tx signal quality improvement (Alexander Chemeris) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Wed, 20 Mar 2013 00:33:29 +0400 > From: Alexander Chemeris <alexander.chemeris at gmail.com> > To: umtrx <umtrx at lists.osmocom.org> > Subject: Tx signal quality improvement > Message-ID: > <CABmJbFV4C0_WBCBuj61U8_2bQjm9x049ciB0yYQDjJdoHxiNGg at mail.gmail.com> > Content-Type: text/plain; charset="utf-8" > > Hi all, > > I've found an issue with out Tx configuration of LMS which led to > constant phase rotation of the transmitted signal. After fixing this > issue I get quite better signal quality on transmit side. I advise > everyone to update to the most recent UHD on the host side to benefit > from this improvement. > > The reason for the issue was that we used the wrong polarity of TX_ > IQ_SEL. As a result, LMS transmitted I from one sample and Q from the > other sample. One of the visible results was a huge I/Q imbalance on > Tx which made it impossible to use multi-ARFCN configurations. We've > solved this issue in software by setting tx_fsinc_polarity and > tx_interleave_mode to proper values in LMS configuration registers. > > Attached screenshots from our E4406A shows signal quality transmitted > by OpenBTS we could have now. Tests are performed with "laurent" > branch of Fairwaves, compiled with SPS (samples per symbol) set to 4. > DC offset and I/Q imbalance are calibrated. > > screen2.gif, screen3.gif - constellation and phase error when LO > leakage is at the center of the signal spectrum, i.e. with no LO > offset on Tx. > > screen4.gif, screen5.gif - constellation and phase error when DC > offset is when LO leakage is shifted to 300kHz away from the signal > spectrum center, i.e, with 300kHz LO offset on Tx. > > screen6.gif - phase error per symbol plots for the same settings as > with screen4.gif and screen5.gif. > > When we implement a true GMSK transmitter we should be able to get > even better phase noise parameters, meaning excellent downlink signal > quality. But even this values are much better than required by the > Standard. > > -- > Regards, > Alexander Chemeris. > CEO, Fairwaves LLC / ??? ??????? > http://fairwaves.ru > -------------- next part -------------- > A non-text attachment was scrubbed... > Name: screen2.gif > Type: image/gif > Size: 14989 bytes > Desc: not available > URL: < > http://lists.osmocom.org/pipermail/umtrx/attachments/20130320/7863d1f1/attachment.gif > > > -------------- next part -------------- > A non-text attachment was scrubbed... > Name: screen3.gif > Type: image/gif > Size: 14347 bytes > Desc: not available > URL: < > http://lists.osmocom.org/pipermail/umtrx/attachments/20130320/7863d1f1/attachment-0001.gif > > > -------------- next part -------------- > A non-text attachment was scrubbed... > Name: screen4.gif > Type: image/gif > Size: 14629 bytes > Desc: not available > URL: < > http://lists.osmocom.org/pipermail/umtrx/attachments/20130320/7863d1f1/attachment-0002.gif > > > -------------- next part -------------- > A non-text attachment was scrubbed... > Name: screen5.gif > Type: image/gif > Size: 15218 bytes > Desc: not available > URL: < > http://lists.osmocom.org/pipermail/umtrx/attachments/20130320/7863d1f1/attachment-0003.gif > > > -------------- next part -------------- > A non-text attachment was scrubbed... > Name: screen6.gif > Type: image/gif > Size: 20776 bytes > Desc: not available > URL: < > http://lists.osmocom.org/pipermail/umtrx/attachments/20130320/7863d1f1/attachment-0004.gif > > > > ------------------------------ > > _______________________________________________ > UmTRX mailing list > UmTRX at lists.osmocom.org > http://lists.osmocom.org/cgi-bin/mailman/listinfo/umtrx > > > End of UmTRX Digest, Vol 9, Issue 16 > ************************************ > > -------------- next part -------------- An HTML attachment was scrubbed... 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