18 Nov
2012
18 Nov
'12
5:40 a.m.
Hi! I just released a major update to the LTE code. There's a new program
called LTE-Tracker that camps on a certain frequency and tracks, any LTE
cells that it finds.
Interesting features (all are in realtime):
- You can see cells popping in and dropping off as the receiver is moved
around the coverage area of the different cells.
- You can see the actual transfer function of the wireless channel
plotted on the screen.
I've also made a small change to CellSearch so that now, it also displays
the number of antennas (ports) on the basestation.
Please let me know of any comments or suggestions!
http://www.evrytania.com/lte-tools/lte-tracker
James
--
*Integrity is a binary state - either you have it or you don’t.* - John
Doerr
18 Nov
18 Nov
10:05 a.m.
Hi James,
On Sun, 18 Nov 2012 05:40:55 +0100, James Peroulas <james(a)peroulas.com>
wrote:
Hi! I just released a major update to the LTE code.
There's a new program
called LTE-Tracker that camps on a certain frequency and tracks, any LTE
cells that it finds.
Interesting features (all are in realtime):
- You can see cells popping in and dropping off as the receiver is
moved
around the coverage area of the different cells.
- You can see the actual transfer function of the wireless channel
plotted on the screen.
I've also made a small change to CellSearch so that now, it also displays
the number of antennas (ports) on the basestation.
Cool!
Please let me know of any comments or suggestions!
I had to apply the attached patch for it to compile on my machine.
Unfortunately i wasn't able to test the tools, as both of them segfaulted
in xc_peak_freq? Backtrace fragment attached.
LTE Tracker v1.0.0 (release) beginning
Search frequency: 1815 MHz
PPM: 120
correction: 1
Found Elonics E4000 tuner
Calibrating local oscillator.
Segmentation fault
LTE CellSearch v1.0.0 (release) beginning
Search frequency: 1815 MHz
PPM: 120
correction: 1
Found Elonics E4000 tuner
Examining center frequency 1815 MHz ...
Segmentation fault
The old copy of commit ef8474ed5d9213c494e8e17b8436208a04844b1a works just
fine at the same time:
C: CP type ; P: PHICH duration ; PR: PHICH resource type
CID fc foff RXPWR C nRB P PR CrystalCorrectionFactor
262 1815M 595h -24.6 N 100 N one 1.0000447970890209426
263 1815M 595h -25.3 N 100 N one 1.0000447969528891701
Also, i noticed that you calculate the expected tuning frequency for e4k
tuners in order to make your calculations more exact. Can you tell us
which tuning errors you get from the e4k driver usually and how this
affects your application?
Nice documentation & videos! Linked the page on the rtl-sdr wiki.
Best regards,
Dimitri
5:09 p.m.
On Sun, Nov 18, 2012 at 3:05 AM, Dimitri Stolnikov <horiz0n(a)gmx.net> wrote:
I had to apply the attached patch for it to compile on
my machine.
Thanks for the patch! cmake is something very new to me :)
Unfortunately i wasn't able to test the tools, as
both of them segfaulted
in xc_peak_freq? Backtrace fragment attached.
Fixed (and pushed)! That was an easy bug to find and was related to the
fact that LTE cells in your area were at such a high frequency (1.8GHz).
The one's I've worked on were in the 700MHz band.
Also, i noticed that you calculate the expected tuning
frequency for e4k
tuners in order to make your calculations more exact. Can you tell us which
tuning errors you get from the e4k driver usually and how this affects your
application?
Well, it's like this. Since the LO and sampling clock are derived from the
same reference, if I can figure out the frequency error of the LO, I will
know the frequency error of the ADC and I can use the frequency error of
the ADC to predict where I should be sampling the data. That way, in
LTE-Tracker, when the dongle's chrystal output stabilizes, the time offset
of the tracked basestations should not change (as long as the dongle itself
is not moving). I needed to calculate the actual LO and sampling
frequencies used by the dongle in order to remove the small time offset
drift I was observing.
As a new feature request, it would be nice for the library to return the
actual frequency that was programmed into the dongle in floating point
(fractions of a Hz sometimes matter). So, if I request 739,000,000Hz, the
library would be able to tell me that the actual programmed frequency was
739000025.5123... Hz. Similarly for the sampling rate.
http://www.evrytania.com/lte-**tools/lte-tracker<http://www.evrytania.co…
Nice documentation & videos! Linked the page on the rtl-sdr wiki.
Thanks for the comments and the link!
James
--
*Integrity is a binary state - either you have it or you don’t.* - John
Doerr
19 Nov
19 Nov
10:22 a.m.
Hi James,
Looks like a great software!
Do you plan to support UHD to support USRPs? In my area (Moscow) we
have LTE in 2500/2600 FDD band and I can't tune to that frequency with
rtl-sdr.
On Sun, Nov 18, 2012 at 8:40 AM, James Peroulas <james(a)peroulas.com> wrote:
Hi! I just released a major update to the LTE code.
There's a new program
called LTE-Tracker that camps on a certain frequency and tracks, any LTE
cells that it finds.
Interesting features (all are in realtime):
You can see cells popping in and dropping off as the receiver is moved
around the coverage area of the different cells.
You can see the actual transfer function of the wireless channel plotted on
the screen.
I've also made a small change to CellSearch so that now, it also displays
the number of antennas (ports) on the basestation.
Please let me know of any comments or suggestions!
http://www.evrytania.com/lte-tools/lte-tracker
James
--
Integrity is a binary state - either you have it or you don’t. - John Doerr
--
Regards,
Alexander Chemeris.
CEO, Fairwaves LLC / ООО УмРадио
http://fairwaves.ru
20 Nov
20 Nov
4:03 a.m.
On Mon, Nov 19, 2012 at 3:22 AM, Alexander Chemeris <
alexander.chemeris(a)gmail.com> wrote:
Do you plan to support UHD to support USRPs? In my
area (Moscow) we
have LTE in 2500/2600 FDD band and I can't tune to that frequency with
rtl-sdr.
Well, it's 'planned', but I don't have any specific schedule for it... I
don't even have a USRP yet :)
James
--
*Integrity is a binary state - either you have it or you don’t.* - John
Doerr
4:52 a.m.
On Tue, Nov 20, 2012 at 7:03 AM, James Peroulas <james(a)peroulas.com> wrote:
On Mon, Nov 19, 2012 at 3:22 AM, Alexander Chemeris
<alexander.chemeris(a)gmail.com> wrote:
Fair enough :)
--
Regards,
Alexander Chemeris.
CEO, Fairwaves LLC / ООО УмРадио
http://fairwaves.ru
Do you plan to support UHD to support USRPs? In my area (Moscow) we
have LTE in 2500/2600 FDD band and I can't tune to that frequency with
rtl-sdr.
Well, it's 'planned', but I don't have any specific schedule for it... I
don't even have a USRP yet :)
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days inactive
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5 comments
3 participants
participants (3)
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Alexander Chemeris -
Dimitri Stolnikov -
James Peroulas